The way most customers handle the risk associated in working with a home contractor is to research and learn more about what they’re buying so they can challenge advice that seems “a bit off”. One thing you may be reading about in your research for a new air conditioning unit is BTUs.
What is a BTU, and why should I pay attention to it?
The standard unit of measurement for heat / thermal energy, a BTU, or “British Thermal Unit”, describes the amount of energy needed to raise or lower the temperature of 1 pound of water by 1 degree. Heat & AC units have BTU value ranges in the thousands.
The BTU value is used as a comparison between heating & cooling systems, often matched against the amount of space you need to heat or cool in a home. For instance, this chart from the Energy Star website about properly sizing BTUs per Square Foot gives a recommendation of 5,000 BTUs for 100-150 square feet of space all the way to 34,000 BTUs for 2,000-2,5000 square feet of space to be cooled. Seems pretty straightforward, right?
It’s not straightforward – seek an HVAC professional.
Although the BTU chart is a helpful guide for doing research, it doesn’t take special scenarios into consideration and could cause an unrealistic idea of what is really needed, resulting in an underage or overage of heating and cooling power, which are both bad outcomes.
Most HVAC providers offer low-cost or free quotes on new furnace or air conditioning units with no obligation to buy, and during the quoting process, they’ll evaluate your home and talk about specific considerations you’ll need to plan for. These may include the structure – meaning the outside wall – of your home and how well-insulated it is; the height of the rooms being heated/cooled; the type and age of windows in your home; the rooms above / below the area to be heated or cooled, and more. If the quote you receive on amount of BTUs required doesn’t fit within the ranges provided on the Energy Star guidelines chart, make sure to ask your HVAC professional to explain their recommendation in detail. If they mention any of these special scenarios, they may be spot on.
As with any home contract work, if you are not working with someone you have experience with and trust, it’s wise to take the time to collect multiple quotes.