Furnace Sizing: How to Ensure Your Installer Gets It Right

Installing a new furnace in your Cleveland area home is a major, costly operation, and you’ll certainly want to make sure that, when the time comes, the job’s done properly. If you’re thinking about a do-it-yourself installation to save some money, this is generally not advised (unless you happen to be a qualified HVAC technician).

This is not an easy procedure, and a non-professional installation could end up not only being unsafe but also voiding the unit’s warranty.Furnace Sizing: How to Ensure Your Installer Gets It Right

You definitely want a qualified installer doing the job and, by “qualified,” this means a technician who goes by the book when it comes to proper furnace sizing for your particular home. The “book,” in this case, is an industry-standard load calculation protocol called Manual J, which should always be used in conjunction with any furnace installation.

It’s estimated that the placement of an oversized furnace occurs in more than 50 percent of these installations in the U.S. The reason is because many installers either use the “rule of thumb” method of furnace sizing or simply duplicate the BTU output of the previous unit, which is likely incorrect. An oversized furnace is more expensive to buy and to operate, will be subject to more wear and tear because of short cycling. It likely will develop maintenance problems such as rust holes in the heat exchanger due to moisture accumulation, which also is a consequence of the furnace running frequent, abbreviated heating cycles.

By properly employing the use of Manual J, which you should insist on from your installer, correct furnace sizing can be accurately determined. During the process, accurate heating load can be calculated by answering the following questions:

  • What’s the exact square footage of your home’s living space?
  • What’s the R-value of insulation in the walls and attic?
  • How many doors and windows are in the house and what are their locations and condition?
  • With what indoor temperature level are you comfortable?
  • How airtight is your home?

Geisel Heating, Air Conditioning and Plumbing has been faithfully serving our Northeast Ohio clients for more than 75 years. Contact us for help or advice on your next furnace installation. We’re available 24/7/365.

Our goal is to help educate our customers in Cleveland, Ohio about energy and home comfort issues (specific to HVAC systems).  For more information about furnace sizingand other HVAC topics, download our free Home Comfort Resource guide.

For those Do it Yourselfers who would rather take control of your own indoor comfort, you can shop our online store for replacement parts, products and accessories!

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