energy savings calculator for boiler replacement projects(1)

7/31/2019 Energy Savings Calculator for Boiler Replacement Projects(1)

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Values in cells are automatically calculated

Manufacturer Buderus

Model GE215

Rated Output (kW) 180

Fuel Mains Gas

Year of manufacture 1989

Are the boilers primarily used for space or process heating? Process

If the boiler(s) is used for process heating then select Method 1 only

(Select from drop down menu)

Method 1 - Seasonal Efficiency of Existing Boiler(s)

Enter the gross seasonal efficiency of the existing boiler(s) 65%

Method 2 - Manufactures Efficiency Data at Full & Part LoadEfficiency at 100% of load 70%

Efficiency at 30% of load 78%

Are the manufactures efficiency details based on net calorific or gross calorific value? Gross CV

Method 3 - Boiler Input & Output

What is the boiler input at full load (100%) in kW? 100

What is the boiler output at full load (100%) in kW? 95

What is the boiler input at part load (30%) in kW? 30

What is the boiler output at part load (30%) in kW? 25

Is the boiler input based on net calorific or gross calorific value of the fuel? Gross CV

Method 4 - Star Rating Label

What is the Star label of the existing boilers? **

Estimated Seasonal Efficiency of Existing Boilers (Gross CV) 65.0%

Manufacturer Buderus

Model GC266

Rated Output 255

Fuel Mains Gas

Year of manufacture 2011

Step 1 - Provide Details of Existing Boiler

Step 2 - Provide Details of Replacement Boiler

Energy Savings Calculator for boiler replacement projects

Cells to be completed by user

Select one of the four methods in the drop down menu and where appropriate fill in the blue cells. Note:Method 1 must be chosen if the boiler(s) are used for process heating. For space heating systems methods 2 to 4

are to be used only if the existing boiler(s) are well maintained and are less than eight years old, otherwise it is

recommended that a boiler combustion efficiency test is conducted and that the results of the test are utilised by a

competent person e.g. boiler engineer to estimate the seasonal efficiency of the boiler(s).



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(Select from drop down menu)


Enter the gross seasonal efficiency of the replacement boiler(s) 91%

Method 2 - Manufactures Efficiency Data at Full & Part Load



Is the efficiency based on net calorific or gross calorific value? Net CV

Method 3 - Boiler Input & Output

What is the boiler input at full load (100%) in kW? 100

What is the boiler output at full load (100%) in kW? 95

What is the boiler input at part load (30%) in kW? 30

What is the boiler output at part load (30%) in kW? 25

Is the boiler input based on net calorific or gross calorific value of the fuel? Net CV

Method 4 - Star Rating Label

What is the Star label of the existing boilers? ****

Estimated Seasonal Efficiency of Existing Boiler (Gross CV) 91.4%

Enter fuel consumption over a recent 12 month period (kWh) 660000

Enter the total cost of the fuel over the 12 month period 24,420

Measurement Period Start Date 4/5/2010Measurement Period End Date 5/1/2011

391 Days

Select building type N/a for process heating

Select closest weather station N/a for process heating

Average Unit Price (/kWh) 0.037

Estimated Annual Energy Savings (kWh) 178102

Estimated % Reduction in Annual Fuel Consumption -28.9%

Estimated Annual Energy Cost Savings 6,590

Hotel

Dublin Airport

Method 1 - Seasonal Efficiency of Replacement Boilers

Select one of four methods in the drop down menu and where appropriate fill in the blue cells. Note:

Method 1 must be chosen if the boiler(s) are used for process heating.

Results - Estimated Annual Energy Savings

Measurement period must be between 01-Jan-2010 and 31-Oct-2011 and the number of days must be between

335 and 395 days

To complete step 3 fill in the requested energy consumption data for a recent 12 month period. The fuel

consumption needs to be inputted in kWh. The measurement period must be between 335 & 395 days.

Step 3 - Provide Details of Past Energy Consumption Data


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1 What is this calculation tool for?

2 How to use the calculation tool

To be able to use the calculation tool the user will need to input:

Once the data is inputted to the calculator the annual kWh and cost savings will be calculat

Seasonal Efficiency of Existing Boilers

- the seasonal efficiency of the replacement boilers or where appropriate the ma-

the fuel consumption of the existing boilers over a recent 12 month period- information on location and building type for degree day correction purposes (f

Evaluating energy savings for boiler retrofit or upgrade solutions

This calculation tool will enable the user to estimate the annual savings associated with repl

with high efficiency boilers in a LTHW single or multi boiler system. The calculation tool can

systems in which all the existing boilers are identical types and all the replacement boilers a

- the seasonal efficiency of the existing boilers or where appropriate the manufa

Boiler efficiency, in the simplest terms, represents the difference between energy input and

period of one year the seasonal efficiency of the boiler is equal to the energy output divided

one year period multiplied by 100.

