New HVAC equipment

3 Questions (And More) to Ask When Looking for Your New HVAC Unit

Recently, a local news station published a story for homeowners, “3 Questions to Ask When Looking for Your New HVAC Unit.” The article was decent, but it was not great. Click here if you want to read it.

Here were the three questions according to the news station article:

  1. Is the unit the right size for your home?
  2. What is the proper SEER rating for your home?
  3. What maintenance will be involved with my unit?

The above questions are good, but they overlook critical components to the effectiveness and efficiency of heating, ventilation, and air conditioning (HVAC) equipment (e.g. forced air furnaces, central AC units). Besides HVAC equipment, the ductwork and thermal envelope must be considered for proper HVAC equipment function in homes.



A key challenge in HVAC is the reality that most homeowners do not enjoy shopping for heating, HVAC products, but all homeowners appreciate the benefits of HVAC in their homes:

  • Comfortable temperatures in your home for every weather season (e.g. Fall, Winter, Spring, Summer)
  • Clean airflow in your home (reducing dust, odors, and airborne allergens)
  • Affordable monthly utility bills (e.g. gas, electric, water, sewer, trash bills)

In order to achieve all of the above HVAC benefits, there’s a lot of details about your HVAC unit you will need to understand. Plus, you will need to make sure the ductwork and thermal envelope of your home are supporting your HVAC equipment appropriately.

Behind the Scenes of Homeowners is the HVAC System
Homeowners want to enjoy their homes. Their home's HVAC system (equipment, ductwork, thermal envelope) works in the background.


The 3-Legged Stool of HVAC

Besides the technical specs of a furnace or AC unit, it’s important to match the technical specs of the HVAC equipment with the non-equipment components of a home’s HVAC system. We refer to it as the three-legged stool of HVAC:

  • Leg 1: HVAC equipment (e.g. furnace, AC unit)
  • Leg 2: Ductwork
  • Leg 3: Thermal envelope

Beware of Air Leakage in Ductwork and Thermal Envelope

Since air is invisible, infrared imaging can be used to actually see the air leakage in your home’s ductwork and thermal envelope. Here’s an example of air leakage in a residential ductwork system:

Duct leakage seen through wrapped ductwork with infrared imaging.

Most people focus on leg #1 (HVAC equipment) and not enough focus on leg #2 (ductwork) and leg #3 (thermal envelope). The ductwork and thermal envelope legs are important because of air leakage.

From a building science perspective, the ductwork and thermal envelope in homes are notorious leaky. Meaning, conditioned air from the HVAC equipment does not properly flow throughout the home’s ventilation system to properly heat, cool, and ventilate all of the rooms.



Are you a homeowner? Make your home more comfortable and efficient by sealing your ductwork. Find an Aeroseal dealer near you to learn more how it works and get started.

Are a contractor? We’d love to chat with you how Aeroseal can help you help your customers. Call us 877-349-3828, email us, or leave a comment below.

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