The world of HVAC can seem complicated for most homeowners. It’s not just about learning the lingo, but about understanding how the different systems actually work and knowing how that fits into your home. HVAC (heating, ventilation, and air conditioning) systems are designed for the sole purpose of making an indoor environment comfortable for its inhabitants through temperature and humidity.
Let’s break down the different components of HVAC systems and how they work in your home.
A home is most commonly heated through a boiler, furnace, or heat pump—each of these units work differently and run on different types of fuel, including solid, liquid, gas, and electricity.
- Boiler: As its name suggests, a boiler burns fuel to heat water to its boiling point, which then runs through pipes as hot water or steam to your home’s radiators to heat the air. While furnaces and heat pumps distribute heat evenly throughout the home, boilers convey heat through radiators and will only heat spaces that have a radiator present.
- Furnace: Using fuel, furnaces heat up a set of coils and then blow the hot air through ducts to spread the heat throughout your home. Regular maintenance includes replacing your air filter at least every three months to ensure that the air flow is not impeded by dirt and debris that your filter catches to keep out of the system.
- Heat Pump: Heat pumps don’t actually produce heat, which makes it the most energy efficient choice of these three units. Instead, they use electricity to move heat from cooler spaces to warmer spaces — in the winter, it moves heat from the outdoors into your home and, in the summer, it moves heat from the indoors out of your home. There are several types of heat pumps that vary in their source for collecting heat (air, water, geothermal), but they all work in a similar fashion when it comes to maintaining the temperature of your home.
Ventilation is the action of circulating air in any space in an effort to control temperature or remove odors, dust, moisture, and other airborne pollutants. This can be done through a whole-house ventilation, natural ventilation, spot ventilation, or a combination of these strategies.
- Whole-house Ventilation: Whole-house ventilation is the general standard in most homes, as it provides controlled ventilation throughout the whole home with the help of a system of fans and ducts that move air in and out of the building. There are a number of types of whole-house ventilation systems — for help determining the system that is right for your home, contact your HVAC provider.
- Natural Ventilation: Just as it sounds, natural ventilation is allowing air to naturally circulate with the help of open windows and doors and trickle vents. While this method does use very little energy, it can’t always be relied upon to maintain comfort levels in extreme conditions. Still, natural ventilation is an important component to any home’s HVAC maintenance as fresh air is needed to improve indoor air quality.
- Spot Ventilation: Ceiling fans, window fans, and exhaust fans are all great choices for localized ventilation needs, as in bathrooms and kitchens. These are all important to have in conjunction with other sources of ventilation.
Homes are cooled through fresh air from the outdoors that has gone through an indoor heat exchanger, where heat is removed via radiation, convection, or conduction. There are two common types of air conditioners to cool your home.
- Central Air Conditioners: Central air conditioners are either split-system or packaged units (more on that below). They are used for cooling and dehumidifying the air that it pumps into your home to decrease the temperature of the house. A central A/C system is more efficient than in-room air conditioners and is generally tucked out of the way outdoors or in your garage.
- In-Room Air Conditioners: As opposed to cooling the whole home, in-room air conditioners do just as they are named — they cool down a single room. They are less expensive than central units, but are not as efficient at lowering temperatures. These are popular choices for apartments and condominiums that are smaller in size.
Now that we have a good idea of what HVAC really means, let’s take a look at the types of mechanisms that helps to ensure your home air is heated, ventilated, and conditioned for maximum comfort.
Split systems are the most classic system, with units inside and outside of the building. Typically, there is an air handler (with an evaporator coil) and an air conditioner (with a condenser coil and a compressor) that works in conjunction with one another for both cooling and heating purposes. Both heat and air conditioning travel through ductwork into your home to maintain the temperature designated by a thermostat.
Dual zone systems are just as they sound—they work with multiple zone temperature sensors that allow you to control the temperature in different zones of a building. Often used in multi-level homes or buildings with rented units, this can be an energy efficient option that also helps to ensure the comfort of everyone inside. As opposed to multiple air conditioning units that are each set to their own temperature, dual zone systems rely on dampers in your ductwork that work similar to vents, directing certain levels of airflow to different zones of a home. This can save on bills and energy usage, since it provides the flexibility of decreasing the energy needed to heat or cool spaces that are infrequently used.
Packaged systems are designed for homes that don’t have space to accommodate the separate components of a split system. Generally, there is a unit that works as both an air conditioner and heat pump, housing both the evaporator and fan coil in one unit. Similar to the split system, a packaged unit moderates the home’s temperature via a digital thermostat.
Regardless of what type of system you have in your home, there are a number of things you can do to ensure that your unit runs smoothly and efficiently for many years. All systems should be inspected, cleaned, and serviced at least once per year. Industry recommendations note that heating units are best serviced at the start of fall (before the cold weather strikes) and air conditioning units at the start of spring (in preparation for summer).
On a more regular basis, you can do your part by changing your HVAC air filters at least every three months. Filters that are left to get clogged up with dirt and debris can reduce air flow, which can decrease heating and cooling efficiency and, in the long run, can damage your system. Filters can go either in the return vent or in the air handler, but not both. If you have two zones in your home, you’ll need to replace two filters. Find out your filter sizes and their locations here. For an installation walkthrough, check out our video.
Some households may consider getting their ducts cleaned to properly maintain their HVAC system, which can cost hundreds (even thousands) of dollars. In fact, this process can even damage your HVAC system so it’s best avoided unless absolutely necessary. Fortunately, regular filter changes ensure that your ductwork is kept clean and clear of debris so that duct cleaning is not needed. High-quality micro-allergen filters are the best choice, as they trap smaller particles than their fiberglass counterparts keeping all of that nasty dust, dander, pollen, and other airborne pollutants out of your air and your ducts.
Owning a home means understanding the intricacies of your HVAC system, among many other things. Contact your HVAC technician if you have any questions or concerns regarding your heating, ventilation, and/or air conditioning units.