Is HVAC terminology Greek to you?

Are you unsure regarding the various terms and jargon thrown about in the heating and cooling industry?

We get that. So let us clear the air — sorry, terrible pun, make that “shed some light” — on what these terms mean and how it all affects you.

It All Begins with HVAC

That’s “Heating, Ventilation and Air Conditioning.” Pronounced “H-vac,” this is the catch-all term for anything that involves a furnace, air conditioner, and/or ductwork. It’s what brings air (hot, cold, or recirculated) through a building, either commercial or residential. Modern HVAC also includes moisture control. In short, it’s all about “environmental comfort.”

Whether we’re talking about a bungalow that’s home to a retired couple, or a large domed stadium that holds 80,000 spectators, HVAC is what enables us to control our environment against the elements. Cold winters and hot summers are no match for a good HVAC system, so long as it’s been maintained and cleaned properly.

Furnaces, Air Conditioners, and Their Various Components

Let’s start with the big boys, and break it down into smaller pieces.

The furnace is what heats the air in the winter. Located in the basement or lowest / coolest area of the building, the furnace is the heart of the forced air heating system. In oversimplified terms, heating involves a combustion chamber and a heat exchanger, with a blower circulating the resulting hot air out through a series of ducts.  

The air conditioner cools the air in the summer. Its primary components are located outside the building, most notably the condenser unit. Air conditioners use refrigeration to chill indoor air, with the resulting gas is being continually compressed and cooled for conversion back to a liquid again.


Central air conditioners use a system of ducts designed to funnel air to and from coils (evaporator coil and condenser coil). In heating, the gas burner or electric coils activate and a heat exchanger warms air pushed through the furnace by the blower fan. This heated air flows through the evaporator coil and is conveyed into supply ducts.

What happens if HVAC coils are not cleaned?

  • Higher than necessary hydro and repair bills
  • Premature component failure
  • Lack of humidity removal
  • Loss of cooling capacity

Ducts, Vents and Returns

Is it important to keep ductwork clean? Absolutely! Cleaning is typically recommended every 2-3 years. What happens when cleaning is neglected? 

  • Dust builds up throughout the house (especially in ducts, registers, holding doors, etc.)
  • Mildew and odors set in
  • Airborne contaminates become a bigger threat
  • Allergy and asthma sufferers will be the first ones to notice
  • Children and pets will be particularly vulnerable
  • In commercial environments, employees could be at risk, leading to unwanted consequences down the road
  • Filters & Indoor Air Quality

On that note, you can see that indoor air quality is greatly influenced by HVAC systems.

The filter is a good place to look first. Be sure to change your furnace filter regularly, and begin with the right filters. Otherwise a buildup of dirt and dust in coils and ducts can lead to growth of microorganisms. Airflow can get reduced through the HVAC system from a clogged filter. If a filter is blown out or isn’t the right size (fit), unfiltered air can pass through the system. We already know what happens to dirty coils. All in all, it’s much less expensive to invest in good filters than having to pay later for removal of dust and dirt from the system.

Another factor for indoor air quality is mold. This often results from too much moisture. One impact of mold is reduced HVAC airflow and degradation of furnace effectiveness. Mold, of course, is also a health threat, ranging from allergy triggers to other physical conditions. Mold can be prevented, however, with regular cleaning and maintenance.

Dryer Vents

The dryer vent is what takes expelled air from the dryer to the exterior of the building. You’ve seen the lint trap on the dryer, and all the dust and particulates that gathers there? Well, imagine what goes out the other end, along with hot air… it’s just a more finely-ground version of that.

How do you know when the dryer vents are dirty? Early signs are excessive moisture building up in the laundry room; and clothes taking longer than usual to dry.

We recommend a dryer vent cleaning every 2-3 years, as part of the ongoing, preventative maintenance of your HVAC system.


The thermostat is where you set the desired temperature for the heating or air conditioning systems. Traditional thermostats only let you set one temperature. Modern thermostats, however, give you programming options. The best one out there, in our opinion (and that’s why we offer it with pride) is the Nest Learning Thermostat. True to its name, Nest alleviates the need to program again and again, instead learning the temperatures you prefer and programming itself to meet your needs. Nest also turns itself to an energy-saving temperature while you are away.

Ongoing HVAC Care

When it comes to a maintaining an efficient and long-lasting HVAC system, getting out ahead of things is key. Regular cleaning is an important part of your continued environmental comfort and clean air.

Modern PURAIR brings the experience and expertise to help make your HVAC system a fine-tuned machine. If we can answer any further questions, or if you’d like to schedule a visit by one of our friendly, professional technician teams, it will be our pleasure to serve you.