ae4 final report

London Office Buildings Tender Report 09.05.2016

10 Storey Office, City Road, London.

1

Executive summary

.This report describes and evaluates the relative merits of several physical changes to the proposed

office block on City Road, London. The heating, ventilation and air conditioning systems are sized

in order to provide adequate fresh air quality and a comfortable working environment for the

workspace. In addition to this, improvements to the materials in the external façade, solar

shielding and changes to the internal design temperatures are simulated with a breakdown of the

reduction in annual energy demand, and the related cost and emissions savings.

The heating demand remained constant throughout, except during internal temperature changes,

which achieved a 9.2% reduction in annual heating demand. By introducing an external façade

with a higher thermal mass, a reduction of 5.2% annual Cooling demand and 3.8% annual fan

power demand were achieved. Introducing the temperature changes achieved a further 1.1%

reduction for cooling and 1.8% for Fan power. By the use of complete solar shielding instead of

temperature changes, a 45.2% reduction in cooling and 52.7% reduction in Fan energy demands

were achieved. Solar shielding was by far the most effective change.

With all physical changes, a total saving of £43925 and 225,183kg of c𝑂2 emission per year can be

achieved due to the reduction in energy demand from 163.87kWh/𝑚2 to 113.61kWh/𝑚2.

The current vertical transport system is insufficient to meet modern building standards. The lift

shaft should be enlarged to occupy a 1.1 by 1.4m, 1000kg lift car.

Similarly, 2 fire exit doors per floor must be introduced to reduce maximum travel distance.

(250)

2

Nomenclature

Qf Fabric Heat Loss (W)

U Thermal transmittance of the material (W/m2.K)

Ti Internal air temperature (oC)

To External air temperature (oC)

A Total Surface area (m2)

ρ Density of Air (Kg/m3)

Qv Ventilation Heat Loss (W)

qv Volumetric flow rate through opening (m3/s)

Cp Specification heat capacity of air (J/Kg.K)

V Volume of room (m2)

Qg Sensible heat gain through glazing (W/m2.K)

Ag Total glazed area (m2)

Ug U value of glazing (W/m2.K)

Qsg Solar gain through glazing (W)

qsg Tabulated Cooling Load (W/m2)

G G value correction factor

CF Correction factor for building response

QΘ+Φ Heat flow into room Φ hours after solar incidence

Te Sol air temperature at time Θ

ƒ Decrement factor

gs Supply moisture content

gr Room moisture content

LH Latent heat gains (W)

L Latent heat of vaporisation capacity

M Mass Flow Rate (m2/s) 3

Nomenclature

HT Total peak casual heat gains (W)

ΔT Difference in air temperature (oC)

Csa Cross sectional area (m2)

Re Reynolds number

v velocity (m/s)

d Diameter of Duct

μ Viscosity (N/m2)

k Roughness coefficient

λ Friction factor

ΔP Pressure drop (Pa)

ΔPFriction Pressure drop due to friction (Pa)

l Length (m)

ζ component loss coefficient

A2 Csa after contraction (m2)

A1 Csa before contraction (m2)

Δpcontration Pressure loss due to contraction (m2)

qs Flow rate after component (m3/s)

qc Flow rate before component (m3/s)

Δpcomponent Pressure drop due to component (Pa)

ΔpTotal Total pressure drop (Pa)

Pair Power transferred to the air by the fan (W)

QT Total Flow Rate (m3/s)

Pelec Electric power supplied to the fan (W)

P Number of people served

w Width of stairs (m2)4

Contents

.Section Page Number

Executive Summary 2

Nomenclature 3

Contents 4

1. Introduction 9

2. Building Information

2.1 Geometry and Internal layout 10

2.2 Occupancy 12

2.3 Ventilation 12

2.4 Fabric types and properties 13

2.5 Air permeability and infiltration rate 13

2.6 Casual heat gains 14

2.7 Thermal conductance 14

3. Extreme Conditions – Heating Season

3.1 Environmental conditions 15

3.2 Fabric heat losses by type 15

3.3 Ventilation losses 16

3.4 Heat gains 17

4. Extreme Conditions – Cooling Season

4.1 Sensible transmission through the glazing 19

4.2 Solar gains through windows 19

4.3 Sol-air gains 20

4.4 Sol-air roof gains 20

4.5 Casual heat gains 20

5

Contents


4. Extreme conditions – Cooling season

4.6 Ventilation heat gains 21

4.7 Peak cooling load 22

5. Boiler Plant

5.1 Boiler sizing 23

5.2 Running costs and emissions 23

6. Air Conditioning

6.1 Sizing the air conditioning system (ACS) 24

6.2 Psychometric process 24

6.2.1 Simulation 1 24

6.2.2 Simulation 2 27

6.3 Design criterion, ACS type 27

6.4 ACS Mechanism, components and air handling

unit (AHU) components 28

6.4.1 ACS mechanism 28

6.4.2 ACS components 28

6.4.3 AHU components 28

6.5 Control strategy 29

6.6 Gross annual running costs 29

7. Ventilation

7.1 Duct configuration 31

7.2 Summer design criteria 32

7.3 Sanitary and non-sanitary and return air paths 33

7.4 pressure drop and supply index run 356

Contents


7. Ventilation

7.5 Pressure loss due to component 37

7.6 Supply diffuser choice 40

7.7 Gross costs, carbon emissions and AHU fans 42

7.7.1 Cost considerations 43

8. Sensitivity Analysis

8.1 Heating 46

8.2 Cooling 46

8.3 Fan energy demand 47

8.4 Total energy demand 47

8.5 Relative merit of each change 48

9. Fire Safety

9.1 Compartmentalization 49

9.2 Horizontal escape 49

9.3 Vertical escape 51

9.4 Protection of ventilation openings 52

9.5 Detection 52

9.6 Hose reels 53

9.7 Sprinklers 55

9.8 Hydrants, risers and landing valves 56

10. Vertical Transport

10.1 Background 59

10.2 Method 59

10.3 Results 417

Contents


10. Vertical transport

10.4 Estimating suitability of lift size 62

10.5 Additional information and analysis 63

11. Conclusion 64

12. References 65

13. Appendix 69

14. CV’s 76

8

1. Introduction

As a specialist building consultancy company, we aim to provide our clients with a

detailed analysis of the solutions we can offer. We create practical energy efficient

solutions, whilst achieving comfortable and functional design complying to UK

regulations.

The key aim of this report is to ensure the current building design is fit for purpose

under limiting conditions, whilst creating a comfortable working environment

through the building services design.

By the use of 5 manual simulations, the energy demand, cost and emissions, for

differing physical changes proposed for the building, will be assessed. These physical

changes come in the form of varying the decrement factor, lag time, building colour,

and indoor air temperatures, and the use of solar shading.

The aforementioned building services include boiler sizing, the size of the air

conditioning system and number of air handling units (AHU) as well as the fan

systems within these, the proposed ductwork layouts for supply and extract, and the

required number and size of diffusers. Additionally the fire protection systems have

been designed with any required architectural changes stated. Vertical transport

systems are also proposed such that the occupant demand within the building is met,

with any architectural changes needed also provided.

London Office Buildings specified that the heating system was to be gas powered and

the cooling to be electrically powered. (220)9


2.1. Geometry and Internal Layout.

The 10-storey proposed office block faces southeast onto City Road, London. It is

rectangular in shape with 9789m2 internal area. Each upper floor is 3.6m in height and

49.5m x 19.74m in plan. In the center of the space are 2 stairwells, space for ducting and

building services, two stores, separate male and female toilets, and 4 lift shafts all facing

into a central lobby.

Table 2.1, Typical Upper Floor Area

Zone Area (m2)

Office Floor 827.25

Male Toilets 58.50

Female Toilets 54.00

Lifts 7.00

Lobby 40.50

Stairwells 15.14

Duct 3.54

Total 1005.93

10


The ground floor is 4.2 meters high and serves as a transit space for people accessing

higher levels of the building; its layout is the same as upper floors but with reduced

floor area due a service access.

Table 2.2, Ground Floor Areas

Zone Area (m2)

Open Plan 626.48

Male Toilets 21.94

Female Toilets 21.94

Lifts 7.00

Lobby 40.50

Stairwells 15.14

Duct 3.54

Total 736.54

For the purpose of this report, the building thermal boundary includes the basement,

3m in depth, following the building footprint. It excludes the lift motor room and

service access.

11

2. Building information

2.2. Occupancy

The occupancy density of the office space was obtained as 10m2 per person[1]. 14m2 per person

would be typical[1], however it is more sustainable to calculate ventilation rates for a higher

density incase of future building population increase. In addition to this, land prices in

London are extremely expensive, a high occupancy density would maximize the number of

workers in the office relative to the cost of land, benefiting the building owner. Increasing the

population density provided extreme values for both casual heat gains and ventilation rates,

which were used to find suitable heating and cooling loads. Taking all these factors into

consideration a total occupancy of 738 was assumed.

2.3. Ventilation

An open-plan office requires a minimum of 10 L/s of fresh air per person[2]. Corridors, stairs

and landing spaces are assumed to be unoccupied and therefore have a ventilation rate of 0

m3/s. Toilets were obtained as 6 L/s per urinal or toilet[3]. The total ventilation required will

be significantly larger as it takes into account casual heat gains from equipment.

12


Table 2.4.1 Limiting U-values

Fabric U-value W/m2.K

Roof 0.25

Wall 0.35

Floor 0.25

Entrance Doors 3.50

Windows 2.20

The lower the U-value, the greater the resistance of the fabrics to heat transfers. From this

table it can be inferred that the greatest heat gains/losses will occur from the glazing and

Entrance doors.

2.5 Air Permeability and Infiltration Rate

Air permeability is the measure of the air tightness of a building. This was found to be

10m3/m2.h at 50 Pa[5]. Using this and the fact that the building is less than 10-storeys the

infiltration was obtained to be 0.4ACH[6] at its peak. The peak value was used to ensure

both the boiler and air conditioning system could cope with extreme circumstances.

2.4. Fabric Types and Properties

The limiting U-values of all building fabrics were obtained[4] and left constant

throughout both simulations. These values are shown in Table 2.4.1.

13


2.7 Thermal Conductance

The product of the U-value and the area of the specific building fabric give the thermal

conductance. The sum of the entire thermal conductance’s can then be found. In the case

of this building it equaled 2.784 kW.m2 for both simulations.

(482)

Table 2.6.1, Casual Heat Gains General Floor

Source QuantityHeat

(W)

Area

(m2)

Sensible

Heat Gain

(W/m2)

Latent heat

gains

(W/m2)

Total

(W/m2)

Total Whole

Building (kW)

PC Computer 82.00 55.00 827.25 5.45 0.00 5.45 40.59

PC Monitor 82.00 70.00 827.25 6.94 0.00 6.94 51.66

Photocopier 4.00 1100.00 827.25 5.32 0.00 5.32 39.60

Scanner 4.00 25.00 827.25 0.12 0.00 0.12 0.90

Occupant 82.00 75.00 827.25 7.43 6.00 13.43 100.02

Lighting 987.00 10.00 0.00 10.00 107.62

Total 35.26 41.26 340.39

2.6 Casual Heat Gains

It was a assumed 1 computer and monitor per person as well as 4 photocopiers and

scanners per floor[7]. The lighting was also obtained as 10 W/m2.

