BTU is an abbreviation for British Thermal Unit, but what does it have to do with keeping you cool this summer? The BTU is also the standard specification for the heat that an air conditioner extracts from a house in a certain time frame. A higher BTU rating means the air conditioner moves more heat faster out of the house.
Sizing Up Your Home
Calculating the precise BTU capacity of an air conditioner for efficient, effective cooling is called sizing. It takes into account the total square footage of a house, as well as factors such as daily exposure to sun, insulation type, and the number of doors and windows. Performed by a professional HVAC contractor, the sizing calculation uses industry-standard software to determine the home’s cooling load. The cooling load is the air conditioner BTU capacity required to cool the home in typical summer conditions.
BTUs By the Ton
Residential central air conditioners are typically rated from 1.5 tons up to 5 tons of cooling capacity. One ton in HVAC terms equals 12,000 BTUs of heat removed from the house every hour by the air conditioner.
Not Too Much, Not Too Little
Accurate BTU sizing is critical for both optimum cooling in the house as well as the lowest operating costs. If the house isn’t properly sized, AC performance and efficiency suffers. Consider the following two scenarios:
Undersizing. An AC unit with insufficient BTU capacity comes with a less-expensive price tag, yet it can be costly to operate. Struggling to meet thermostat settings, the unit will run very long cooling cycles, consuming excess energy and raising monthly operating costs. It will also incur more wear and tear and have shorter service life.
Oversizing. An AC with excessive BTU capacity tends to “short cycle,” — turning on and off rapidly — which accelerates wear on components. Temperature control is then uneven, with some rooms too warm and others overly cool. Because the unit cycles off rapidly, the AC dehumidifying function is not fully functional and the home feels humid and clammy.
Get more facts and figures about the BTU capacity of air conditioners by contacting the professionals at Air Assurance.