Sizing the Furnace: Whether New or Replacement, Do It Right

Sizing the Furnace: Whether New or Replacement, Do It Right

If it’s time to install a new furnace, you’re probably considering efficiency ratings and advanced features to maximize savings and comfort. Or, perhaps you were happy with your old furnace and you’re thinking of simply replacing it with one the same size (BTUs). In order to get the most out of your furnace investment, correctly sizing the furnace is a crucial first step to enjoy maximum benefits and performance.

Furnace Sizing

There are three very good reasons why sizing the furnace correctly is important, and they are all interconnected:

  • Comfort – Balanced airflow is important for maintaining comfortable temperatures from room to room, which also helps boost indoor-air quality.
  • Heating efficiency (AFUE) — An over-sized furnace quick-cycles, which is uncomfortable, increases wear and wastes fuel.
  • Maintenance and life span — Furnaces are constructed to temper moisture, as well as heat. Quick-cycling increases deterioration caused by moisture on furnace components, creating maintenance issues and shortening the furnace’s life span.

Professional Furnace Installation

Professional furnace installation begins with accurate sizing, and sizing the furnace accurately begins with asking the homeowner the right questions. These are just a few questions you should expect from your HVAC professional:

  • Have you undertaken home-efficiency upgrades in recent years? An important part of sizing the furnace is measuring your home’s heating load using industry standard Manual J. Home-efficiency upgrades (e.g. adding insulation) help hold in heat, which boosts comfort and fuel efficiency. A knowledgeable HVAC pro should recommend efficiency upgrades prior to furnace installation.
  • Do you have, or are you considering installing, high-efficiency windows and doors? Storm windows and efficient doors help lower your home’s heating load and reduce wear on the furnace.
  • Is your chimney in good condition? New furnaces by reputable manufacturers offer minimum 80 to 89 AFUE (mid-efficiency) and 90 to 98 AFUE (high-efficiency, modulating and condensing furnaces). Furnaces with 90-plus AFUE require sealed sidewall venting through PVC piping. If you have an old chimney, discuss the installation options best suited for your new furnace with your HVAC pro.

For more details about sizing the furnace in your Monmouth County area home, contact Aggressive Mechanical Contractors today.

Our goal is to help educate our customers in Monmouth County, New Jersey and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about furnaces and other HVAC topics, download our free Home Comfort Resource guide.

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