14


Five sets of conditions were applied to the building. These conditions are outlined in

tables 8.1 to 8.4. (18)

Table 8.2, Simulaition 2a

Condition Variable

Condition

Exterior colour Light

Solar Sheilding Total

Decrement Factor 0.2

Lag Time (hrs) 8

Summer Ti C 24

Winter Ti C 19

Table 8.1, Simulaition 1

Condition Variable

Condition

Exterior colour Dark

Solar Sheilding No


Lag Time (hrs) 1

Summer Ti C 22

Winter Ti C 21

Table 8.3, Simulaition 2b

Condition Variable Condition


Solar Sheilding No


Lag Time (hrs) 8

Summer Ti C 24

Winter Ti C 19

Table 8.4, Simulaition 2c

Condition Variable

Condition


Solar Sheilding Total


Lag Time (hrs) 8

Summer Ti C 22

Winter Ti C 21

Table 8.5, Simulaition 2d

Condition Variable Condition


Solar Sheilding No


Lag Time (hrs) 8

Summer Ti C 22

Winter Ti C 21

15


3.1 Environmental Conditions

In order to size the boiler for the worst conditions, a temperature of -3°C was used for the

design outdoor temperature, as this temperature is either equalled or exceeded for 99.6% of

the total hours in a year in London [8]. For Simulation 1 a design indoor temperature of 21°C

[9] was the most appropriate in order to neglect heat transfer between rooms, giving a

temperature difference for calculation of 24°C. For Simulation 2a and 2b we reduced this

temperature by 2°C in order to assess the effect of reduced temperature difference on fabric

heat loss.

3.2 Fabric heat losses by type

The steady state conduction fabric losses varied according to the thermal transmittance of

the material on the buildings thermal boundary. The total heat loss for each material was

calculated as in Equation 3.2.1.

Equation 3.2.1, Fabric Heat Loss

𝑄𝐹 = 𝑈𝐴(𝑇𝑖 − 𝑇𝑜)

Where 𝑄𝐹 is the fabric heat loss (W), U is the thermal transmittance of the material (𝑊/𝑚2𝐾), A is the total surface area of each material (𝑚2), 𝑇𝑖 is the index temperature (°C) and 𝑇𝑜 is the external temperature (°C).

Example Calculation 3.2.1, Fabric Heat Loss, Windows, General floor:

𝑄𝐹 = 2.2 × 158.98 24 = 8.394𝑘𝑊

A calculation of the total fabric heat loss per material, per floor, was necessary due to varying surface areas.

16


Table’s 3.2.1 and 3.2.2 show the peak fabric heat loss by material type for Simulations 1 and 2n

respectively.

Table 3.2.1 - Fabric loss by type - Simulation 1

Fabric Qf (W)

Windows 77644.61

Walls 28698.74

Roof 5675.25

Floor 545.45

Basement 5837.76

Doors 2225.66

Total 120627.46

Table 3.2.2 - Fabric loss by type - Simulation 2n

Type Qf (W)

Windows 70892.90

Walls 26203.19

Roof 5181.75

Floor 498.02

Basement 5059.39

Doors 2032.13

Total 109867.38

A 10% decrease in fabric heat loss is achieved by decreasing the design indoor

temperature by 2°C. Windows account for almost 65% of the total fabric heat loss and

walls roughly 25%.

3.3 Ventilation losses

Equation 3.3.1, Ventilation heat loss

𝑄𝑉 = 𝑞𝑣𝜌𝑐𝑝 𝑇𝑖 − 𝑇𝑜

For air at ambient temperatures, ρ ≈ 1.20 𝑘𝑔.𝑚−3 and 𝑐𝑝 ≈ 1000 𝐽. 𝑘𝑔−1. 𝐾−1, hence:

𝑄𝑉 = 𝑞𝑣 𝑇𝑖 − 𝑇𝑜 /3

Where, 𝑄𝑉 is the heat transfer by ventilation (W), 𝑞𝑣 is the volumetric flow rate through opening (m3·s–1), 𝑐𝑝 is the specific heat capacity of air (𝐽. 𝑘𝑔−1𝐾−1), ρ is the density of air

(kg·𝑚3), 𝑇𝑖 and 𝑇𝑜 are the indoor and outdoor temperature.

Equation 3.3.2, Volume flow rate

Total volume flow rate, 𝑞𝑣 = Infiltration rate (ACH) + Ventilation rate (ACH) x V

Where, V is the Volume of the room (𝑚2)

17


Example Calculation 3.3.2, Ventilation heat loss, Open plan office area, General floor, Simulation 1.

𝑞𝑣 = 0.99 + 0.4 × 2978.1 = 4139.6 𝑚3/𝑠

𝑄𝑉 = 4139.6 23 /3 = 3173.7 𝑊

3.4 Heat gains

It was assumed that the heating season starts on the 1st of October and continues through to

the 1st of May, and that no heating is required during the cooling season (the remainder of the

year). It was also assumed for simplicity that there are no casual heat gains during the

heating period. (235)

18


When sizing the air conditioning system, extreme values were chosen to find the peak-

cooling load. Although for the majority of the time this load will never be reached, the

system needs to have the ability to provide this cooling power if necessary.

To find the peak-cooling load, the heat gains of 6 different variables need to be summed.

Sensible transmission through the glazing

Solar gains through the glazing

Sol-air gains

Roof sol-air gains

Casual heat gains

Ventilation heat gains

These gains are quasi-dynamic (varying with time) as a result of changing outdoor air

temperatures. All examples show results for 11:30 on 21st May, the time found to produce

the peak-cooling load.

19


Equation 4.1.1, Sensible Transmission through the Glazing

𝑄𝑔 = 𝐴𝑔 × 𝑈𝑔 × 𝑡𝑜 − 𝑡𝑖

Where Qg is the sensible gain through the glazing (W), Ag is the total glazed area (m2), Ug is the U-value of theglazing (W/m2.K)[10], ti is the internal air temperature (°C)[11], to is the external air temperature (°C)[12].

Example Calculation 4.1.1, Sensible Transmission through the Glazing, Small Window

𝑄𝑔 = 5.53 × 2.2 × 23 − 22

𝑄𝑔 = 14.45𝑊 per window

4.2. Solar Gains Through Windows

This shows the radiant heat gain through the windows as a result of the sun. It takes into

account building orientation, location, time of day, and glazing configuration (G-value) as

well as the building response factor.

4.1. Sensible Transmission through the Glazing

This is a measure of heat transfer through the glazing as a result of the difference in

internal and external air temperatures.

Equation 4.2.1, Solar Gains through Windows

𝑄𝑠𝑔 = 𝑞𝑠𝑔 × 𝐺 × 𝐶𝐹 × 𝐴

Where Qsg is the solar gains through the glazing (W), qsg is the tabulated cooling load (W/m2)[13], G is the G-Value correction factor for glazing type[13], CF is the correction factor for building response, fast response is 0.83, slow response is 0.72[13], A is window are (m2)

Example Calculation 4.2.1, Solar Gains through Windows, SE Surface

𝑄𝑠𝑔 = 476 × 0.72 × 0.83 × 186.62

𝑄𝑠𝑔 = 174997.41𝑊

This method is repeated for each building surface, which are then summed to find the

total gain.

20


4.3. Sol-air Gains

This is a fictitious outdoor air temperature that allows the heat flow as a result of both

radiant and convective transfer to be calculated.

Equation 4.3.1, Sol-air Gains considering thermal capacity

𝑄𝜃+𝜙 = 𝑈𝐴 𝑡𝑒𝑚 − 𝑡𝑟 + 𝑈𝐴 𝑡𝑒 − 𝑡𝑒𝑚 𝑓

Where Qθ+ϕ is the heat flow into the room ϕ hours after solar incidence (W), U is the U-value for the exterior

wall (W/m2.K)[10], A is the area of the exterior wall (m2), tem is the 24hr mean sol-air temperature (°C)[5], te

sol-air temperature at time (θ) of solar incidence (°C)[14], tr is the room temperature (°C), ƒ is decrement

factor [15].

Example Calculation 4.3.1, Sol-air Gains considering thermal capacity, SE Dark Surfacewith a decrement factor of 0.9 and a lag time of 1hr

𝑄𝜃+𝜙 = 0.35 × 1229.03 27.47 − 22 + 0.35 × 1229.03 55 − 27.47 0.9

𝑄𝜃+𝜙 = 13011.48𝑊

4.4. Sol-air Roof Gains

The sol-air gains for the roof also were found using Equation 4.3.1.

4.5. Casual Heat Gains

Casual heat gains are defined in building specification, section 2.6.

21


4.6. Ventilation Heat Gains

Ventilation heat gains will vary depending on the outdoor air temperature.

Equation 4.6.1, Total Air Change Rate

𝑉𝑒𝑛𝑡𝑖𝑙𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑒 + 𝐼𝑛𝑓𝑖𝑙𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑒 = 𝑇𝑜𝑡𝑎𝑙 𝐴𝑖𝑟 𝐶ℎ𝑎𝑛𝑔𝑒 𝑅𝑎𝑡𝑒

Where Ventilation rate (h-1)[16] and Infiltration rate (h-1)[17] can be assumed.

Example Calculation 4.6.1, Total Air Change, Open plan office

0.991 + 0.4 = 1.391

Equation 4.6.2, Ventilation Rate (m3/s)

𝑉𝑜𝑙𝑢𝑚𝑒 × 𝑇𝑜𝑡𝑎𝑙 𝐴𝑖𝑟 𝐶ℎ𝑎𝑛𝑔𝑒 𝑅𝑎𝑡𝑒

3600= 𝑉𝑒𝑛𝑡𝑖𝑙𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑒

Where volume is the volume of the room for which the ventilation rate is being calculated (m3), Total Air Change Rate has been previously calculated (h-1), 3600 is the number of seconds in 1 hour, Ventilation rate is the air changes in the room (m3/s).

Example Calculation 4.6.2, Ventilation Rate (m3/s)

2978.1 × 1.391

3600= 1.151

Equation 4.6.3, Ventilation Thermal Conductance (W/K)

𝑉𝑒𝑛𝑡𝑖𝑙𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑒 × 𝐻𝑒𝑎𝑡 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 𝑜𝑓 𝑎𝑖𝑟 = 𝑉𝑒𝑛𝑡𝑖𝑙𝑎𝑡𝑖𝑜𝑛 𝑇ℎ𝑒𝑟𝑚𝑎𝑙 𝐶𝑜𝑛𝑑𝑢𝑐𝑡𝑎𝑛𝑐𝑒

Where the Ventilation rate has been previously calculated (m3/s), the Heat capacity of air could be obtained (J/m3.K)[18]

Example Calculation, 4.6.3, Ventilation Thermal Conductance (W/K)

1.042 × 1200 = 1250.05

22


Equation 4.6.4, Ventilation Heat Gains

𝑄𝑣 = 𝑇ℎ𝑒𝑟𝑚𝑎𝑙 𝐶𝑜𝑛𝑑𝑢𝑐𝑡𝑎𝑛𝑐𝑒 × 𝑇𝑜 − 𝑇𝑖

Where Qv is the ventilation heat gains (W), Thermal Conductance is previously calculated (W/K), To is the outdoor air temperature (°C)[15], Ti is the internal air temperature (°C)[18].

Example Calculation 4.6.4, Ventilation Heat Gains

𝑄𝑣 = 1250.05 × 23 − 22

𝑄𝑣 = 11941.5 𝑊

4.7. Peak Cooling Load

The heat gains shown in sections 4.1, 4.2, 4.3, 4.4, 4.5, and 4.6 were then repeated for

every hour in each month and summed to obtain the maximum heat gain. This was found

to be on 1130 on the 21st May with a value of 616.56 kW. (288)

23

5. Boiler Plant

5.1. Boiler sizing

The peak heat loss from the building is found by combining the fabric heating losses with

those of the ventilation. The results of which are shown in section 3.2 and 3.3 respectively.

This comes to 467.99 kW in Simulation 1, in Simulation 2 this comes to 426.69 kW.

However in order to find the boiler capacity the peak heat losses must be multiplied by the

plant size ratio. The plant size ratio ensures that the heating system is able to bring the

building up to design temperature in the required time. In Simulation 1, the building is of a

light thermal mass, this gives a plant size ratio of 1.3[]. In Simulation 2, the building is now

of a heavy thermal mass resulting in an increased plant size ratio of 1.8.

