One of the keys to properly maintaining your HVAC system is in understanding the parts and learning more about your furnace and air conditioner to make finding problems an easier task. Breakdowns are expensive and a huge inconvenience, but can be minimized if you know more about your system.

Whether it is cooling your home in the summer or heating it in the winter, your HVAC system is a part of everyday life. As a homeowner, it is important that you understand the key roles your HVAC system plays and how the individual parts operate in order to get the most out of your system. When one part of your HVAC system is in need of work, the whole system suffers. For example, a clogged filter will affect the other components of your system. And while correcting this problem is quite easy and something you can do on your own, this is not always the case. You might have a problem that you can’t handle on your own and need to call Total Care Heating and Air, your HVAC service in Riverside, to resolve the issue.

Let’s start out with something easy. HVAC stands for heating, ventilation and air conditioning. And whether it is a residential or commercial system, they all share the same basic parts and do the same thing, heat or cool the indoor space. Here is a list of the components of an HVAC system


The thermostat is the most visible part of your system as it will be mounted on a prominent and easily accessible wall in your home. Whether you have a simple manual thermostat or a programmable thermostat, you will still need to set it for your desired temperature. When the ambient temperature you have chosen becomes too hot or too cold, the thermostat triggers the evaporator coil-condensing unit or the heat exchanger to begin circulating warm or cool air as needed.

The HVAC thermostat is the nerve center of your heating and cooling system. It is the main control point and determines how much warm or cool air to be delivered into your home. Though it might seem to be a mystery to you, your thermostat is actually a relatively simple device.

Simple thermostats have three major elements: A bimetallic coil or strip, contact and heat anticipator.

The bimetallic strip is basically just two pieces of metal joined together that expand at different rates given the temperature. As one side expands more than the other, the metal strip curves one way or another. This is what triggers the contact.

The contact is kind of like a switch for lights. As the bimetallic strip moves, it will either close or open the contact, which either turns on your HVAC unit or shuts it down.

The heat anticipator is an electrical resistance device that fine-tunes the point at which your furnace or air conditioner turns on and off.

Most of you probably have a programmable thermostat. This is a digital thermostat that has a brain. These thermostats allow you to program modes for heating and cooling by the day, week, hour, really for whatever time frame you desire. Some digital thermostats even tell you when you need to change out your filter.

You might have a smart device in your home, like an Amazon Echo or a Google Home Smart Speaker. If you also have a smart thermostat, you can use them to control your HVAC system. You can also control your HVAC system through your smart thermostat from an app from your smartphone or tablet. This means you can turn your heat up or down while you are at work. Pretty amazing.


The furnace is a key component to any HVAC system. As it is also the largest, it requires substantial space. This is why you will often see furnaces in the basement, the crawlspace, the attic and even in special closets built just for them.

The function of your furnace is to heat air which is to be distributed throughout your home. This is accomplished in one of four ways: Combustion (the burning of coal, propane or natural gas), heat pump, electric resistance or solar energy collected on site.

You wake up in the morning and it is exceptionally cold, so you go to the thermostat and turn up the heat. This is when your furnace gets the call for heat.

The inducer fan starts and the pressure switch closes. The presser switch works to counter the negative pressure caused by the inducer fan. The pilot light or electronic ignition lights the burner inside the combustion chamber, this creates heat. Once warmed, the air is then pushed through the house and you feel nice and toasty warm.

Heat pumps are another common furnace option. Basically, they transfer hot or cold energy from one area to another. A heat pump either cools or heats the air adjacent to its condenser coils.

If you experience any problems with your furnace, it is best that you leave any repairs to the pros.

Heat Exchanger

Simply put, a heat exchanger is a device which transfers heat from one medium to another. Heat is transferred by conduction through the exchanger materials which separate the mediums that are used.

The heat exchanger is a critical part of your HVAC system as it is responsible for heating the inside of your home. It is also very dangerous if it is not properly cared for.

Not to worry, modern heat exchangers come with a number of safety features, but it is still important to have it checked on a regular basis by a professional from Total Care Heating and Air.

Evaporator Coil

Evaporator coils are part of the cooling aspect of your HVAC system. An evaporator coil is a part of your air conditioner that absorbs the heat from the air in your house.

Air conditioners don’t produce cold air in the same way your furnace produces heated air. The condenser coil contains refrigerant that absorbs heat from the house and carries it outdoors and releases it. The refrigerant is continually circulating to remove more and more hot air from your home until the house cools to your preferred temperature.

Evaporator coils are often made from steel, copper or aluminum because metals conduct heat quite easily. The coils can be found in your air handler where the blower fan is. Because of its location and the way it operates, it is important that you keep your evaporator coil clean as a dirty one is sure to cause trouble.


The ducts running throughout your house represent a system of hollow aluminum tubes and conduits that carry treated air. The lightweight material makes an excellent way for the treated air to go to its destination.

Ducts are easy to ignore because you hardly ever see them. They are often hiding in your basement or attic. Over time, your ducts may spring leaks and lose air. If you can get to them, it is important to inspect them from time to time. If you do happen to find leaks, you can use a special kind of tape to make temporary repairs.

If you can’t get to your ducts or the leaks are too big to be patched with tape, then you should call Total Care Heating and Air.


If you are a homeowner, you should know where your filters are located and how to either clean them or change them out.