Why You Need to Use a Certified HVAC Installer

The following post is from Michael Miranda, LEED AP, HERS Rater—Outreach Manager, for the BlueGreen Alliance Foundation’s Building Clean initiative. 

Your heating system (furnace, boiler, or heat pump) is likely to die during the middle of winter when it is working the hardest. The same is true with your air conditioner (A/C or heat pump) when it is trying to pump all that heat out of your home, during the peak of summer. It will typically die at the most inconvenient time, and you will want to rush to get it replaced.

Instead of scrambling to find companies online, looking through their reviews, calling to see how much they will charge and who is available to come by during their busy season, we recommend taking the following steps now, so you are ready when you suddenly have no heat or air conditioning.


U.S. Department of Energy Home Improvement Expert™ highlights that “research findings reveal most HVAC installations do not meet manufacturer specifications, which can reduce efficiency up to 20% and cause comfort problems.” In California, similar issues were found1 and even basic maintenance tasks were often performed incorrectly.2 Heating and cooling your home is typically more than 50% of your utility bills, so poor-quality installations will keep utility bill savings out of your wallet.

I’m sure you have heard horror stories about contractors, if not having experienced it yourself. That is why it is best to choose a certified HVAC installer, and you can easily find some below.

Three resources to find local, certified HVAC installers by zip code:
NATE-Certified Technician—some rebate programs require NATE-certified installers3.

The ENERGY STAR Certified Homes program requires that HVAC installers are credentialed by one of these two programs: ACCA’s Quality Assured (QA) Contractor or Advanced Energy’s Energy Star Credentialed HVAC Contractors.


Pricing can vary greatly between installers, so it is always best to get two to three quotes.

Is your air conditioner or heating system showing some signs of old age? If so, then you might want to call two or three installers for a quote on a new system during the off-season, when prices tend to be lower. Replacing your old HVAC system in the off-season can save you money, compared to prices you might get during the peak season. The lifetime of HVAC systems varies, with air conditioners lasting around 16 years, furnaces around 20 years, and boilers around 24 years.


Installing ENERGY STAR-certified products is worth it. You should check the websites of your energy utilities or local energy efficiency organization, as they might provide rebates for energy-efficient systems. If you are having trouble finding rebates, check the Database of State Incentives for Renewables & Efficiency (DSIRE) website, and enter your zip code.

To compare quotes, a higher efficiency product will have a higher SEER, CEER, EER, HSPF, or AFUE efficiency rating.

A good HVAC installer will do load sizing calculations (ACCA Manual J) to right-size your HVAC system. Right-sizing the HVAC system allows it to operate at peak efficiency, and oversized systems usually cost more than right-sized systems. An oversized system will also short-cycle, by turning on, running for a few minutes, turning off, and then turning back on just a few minutes later. This reduces the efficiency and life of the equipment. It is specifically important with air conditioners because the short cycling does not allow the air conditioner to dehumidify the air.


You can find American made building products, including HVAC products at www.BuildingClean.org

You can search by product type/CSI-code, for furnaces, air conditioners, boilers, and heat pumps. Support American manufacturing and jobs, by buying American-made products. There are more than 900 manufacturing sites across the United States producing HVAC products and components.

Just 50 of the more than 900 manufacturing sites across the USA producing HVAC products and components


Tell the HVAC installer that you want them to add the U.S. Department of Energy Home Improvement Expert™ Checklist to your contract, and that they need to complete it and sign it before you will make the final payment.

You can download the checklists for different types of HVAC work, on their website under the Heating & Cooling and Fresh Air System sections.

1. The California Energy Commission (CEC) in a 2008 report estimated that 85% of central air conditioning system replacements and 50% of central air conditioning systems installed in residential new construction did not meet the manufacturer’s quality control specifications for airflow and refrigerant charge, and the CEC’s duct sealing requirement (less than 10% duct leakage to outside).

2. NMR: Field observations of 13 technicians servicing units with preset faults revealed that even basic maintenance tasks were often performed incorrectly.  Often the most impactful tasks for improved energy performance were not even attempted.

3. The Southern California Edison (SCE) residential quality installation and quality maintenance program requires that 50% of an HVAC contractor’s technicians be certified by North American Technician Excellence (NATE).