Indoor Air Quality Glossary

Here are a few terms to help our customers navigate an air quality emergency. These terms are important to understand so you can pinpoint which solutions are the best for your unique issues, and how to take advantage of our team to get them quickly and adequately installed. These terms might also help you to avoid hiring an amateur who doesn’t know quite as much as they should!

• IAQ. Indoor air quality. The overall term used to describe anything that impacts your home’s air quality.
• MERV. Minimum efficiency rating value. This is a standard value used to determine how thick a residential or commercial filter might be.
• HVAC. Heating, ventilation, and air conditioning. This term encapsulates your whole home comfort system, including air quality.
• CO. Carbon monoxide, the invisible and dangerous gas that can be the result of combustion. This is often confused with carbon dioxide, which is very different but can still be just as dangerous.
• CO2. A common gas found in the environment that is the product of the human respiratory process.
• PM. Particulate matter. This is usually followed by a number which describes how large the diameter of a pollutant particle is. Filters with powerful MERV ratings can stop particulates with a very tiny diameter from entering your air.
• VOC. Volatile organic compounds. These are pollutants that are often produced from cooking smoke, paint, and other chemicals that release fumes. These can be hazardous when inhaled and should be limited.
• AQI. Air quality index. This term will be used to denote the quality of the outside air quality, which can be very important during wildfire season.
• EACs. Electronic air cleaners. These are systems that charge particles in the air to draw them in for cleaning.

Indoor Air Quality Frequently Asked Questions (an "IAQ FAQ")

Question: Will a bigger filter help?

Your home’s HVAC system is equipped with a system filter that uses a MERV rating system. While standard filtration (typically a MERV 11 filter) does contribute to indoor air quality, it is important to note it is designed to protect the equipment. So, does upsizing or increasing the MERV rating of a filter help? The short answer is yes, but there is a very possible negative impact, too. Higher MERV rated filters can significantly increase the static pressure of your home’s duct system. Static pressure is like the blood pressure of your home’s HVAC system. Static pressure that is too high is actually the number one cause of equipment failure. So attempting to increase the size of the filter without taking into account the entire system can potentially lead to equipment failure.

Question: How can I check the static pressure of my home? 

A Barron Home Performance Expert can test the static pressure of your duct system to determine what’s necessary to increase filtration. Contact us today to schedule a Home Performance Assessment.

Question: Should I run my fan all the time (on "constant fan" or "recirculate") to help increase filtration and to help keep outdoor air from getting into my home? 

The answer is yes, but only IF you have a sealed duct system.

If you have a sealed duct system, great! You can run the constant fan. To set the fan to constant fan mode, please refer to your thermostat / HVAC systems user manuals.

That said, EPA experts have found that most existing duct systems leak between 20-45% or more. If your duct system is leaky like most systems, the reality is you can actually create a negative air pressure situation in your home which means you can bring in a significant amount of unwanted outside air (see our video on Home Performance) Negative air pressure situations increase "infiltration". For more about duct sealing and the unique Aeroseal process, please read here. Aeroseal is our number one requested service. And remember, with all of our services we guarantee 100% satisfaction.

Note: if you have a fresh air intake on your HVAC system, be sure to close the damper before running the fan.

Question: Are there other types of filtration with less impact on static pressure? 

Yes. Electronic air cleaners (often referred to as EACs) filter the air by positively charging particles as they move through the unit. The particles are then captured by negatively charged collector plates. This process allows them to have much less impact on static pressure.

Question: Do ionizers or air purifiers help protect my indoor air quality?

Yes, air purifiers like the REME HALO or HALO LED can assist in IAQ in several ways.
Using ultraviolet light to eradicate pollutants, air scrubbers also produce hydro-peroxide plasma to purify the air inside your home. The charged plasma causes particles to stick together, making them larger and easier for filters to catch.

Question: What is the best filter option? 

Taking the specifics of your home into account is critical. Once you’ve done that, you can explore several solutions that do include higher MERV filtration, HEPA bypass filters, air purifiers, EACs, Aeroseal® for duct sealing, and WholeHome™ sealing.

Question: Is there a WholeHome™ approach to IAQ?

Yes. We call it the Ultimate IAQ package.

Question: I have a "ductless" mini-split, what are my options?

Good news! With a ductless heat pump you are already halfway to better air quality. As we’ve noted already, leaky ducts are a major cause of negative pressure and infiltration (unwanted outside air being pulled inside the home).  Homes that use Ductless already have eliminated the ductwork – and do not have leaky ducts to contend with. You’re halfway there!  The other considerations are the overall air envelope of the home (which you can test with a Home Performance Assessment), and point-of-use air purifiers like the RGF Clear Sky MS and Mini Split PHI Air Purification system.