Dr. Ahmed F. Elsaftysmartlearnconference.org/presentations/Session1/07-AhmedFarouk.pdf · Dr. Ahmed...
Transcript of 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
Energy efficient cooling technologies
What
Why
How
Why
Oil Prices
Energy efficient cooling technologies
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
Energy efficient cooling technologies
What
Why
How
Why
Environmental Violation
Montreal Protocol, 1987
Dr. Ahmed F. Elsafty
The Kyoto Protocol, 1997
Ozone DepletionGlobal Warming
Energy efficient cooling technologies
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.
Energy efficient cooling technologies
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
Energy efficient cooling technologies
What
Why
How
How
-Ventilation-Evaporative cooling-Air conditioning- Other cooling technologies
-Absorption cooling- Radiant cooling- Earth cooling tubes
Energy efficient cooling technologies
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.
Energy efficient cooling technologies
What
Why
How
How
Energy efficient cooling technologies
What
Why
How
-Air conditioning: general -How does it work
How
Energy efficient cooling technologies
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
Dr. 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
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
Dr. Ahmed F. Elsafty
Electric Motors
Dr. Ahmed F. Elsafty
• 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
Energy efficient cooling technologies
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
Dr. Ahmed F. Elsafty
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.
Dr. Ahmed F. Elsafty
Dr. Ahmed F. Elsafty
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
Dr. Ahmed F. Elsafty
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)
Dr. Ahmed F. Elsafty
Thermal Insulation
A vacuum is an excellent insulator!!!
Dr. Ahmed F. Elsafty
Windows
How Much Window Area? (guide only)
Recommended % of Wall AreaFacing Direction
60 %North
30 %South
15 %East
0-7 %West
Dr. Ahmed F. Elsafty
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
Dr. Ahmed F. Elsafty
Choosing Insulation
When choosing what sort of insulation is appropriate for your home you may want to:
Dr. Ahmed F. Elsafty
• 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.
Dr. Ahmed F. Elsafty
• 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.
Dr. Ahmed F. Elsafty
Maintenance
Dr. Ahmed F. Elsafty
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.
Dr. Ahmed F. Elsafty
Heat Exchangers Fouling
Dr. Ahmed F. Elsafty
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.
Dr. Ahmed F. Elsafty
DDC [Direct Digital Control]
Dr. Ahmed F. Elsafty
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
Dr. Ahmed F. Elsafty
Energy Audits
• Energy audit refers to a month-by-month accounting, survey, and analysis of energy use in a building.
Dr. Ahmed F. Elsafty
• 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.
Dr. Ahmed F. Elsafty
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.
Dr. Ahmed F. Elsafty