FAQs about your MA air conditioning installation

Questions and answers for homeowners wanting verification of proper central air conditioning installation.

What is the value of this QIV service to consumers?

Quality Installation Verification (QIV) testing ensures that your AC system is properly charged and has sufficient airflow. Using a COOL SMART Participating Contractor provides this benefit, which is not always performed by other HVAC technicians. The QIV service also helps the air conditioner operate more efficiently, meaning it's less expensive to operate and should last longer with fewer repairs.

My system is new - how can refrigerant charge be a problem?

Incorrect refrigerant charge is a common problem with residential air conditioning systems across the country. Contrary to most consumers' expectations, even newly installed air conditioning systems are often incorrectly charged.

In a recent New England study, air conditioning systems were tested for refrigerant level. Of the units tested, 31% were under-charged, while 28% were over-charged. This means only 41% - less than half - of all the units tested were properly charged. These results are consistent with other industry research in studies throughout the U.S.

If we are getting cool air, how bad can refrigerant charge problems be?

Incorrect charge significantly reduces the cooling capacity and energy efficiency of your unit and can also damage your system. If a unit is significantly undercharged, the compressor can overheat, causing it to burn up internally. Overcharging can flood the compressor with liquid refrigerant, causing the piston to catastrophically fail. In both cases, premature compressor failure is the likely result. In a recent test of air conditioners installed in Massachusetts, 14% of the units tested were severely over- or undercharged, which, as mentioned above, will likely cause early compressor failure if not detected and corrected.

If air is flowing out of the ducts, what could the airflow problem be?

Almost all air conditioners are designed to operate with between 350 and 400 cubic feet of air per minute flowing across the indoor coil of the unit for every ton (12,000 BTUH) of cooling capacity. When the airflow is greater than the manufacturer's recommendation, your system will have difficulty removing humidity from the air, leaving your house cool but humid. If the airflow is less than manufacturer's recommendations, your system will have to operate much longer to cool your house, and may even cause your system to ice up, leaving you with no air conditioning, and possibly a damaged compressor. Low airflow has the same effect as making your system smaller (less tons). In both cases, you will use more electricity to cool your house. QIV testing will verify that your system is operating at optimal capacity.

Checking Airflow is Important!

“An efficient system starts with proper air flow. Low air flow = low capacity = energy wasted, compressing excess refrigerant. Cool the house, don't flood the compressor.”
-Senior manager, compressor manufacturer

Twelve different energy studies have been conducted on airflow in the past several years. Each study found that, on average, 70% of all home air conditioners have inadequate airflow. The average home air conditioner's airflow is 20% below the manufacturer's recommended level.

What steps are involved in the QIV process?


There are four basic steps. The report and instruments used will vary slightly depending on which type of verification tool the contractor uses.

  1. Contractor phones in, or enters on a small computer, the test data about your air conditioning system.
  2. Data analysis on-site or via phone generates results of refrigerant charge and airflow test data.
  3. If tests show manufacturer's equipment specifications for charge and airflow are not met, the system provides feedback with suggested modifications; technician completes work*, retests unit and resubmits results.
  4. Homeowner receives a report with information explaining test results.

*In many cases, obtaining correct airflow may require additional work, such as duct sealing or changes to the duct system, for which there may be additional costs. Even if there are extra costs, they are well worth the investment in system performance, equipment reliability and long-term energy savings.

What are some other indicators of a quality installation that I should look for in addition to refrigerant charge and airflow?

There are important elements to consider in achieving the best performance and reliability from your cooling or heating system. These may include proper system sizing, duct sealing, having work done by a NATE-certified contractor, insulating and tightening your home, and conducting combustion safety tests.