Evaporator Coil – the evaporator coil is responsible for absorbing heat into the coils and the refrigerant. The evaporator coil is an essential component of vapor compression refrigeration. This is usually done as result of passing air or water over the evaporator coil where a heat exchange process takes place. Heat leaves the air or water (whatever medium is used) and is absorbed into the coil and the liquid refrigerant. As more and more heat is absorbed by the evaporator coil and the refrigerant again changes state from a liquid to a refrigerant vapor. By the time the refrigerant leaves the evaporator coil the refrigerant should be all vapor and ready to be received again by the refrigeration compressor.
A new evaporator coil replacing an old leaking coil
The evaporator coil is typically inside the air handling unit or it can be installed in the duct work near the air handling unit. When the air handler blower turns on and the condenser is running refrigerant flows from the compressor through the condenser coils and then through the metering device. and into the evaporator coil. The refrigerant changes state in the evaporator coil and again in the condensing unit. In the evaporator coil the change of state is from a liquid to a vapor while in the condenser the change of state is from a vapor to a liquid. This is all necessary for the process of refrigeration to work properly. The typical evaporator coil is constructed of copper with aluminum fins surrounding the copper coils. The aluminum adds surface area to the copper coils and enhances the heat exchange rate making the coils more efficient.
Components of Vapor Compression Refrigeration – The Evaporator Coil
Chilled water systems are mainly used in large commercial HVACair conditioning systems and industrial cooling applications although there are some residential and light commercial HVAC chilled water systems in use. Chilled water systems are popular because they use water as a refrigerant. Water is far less expensive than refrigerant. This makes them cost effective especially in commercial HVAC air conditioning applications. Instead of running refrigerant lines over a large area of the building water pipes are ran throughout the building and to evaporator coils in air handlers for HVAC air conditioning systems. The chilled water is pumped through these pipes from a chiller where the evaporator coil absorbs heat and returns it to the chiller to reject the heat.
Cooling towers use the process of evaporation to cool or removes heat from the condenser water that was transferred to the water in the chiller condenser barrel. The heat is absorbed at the load in this case in a data center on a data center floor. The servers and electrical equipment produce a massive amount of sensible heat. The heat is absorbed by computer room air conditioners or computer room air handlers. These systems, computer room air handlers and air conditioners, have chilled water coils. The chilled water originates at the chiller into the primary loop. The water circulates through the primary loop and makes its way into the secondary loops of the chilled water loop. Continue reading “Cooling Tower Evaporation Cools Water” »
This large HVAC condenser pump serves a new chiller located in a data center. This pump pumps condenser water through the condenser chiller barrel and to a cooling to reject the heat absorbed in the chillers evaporator barrel. The pump works to move the water from the chiller to the cooling and then back through the chiller again. The water is diluted with a glycol solution to prevent freezing in the winter time when the chiller needs to run at low ambient temperatures. Continue reading “Large Condenser Pump for a Chilled Water System” »
To properly troubleshooting air conditioners one needs to understand some basics of air conditioners including refrigeration, electricity, electrical components and how electro-mechanical controls work, basic air conditioner components and air conditioner sequence of operation. Before troubleshooting air conditioners you need to identify the basic problem of the air conditioner. Is a component not working and why is the component not working. For example, is the compressor working and if the compressor is not working is it the compressor that is bad or is it an electro-mechanical component that controls the compressor with the problem that will prevent the air conditioner from running? So in the process of troubleshooting air conditioning not only do you need to know the basics of air conditioners you also need to understand basic techniques for troubleshooting air conditioners. Continue reading “Air Conditioner Troubleshooting” »
This Trane HVAC chiller serves four different apartments. Chilled water systems offer a great way for multi-zone air conditioning. From small apartment buildings to large commercial buildings chilled water systems can serve multi-zone air conditioning systems. From one air conditioning zone to hundred the only limitation is the size of the chiller. If the air conditioning zoning system (the load) is matched up with the right sized chiller (in tons) the system will serve all air conditioning zones and keep all the occupants comfortably cool. Chilled water systems can also be integrated with the boiler system so that the same system can be used for heating and cooling. A good control system will add efficiency and more comfort to the system. Continue reading “Trane Chilled Water Systems – Multi-Zone Air Conditioning Systems” »
Can an HVAC Technician “Park” Refrigerant in the Condenser?
Technicians often pump the refrigerant into a part of the system where it can be sealed off from the part of unit they are working on.
We are in the process of getting estimates to replace our evaporator/blower of a 2 piece unit. When asked about the process out of curiosity the HVAC guy told us since the the system holds pressure and the refrigerant/condenser is new he will just “park” the refrigerant in the compressor, then cut the line to the evaporator, attach the new one and open the the compressor valves to get the system up and running. Is this possible? Can a compressor hold all the refrigerant of an HVAC system?
Central Air Conditioner Prices – The Cost of Air Conditioners
Properly Installed Condensing Unit is important
So you are looking to buy a new central air conditioning system and you want to know what the price of the new air conditioner will be after the it is all said an done and the new air conditioner is installed and the contractor walks out the door? The price of a new air conditioner is a popular subject because I get several emails every month asking me how much it would cost to install a new air conditioner. First it is a loaded question because no air conditioner installation job is the same with some air conditioner installation jobs being more difficult than another air conditioner installation job. The fact is I cannot give anyone the price of their new air conditioner without first seeing the job. The fact is no one can give you a fair a reasonable price of a new air conditioner cost without first seeing the job first and doing a little homework.
When you look at buying a new HVAC system it will surely arise when the HVAC salesman or HVAC contractor who comes to give you an estimate will show an HVAC system that has a variable speed motor or the GE ECM (Electronically Commutated Motor) installed in it. These are systems that have a higher efficiency rating than the HVAC equipment that has the typical electric blower or condenser fan motor. The ECM (Electronically Commutated Motor) uses less energy than the standard PSC motor that is commonly used in air handlers and condensers to mover air. The ECM motor also offers more control which has good benefits in HVAC applications. Continue reading “Variable Speed GE ECM Condenser & Blower Motors” »