dr. ahmed f. elsaftysmartlearnconference.org/presentations/session1/07-ahmedfarouk.pdf · dr. ahmed...

Dr. Ahmed F. Elsafty

Prof. – Mechanical Engineering

College of Engineering and Technology

Arab Academy for Science, Technology and Maritime Transport

AAST&MT

Energy efficient cooling technologies

What

Why

How

What

- Energy efficiency: - the ratio of the energy output of a piece of equipment to its energy input, in like units to produce a dimensionless ratio. - indicator to ensure valuable energy is not wasted

- Energy efficient technologies:- technologies to convert energy sources into useful heat or cool air for your home- Heating, cooling, lighting, and air conditioning

- Energy efficient cooling technologies:- technologies using in cooling buildings with efficient energy consumption


What

Why

How

Why

Oil Prices


What

Why

How

Why

Saving Money

Reducing the amount of energy you

use will help lower your fuel bills. Lower bills means more money in your pocket to spend on what you want.

Electric Consumption:

Due to the hot and humid summer climate in Egypt, the

energy demand for air conditioning is quite extensive

http://www.clipartreview.com/_gallery/_pages/r_260.html


What

Why

How

Why

Environmental Violation

Montreal Protocol, 1987


The Kyoto Protocol, 1997

Ozone DepletionGlobal Warming


What

Why

How

How

Design. Various alternatives should be compared and analysed in terms of either payback years or life-cycle cost to determine which is most energy-efficient and cost-effective. Environmental Impacts should be considered.

Construction and installation. Roof and external walls should be well insulated. The amount of air leakages from the ducts, and the duct and pipe insulation all affect the energy use.

Commissioning. The capacity of equipment, the air and water balance, and the coordination between various components and control systems should be carefully measured, adjusted, and commissioned. A poorly commissioned HVAC&R system will never function efficiently as specified.

Operation & Maintenance. The energy use for Chillers, compressors, fans, pumps, boilers, and furnaces should be monitored, periodically checked, investigated, reduced, and improved.


What

Why

How

How

•Using Environmental Friendly Air conditioning system [Renewable HVAC System]

•An energy-efficient HVAC system maintains a comfortable indoor environment with an acceptable indoor air quality (IAQ) and consumes optimum energy resources.

•Energy Efficiency during Design, Construction, Commissioning, and Operation

•Retrofitting and Upgrading existing systems


What

Why

How

How

-Ventilation-Evaporative cooling-Air conditioning- Other cooling technologies

-Absorption cooling- Radiant cooling- Earth cooling tubes


What

Why

How

-Ventilation:- natural ventilation or forcing air through your home with fans- the least expensive and most energy-efficient way to cool buildings

How

Air Flow Patterns

ASHRAE Fundamentals 1997

Evaporative Cooling (Swamp Cooling)•In low-humidity areas, evaporating water into the air provides a natural and energy-efficient means of cooling.

•Suitable for homes in dry climates.


What

Why

How

How


What

Why

How

-Air conditioning: general -How does it work

How


What

Why

How

-Air conditioning: types of air conditioners-Room air conditioner

How

What is Energy Labelling?

• Energy labelling is a new way of allowing consumers to easily compare and rate the efficiency of air conditioners, similar to that used for domestic appliances such as fridge's and washing machines etc.

Sample of the Australian Energy Labels for

Room Air ConditionersDr. Ahmed F. Elsafty


Syria

EU Egypt India

Tunis USA

Checklist For Proper Installation Of Split Air-conditioning System

• If your air-conditioner was installed improperly, chances are it may not be operating at its designed efficiency and you may not be getting the most out of your air-conditioner.

a) Indoor unit

b) Outdoor unit

c) Piping

http://www.nccc.gov.sg/energylabel/indoor.shtm

http://www.nccc.gov.sg/energylabel/outdoor.shtm

http://www.nccc.gov.sg/energylabel/piping.shtm

Indoor Unit

8

Choose the right type and capacity&

Avoid placing in direct sunlight

Placing the indoor unit too high will result in more area to be cooled

Keep the air inlet and outlet clear of any obstacles to ensure proper airflow

Clean air filters regularly 8. Close all windows and doors when the air-conditioning is turned on

Outdoor Unit Place away from direct sunlight. Where possible, install protective awning

Do not block the fan opening

During regular maintenance, clean the condenser fins to ensure good heat rejection from the condenser.

Piping

Use the correct pipe size

Ensure that pipes are well insulated. Where insulation is not possible, use a

cork tape to cover up any exposed pipe

Do not install 2 or more pipes within a single insulation sleeve

Drainpipes

should be installed with a descending gradient.

Ensure joints are properly tightened and free from defects to prevent refrigerant leakage.

Air Curtains


Electric Motors


• Investing in a high-efficiency electric motor can help you reduce your energy costs.

• VARIABLE SPEED DRIVES

• In many applications, electric motors do not have to run at full speed for the entire operation.

• With a variable speed drive (VSD) installed, the speed – and energy consumption – can be varied with the load requirement.

VRV or VRF


What

Why

How

-Central air conditioner

How

Absorption Cooling

• Absorption cooling is essentially an air conditioner driven not by electricity, but by a heat source such as natural gas.

• natural gas is the most common heat source for absorption cooling.

• Although mainly used in industrial or commercial settings, absorption coolers are now commercially available for large residential homes.

•Absorption cooling usually only makes sense in homes

without an electricity source.

but may also be employed to make use of renewable energy.