Now the boiler capacity can be found. For Simulation 1, a boiler of 608.39 kW is required

compared with a capacity of 768.05 kW for Simulation 2.

5.2 Running Costs and Emissions

The Boiler in both simulations is gas powered costing 5 p/kWh. Monthly heating load was

calculated assuming the boiler ran for 13 hours a day every weekday. It was assumed that

the heating season lasted between 1st October and the 30th April, 7 winter months. This

led to a energy demand of 652734.57 kWh for Simulation 1 and 59542.53 kWh for

Simulation 2a, the lowest of all simulations.

(226)

24

6. Air Conditioning

6.1 Sizing the Air Conditioning System (ACS).

From the maximum cooling load, the office block’s ACS can be

sized. This was found to be 671KW. The ACS is primarily used for

cooling and is the main cooling source within the building, the only

other being the heat loss due to conduction in winter periods.

A definite volume of air was found that was required to meet the

needs of the office space, both in terms of heat gains and the fresh

air required for the occupants shown in Table 6.1.1.

The proportion of fresh air is displayed in Table 6.1.2 and

accounted for in the Psychrometric chart

Table 6.1.1

FloorRequired volume

of air (m3/s)

1 3

2-9 5.77

10 6.14

Table 6.1.2

FloorProportion of fresh

air %

1 10.67

2-9 14.21

10 13.35

6.2 Psychrometric Process

6.2.1 – Simulation 1

Figure 6.2.1.1 – Finding room point

25

6. Air Conditioning

Figure 6.2.1.2 Finding supply point

Figure 6.2.1.3 Plotting outdoor point

26

6. Air Conditioning

Figure 6.2.1.4 Plotting mixing point and Final cycle

Equation 6.2.1.1, Calculating supply moisture content

𝑔𝑠 = 𝑔𝑟 −𝐿𝐻

𝐿𝑥𝑀

Where, gs is Supply Moisture Content, gr is Room Moisture Content taken from Figure 6.2.1,

LH is Latent Heat Gains (W), L is Latent Heat Vaporization Capacity (kJ/kg), M is Mass Flow

Rate (m3/s)

Example Calculation 6.2.1.1, Supply moisture content

𝑔𝑠 = 0.0085 −44.67

2450𝑥17.05

𝑔𝑠 =0.0074

27

6. Air Conditioning

6.2 - Simulation 2 – Psychrometric process with simulation 2 conditions applied

6.3 Design criterion, ACS type

The system designed for this office block is a variable air volume (VAV) air conditioning system

(ACS). It was chosen due to the varying throws from each diffuser and changes in the proportion of

air exiting each diffuser which maintains a constant volume of air being supplied to the office per

m2.

To simplify the system, minimising the number of air handling units, it was decided to set the

fresh air proportion to the maximum value of 14.21% for the whole building, with 85.79% being re-

circulated. Although this may increase building running costs as the fan will continue at a constant

rate rather than meeting the demand, it will reduce capital costs minimising the amount of

ductwork, but also provide more space within the building that would otherwise house extra ducts.

28

6. Air Conditioning

Table 6.3.1 – Advantages and Disadvantages of a VAV system

VAV System

Advantages Disadvantages

Incredibly useful in an office as the temperature can be

controlled throughout the year to meet the occupants needs.

It uses a lot of space, which is already limited in this

building

Also has the ability to vary the flow rate from the diffusers as

well as the mixing point to meet the fresh air demand

reducing running costs.

The fan-assisted terminal units can increase noise

levels potentially disrupting people working.

6.4 - ACS Mechanism, components and AHU Components

6.4.1 ACS Mechanism

The ACS mechanism is made up of 5 key areas. They are the condensing mechanism, drying

mechanism, expanding mechanism, evaporating mechanism and compressing mechanism. The

ambient air passes through the condenser into a blower motor before being passed through the

evaporator and produced as conditioned air.

6.4.2 ACS components

The components that carry out said mechanisms are the condenser fan, drier, expansion valve,

evaporator and compressor clutch.

6.4.3 AHU components

The components that make up the AHU system for the office building are the supply duct, the fan

compartment, the heating coil, the cooling coil, the filter compartment and mixing box.

29

6. Air Conditioning

6.5 - Control strategy

The air condition system will run between 1st May to 30th September, the 5 warmest months.

Since the ACS is VAV the required level of cooling to any number of zones can be controlled.

This is advantageous for periods when the building isn’t at full occupancy (7am-9am and

6pm-8pm). The air flow rates will be reduced during these periods to save on energy as the air

volume rate required will be limited.

6.6 - Gross annual running costs

To estimate the annual running cost, first the peak cooling load was found and root mean

square taken to find the average. Then the root mean square of causal heat gains was found to

calculate Pelec. The sum of these dictated the cooling load to find the total cooling demand.

Table 6.6.1, Simulation 2a Air conditioning

Pelec (kW)Hours/Y

ear

Total Demand

(Kwh)Cost (£)

Cost/m2

(£)

Emission Factor

(C02/kWh)

CO2 Cost

(KgCO2)

Cost/m2

(KgCO2)

1.14 1430 516737.74 0.1 5.29 0.49 253201.5 25.92

Table 6.6.1, Simulation 1 Air conditioning

Pelec (kW)Hours/Y

ear

Total Demand

(Kwh)Cost (£)

Cost/m2

(£)

Emission Factor

(C02/kWh)

CO2 Cost

(KgCO2)

Cost/m2

(KgCO2)

2.56 1430 955992.3 0.1 9.79 0.49 468436.2 47.96

Table 6.6.1, Simulation 2b Air conditioning

Pelec (kW)Hours/Y

ear

Total Demand

(Kwh)Cost (£)

Cost/m2

(£)

Emission Factor

(C02/kWh)

CO2 Cost

(KgCO2)

Cost/m2

(KgCO2)

2.38 1430 897045.38 0.1 9.18 0.49 253201.49 25.92

30

6. Air Conditioning

Table 6.6.1, Simulation 2c Air conditioning

Pelec (kW)Hours/Y

ear

Total Demand

(Kwh)Cost (£)

Cost/m2

(£)

Emission Factor

(C02/kWh)

CO2 Cost

(KgCO2)

Cost/m2

(KgCO2)

1.19 1430 531429.14 0.1 5.44 0.49 260400.3 26.66

Table 6.6.1, Simulation 2d Air conditioning

Pelec (kW)Hours/Y

ear

Total Demand

(Kwh)Cost (£)

Cost/m2

(£)

Emission Factor

(C02/kWh)

CO2 Cost

(KgCO2)

Cost/m2

(KgCO2)

2.43 1430 911733.76 0.1 9.33 0.49 446749.5 45.74

(448)

31

Figure 6.1.1 – 3D projection of duct layout with diffuser throw, Ground floor

Figure 6.1.2 – 3D projection of Diffuser on duct, Ground floor

7. Ventilation

7.1, Duct configuration

The first step to design the duct configuration is to obtain the noise limit of 7.5 m/s [21]. By

ensuring the velocity was less than 7.5 m/s the throw was selected using the Gilbert

nomogram for each diffuser based on geometric limitations respectively. Once the throw was

defined the layout of the diffusers were drawn using the diameters. The configuration of the

ducts was then drawn connecting each diffuser to the main duct in the best possible way to

limit duct lengths.

Figure 7.1.3 Supply for General Floor, illustrating throw of each diffuser

Figure 7.1.4 Supply for Ground Floor, Illustrating throw of each diffuser

32

7. Ventilation

7.2 Summer design Criteria

The summer design temperature is 22oC. Therefore the system must be designed to have the

capability to meet the peak cooling load of 95592.3 kWh. This peak cooling load falls on the

21st May at 11:30 am.

Equation 7.2.1, Volume flow rate for each floor

𝑄 =𝐻𝑇𝜌𝐶𝑝∆𝑇

Where, HT = Total peak casual heat gains (W) – [22], ρ = density of air

(Kg/m3), Cp = Specific Heat Capacity of Air, ΔT = Difference in Indoor

and outdoor temperature (oC)

Example Calculation, 7.2.1 – Volume flow rate for each floor

𝑄 =69.94

1.2𝑥1.01𝑥10

Q = 5.77 (m3/s)

Table 7.2.1, Volume Flow rate for Each floor

Floor Heat Gains KWVolume of air required

(m3/s)

1 36.34 2.99

2 69.98 5.77

3 69.98 5.77

4 69.98 5.77

5 69.98 5.77

6 69.98 5.77

7 69.98 5.77

8 69.98 5.77

9 69.98 5.77

10 74.42 6.13

33

7. Ventilation

7.3, Sanitary and Non-sanitary and return air paths.

No supply was provided to the toilet resulting in a negative pressure, aiding the

extraction of unsanitary air. Office and toilet ducts are kept separate, such that

unsanitary toilet air does not mix with office floor air.

Table 7.3.1 supply – open plan

Floor Area covered (m2)Air required per m2,

(m3/s)Volumetric flow rate

(m3/s)Volumetric flow rate at

each floor

1 156.53 0.0062 0.96 0.96

2 326.54 0.0093 3.04 4.01

3 326.54 0.0093 3.04 7.06

4 326.5 0.0093 3.04 10.10

5 326.54 0.0093 3.04 13.15

6 326.54 0.0093 3.04 16.20

7 326.54 0.0093 3.04 19.24

8 326.54 0.0093 3.04 22.29

9 326.54 0.0093 3.04 25.33

10 326.54 0.0099 3.23 28.57

Return air paths are dictated by layout of extract diffusers. Extract diffusers are

placed in between the supply diffusers to prevent short circuiting. This allows the

conditioned air to mix in the room.

34

7. Ventilation

Figure 7.2.1 Extract layout for General Floor

Figure 7.2.2 Extract Layout for Ground Floor

35

7. Ventilation

7.4 Pressure drop and Supply Index Run

7.4.1 Friction Pressure drop

Equation 7.4.1.1, Cross sectional area of duct and diameter. Found from

combined supply volume flow rate

𝐶𝑠𝑎 =𝑄𝑣𝑉

Where, CSa is Cross Sectional Area (m2), Qv is Volume flow rate (m3/s), V is Velocity

(m/s)

Example Equation 7.4.1.1, Cross sectional area of duct and diameter.

Found from combined supply volume flow rate

𝐶𝑠𝑎 =1.356

7

Csa = 0.194

Equation 7.4.1.2, Reynolds number calculated using diameter found from

CSA

𝑅𝑒 =𝜌𝑣𝑑

𝜇

Where, ρ is density (kg/m3), v is Velocity (m/s), d is Diameter (m), μ is Viscosity

(N/m2)

Equation 7.4.1.2, Reynolds number

𝑅𝑒 =1.2𝑥3.6𝑥0.7

0.000018

Re = 166219

36

7. Ventilation

Equation 7.4.1.3, The Haaland Equation for turbulent flow, to find friction factor, λ

𝜆 = (1

(−1.8log[6.9𝑅𝑒+ (

𝑘𝑑3.71)1.11]

)2

Where Re = Reynolds number, k = Roughness Coefficient assuming steel duct

= 0.09[23]. d = diameter

Equation 7.4.1.3, The Haaland Equation for turbulent flow, λ

𝜆 = (1

(−1.8log[6.9166219

+ (

0.090.73.71)1.11]

)2

λ = 0.022

Equation 7.4.1.4, Pressure drop per unit length

𝛥𝑃/𝑚 =𝜆𝜌𝑣

2𝑑

Equation 7.4.1.4, Pressure Drop per unit length

𝛥𝑃/𝑚 =0.022𝑥1.2𝑥3.62

2𝑥0.7

𝛥𝑃/𝑚 = 0.25Pa/m

37

7. Ventilation

Equation 7.4.1.5, Pressure drop due to Friction

∆𝑃𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛= ∆𝑃/𝑚𝑙

Where, l = length of duct (m)

Example Calculation7.4.1.5, Pressure drop due to Friction

∆𝑃𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛= 0.25𝑥3.6

∆𝑃𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛= 0.9Pa

7.4.2 Pressure Loss due to component

Equation 7.4.2.1, Alternative CSA ratios used to calculate ζ (Component

Loss Coefficient) for contraction.

