How HVAC Systems Work in Annapolis, MD

You’re probably familiar with the acronym HVAC, but do you know what the letters stand for? Fully spelled out, HVAC means heating, ventilation, and air conditioning. An HVAC system manipulates your indoor air quality, from the temperature and the humidity level to the cleanliness of the air. Here in the State of Maryland, our hot summers and frigid weather make a reliable heating and cooling system vital to our year-round comfort indoors.

At Barstow and Sons Heating and Cooling in Annapolis, MD, we’ve been keeping our neighbors cool in the summer and warm in the winter for almost 40 years. As a family-owned and operated business, we take pride in customer service and offer you fair, upfront pricing so there are no disappointing surprises.

How an HVAC system works

There are a few different HVAC systems, including window units, packaged heating and cooling systems, and central A/C systems. Many commercial and residential properties use central A/C systems. Here, we’ll explain how central A/C works in addition to how the compressor and air handler make the HVAC system work.

Central A/C

Most residences, from condominium buildings to standalone houses, use central A/C systems. Central A/C systems do double duty as a heating and cooling unit in one, with each function housed separately. In these systems, the cooling fan, the condenser coil, and the compressor live in a condensing unit. The evaporator coil often is contained inside an indoor air handler unit. Your system will usually be installed on the furnace. If you have an electric furnace, you will have a blower in the system.


The compressor is always electric. It works by pumping the refrigerant across the entire HVAC system. In the process, it gathers up the indoor heat and expels it out of the building using the condenser coil. The condenser coil also helps lower your home’s humidity and temperature by extracting moisture and heat from the air. Any water collected condenses as vapor on the coil and drips into the drain pan. The condensate drain removes the moisture to the outside of your home.

Air handler

The air handler’s fan disseminates the cooled air throughout the space that’s being air conditioned. Meanwhile, the heat blows outside after it has flowed through the evaporator coil.

Maintenance tips

Your HVAC system is comprised of many moving parts and elements that can suffer damage or require repairs if not maintained properly. Below are some maintenance tips for your HVAC system.

Regularly replace air filters

The ventilation cycle begins with the air return. Air return parts should be routinely dusted to prevent dirt and other debris from clogging your filters. To retain the air quality in your home, you need to check and change out the filters on a regular basis. This is recommended monthly if you have pets, smokers, or allergy sufferers in your house.

Clean out HVAC ducts

Create an annual schedule to test the exhaust outlets for buildup and to clean the coils. The ducts should be professionally cleaned every two to five years.

Trim nearby plants

Your outdoor unit provides air flow, so it will need plenty of breathing room. Plants should be trimmed around the unit to avoid blocking the unit’s vents.

Check refrigerant levels

If you notice your refrigerant level is running low, a leak might be the culprit. Have your repair technician check for this possibility to ensure your system is intact.

Quality HVAC services you can trust

To learn more about your HVAC system and to schedule service, contact Barstow and Sons in Annapolis, MD, today!

Call 410-544-2606 to learn more.


Our Values

  • Family Owned and operated
  • We specialize in Carrier heating, cooling & air quality systems
  • Fair pricing
  • Great Customer Service
  • Upfront Pricing

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