What

Why

How

How Energy efficient cooling technologies


Vapor Absorption system (VAS)

Combined Cooling Heating and Power[CCHP]

• Trigeneration implies the simultaneous production of mechanical power (electricity), heat and cooling from a single fuel.


Earth Cooling Tubes

•Earth cooling tubes involve

routing air through underground

tubes or chambers to achieve a

cooling effect.

•Although a few hundred systems

were build in the 1970s and

1980s, in practice the technology

is not effective both technically

and economically.

•Cooling tubes are long,

underground metal or plastic

pipes through which air is drawn.

•As the air travels through the

pipes, it gives up some of its heat

to the surrounding soil, entering

the house as cooler air

What

Why

How

How Energy efficient cooling technologies

Ground Heat Pump in Winter[Heating Mode]Dr. Ahmed F. Elsafty

Ground Heat Pump in Summer[Cooling Mode]Dr. Ahmed F. Elsafty

Sea Water Air Conditioning System [SWAC]

600m

6 deg CDr. Ahmed F. Elsafty

Shading• Sun path

• Shading types

• Orientation


Windows and Glazing

• Careful specification of window and glazing systems is essential to the energy efficiency and comfort of all buildings

Factors affecting window performance(Courtesy of Energy User News)


Thermal Insulation

A vacuum is an excellent insulator!!!


Windows

How Much Window Area? (guide only)

Recommended % of Wall AreaFacing Direction

60 %North

30 %South

15 %East

0-7 %West


Thermal Insulation

• Thermal insulation is used to minimize the heat transfer in many everyday situations. It is done by reducing conduction, convection and/or radiation effects.

• The R-value is a standard of measurement of this insulation.

Material R-value

Hardwood siding (1 in. thick) 0.91

Wood shingles (lapped) 0.87

Brick (4 in. thick) 4.00

Concrete block (filled cores) 1.93

Fiberglass batting (3.5 in. thick) 10.90

Fiberglass batting (6 in. thick) 18.80

Fiberglass board (1 in. thick) 4.35

Cellulose fiber (1 in. thick) 3.70

Flat glass (0.125 in thick) 0.89

Insulating glass (0.25 in space) 1.54

Air space (3.5 in. thick) 1.01

Free stagnant air layer 0.17

Drywall (0.5 in. thick) 0.45

Sheathing (0.5 in. thick) 1.32

Reference Hyperphysics Georgia State University


http://hyperphysics.phy-astr.gsu.edu/hbase/tables/rvalue.html

Choosing Insulation

When choosing what sort of insulation is appropriate for your home you may want to:


• Compare R-values, the bigger the R level the better

• Check for performance guarantees or test certificates

• Compare environmental benefits, for example, recycled content

• Consider if it suits the application and will it fit in the space available

Lighting

• Investing in high-efficiency lighting will pay for itself in energy savings in just a short time.


• Lighting can account for as much as 30 percent of your total electric bill.

• A typical lighting system with inefficient equipment can waste more than 50 percent of the energy it consumes.

Daylighting

• Daylighting is the controlled admission of natural light into a space through windows to reduce or eliminate electric lighting.

• By providing a direct link to the dynamic and perpetually evolving patterns of outdoor illumination, daylighting helps create a visually stimulating and productive environment for building occupants, while reducing as much as one-third of total building energy costs.


Maintenance


Cooling Towers ?Want to save Energy? Look at your cooling Tower

• Improving the chiller performance indirectly affected with cooling Tower performance.

• Making sure the tower is sized correctly.

• VSD fans

• More efficient fill

• Using set of nozzles to give better distribution over the fill.

• Proper maintenance.


Heat Exchangers Fouling


BMS• A computerised system based

on a network of controllers offering closer control and monitoring of building services performance, including heating, ventilation, air conditioning and sometimes lighting.

• This is shown on a computer screen in real time and allows the performance of plant to be monitored and settings to be changed easily.


DDC [Direct Digital Control]


Electric Lighting Controls

• When electric lighting controls are used properly, energy will be saved and the life of lamps and ballasts can be extended. Lighting controls will help reduce energy by:– Reducing the amount of power used during the peak demand period

by automatically dimming lights or turning them off when they are not needed

– Reducing the number of hours per year that the lights are on

Various types of occupancy sensors and photosensors


Energy Audits

• Energy audit refers to a month-by-month accounting, survey, and analysis of energy use in a building.


• This energy use is checked against a budget or an energy estimate based on an hour-by-hour detailed system simulation in order to identify energy efficiency opportunities.

Green Building

• Basics. A green building implies a building, including HVAC&R systems, that is energy-efficient and environmental friendly.

• GBA Tool. The second-generation assessment method developed during the Green Building Challenge (GBC ’98) process is called the green building assessment (GBA) tool.


Summing up• Energy efficiency is essential for the mitigation of CO2

emissions

• Source of Energy: Using Renewable Energy resources

• HVAC Components: Selecting energy efficient HVAC System

• Building: Good Insulation, Lighting Improvements…

• Control System: Building Management System [BMS]

• Energy Audit: Metering and Reviewing

Energy Efficient system could save up to 50% of HVAC Energy Bills.



Thank YouAhmed Elsafty

[email protected]

Ancient Proverb

dr. ahmed f. elsaftysmartlearnconference.org/presentations/session1/07-ahmedfarouk.pdf · dr. ahmed...

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