We Chicagoans are currently in the very small sweet spot between when our heating is on and when air conditioning has to kick on to keep us comfortable. Ever wondered what types of considerations there are for cooling an entire building?
In the building’s HVAC system, the air conditioning and furnace are all part of the same system. Technically called a “split system”, this typically involves an outdoor unit containing the condenser and compressor and an indoor unit containing the evaporator coil and blower.
Most people don’t know that air conditioning work just as much by removing hot air from the inside as it does by blowing cooler air inside.
The compressor condenses and circulates the refrigerant through the outdoor unit, changing it from a gas to a liquid. The liquid is then forced through the indoor evaporator coil or cooling compartment. The indoor unit’s fan circulates the inside air to pass across the evaporator fins, which exchange thermal energy with the air around them. There, the refrigerant turns from liquid into vapor, removing any heat from the surrounding air. As the heat is removed from the air, the air is cooled and blown back into the ductwork.
From that point, the condenser or outdoor unit then turns the refrigerant vapor back into a liquid, removing any heat. By the time the fluid leaves the evaporator again, it is a cool, low-pressure gas, eventually returning to the condenser to begin its trip all over again.