Yes, size does matter, but, when it comes to a furnace installation, bigger is not always better. The proper sizing of your heating system is one of the most important aspects in your selection a new furnace. When you have a correctly sized furnace, it will give you a high level of comfort, while also providing the highest efficiency. If your system is too large, it will "short cycle," frequently turning on and off.
If your furnace is short cycling, comfort is limited due to the system repeatedly turning itself on and off, and will also decrease the unit's operating life. Regardless, the issue of sizing is not so critical that you must nail the requirements down to the very last BTU. New furnaces are most times sold in increments of 20,000-25,000 BTUs. Furnace manufacturers understand that home heating does not require exact BTUs, and so the units reflect this.
So, if you end up being off by 20 percent, there is no real issue. Regardless, if you discover that the heating requirement is roughly 10 percent or more above a chosen furnace's capacity, it is better to increase to the next size furnace. What is the best way to select the proper furnace size for your home? Have a heating contractor provide you with an evaluation of your sizing needs.
An experienced furnace installer will become familiar with your home's floor plan. However, if you receive multiple evaluations, expect that the heating contractors will likely not always agree on the correct size. Therefore, ask for some additional information. If heating professional uses only your home's square footage, there is no certainty the heating unit will work correctly. Heating industry studies have revealed that over 50% of the furnaces sold are "dramatically oversized." By this, they mean the furnaces are producing upwards of double the actual BTU's required, but the industry is working to fix this issue with training programs and industry standard sizing procedures.
What haven't we covered yet that is important to you? If you would like to talk about how equipment size is determined for a furnace installation, or need more information, please contact us.