𝜁 = 0.5[ 1 −𝐴2𝐴1

0.75

]

Where, A2 = Cross sectional area after Contraction, A1 = Cross sectional area

before Contraction.

Example Equation 7.4.2.1, Alternative CSA ratios used to calculate ζ

(Component Loss Coefficient) for contraction.

𝜁 = 0.5[ 1 − 0.6 0.75]

𝜁 = 0.25

38

7. Ventilation

Equation 7.4.2.2, Contraction Pressure drop using Equation 7.4.2.2

∆𝑃𝐶𝑜𝑛𝑡𝑟𝑎𝑐𝑡𝑖𝑜𝑛= 0.5𝑥𝜌𝑥𝑣2𝑥𝜁

Where, ζ = Component loss coefficient calculated in Equation 7.4.2.1

Example Equation 7.4.2.2, Contraction Pressure drop using Equation 7.4.2.2

∆𝑃𝐶𝑜𝑛𝑡𝑟𝑎𝑐𝑡𝑖𝑜𝑛= 0.5𝑥1.2𝑥3.62𝑥0.25

∆𝑃𝐶𝑜𝑛𝑡𝑟𝑎𝑐𝑡𝑖𝑜𝑛= 1.96

Table 7.4.2.1 – Example calculation of flow ratio for Component loss coefficient equation.

Junction Configuration Flow qs/qc Calculation

T1 B Diverging T1c/D1T1

T2 A Diverging Gt2/T2H

T3 B Diverging T3N/D1T3

T4 B Diverging T4C/D1D

T5 A Diverging KT5/T5J

T6 B Diverging T6M/D2T6

Equation 7.4.2.3, Flow Ratio

𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑖𝑜 =𝑞𝑠𝑞𝑐

Where, qs = flow after component (m3/s) , qc = flow before component (m3/s)

39

7. Ventilation

Example Equation 7.4.2.3 Flow Ratio

𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑖𝑜 =1.35

4.4

𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑖𝑜 = 0.3

Flow ratio of 0.3 then equates to a value of ζ = 0.18[24]

Equation 7.4.2.4, Component Pressure Drop

∆𝑃𝐶𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡= 0.5𝑥𝜁𝑥𝜌𝑥𝑣2

Example Calculation 7.4.2.4, Component Pressure Drop

∆𝑃𝐶𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡= 0.5𝑥0.18𝑥1.2𝑥3.62

∆𝑃𝐶𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡= 1.4

40

7. Ventilation

Equation 7.4.2.5, Total Pressure drop

∆𝑃𝑇𝑜𝑡𝑎𝑙= ∆𝑃𝐹𝑟𝑖𝑐𝑡𝑖𝑜𝑛+∆𝑃𝐶𝑜𝑛𝑡𝑟𝑎𝑐𝑡𝑖𝑛+∆𝑃𝐶𝑜𝑚𝑝𝑜𝑛𝑒𝑛𝑡

Example Calculation 7.4.2.5 Total Pressure drop

∆𝑃𝑇𝑜𝑡𝑎𝑙=0.9+1.95+1.4

∆𝑃𝑇𝑜𝑡𝑎𝑙= 4.26

The supply index run is obtained as the run with the greatest ΔP which is

from the AHU on the 10th floor to the ground floor onto diffuser p in Duct

2 and has a pressure drop of 1051.169 Pa.

7.5 – Supply Diffuser choice

Table 7.5.1 – Data for Gilbert Nomogram

Branch Velocity (m/s) Throw (m) Volume flow rate (m3/s)

I 2.86 3.3 0.32

41

7. Ventilation

Figure 7.5.1 - Example nomogram used to define size of supply

diffuser.

Table 7.5.2 – Results from nomogram for diffuser dimensions

Grille I

Width (mm) 375

Height (mm) 325

42

7. Ventilation

7.6 – Gross Costs, Carbon emissions and AHU fans

Equation 7.6.1 – Fan Power

𝑃𝑎𝑖𝑟 = ∆𝑃 𝑥𝑄𝑇

Where, ΔP = Pressure drop (Pa), QT = Total flow rate (m3/s)

Example Calculation 7.6.1, Fan Power

𝑃𝑎𝑖𝑟 = 256.218 𝑥3.69

𝑃𝑎𝑖𝑟 = 946.1W

Equation 7.6.2 – Electric Power

𝑃𝑒𝑙𝑒𝑐 =𝑃𝑎𝑖𝑟𝜇

Where, Pair is calculated in Equation 7.6.1, μ is Efficiency [25]

Example Equation 7.6.2 – Electric Power

𝑃𝑒𝑙𝑒𝑐 =946.1

0.9

𝑃𝑒𝑙𝑒𝑐 = 1051.17𝑊

43

7. Ventilation

Table 7.6.1 Supply Electric Power

Index run – Supply

Duct Area ΔP Qt Pair μ Pelec

2 T6 - P 325.55 2.64 858.17 0.9 953.52

1 T4 - G 113.60 2.48 281.24 0.9 312.49

1 Toilet 899.59 0.02 21.49 0.9 23.87

2 Toilet 867.51 0.05 39.94 0.9 44.38

Table 7.6.2 Extract Electric Power

Index run - Extract

Duct Area ΔP Qt Pair μ Pelec

1 T1 - I 111.08 2.56 283.8 0.9 315.35

2 T4 - s 97.6 5.28 515.28 0.9 572.54

1 Toilet 899.94 0.02 21.49 0.9 23.89

2 Toilet 866.79 0.05 39.91 0.9 44.34

The number of AHU fans corresponds to the number of extract and supply run

systems which is 6. Therefore there will be 6 AHU fans.

7.6.1 Cost Considerations

In order to minimise gross running cost, components in the duct work are kept to

a minimum. Straight paths are augmented rather than bent. Total length is

restricted to minimise pressure drop and power needed. (299)

44


Figure 8.1, Energy Proportions, Simulation 1

0

500000

1000000

1500000

2000000

1 2a 2b 2c 2d

Ene

rgy

De

man

d (

kWh

)

Simulation

Fan EnergyDemand (kWh)

Cooling Demand(kWh)

HeatingDemand (kWh)

HeatingDemand (kWh)

CoolingDemand (kWh)


HeatingDemand (kWh)

CoolingDemand (kWh)


HeatingDemand (kWh)

CoolingDemand (kWh)


HeatingDemand (kWh)

CoolingDemand (kWh)


HeatingDemand (kWh)

CoolingDemand (kWh)


Figure 8.2, Energy Proportions, Simulation 2a

Figure 8.3, Energy Proportions, Simulation 2b

Figure 8.4, Energy Proportions, Simulation 2c

Figure 8.5, Energy Proportions, Simulation 2d

Figure 8.6, Annual Energy Demand Comparison

Figures 8.1 to 8.6 show the proportion of energy demand for Heating, Cooling and Fan

power for each simulation and a comparison of the 5 simulations. The figures show

that the greatest reductions in energy demand come from reducing cooling load. (41)

45


8.1. Heating

The lowest heating demand is shown in Simulations 2a and 2b, a decrease of 9% on

the largest value. (19)

Table 8.1.1, Heating Demands

SimulationHeating Demand

(kWh)

1 652734.57

2a 595423.53

2b 595423.53

2c 652734.57

2d 652734.57

This is a result of the winter internal temperatures being decreased by 2°C. By

reducing winter internal temperatures there is an associated heat loss reduction

due to the decreased temperature difference - by Equations 3.1 and 3.2. (37)

8.2. Cooling

Simulation 1 exhibits the greatest cooling demand due to the short lag time. Heat

gains are transmitted directly into the building during occupied hours and these

this offset by the cooling load. In simulations 2.n increased lag time means the

largest sol-air gains do not affect the internal temperature until after occupied

hours, resulting in a cooling load decrease of 5%. Additionally complete solar

shading removes solar transmission which results in decreased cooling demand in

Simulations 2a and 2b of an additional 40%. (83)

46


Table 8.2.1, Cooling Demand

SimulationCooling Demand

(kWh)

1 952330.75

2a 515104.65

2b 893636.07

2c 529725.62

2d 908257.04

8.3. Fan Energy Demand

The fan runs constantly during the heating and cooling system in order to provide the

fresh air requirement for the room occupants. In summer it runs at an increased rate

to accommodate for the increased heat gain. Therefore the required fan energy

decreases proportional to the cooling demand.

(48)

Table 8.3.1, Fan Energy Demand

SimulationFan Energy Demand

(kWh)

Heating Season 848.53

1 3661.54

2a 1663.09

2b 3409.30

2c 1703.52

2d 3476.73

8.4. Total Energy Demand

The greatest energy demand occurs for Simulation 1 due to it’s low thermal density,

large temperature difference between indoor and outdoor and high solar exposure.

Simulation 2a has the lowest total energy demand (31% less).

(35)

47


8.5. Relative Merit of each Change

The results demonstrate that a change in building colour and an increase in lag time

significantly reduces total energy demand from 163.17kWh/𝑚2to 159.69kWh/𝑚2

(2.5%). This will result in a cost saving of £4425.85 and emissions saving of 21686 kg

cO2per year. Savings can be further increased by changing the design indoor air

temperature to 19°C in winter and 24°C in summer. This would reduce the total

energy demand by a further 8.03kWh/𝑚2 per year (5%). To better improve however,

would be to add solar shading, potentially in the form of louvers. This would result in a

total decrease of 42.9kWh/𝑚2energy demand per year, with a cost saving of

£42456.32 and emissions saving of 217985kg cO2. The maximum possible savings are

found using the parameters stated for Simulation 2a. This would provide a total cost

saving of £43925.46 and emissions saving of 225183kg cO2per year when compared

with Simulation 1. (149)

Table 8.4.1, Total Energy Demand

SimulationTotal Energy

Demand (kWh)Annual cost

(£)Annual CO2

Emission

Total Energy Demand

(kWh/M2)

Annualcost (£/m2)

Annual CO2 emissions (kg/m2)

1 1601824.58 128158.77 588358.87 163.87 13.11 60.19

2a 1110528.19 81529.80 363175.20 113.61 8.34 37.15

2b 1489059.61 119560.57 549525.94 152.33 12.23 56.22

2c 1182460.19 82998.94 370373.99 120.97 8.49 37.89

2d 1560991.61 121029.41 556723.25 159.69 12.38 56.95

48

9. Fire Safety

9.1 Compartmentalisation

Each storey is separated by fire resistant floors and doors.

Figure 9.1.1 shows the fire protected shaft housing the ducts

and the stairs. The fire doors will match the separating

construction and so are maximum 75mm.

From Table A1[26], the firefighting shaft exterior should

provide at least 120 minutes. Table 12[27] shows there is no

limit on floor area. As both stairs are entered at each level

via a protected lobby, both stairs can be assumed available.

Figure 9.1.1 - Fire protected shaft (red)

Equation 9.2.1 Maximum Distance to nearest fire exit .

14.49 + 6.6 + 15.38 = 36.47𝑚

2 fire doors should be added on each side of the service area [28]

49

9.2 Horizontal escapeFigure 9.2.1, Suggested Fire escape door example

Figure 9.2.2, Maximum travel distances in one direction, Ground Floor

9. Fire Safety

Figure 9.2.3 – Maximum travel distance in multiple directions on floor 1-9

Figure 9.2.4 – Maximum travel distance in one direction on floor 1-9

Equation 9.2.2 Maximum Distance to nearest fire exit when travel is possible in multiple directions

11.76 + 4.5 + 4.5 = 20.76𝑚

Equation 9.2.3 Maximum Distance to

nearest fire exit when travel is possible in

one direction.