Using metered data is the most accurate method of determining the seasonal efficiency of

very few existing heating systems have sufficient metering to monitor both the fuel supply ainstances where metered data is unavailable the seasonal efficiency needs to be estimated

test results or from the manufactures boiler efficiency test data. The manufacturers test da

boilers in their as new condition, over time the efficiency of a boiler will reduce due to wear

recommended that if the existing boilers are poorly maintained or are 8 years old or more th

data be used for estimating the seasonal efficiency of the boiler as, in these instances, usin

likely result in an over estimate of the seasonal efficiency. It is the responsibility of the user

efficiency estimate is calculated to a reasonable degree of accuracy and should be calculat

such as a boiler engineer.

It is not necessary for the user to estimate the seasonal efficiency of the boiler where the usmanufacturers test data for a space heating system. Instead the user can chose to input th

the calculator and the calculator will automatically calculate the seasonal efficiency of the b

the calculator to calculate the seasonal efficiency of a boiler is based on the procedure des

Building Services Compliance Guide issued by the Department of Communities and Local

user can choose to input the manufactures data using three different methods and which m

depends on the data available to the user. The user can either input the full load and part lo

output of the boiler at full and part load or the user can input the star rating of the boiler. Se

information on inputting manufactures data.


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Seasonal Efficiency of the Replacement Boilers

3 Manufacturers test data

The user can input the manufactures:

- full and part load efficiency data, or- input and output data at full and part load, or- star rating data

Full and Part Load Efficiency

Full Load

Average boiler

watertemperature (in

Part

Load

Averageboiler

water

temperat

ure (in

C) C)

Standard

boilers

Low

temperat

ure

boilers(*)

Gas

condensi

ng

boilers

(*) Including condensing boilers using liquid fuels.

(**) Temperature of boiler water-supply.

If the boiler is used for process heating then the user must input the seasonal efficiency of t

derived from metered data, combustion efficiency tests or the manufacturers data.

If the boilers are to be used for space heating purposes then the user can input the relevant

calculator will automatically calculate the seasonal efficiency. If the boilers are used for promust separately calculate the seasonal efficiency of the replacement boilers and input the e

The manufactures data should only be inputted to the calculator where the boilers are usedonly.

The full and part load efficiency to be entered into the calculator depends on the type of boil

temperature of the boiler and the available manufacturers test data. All modern boilers sold

according to the following conditions:

Type of

Boiler

70 50

70 40

70 30 (**)


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Where:

Manufactures Input or Output Data

Full Load

Average boiler

water

temperature (in

Part

Load

Average

boiler

water

temperat

ure (in

C) C)

Standard

boilers

Lowtemperat

ure

boilers

(*)

Gas

condensi

ng

boilers

(*) Including condensing boilers using liquid fuels.

(**) Temperature of boiler water-supply.

Where:

40

- average temperature of the boiler water: is the average of the water temperatuboiler

- full load: 100% of rated output- Part Load: 30% of rated output

In most cases the manufacturer will also have test data for different flow and return temper

above table. The data the user will use will depend on the likely flow and return temperature

- average temperature of the boiler water: is the average of the water temperatuboiler

- full load: 100% of rated output- Part Load: 30% of rated output

In most cases the manufacturer will also have test data for different flow and return temper

above table. The data the user will use will depend on the likely flow and return temperature

Type of

Boiler

70 50

The user can enter the full and part load efficiency based on the gross or net calorific value

automatically convert the net efficiency to gross efficiency if the user inputs the net efficienc

The boiler input and output data to be entered into the calculator depends on the type of boi

temperature of the boiler and the available manufacturers test data. All modern boilers sold

according to the following conditions:

70 30 (**)

70


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Star Rating

Efficiency at full load (100%) = 87 + 2log(235) = 91.7% (Net Calorific Value)

Efficiency at part load (30%) = 83 + 3log(235) = 90.1% (Net Calorific Value)

4 Calculation methodology

The user will simply select the star rating and enter the rated output of the boiler. The calcul

calculate the seasonal efficiency of the boiler(s).

