Commercial Cooling: Window, PTAC and Service Parts

Cooling capacity and supply voltage: sizing the unit

Air conditioners are rated in BTU per hour; 12,000 BTU/h equals one ton of cooling. A 6,000 BTU/h window unit suits a small room, and capacity must reflect floor area, ceiling height, sunlight and the heat from people and equipment. Oversizing is not better: a unit that is too large cools quickly and then cycles off before it removes humidity.

Supply voltage splits the category. Window units usually run on 115 V household circuits, while packaged terminal units (PTACs) in hotels and offices are supplied at 208, 230 or 265 V. A PTAC power cord must match the unit's voltage, amperage and electric heater rating, such as 5.0 kW at 265 V; a cord for another rating is unsafe. Confirm the plug and receptacle shape too.

Drain kits, scales and air circulators: the supporting gear

Condensate has to go somewhere. Internal drain kits route water from a wall unit into a drain, and they are specific to the unit family, so match the model number. Refrigerant scales weigh the charge, which manufacturers specify by weight, and the scale's capacity, 110 lb for example, should exceed the cylinder it will carry. Check the scale's resolution and power source.

Air circulators move air around a space rather than cooling it. A heavy-duty circulator helps spread cooled air, dry surfaces and ventilate workshops and garages, but it adds no cooling by itself. Rate it by airflow and by whether it needs mains power, and keep it away from wet areas unless it is built for them.

Questions about Commercial Cooling: Window, PTAC and Service Parts

What does BTU per hour mean for an air conditioner?

It is the amount of heat the unit can remove from the air in an hour. Manufacturers publish room-size guides, and capacity should be adjusted for sun, ceiling height and occupants. Twelve thousand BTU/h equals one ton of cooling.

Can I use any power cord on a PTAC?

No. Use the cord made for the unit's voltage, amperage and electric heater rating. A cord for 265 V and 5.0 kW is different from one for 208 or 230 V, and the wrong cord can overheat or fail to fit the receptacle.

Why use a refrigerant scale?

Systems are charged by weight, so a scale shows how much refrigerant has gone in or been recovered, which is more reliable than judging by pressure alone. Pick one with a capacity above the cylinder's weight and a clear display.