15.48 + 4.5 = 19.98

Where, this results in another fire door

being installed on each stairwell50

Figure 9.2.5, Suggested Fire escape door example, Typical Upper Floor.

9. Fire Safety

Table 9.2.1, Minimum number of escape routes from a room

Zone

Peak time occupancy / no. of

people

No. of exits

available

Does it comply

regulations?[29]

General

floor82 2 Yes

Ground

floor32 1 Yes

9.3 Vertical escape

The stairs are the same width throughout the whole building of 1200mm. This falls above all

minimum stair widths given in Table 6 [28].

Assuming that escape will be a simultaneous evacuation, with the current constant stair width

of 1200mm, no change is needed on any floor to be within the regulations provided by Table 7

[30].

Protected lobbies or corridors are needed on each level except the top story as the stairs serve a

height greater than 18m [31].

The fire exit doors to the stairs are 1500mm in width. This is over the minimum 850mm limit

for a maximum of 110 persons per floor as mentioned in Table 4 [32]. This also provides escape

if one exit is discounted. [121]

Equation 9.3.1 – Minimum stair width

𝑤 =𝑃 + 15𝑛 − 15

150 + 50𝑛

Where, P = Number of people served, w = Width of the stairs (m), n = Number of storeys

served N.B. P is divided by the number of stairways if there is more than one available.

51

9. Fire Safety

Example Calculation 9.3.1, Minimum stair width

𝑤 =(7702 ) + 15(9) − 15

150 + 50(9)

𝑤 = 842𝑚𝑚

Therefore keeping the stairs width at 1200mm will ensure a safe escape route

9.4 Protection of ventilation openings

The use of the protected shafts to provide a safe escape to occupants is advised. Fire

protected ductwork may be feasible however would greatly increase costs for the whole

ductwork to possess the same fire resistance as the shafts.

Fire detection is needed to accurately control the fire dampers. As the smoke will already

be in the ductwork when a fire starts, it is necessary to place smoke and temperature

detectors outside the diffusers so that the dampers can isolate the specific sections of

ductwork. [84]

9.5 Detection

Manual fire alarms should be positioned towards the fire exit so that they are not

increasing their distance from the escape routes. The fire alarms will alert the control

board to see which alarm has been initiated. [37]

52

9. Fire Safety

Figure 9.5.1 - Notional location of manual fire alarms (red) – General floor

Figure 9.5.2 - Notional location of manual fire alarms (red) – Ground floor

9.6 Hose Reels

Table 9.6.1, Open floor space

Zone Open floor space / m²

General floor 477.61

Ground floor 618.89

53

Figure 9.5.3, Example eocation of fire hose and manual alarm, Ground Floor.

9. Fire Safety

There must be one hose per 800 m2 of floor space and it must also have a water supply

which is at least 24ls-1 to produce a 6m jet. The hose reel needs to be capable of reaching

within 6m of every part of the space [33]. The hose reels be a length of 40m.

[57]

Figure 9.6.1 - Notional location of hoses (green) – Ground floor

Figure 9.6.2 - Notional location of hoses (green) – General floor

54

9. Fire Safety

9.7 Sprinklers

Office building must possess sprinklers[34]. Both systems require risers which will be wet in the

summer and dry in the winter for when the ambient temperature drops below o°C

Table 9.7.1, Spacing between sprinklers

Maximum spacing between sprinklers 4.572m [35]

Minimum spacing between sprinklers 1.829m [35]

The sprinkler system for each floor will consist of risers (blue), main distribution pipe (red),

range pipes (green), arm pipes (black) and sprinkler heads (crosses). The sprinkler heads will

operate at a temperature of 65°C. This occurs via a fusible link that melts at 65°C and opens

the sprinkler head. The flow of water sets of the main fire alarm system and will alert the

control board which arm pipe(s) has been affected to locate the fire quickly.

Figure 9.7.1 Notional location of sprinkler system – General floor

55

9. Fire Safety

Figure 9.7.2 Notional location of sprinkler system – Ground floor

Table 9.8.1, Landing valve specification

Landing valve minimum height above

finished floor 750mm [33]

Bore width 150mm [33]

Figure 9.8.3 Illustrating drop pipes (orange)

56

9.8 Hydrants, Risers and Landing Valves

9. Fire Safety

Figure 9.8.1 Notional location of hydrants (red)

Landing valves are positioned on

each floor in the protected lobbies

next to each protected stairwell and

are supplied via a riser, taking its

water from the water tank or a

hydrant, in summer or winter

respectively. [50]

Figure 9.8.2 Notional location of inlets (red) and landing valves (purple) – Ground Floor

57

9. Fire Safety

Figure 9.8.3 Notional location of water tank

(blue) and riser (blue)

Figure 9.8.4 Notional location of risers (blue) and landing

valves (purple)

The use of the building may change in the future. Therefore the estimate of fire severity may need to

be either increased or monitored to consider the likelihood of the fire load increasing/decreasing if

the function of the building changes. [50]

58


10.1 Background

‘First Model’ of mathematical formula described [36] provides ‘satisfactory solution for 90-95% of

[vertical transport] designs’. For this reason it is the best model to gain an estimate of the ability of

the current lift shafts to handle the building occupancy. Following are the equations used and a

description of the method. Table 10.1.1 shows the terms and definitions for this section.

Equation 10.1.1, Performance Time (T).

𝑇 = 𝑡𝑓 1 + 𝑡𝑠𝑑 + 𝑡𝑐 + 𝑡𝑜 − 𝑡𝑎𝑑

Equation 10.1.2, Floor Transit Time (𝒕𝒗).

𝑡𝑣 = 𝑑𝑓/𝑣

Equation 10.1.3, Average Interfloor Distance 𝑫𝑻)

𝑑𝑓 =𝐷𝑇𝑁

Equation 10.1.4, Average Highest Reversal Floor (H).

𝐻 = 𝑁 −

𝑖=1

𝑁−1𝑖

𝑁

6.3

Equation 10.1.5 – Average Number Of Stops (S).

𝑆 = 𝑁 1 − 1 −1

𝑁

𝑃

Equation 10.1.6, Round Trip Time (RTT).

𝑅𝑇𝑇 = 2𝐻𝑡𝑣 + 𝑆 + 1 𝑇 − 𝑡𝑣 + 2𝑃𝑡𝑝

Equation 10.1.7, Up-peak Interval (UPPINT).

𝑈𝑃𝑃𝐼𝑁𝑇 =𝑅𝑇𝑇

𝐿59

10.2 Method


Equation 10.1.8, Up-peak Handling Capacity (UPPHC).

𝑈𝑃𝑃𝐻𝐶 =300𝑃

𝑈𝑃𝑃𝐼𝑁𝑇/𝑈

Equation 10.1.9, Percentage Population Served (%POP).

%𝑃𝑂𝑃 =𝑈𝑃𝑃𝐻𝐶𝑥100

𝑈𝑃𝑃𝐼𝑁𝑇

Equation 10.1.10 – Average Number Of Passengers

𝑃 = 0.8𝐴𝐶

Table 10.1.1 - Terms and Definitions.

Term Definition

tfAverage single floor flight time (s)

tsd Start delay (s)

to Door opening time (s)

tc Door closing time (s)

tad

Advanced door openining time (s). i.e. overlap of lift levelling and door opening mechanisms

DtTotal travel distance from main terminal to highest served floor

N Number of served floors

L Number of lifts

AC Actual capacity of the lift

Table 10.1.2 - Assumptions

Assumptions:

No Manufacturers Data for to, tc,

tsd, tad,

Average passenger transfer time

is 1.2s [41]

i.e. no elderly and people in

moderate rush

Centre opening lift doors

Figure 10.1 – Showing centre opening doors and landing call system.

60


10.3 Results

First, an estimate for the actual capacity of the lifts is calculated.

Estimated floor area of each lift (from plans) :

Equation 10.1.1, Example Calculation𝑇 = 5.3 + 0.5 + 2 + 2 − 1 = 8.8s

Equation 10.1.3, Example Calculation𝑑𝑓 = (4.2 + 9 × 3.6)/10 = 3.66𝑚

Equation 10.1.4, Example Calculation

𝐻 = 9 −

𝑖=1

8𝑖

9

6.3

= 8.3m

Equation 10.1.2, Example Calculation𝑡𝒗 = 3.66 ÷ 1.6 = 2.2875𝑠


9 1 − 1 −1

9

6.3

= 4.72

Table 10.1.2, Performance

Time Values

Value Time (s) Source

𝑡𝑓 5.3 [37]

𝑡𝑠𝑑 0.5 [38]

𝑡𝑜 2 [39]

𝑡𝑐 2 [39]

𝑡𝑎𝑑 1 [40]

Example Calculation:

𝐸𝑠𝑡𝑖𝑚𝑎𝑡𝑒𝑑 𝑓𝑙𝑜𝑜𝑟 𝑎𝑟𝑒𝑎 = 1.75𝑚 × 1𝑚 = 1.75 𝑚2

Assuming average passenger weight 75kg and floor area of 0.21𝑚2 [48].

Therefore the greatest load available for the space is 630kg [49]

This gives: Max area = 1.66𝑚2, Actual Capacity (AC) = 7.9 – [45]

By Equation 1.10 this gives P = 6.32.

Now that we have the available lift capacity by design constriction, the necessary lift size to handle the

occupancy must be calculated. This is done following the method mentioned on the previous page.

Typical lift dynamics suggest that, for a building height of 37.6m, the lift should have a rated speed of

1.6m/s [42].

In order to calculate Performance time, 𝑡𝑓 1 , 𝑡𝑠𝑑 , 𝑡𝑐 , 𝑡𝑜, and 𝑡𝑎𝑑 were first obtained. These values are

organised in Table 1.1.

61


Estimating suitability of lift size.

Lifts should be able to carry 13% of the population every 5 minutes. [44]

Accounting for 10% absenteeism [43], lift must handle: 820 × 0.9 × 0.13 = 96 people per 5 mins.

Interval time (UPPINT) is 22.5s, so the number of trips in 5 minutes: 5 × 60 ÷ 22.5 = 13.3

This means a lift of capacity 7.4 people is needed to carry 96 people in 5 minutes.

Therefore the 630kg load (with AC = 7.9) lift is suitable to carry 13% of the buildings population at

the chosen lift speed.

Lift roping system.

Due to the 4.5m tall lift motor room pictured in figure 3, a simple single wrap 1:1 pulley system is

feasible choice and will provide the necessary performance [52]

Figure 10.3, Lift Motor Room.

Equation 10.1.6, Example CalculationRTT= 2 8.21 2.2875 + 4.71 + 1 8.8 − 2.2875 + 2 6.3 1.2 = 90.01𝑠


𝑈𝑃𝑃𝐻𝐶 =300(6.3)

22.35= 84.25


𝑈𝑃𝑃𝐼𝑁𝑇 =89.4

4= 22.35s

Equation 10.1.9 Example Calculation

%𝑃𝑂𝑃 =84.25𝑥100

820=10.274%

62


10.4 Additional information and analysis

The calculated values imply a suitable vertical transport design. In addition to this, having 2.5 lifts per

floor and 22.5s interval time imply ‘above average’ and ‘very good’ quality of service (QOS)

respectively [51]. Also, the orientation of the lift group complies with recommended layouts [45] (See

Figure 10.2)

However, this design does not consider access to the basement. The RTT can be expected to increase

by 15s per lift in serving one basement floor [46]. Since it is suggested that all lifts in one group should

serve the same floors this would result in a dramatic increase in RTTINT; and increase necessary

capacity from 7.4 to 8.5. Resulting in a lift size greater than the available area and decreased QOS.

Although increasing the lift shaft size this would increase capital cost, it would also allow for future

population increase and allow the lifts to comply with firefighting and Disability access lifts codes.

