COMMERCIAL HVAC CHILLER MAINTENANCE TIPS & ADVICE
Commercial HVAC systems are designed to both dehumidify and cool your building or facility while keeping an eye on crucial HVAC targets: cost-effectiveness and optimal interior temperature. An optimally maintained chiller used in the HVAC system is critical to achieving these goals.
A chiller is the HVAC component responsible for transferring heat from the internal environment to the external environment.
Heat transfer–moving heat from one space to another–always goes from hot to cold (heat never moves from a cold area to a warmer one). HVAC systems can harness this process, through vapor compression or vapor absorption, by implementing an HVAC chiller to help maintain comfortable indoor temperatures.
A chiller alters the physical properties of the coolant to transfer heat from one place to another. Chemistry’s Gay-Lussac’s law tells us that the pressure-temperature relationship has fixed parameters. The law says if you increase the pressure on coolant, then the temperature goes up. The reverse is also true: reduce the pressure and the temperature drops.
When coolant circulates through various parts of an HVAC chiller, its properties change:
- As pressure changes occur, the coolant goes from a liquid to a gas state by boiling in the evaporator. It’s here the refrigerant absorbs heat, causing a temperature drop.
- In the compressor, the coolant is removed from the evaporator but keeps its low pressure. The compressor simultaneously raises the pressure in outgoing refrigerant vapor to release heat when it reaches the condenser.
- The refrigerant transitions from gas to a liquid state when it condenses, in the condenser and its heat is carried away by the cooling air or water medium.
All this happens in a seamless progression with an HVAC chiller operating at peak levels.
Air-Cooled vs. Water-Cooled Chillers
An air cooler typically funnels the refrigerant through coils with air forced over and across them by high power fans that remove heat— venting to the exterior of the building.
A water cooler involves a second heat transfer from the refrigerant to the water. It’s sent up and circulated through a tower to remove the heat that radiates into the air above ground level.
Both types of cooling systems require maintenance to maintain operational efficiency.