The Poway Air Conditioning Rule of Thumb

The cooling capacity of an air conditioning system in Poway is expressed in BTU’s or tons. One ton of cooling capacity equals 12,000 BTU’s/hour of cooling capacity.

“One ton” of cooling capacity, historically, referred to the cooling capacity of a ton of ice. Tons of ice does not explain a key ingredient in the comfort produced by air conditioning systems, dehumidification of indoor air – that is, taking water out of the air.

Cool air can hold less water (in the form of water molecules or gaseous form of H2O) than warm air. Think of the warmer air as having more space between the gas molecules for the water molecules to remain suspended.

When we cool the air, we in effect are squeezing the water molecules out of the air. When an air conditioner blows warm humid building air across an evaporator coil in the air handler unit, it is not only cooling the air, it’s squeezing out some of the water in that air. Both of these effects, cooler air and drier air, increase the comfort for building occupants

A home inspection does not involve the calculations of heat gain necessary to decide if the cooling capacity on a building is adequate, but the inspector is expected to examine and report on the rated system capacity (such as “36,000 BTUH”) and on the presence or absence of cooling sources in the habitable rooms of the building.

Air conditioning capacity requirement:

A simple rule of thumb for Poway air conditioning relatively cool climates such as Poway, Escondido, or San Marcos California: one ton per 400 sq .ft. (Commercial) or one ton per 500 to 1000 sq .ft. (Residential)

Or we estimate an air conditioning requirement of one ton per 400 to 800 sq .ft. for Space Pak Systems.

Or a 3000 sq .ft. house may require a 5-ton unit. Or count the supply outlets: 10 outlets @ 100 cfm (estimated) = 1,000 cfm = 2.5 tons needed.

Never buy an air conditioner that has more tons or BTUs of capacity than you actually need. For additional information regarding your Air Conditioners capacity or output call United Plumbing Heating Air & Electric.