These codes suggest a lift size of no smaller than 1100mm by 1400mm. [47]

It is also advised that offices have a lift size of no less than 1000kg except in special circumstances

[52]. For these reasons it should be suggested that the architect increases the size of the lift shafts to

allow a 1000kg 1100mm by 1400mm lift.

Figure 10.2 – Showing lift group.

63

Conclusion

.

Through the running of 5 simulations with varying combinations of conditions and

said analysis of these conditions, the following sets of findings and

recommendations can be concluded.

• The heating demand can be reduced by decreasing the design internal

temperature. However the heating demand is unaffected by material properties

such at lag time and decrement factor.

• Whilst the boiler must be designed for extreme conditions, in reality the majority

of heat loss would be offset by casual and sensible heat gains. This would also

reduce the annual energy demand of the building significantly.

• The physical changes that reduced the total cooling load are ranked in order of

effectiveness below:

1) Complete solar shading,

2) Higher thermal mass and light colour in the external façade,

3) Increased set-point indoor summer temperatures

These changes all reduce the cooling load significantly, with solar shading being at

least 4 times more effective than the other changes.

• The current vertical transport system is inadequate to meet current UK

regulation for disabled and fire access and would benefit from and enlarged lift

shaft.

• Additional fire escapes are necessary in order to reduce the maximum travel

distance in the event of a fire.

• The vertical duct shaft must be enlarged in order to occupy the ducting.

(208)

64

References

[1] British Council for Offices. Occupier Density Study, 2013; Figure 2

[2] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 1.5, Table 1.5

[3] HM Government, Approved document F, 2000; Section 6.8, Table 6.1A

[4] HM Government, Approved document L2A, 2010; Section 4.3.2, Table 4

[5] HM Government, Approved document L1, 2002; Section 1.35

[6] The Chartered Institution of Building Services Engineers. CIBSE Guide B, 2015; Table 4.19

[7] The Chartered Institution of Building Services Engineers. CIBSE Guide F, 2015; Table 12.3-12.7

[8] Chartered Institution of Building Services Engineering, CIBSE Guide A, 2015, Table 2.5

[9] Chartered Institution of Building Services Engineering, CIBSE Guide A, 2015, Table 1.5.

[10] HM Government. Approved Document L2A, 2010; Section 2.41, Table 3

[11] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 1.5, Table 1.5

[12] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 2.8.4, Table2.14

[13] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Table 5.19

[14] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 2.8.4, Table 2.14 (g)

[15] London Office Buildings. London Office Buildings Tender Specifications, 2016; Section 3

[16] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 4.2.3

[17] The Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Table 4.19

[18] Engineering Toolbox (no date) Air properties. Available at: http://www.engineeringtoolbox.com/air-properties-d_156.html (Accessed: 13 May 2016).

[19] Chartered Institution of Building Services Engineers. CIBSE Guide B, 2015; section 1.4.7.3, Table 1.11

[21] Chartered Institution of Building Services Engineers. CIBSE Guide A, 2015; Section 3.3.3,Table 3.2

[22] Chartered Institution of Building Services Engineers. CIBSE Guide C, 2015; Section 4.3.3,Table 4.1

65

References

23] Chartered Institution of Building Services Engineers. CIBSE Guide C, 2015; Section 4.10.6.3,Table 4.28

[24] Chartered Institution of Building Services Engineers. CIBSE Guide C, 2015; Section 4.10.6.3,Table 4.32

[25] Chartered Institution of Building Services Engineers. CIBSE Guide B, 2015; section 2.5.11.3,Table 2.53

[26] Chartered Institution of Building Services Engineers. CIBSE Guide C, 2015; Section 4.10.6.3,Table 4.32

[27] Chartered Institution of Building Services Engineers. CIBSE Guide B, 2015; section 2.5.11.3,Table 2.53

[28] HM Government. Fire safety. The Building Regulations 2010. 2013, Volume 2. Appendix A1

[29] HM Government. Fire safety. The Building Regulations 2010. 2013, Volume 2. Section B3, 8.1

[30] HM Government. Fire safety. The Building Regulations 2010. 2013, Volume 2. Section B1, 3

[31] HM Government. Fire safety. The Building Regulations 2010. 2013, Volume 2. Section B1 4.1


[33] HM Government. Fire safety. The Building Regulations 2010. 2013, Volume 2. Section B1, Paragraph 4.34


[35] British Standards Agency. Fire extinguishing installations and equipment on premises. Recharging of portable fire extinguishers. Code of practice. BS 5306-9:2015.2015.

[36] Chartered Institution of Building Services Engineers, Guide D, Section 3.1

[37] Chartered Institution of Building Services Engineers, Guide D, Section 3.5.9





[42] British Standards Institution, BS 5655-6:2011, Section 6.2, Table 6

66

References



[45] British Standards Institution, BS 5655-6:2011, Section 6.4.6, Figure 2

[46] British Standards Institution, BS 5655-6:2011, Section 6.5

[47] British Standards Institution, BS 5655-6:2011, Section 6.4.6


[49] Chartered Institution of Building Services Engineers, Guide D, Section 3.5.7, Table 3.1

[50] London Borough of Redbridge (2005) Guidelines For Disability Access In Buildings. Available at: https://www2.redbridge.gov.uk/cms/planning_and_the_environment/building_control/idoc.ashx?doc id=0653b18b-2a05-4caa-aebf-0b839a1149dc&version=-1

[51] British Standards Institution, BS 5655-6:2011, Section 6.4.5, Table 8


[53] Chartered Institution of Building Services Engineers, Guide D, Section 7.14.6, Diagram (a)

[36] Chartered Institution of Building Services Engineers, Guide D, Section 3.1






[42] British Standards Institution, BS 5655-6:2011, Section 6.2, Table 6



[45] British Standards Institution, BS 5655-6:2011, Section 6.4.6, Figure 2

[46] British Standards Institution, BS 5655-6:2011, Section 6.5

67

References



[49 Chartered Institution of Building Services Engineers, Guide D, Section 3.5.7, Table 3.1

[50] London Borough of Redbridge (2005) Guidelines For Disability Access In Buildings.

Available at:

https://www2.redbridge.gov.uk/cms/planning_and_the_environment/building_control/ido

c.ashx?doc id=0653b18b-2a05-4caa-aebf-0b839a1149dc&version=-1

[51] British Standards Institution, BS 5655-6:2011, Section 6.4.5, Table 8


[53] Chartered Institution of Building Services Engineers, Guide D, Section 7.14.6, Diagram (a)

[54] Chartered Institution of Building Services Engineers, Guide B, Section 1.4.7.3, Table 1.11

68

Appendix A

69

Table 1.A1, Fabric heat Losses

ZoneHeat Transfer Component

Material Area (m2) U-Value (W/m2) T in ( ͦC) T out ( ͦC) Qf (W) Qf, Zone (W) Total Qf, Zone (W)

General Floor Windows (N) 60.825 2.200 21 -2 3077.75 10802.89 75620.251

Windows ( E) 18.664 2.200 21 -2 944.40

Windows (S) 60.825 2.200 21 -2 3077.75

Windows (W) 18.664 2.200 21 -2 944.40

Walls (N) Pre Cast Concrete 19.959 0.350 21 -2 160.67

w/ Render 31.680 0.350 21 -2 255.02

w/ Render and Plastic Tiles 63.360 0.350 21 -2 510.05

Walls ( E) Pre Cast Concrete 22.454 0.350 21 -2 180.75

w/ Render 9.792 0.350 21 -2 78.83


Walls (S) Pre Cast Concrete 10.373 0.350 21 -2 83.50

w/ Render 44.352 0.350 21 -2 357.03


Walls (W) Pre Cast Concrete 22.454 0.350 21 -2 180.75

w/ Render 9.792 0.350 21 -2 78.83


Ground Floor Windows (N) 38.707 2.200 21 -2 1958.58432 13708.0355 13708.0355

Windows ( E) 18.662 2.200 21 -2 944.31744

Windows (S) 49.766 2.200 21 -2 2518.1596

Windows (W) 18.662 2.200 21 -2 944.31744


w/ Render 0.000 0.350 21 -2 0

w/ Render and Plastic Tiles 0.000 0.350 21 -2 0


w/ Render 0.000 0.350 21 -2 0



w/ Render 0.000 0.350 21 -2 0



w/ Render 0.000 0.350 21 -2 0


Floor 892.140 0.250 21 15 1338.21

Door 27.648 3.500 21 -2 2225.664

Top Floor Windows (N) 60.825 2.200 21 -2 3077.745 16435.20338 16435.20338

Windows ( E) 18.662 2.200 21 -2 944.31744

Windows (S) 60.825 2.200 21 -2 3077.745

Windows (W) 18.662 2.200 21 -2 944.31744


w/ Render 15.206 0.350 21 -2 122.41152



w/ Render 4.896 0.350 21 -2 39.4128



w/ Render 15.206 0.350 21 -2 122.41152



w/ Render 4.896 0.350 21 -2 39.4128


Roof 987.000 0.250 21 -2 5675.25

Second Floor Windows (N) 38.707 2.200 21 -2 1958.55396 10364.42238 10364.42238

Windows ( E) 18.664 2.200 21 -2 944.3984

Windows (S) 60.825 2.200 21 -2 3077.745

Windows (W) 18.664 2.200 21 -2 944.3984


w/ Render 15.206 0.350 21 -2 122.41152



w/ Render 4.896 0.350 21 -2 39.4128



w/ Render 15.206 0.350 21 -2 122.41152



w/ Render 4.896 0.350 21 -2 39.4128


Floor 94.860 0.250 21 -2 545.445

Basement 1392.570 0.279 15 0 5837.760432 5837.760432 5837.760432

Total Loss 121965.6727

Table 2.A1 Ventilation Heat Losses

Floor Space Air Supply rate (l/spp) OccupancyAir Supply Rate

(l/s)Volume (m3) Air Supply Rate (h-1) Infiltration Rate (ACH)

Total Air Change Rate (ACH)

Ti (⁰C) To (⁰C) ΔT Ventilation loss Total Ventilation loss

Floor 1 - 9 Office floor 10 82 820 2978.1 0.991236023 0.4 1.391236023 21 -2 23 31764.84 314843.8205

Toilet Female 6 5 30 78.408 1.377410468 0.4 1.777410468 21 -2 23 1068.4512

Toilet Male 6 4 24 110.484 0.782013685 0.4 1.182013685 21 -2 23 1001.2176

Stairs 1 0 0 0 54.4896 0 0.4 0.4 21 -2 23 167.10144

Stairs 2 0 0 0 54.4896 0 0.4 0.4 21 -2 23 167.10144

Store E 0 0 0 22.6512 0 0.4 0.4 21 -2 23 69.46368

Store W 0 0 0 22.6512 0 0.4 0.4 21 -2 23 69.46368

Duct 0 0 0 12.7512 0 0.4 0.4 21 -2 23 39.10368

Lobby 10 0 0 145.8 0 0.4 0.4 21 -2 23 447.12

Lifts 0 0 0 61.56 0 0.4 0.4 21 -2 23 188.784

Ground floor Open Plan 10 6 60 2631.208 0.082091572 0.4 0.482091572 21 -2 23 9725.037867 22417.24992

