What are the various commercial heat pumps?
Mechanical heat pump: The mechanical heat pump is the most commonly used and commercially feasible heat pump. There are two types
• DX Heat Pump:
This is called the Direct Expansion heat pump. Here the whole refrigerant volume at the opening of the expansion device is delivered in the evaporator. Alarge portion of therefrigerant evaporates due toexpansion. The refrigerant is mostly gaseousand partly liquid. It now enterstheevaporator. The liquid part of refrigerant evaporates in the evaporator. When most of the refrigerant isevaporated, it is slightly superheated andmoved to the compressor. Superheating is crucial here to prevent liquid slugging, which can damage the compressor. Once it reaches the compressor the regularcycle of aheat pump takes place to release heat.
• Pump system:
In this system liquid refrigerant is moved to the evaporator. Inside the evaporator the refrigerant is partly evaporated. The refrigerantwhich is amixture of gas and liquid now is sent to separator vessel. In the vessel the liquid and gaseousrefrigerant is separated. The gaseous part goes to the compressor to complete regular cycle of a heat pump. The liquid part goes to evaporator again.
The pump mechanism has an advantage. As you will only supply fluid refrigerant, a moderately-sized evaporator will do. But in these units you need an additional refrigerant pump and separation vessel. These pumps aremostly used in industrial sets ups.
Superheating ofthe refrigerant in dx systems leads to releaseof high temperatures. This can demolish the compressor oil.
Gas engine heat pump:
The gas engine heat pumps work in the same way as a mechanical heat pump. The only notable differenceisthat the heat pump is powered by a gas engine instead ofan electric motor. Here the heat from the motor cooling and flue gases is utilized as well. These heat pump systems have high heating output even with low outdoor air temperatures.They have higherenergy efficiency. You have lower running cost as you are not using electricity. It is eco-friendly as there will be less CO2 emissions.
These heat pumps are often used in restaurants, showrooms, shops, offices, hotels, schools, care-centers, sports clubs, factories and such other places.
Absorption heat pump:
It works in the same way as air-air heat pump. The only notable difference is that instead of using a refrigerant it uses Lithium-Bromideor ammonia in water. The driving force in this type of heat pump is thermal energy. Absorption heat pumps can be very useful where both heating and cooling are necessary. These are powered by natural gas, solar power, propane, or geothermal heated water.
In theseammonia (NH3) is used as refrigerant. It is evaporated into gas inan evaporator. Instead of sending it to a compressor, NH3 is absorbed in water. This leads to release of heat. Thenext step is removing ammonia from water. It is here that a heat source is needed. The source boils the liquid to evaporatethe ammonia out. The gaseous ammonia flows towards the condenser. Inside the condenser the NH3 releases heat to its environments and condensate. The pressure of liquid Ammonia is further lowered in an expansion device. It goes towards the evaporator to start the cycle once again. A key part of these heat pumps is generator absorber heat exchanger technology, or GAX. This collects and uses the heat that is released when ammonia is absorbed in water. These days you will get these heat pumps withhigh-efficiency vapor separation, variable ammonia flow rates, and low-emissions, variable-capacity combustion of the natural gas.
Adsorption heat pump:
It just works like an absorption heat pump. The only difference is that it uses a solid instead of a fluid as absorption medium. Here is a list of combinations that work in adsorption heat pumps
• Silica gel – H2O
• Zeolite – H2O
• Active carbon – MeOH
• Active carbon/salt - NH3
Transcritical CO2 heat pump:
This is in contrast with regular compressor systems where heat release takes place at a fixed temperature. Here heat release takes place above the critical pressure of 71 Bars. The refrigerant cools down and not condensate as in other heat pumps. These heat pumps are more efficient. For higher heat output water at lowertemperature is needed.
Thermoacoustic heat pump:
This is based on the science principle that difference in temperature cangenerate sound waves. And in a reverse way a sound wave can generate a temperature difference. Here sound wave is generated with low temperature waste heat. This wave is used to create temperature difference in a high temperature medium. These heat pumps have not been built or utilized at a commercial scale yet.
Cost of buying and installing heat pump is a fat investment. Buying and installing a 3-ton heat pumps in a residence could start from $4500 and go up to $8000 and more. That gives you a fair idea what could be the cost of 20 to 50-ton heat pumps that will be needed in commercial sets ups.
Sections Coming:
• Hybrid Heat Pumps
• Maintenance cost of commercial Heat pumps
• Where to find installation and maintenance professions?
• Tax rebates for buying commercial Heat pumps
• Top Brands of Commercial Heat Pumps with distributors
What is an HVAC system?
Heating, Ventilating, and Air Conditioning (HVAC) equipment arewidelyusedtoday to cool or heat residential, commercial or industrial buildings, according to seasonal needs. These systems also play a key role in disinfecting your indoor air from aerial contaminants such as odors, volatile organic compounds producedby furnishings, chemicals used for cleaning, and dust mites, molds etc. A properly designed system will provide fresh and breathable air round the year. Here are some major types of