A BTU is a British Thermal Unit, or Even a Step of thermal or heat energy. BTUs are used to determine renewable energy output in various apparatus, such as furnaces. A normal home furnace generates thousands of BTUs and installing one which meets your house’s heating needs is vital. If your house’s furnace is too big, it will turn on and off too frequently and eliminate efficiency and, when it’s too small, it will run too frequently and won’t adequately heat your home.
BTUs per Square Foot
Heating and ac contractors utilize various load calculations to ascertain furnace sizes for houses and these calculations tend to be intricate. But there will also be”rule-of-thumb” estimations you can use to pick a furnace dimensions for your property. For cooler climates, a very broad estimate of furnace sizing would be to pick one which generates 40 to 45 BTUs per square foot. In 40 to 45 BTUs per square foot, you would need a 100,000 to 112,500 BTU furnace to warm your 2,500-square-foot home.
Heating Degree-Day Calculation
A heating degree-day calculation, using the month of July as a factor, is a more precise way of estimating furnace dimensions. Natural gas for a furnace is priced by the therm, or per 100,000 BTUs. Therms are listed on your house’s gas bill in yearly and monthly usage prices. The heating degree-day calculation to get a furnace is 50 x heating therms x ray efficiency = load in BTUs/hour. Your furnace must produce a certain load, measured in BTUs per hour, to warm your home.
Calculating Your Furnace Size
Suppose your home uses 1,500 therms of natural gas each year, your July usage rate is 25 therms and your furnace is 82% effective. For a heating degree-day calculation, subtract 12 x 25, or your July utilization rate, from the yearly therm usage rate of 1,500, or 1,500 – 300 = 1,200, or your home’s therm heating load. Your house’s heating degree-day calculation formula would be 50 x 1200 x .82, or 49,200. Employing heating degree-day calculations, a 50,000 BTU furnace may adequately heat your home.
Furnace Heating Efficiency
New furnaces include a yellow energy guide attached that supplies their energy efficiency ratings. Various furnaces also deliver different efficiency levels. For instance, if your furnace is 82% effective, it’s delivering 82 percent of its fuel into your house as heating. The greater your furnace’s efficiency, the lower its fuel usage rate is, meaning it won’t be as costly to operate. Cheaper furnaces also often cost more, at least up front, but they’re typically less costly over the long run.