Corridor 1 10 0 0 119.07 0 0.4 0.4 21 -2 23 365.148

Corridor 2 10 0 0 54.054 0 0.4 0.4 21 -2 23 165.7656

Corridor 3 10 0 0 158.36 0 0.4 0.4 21 -2 23 485.6373333

Corridor 4 10 0 0 54 0 0.4 0.4 21 -2 23 165.7656

Corridor 5 10 0 0 39.69 0 0.4 0.4 21 -2 23 121.716

Lobby 10 0 0 145.8 0 0.4 0.4 21 -2 23 447.12

Toilet Female 6 3 18 79.002 0.820232399 0.4 1.220232399 21 -2 23 739.0728

Toilet Male 6 3 18 79.002 0.820232399 0.4 1.220232399 21 -2 23 739.0728

Stair 1 0 0 0 77.1408 0 0.4 0.4 21 -2 23 236.56512

Stair 2 0 0 0 77.1408 0 0.4 0.4 21 -2 23 236.56512

Duct 0 0 0 12.7512 0 0.4 0.4 21 -2 23 39.10368

Lifts 0 0 0 61.56 0 0.4 0.4 21 -2 23 188.784

Basement Open plan 10 0 0 2857.14 0 0.4 0.4 21 -2 23 8761.896 8761.896

Total Loss 346022.9664

Total Peak Heating Load

467988.6391 467.9886391

Plant size Ratio 1.3

Heating demand 608385.2308 W

608.3852308 KW

Appendix B

Table 1.B1, Solar Conduction through the glazing

G-Value 0.72

Response Factor

0.8360.5111606

618.3564590

255.4772983

618.3564590

2

May Wall SE Area (m2) G-ValueResponse

FactorSolar Gain SW Area (m2) G-Value

Response Factor

Solar Gain NW Area (m2) G-ValueResponse

FactorSolar Gain NE Area (m2) G-Value

Response Factor

Solar Gain Total Gain

Time

07:30 366 615.1968 0.72 0.83134556.828

4155 186.624 0.72 0.83

17286.60787

128 564.0192 0.72 0.8343143.4078

6370 186.624 0.72 0.83

41264.80589

236251.65

08:30 447 615.1968 0.72 0.83164335.798

6171 186.624 0.72 0.83

19071.03191

143 564.0192 0.72 0.8348199.2759

7302 186.624 0.72 0.83

33681.00372

265287.1102

09:30 493 615.1968 0.72 0.83181247.312

6184 186.624 0.72 0.83

20520.87644

157 564.0192 0.72 0.8352918.0862

1184 186.624 0.72 0.83

20520.87644

275207.1517

10:30 509 615.1968 0.72 0.83187129.578

3196 186.624 0.72 0.83

21859.19447

167 564.0192 0.72 0.8356288.6649

4155 186.624 0.72 0.83

17286.60787

282564.0456

11:30 476 615.1968 0.72 0.83174997.405

3226 186.624 0.72 0.83

25204.98954

174 564.0192 0.72 0.8358648.0700

6165 186.624 0.72 0.83 18401.8729

277252.3378

12:30 404 615.1968 0.72 0.83148527.209

5333 186.624 0.72 0.83 37138.3253 178 564.0192 0.72 0.83

59996.30156

169 186.624 0.72 0.8318847.9789

1264509.815

3

13:30 306 615.1968 0.72 0.83 112498.332 424 186.624 0.72 0.8347287.2370

2177 564.0192 0.72 0.83

59659.24368

168 186.624 0.72 0.83 18736.4524238181.265

1

14:30 205 615.1968 0.72 0.8375366.5295

7487 186.624 0.72 0.83

54313.40667

173 564.0192 0.72 0.8358311.0121

9164 186.624 0.72 0.83

18290.34639

206281.2948

15:30 182 615.1968 0.72 0.83 66910.7726 513 186.624 0.72 0.8357213.0957

3174 564.0192 0.72 0.83

58648.07006

157 186.624 0.72 0.8317509.6608

8200281.599

3

16:30 171 615.1968 0.72 0.8362866.7149

1502 186.624 0.72 0.83 55986.3042 211 564.0192 0.72 0.83 71119.2114 146 186.624 0.72 0.83

16282.86935

206255.0999

17:30 157 615.1968 0.72 0.8357719.7324

1455 186.624 0.72 0.83

50744.55859

325 564.0192 0.72 0.83 109543.809 132 186.624 0.72 0.8314721.4983

2232729.598

3

Table 2.B1, Sol-Air Gains, May

May Render

Area 1229.0318 m2 120.8883738

U-Value 0.35 W/m2/k

t_r 22 °C

t_em 27.47916667 °C

f 0.9

φ 1 hours

SE Sun Time lag time Sol-air temp Qm Q_theta Q_theta+phi

theta (hours) (hours) dark, Teo

1 2 11.3 2356.924525 -4602.724091 -3906.759229

2 3 10.7 2356.924525 -4860.820769 -4139.04624

3 4 9.7 2356.924525 -5290.981899 -4526.191257

4 5 9.3 2356.924525 -5463.046351 -4681.049263

5 6 11.1 2356.924525 -4688.756317 -3984.188233

6 7 25.8 2356.924525 1634.612294 1706.843517

7 8 37.9 2356.924525 6839.561967 6391.298223

8 9 48.5 2356.924525 11399.26995 10495.0354

9 10 54.2 2356.924525 13851.18839 12701.762

10 11 57 2356.924525 15055.63955 13785.76805

11 12 55 2356.924525 14195.31729 13011.47801

12 13 50.4 2356.924525 12216.57609 11230.61094

13 14 42.4 2356.924525 8775.287052 8133.450799

14 15 33 2356.924525 4731.77243 4494.287639

15 16 30.9 2356.924525 3828.434057 3681.283104

16 17 29.3 2356.924525 3140.176249 3061.851077

17 18 26.9 2356.924525 2107.789537 2132.703036

18 19 24.5 2356.924525 1075.402825 1203.554995

19 20 20.9 2356.924525 -473.177243 -190.1670662

20 21 17.4 2356.924525 -1978.741198 -1545.174626

21 22 14.9 2356.924525 -3054.144023 -2513.037168

22 23 13.1 2356.924525 -3828.434057 -3209.898199

23 24 12.9 2356.924525 -3914.466283 -3287.327202

24 25 12.4 2356.924525 -4129.546848 -3480.899711

25 26 11.3 2356.924525 -4602.724091 -3906.759229

26 27 10.7 2356.924525 -4860.820769 -4139.04624

27 28 9.7 2356.924525 -5290.981899 -4526.191257

28 29 9.3 2356.924525 -5463.046351 -4681.049263

29 30 11.1 2356.924525 -4688.756317 -3984.188233

30 31 25.8 2356.924525 1634.612294 1706.843517

31 32 37.9 2356.924525 6839.561967 6391.298223

32 33 48.5 2356.924525 11399.26995 10495.0354

33 34 54.2 2356.924525 13851.18839 12701.762

34 35 57 2356.924525 15055.63955 13785.76805

35 36 55 2356.924525 14195.31729 13011.47801

36 37 50.4 2356.924525 12216.57609 11230.61094

37 38 42.4 2356.924525 8775.287052 8133.450799

38 39 33 2356.924525 4731.77243 4494.287639

39 40 30.9 2356.924525 3828.434057 3681.283104

40 41 29.3 2356.924525 3140.176249 3061.851077

41 42 26.9 2356.924525 2107.789537 2132.703036

42 43 24.5 2356.924525 1075.402825 1203.554995

43 44 20.9 2356.924525 -473.177243 -190.1670662

44 45 17.4 2356.924525 -1978.741198 -1545.174626

45 46 14.9 2356.924525 -3054.144023 -2513.037168

46 47 13.1 2356.924525 -3828.434057 -3209.898199

47 48 12.9 2356.924525 -3914.466283 -3287.327202

48 49 12.4 2356.924525 -4129.546848 -3480.899711

13785.76805

Appendix B

Table 3.B1, Ventilation Thermal Conductance

Zone Volume/mᶟVentilation rate/hˉ¹

Infiltration rate/hˉ¹

Total Air Change Rate

Ventilation rate/mᶟhˉ¹

Ventilation rate/mᶟsˉ¹

Volumetric heat capacity of air/JmˉᶟKˉ¹

Ventilation thermal conductance/WKˉ¹

Basement Open plan 2857.140 0.000 0.400 0.400 1142.856 0.317 1200 380.952 380.952

13404.410

Ground Floor

Open plan 2631.208 0.082 0.400 0.482 1268.483 0.352 1200 422.828

593.702

Corridor 1 119.070 0.000 0.400 0.400 47.628 0.013 1200 15.876

Corridor 2 54.054 0.000 0.400 0.400 21.622 0.006 1200 7.207

Corridor 3 158.360 0.000 0.400 0.400 63.344 0.018 1200 21.115

Corridor 4 54.000 0.000 0.400 0.400 21.600 0.006 1200 7.200

Corridor 5 39.690 0.000 0.400 0.400 15.876 0.004 1200 5.292

Lobby 145.800 0.000 0.400 0.400 58.320 0.016 1200 19.440

Toilet F 79.002 0.820 0.400 1.220 96.398 0.027 1200 32.133

Toilet M 79.002 0.820 0.400 1.220 96.398 0.027 1200 32.133

Stair 1 77.141 0.000 0.400 0.400 30.856 0.009 1200 10.285

Stair 2 77.141 0.000 0.400 0.400 30.856 0.009 1200 10.285

Duct 12.751 0.000 0.400 0.400 5.100 0.001 1200 1.700

Lift 61.560 0.000 0.400 0.400 24.624 0.007 1200 8.208

Floor 1-9

Office floor 2978.100 0.991 0.400 1.391 4143.252 1.151 1200 1381.084

12429.756

Toilet F 78.408 1.377 0.400 1.777 139.362 0.039 1200 46.454

Toilet M 110.484 0.782 0.400 1.182 130.592 0.036 1200 43.531

Stairs 1 54.490 0.000 0.400 0.400 21.796 0.006 1200 7.265

Stairs 2 54.490 0.000 0.400 0.400 21.796 0.006 1200 7.265

Store (East) 22.651 0.000 0.400 0.400 9.060 0.003 1200 3.020

Store (West) 22.651 0.000 0.400 0.400 9.060 0.003 1200 3.020

Duct 12.751 0.000 0.400 0.400 5.100 0.001 1200 1.700

Lobby 145.800 0.000 0.400 0.400 58.320 0.016 1200 19.440

Lifts 61.560 0.000 0.400 0.400 24.624 0.007 1200 8.208

Table 3.B1, Ventilation Heat Gains

May Time

Ventilation thermal conductance/WKˉ¹ Tr, (°C) To, (°C)

Total Heat Gains (W)

07:30 13404.410 22.000 18.5 -46915.43383

08:30 13404.410 22.000 19.9 -28149.2603

09:30 13404.410 22.000 21.1 -12063.9687

10:30 13404.410 22.000 21.6 -5361.763866

11:30 13404.410 22.000 23 13404.40967

12:30 13404.410 22.000 23.2 16085.2916

13:30 13404.410 22.000 23.6 21447.05546

14:30 13404.410 22.000 24.1 28149.2603

15:30 13404.410 22.000 23.5 20106.6145

16:30 13404.410 22.000 22.5 6702.204833

17:30 13404.410 22.000 21.5 -6702.204833

Appendix B

.

72

Table 5.B1Roof Sol-air Temperatures

Roof

Area 987 m2

U-Value 0.54 W/m2/k

t_r 22 °C

t_em 26.2 °C

f 0.17

φ 9 hours

May

Sun Time Ѳ (h) lag Time ф (h)Sol-air temp

Dark TeoQm Q_Ѳ Q_Ѳ+ф

1 10 9.6 2238.516 -6608.952 734.44644

2 11 9 2238.516 -6928.74 680.08248

3 12 7.7 2238.516 -7621.614 562.2939

4 13 7.3 2238.516 -7834.806 526.05126

5 14 9.7 2238.516 -6555.654 743.5071

6 15 15.2 2238.516 -3624.264 1241.8434

7 16 23.2 2238.516 639.576 1966.6962

8 17 31.8 2238.516 5223.204 2745.91296

9 18 38.2 2238.516 8634.276 3325.7952

10 19 44 2238.516 11725.56 3851.31348

11 20 47.6 2238.516 13644.288 4177.49724

12 21 50.3 2238.516 15083.334 4422.13506

13 22 50.4 2238.516 15136.632 4431.19572

14 23 49.3 2238.516 14550.354 4331.52846

15 24 46.7 2238.516 13164.606 4095.9513

16 25 41.9 2238.516 10606.302 3661.03962

17 26 35.9 2238.516 7408.422 3117.40002

18 27 29.9 2238.516 4210.542 2573.76042

19 28 21.5 2238.516 -266.49 1812.66498

20 29 15.8 2238.516 -3304.476 1296.20736

21 30 12.9 2238.516 -4850.118 1033.44822

22 31 10.9 2238.516 -5916.078 852.23502

23 32 10.7 2238.516 -6022.674 834.1137

24 33 10.4 2238.516 -6182.568 806.93172

Appendix B

.