The calculator estimates savings by subtracting the annual fuel consumption for the heating

annual fuel consumption post the installation of the replacement boilers. The tool requires t

consumption for the heating system over a recent 12 month period (365 days 30 days) an

inputs the start and end date of the measurement period. For a process heating system the

then calculated as follows:

If the heating system is used for space heating the user must identify the nearest weather s

The calculator then assumes that a percentage of the fuel is used for heating hot water bas

the remainder is assumed to be used for space heating. Annual fuel consumption is then ca

Annual fuel consumption = (fuel consumption during measurement period / number of days

365

Take for example a boiler that has an output of 235kW and according to the name plate the

(indicated by the number of stars on the name plate). Therefore the efficiency of the boiler a

calculated as follows:

The user can enter the boiler input and output data based on the gross or net calorific value

automatically convert the input data from net to gross if the net value is entered.

Some boilers manufactured from 1998 or later have a star rating on the boiler name plate. I

the calculation tool can be used to estimate the seasonal efficiency of a boiler based on thepreferable to use the efficiency or input and output data at full and part load which will result

of the seasonal efficiency. The following table shows the efficiency of the various star label


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* The weather year is standardised at 2021 degree days per year, to the base 15.5C

Savings = 100,000 - (100,000*0.75)/0.91 = 15,582kWh.

Net & Gross Calorific Value

Fuel Conversion

Factor

LPG 0.921

Oil 0.937

Natural

Gas

0.901

% Fuel Utilised for Space Heating

Building Type

Percent of

fuel pro-

rated to

degree

days

General office 55%

High street agency 0%

General retail 0%

Large non-food shop 55%

Small food store 0%

Large food store 55%

Restaurant 30%

Bar, pub or l icensed cl 40%

Hotel 45%

Cultural activities 55%

Entertainment halls 55%

Swimming pool centre 55%

Fitness and health cen 40%

Dry sports & leisure fa 55%

The % of fuel assumed to be used for space heating purposes is based on the building typethe percentage fuel assumed to be used for space heating purposes for each building type:

To calculate the annual fuel consumption post the installation of the replacement boilers the

existing heat demand by simply multiplying the existing annual fuel consumption by the exiThe annual fuel consumption post the installation of the replacement boilers is then estimat

demand by the seasonal efficiency of the replacement boilers. As an example, if the annual

100,000kWh, the existing seasonal efficiency is 75% and the seasonal efficiency post the in

boilers is estimated to be 91% then the annual savings is calculated by the calculator as foll

The net calorific value of a fuel excludes the latent heat of water vapour in the exhaust and

calorific value. Efficiency test results and European standards normally use net calorific val

based on the net calorific value of the fuel the calculator converts to gross values using the

conversion factors:

Annual fuel consumption = {(fuel consumption during measurement period * % space heati

during measurement period) X 2021*} + {(fuel consumption during measurement period X

of days in the measurement period) x 365}


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Covered car park 0%

Public buildings with li 55%

Schools & seasonal p 55%

University campus 55%

Clinic 55%

Hospital -clinical & res 55%

Long term residential 55%

General accommodati 55%

Emergency services 55%

Laboratory / operating 55%

Station 55%

Terminal 55%

Workshop 55%

Storage facility 70%

Cold storage 55%

As an example, a clinic that consumes 100,000KWh over the measurement period is assu

for space heating purposes whilst the remaining 45,000kWh is assumed to be consumed fo


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d.

nufactures efficiency data

r space heating systems only)

acing all the existing boilers

only be used for multi boiler

re identical types.

tures efficiency data

energy output. Over the

by the energy input over a

n existing boiler. However

d the heat output and so infrom combustion efficiency

a was determined for the

nd tear and therefore it is

at combustion efficiency test

the manufactures data will

o ensure that the seasonal

d by a competent person

er intends on using themanufactures test data into

iler. The procedure utilised by

ribed in the Non Domestic

overnment in the UK. The

ethod the user chooses

ad efficiency, the input and

section 3 for further


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e existing boiler whether its

manufactures data and the

ess heating then the userfficiency into the calculator.

for space heating purposes

er, the likely operating

in the EU are tested


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res at the entry and exit of the

tures as well as those in the

s during operation.

res at the entry and exit of the

tures as well as those in the

s during operation.

of the fuel. The calculator will

y.

ler, the likely operating

in the EU are tested


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ator will then automatically

system from the estimated

e user to enter the fuel

d also requires that the user

annual fuel consumption is

ation and the building type.

d on the building type while

lculated as follows:

in the measurement period) x

boiler is a 2 star boiler

t full and part load is

of the fuel. The calculator will

a boiler has a star rating then

star rating however it is morein a more accurate estimate

:


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. The following table shows

calculator estimates the

ting boiler seasonal efficiency.d by dividing the heat

fuel consumption is

stallation of the replacement

ows:

so is lower that the gross

es. If the user inputs data

following net to gross

ng / number of degree days

hot water heating / number


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ed to consume 55,000kWh

r hot water heating.

energy savings calculator for boiler replacement projects(1)

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