73

Table 7.B1, Peak Cooling Load Calculations

May Time

Sensible Transmission

Through the Glass (W)

Solar Gains Through

the Windows

(W)

Sol-air (W)

Casual heat gains (W)

Roof Sol-air (W)

Ventilation Heat Gains

(W)

Total Cooling Load (W)

07:30 -12445.29 236251.65 18912.82 340392.90 2745.91 -46915.43 538942.56

08:30 -7467.18 265287.11 20720.40 340392.90 3325.80 -28149.26 594109.77

09:30 -3200.22 275207.15 20515.80 340392.90 3851.31 -12063.97 624702.98

10:30 -1422.32 282564.05 21676.68 340392.90 4177.50 -5361.76 642027.04

11:30 3555.80 277252.34 19540.84 340392.90 4422.14 13404.41 658568.42

12:30 4266.96 264509.82 16507.30 340392.90 4431.20 16085.29 646193.46

13:30 5689.28 238181.27 19809.13 340392.90 4331.53 21447.06 629851.15

14:30 7467.18 206281.29 24734.72 340392.90 4095.95 28149.26 611121.31

15:30 5333.70 200281.60 26923.09 340392.90 3661.04 20106.61 596698.94

16:30 1777.90 206255.10 25809.02 340392.90 3117.40 6702.20 584054.53

17:30 -1777.90 232729.60 12340.17 340392.90 2573.76 -6702.20 579556.32Total

AverageTotal

monthly

609620.5913411652

.95

Peak Cooling

Load (W)658568.42

Table 6.B1, Sensible Transmission through the glazing

May Big Window Time U-Value Area Tr ToCooling Load per window

Number of windows

Total Cooling Load

07:30 2.2 6.5664 22 18.5 -50.56128 230 -11629.0944

08:30 2.2 6.5664 22 19.9 -30.336768 230 -6977.45664

09:30 2.2 6.5664 22 21.1 -13.001472 230 -2990.33856

10:30 2.2 6.5664 22 21.6 -5.778432 230 -1329.03936

11:30 2.2 6.5664 22 23 14.44608 230 3322.5984

12:30 2.2 6.5664 22 23.2 17.335296 230 3987.11808

13:30 2.2 6.5664 22 23.6 23.113728 230 5316.15744

14:30 2.2 6.5664 22 24.1 30.336768 230 6977.45664

15:30 2.2 6.5664 22 23.5 21.66912 230 4983.8976

16:30 2.2 6.5664 22 22.5 7.22304 230 1661.2992

17:30 2.2 6.5664 22 21.5 -7.22304 230 -1661.2992

Small Window Time U-Value Area Tr ToCooling Load per window

Number of windows

Total Cooling Load

07:30 2.2 2.2 22 18.5 -16.94 40 -677.6

08:30 2.2 2.2 22 19.9 -10.164 40 -406.56

09:30 2.2 2.2 22 21.1 -4.356 40 -174.24

10:30 2.2 2.2 22 21.6 -1.936 40 -77.44

11:30 2.2 2.2 22 23 4.84 40 193.6

12:30 2.2 2.2 22 23.2 5.808 40 232.32

13:30 2.2 2.2 22 23.6 7.744 40 309.76

14:30 2.2 2.2 22 24.1 10.164 40 406.56

15:30 2.2 2.2 22 23.5 7.26 40 290.4

16:30 2.2 2.2 22 22.5 2.42 40 96.8

17:30 2.2 2.2 22 21.5 -2.42 40 -96.8

Front Door Time U-Value Area Tr ToCooling Load per window

Number of windows

Total Cooling Load

07:30 2.2 9 22 18.5 -69.3 2 -138.6

08:30 2.2 9 22 19.9 -41.58 2 -83.16

09:30 2.2 9 22 21.1 -17.82 2 -35.64

10:30 2.2 9 22 21.6 -7.92 2 -15.84

11:30 2.2 9 22 23 19.8 2 39.6

12:30 2.2 9 22 23.2 23.76 2 47.52

13:30 2.2 9 22 23.6 31.68 2 63.36

14:30 2.2 9 22 24.1 41.58 2 83.16

15:30 2.2 9 22 23.5 29.7 2 59.4

16:30 2.2 9 22 22.5 9.9 2 19.8

17:30 2.2 9 22 21.5 -9.9 2 -19.8

Total Time

07:30 -12445.2944

08:30 -7467.17664

09:30 -3200.21856

10:30 -1422.31936

11:30 3555.7984

12:30 4266.95808

13:30 5689.27744

14:30 7467.17664

15:30 5333.6976

16:30 1777.8992

17:30 -1777.8992

Appendix C

74

Table 4.A1 - Duct 1, Open Plan Supply

Floor Area covered (m2)Air required per m2, (m3/s)

Volumetric flow rate (m3/s)

Volumetric flow rate at each floor

1 156.54 0.00 0.37 0.37

2 326.54 0.00 1.20 1.57

3 326.54 0.00 1.20 2.77

4 326.54 0.00 1.20 3.96

5 326.54 0.00 1.20 5.16

6 326.54 0.00 1.20 6.36

7 326.54 0.00 1.20 7.56

8 326.54 0.00 1.20 8.75

9 326.54 0.00 1.20 9.95

10 326.54 0.00 1.24 11.19

Table 4.a2 Supply flor rates

Floor Room DiffusersVolume flow

rate/m2 Unit volume flow rate (m3/s/m2)

General

Open plan 15 0.0014 9E-05

Male 1 0.0012 1E-03

Female 1 0.0018 2E-03

Ground

Open plan 16 0.0006 4E-05

Male 1 0.0014 1E-03

Female 1 0.0014 1E-03

Basement Open plan 1 0.0003 3E-04

Table 4.A3 - Supply Pressure Drop Duct 2

Duct Floor Section

Volume Flow Rate (m3/s)

Velocity (m/s) CSA M2 Diameter Re 1/(λ^0.5) λ

Pressure Drop per unit length (Pa/m)

Length (m)

Friction pressure drop (Pa)

CSA ratio A2/A1

ζ Contraction Pressure Drop Flow Ratio

ζ

T junction Pressure drop

Total Pressure Drop

2

1V1 0.3738 7.5 0.0498 0.252 60473 4.6736 0.046 6.13212 3.6 22.07562

Branch 1 0.238 0.41 13.7632 0.23798 0.18 60.75 96.5888

2V2 1.5707 7.5 0.2094 0.5165 123964 6.1076 0.027 1.75167 3.6 6.306

Branch 2 0.568 0.27 8.99936 0.56753 0.02 6.75 22.0554

3V3 2.7677 7.5 0.369 0.6856 164552 6.6734 0.022 1.10533 3.6 3.979185

Branch 3 0.698 0.2 6.87301 0.69809 0.02 6.75 17.6022

4V4 3.9646 7.5 0.5286 0.8206 196945 7.0323 0.02 0.83165 3.6 2.993924

Branch 4 0.768 0.17 5.63913 0.7681 0.05 16.875 25.5081

5V5 5.1615 7.5 0.6882 0.9363 224717 7.2959 0.019 0.67717 3.6 2.437799

Branch 5 0.812 0.14 4.82261 0.81176 0.05 16.875 24.1354

6V6 6.3585 7.5 0.8478 1.0392 249415 7.5042 0.018 0.57671 3.6 2.07615

Branch 6 0.842 0.13 4.23744 0.84158 0.05 16.875 23.1886

7V7 7.5554 7.5 1.0074 1.1328 271879 7.6764 0.017 0.50558 3.6 1.820085

Branch 7 0.863 0.11 3.79493 0.86324 0.12 40.5 46.115

8V8 8.7524 7.5 1.167 1.2193 292623 7.8233 0.016 0.45227 3.6 1.628154

Branch 8 0.88 0.1 3.44709 0.8797 0.12 40.5 45.5752

9V9 9.9493 7.5 1.3266 1.3 311991 7.9514 0.016 0.41064 3.6 1.4783

Branch 9 0.889 0.1 3.2357 0.88943 0.12 40.5 45.214

10V10 11.186 7.5 1.4915 1.3784 330815 8.0684 0.015 0.37612 3.6 1.354027

Branch 10

46.14924 54.8125 246.375 345.983

2 1 T6 - P 1.0182 33.55 45.9179

Appendix C

75

Table 4.a4 Extract Pressure Drop

Duct Floor SectionVolume Flow Rate (m3/s) Velocity

(m/s)

CSA M2 Diameter Re 1/(λ^0.5) λPressure Drop per

unit length (Pa/m)

Length (m)Friction

pressure drop (Pa)

CSA ratio A2/A1

ζContraction

Pressure DropFlow Ratio ζ

T junction Pressure drop

Total Pressure

Drop

1

1 V1 0.386680301 7.5 0.051557 0.256278 61506.61 4.707489 0.045125 5.94271107 3.6 21.39375985

Branch 1 0.222242 0.414098 13.97581943 0.222242 0.18 6.075 41.44458

2 V2 1.739909007 7.5 0.231988 0.543623 130469.5 6.209737 0.025933 1.610013825 3.6 5.796049769 0

Branch 2 0.562506 0.268967 9.077635513 0.562506 0.02 0.675 15.54869

3 V3 3.093137714 7.5 0.412418 0.724827 173958.4 6.784418 0.021726 1.011612999 3.6 3.641806796 0

Branch 3 0.695655 0.204878 6.914618852 0.695655 0.02 0.675 11.23143

4 V4 4.446366421 7.5 0.592849 0.869035 208568.4 7.146894 0.019578 0.760329652 3.6 2.737186748 0

Branch 4 0.766668 0.167861 5.66531322 0.766668 0.05 1.6875 10.09

5 V5 5.799595127 7.5 0.773279 0.992507 238201.6 7.412283 0.018201 0.618922749 3.6 2.228121895 0

Branch 5 0.810812 0.14343 4.840765406 0.810812 0.05 1.6875 8.756387

6 V6 7.152823834 7.5 0.95371 1.102233 264535.9 7.621755 0.017214 0.527096956 3.6 1.89754904 0

Branch 6 0.84091 0.125951 4.250853495 0.84091 0.05 1.6875 7.835903

7 V7 8.506052541 7.5 1.13414 1.201984 288476.1 7.794821 0.016458 0.462128621 3.6 1.663663036 0

Branch 7 0.862746 0.112749 3.80529422 0.862746 0.12 4.05 9.518957

8 V8 9.859281247 7.5 1.314571 1.294068 310576.4 7.942282 0.015853 0.41345282 3.6 1.48843015 0

Branch 8 0.879311 0.102381 3.455373927 0.879311 0.12 4.05 8.993804

9 V9 11.21250995 7.5 1.495001 1.380022 331205.2 8.070747 0.015352 0.375457103 3.6 1.351645571 0

Branch 9 0.889116 0.096077 3.242612379 0.889116 0.12 4.05 8.644258

10 V10 12.61084965 7.5 1.681447 1.463547 351251.3 8.188136 0.014915 0.343951346 3.6 1.238224845

Branch 10

43.4364377 55.22828644 24.6375 122.064 147.3355

1 T1 - I 0.986932968 0 25.27153

CV’s

.

76

CV’s

.

77

CV’s

.

78

CV’s

.

79

CV’s

.

80

CV’s

.

81

CV’s

.

82

CV’s

.

83

CV’s

.

84

ae4 final report

Documents