A multi-zone HVAC system can be a fantastic investment that will greatly improve your home’s comfort. This type of system will provide you far greater control over your home’s heating and cooling and is ideal for overcoming hot and cold spots that plague many homes. In this guide, you’ll learn all you need to know about multi-zone HVAC systems, including how they work and what benefits this type of system can provide to your home.
What Is a Multi-Zone HVAC System
Virtually all ducted central heating and air conditioning systems can be upgraded to a multi-zone or zone-control system. This type of system splits the home up into multiple smaller areas or zones by installing automatic dampers at various points in the supply ductwork. Each damper is essentially a metal gate that can open as needed to allow hot or cold air to flow to that zone or close to block air from flowing to the zone.
Instead of having one central thermostat that controls the temperature for the entire home, separate thermostats are installed in each zone and wired to the main HVAC control board. Each thermostat controls the temperature for that zone only and is linked to the automatic damper that controls the airflow to that zone.
How Multi-Zone HVAC Systems Control Temperature
Each thermostat in a multi-zone system works independently, and all of them can signal the heating or air conditioning to turn on and off. When the temperature in any of the zones rises higher than the thermostat setting in the summer or gets colder than the setting in the winter, the thermostat in that zone will signal the HVAC system to start running and for the damper in that zone to open. If only that zone currently needs heating or cooling, the rest of the dampers will remain shut so that air only flows to one zone. As soon as the temperature in that zone reaches the thermostat setting, the thermostat will signal the HVAC system to turn off.
If multiple zones or the entire home needs heating or cooling, the HVAC system will supply air to the different zones until each one reaches the desired temperature. Once one zone is the desired temperature, the thermostat in that zone will signal the damper to close so that that room or area no longer receives hot or cold air. However, the HVAC system will continue running and supplying air to the other zones until they all reach the desired temperature.
In a zone-control system, you can adjust the temperature for each zone without any impact on all of the others. You can also simply turn the thermostat in any of the zones off so that the zone never receives heating or air conditioning. This can be useful if you have any rooms that you rarely, if ever, use or if you have a room or area that always stays sufficiently cold in the summer or sufficiently warm all winter. For instance, basements usually tend to stay cooler while upper floors in a home are usually warmer, and a zoned system allows you to compensate for these differences by setting the temperature in the various zones higher or lower as needed.
One of the most effective ways to use a multi-zone system is by setting the temperature on the lower levels slightly higher in the winter and keeping the temperature on the upper floors slightly lower. All of the heat being supplied to the lower floors will slowly rise and keep the upper floor warmer without the heating system needing to supply hot air to the upper floor as often.
If you have a room with lots of large windows or skylights that tends to stay warmer than you want in the summer, you can also set the system up so that the room is a single zone. This will allow you to turn the temperature lower so that the room receives more air conditioning than the rest of the house to help make it cooler and more comfortable.
Benefits of a Multi-Zone HVAC System
One of the biggest benefits of upgrading to a multi-zone system is that it can greatly reduce your cooling and heating costs. Since your HVAC system won’t always need to cool or heat all of the zones at once, the cooling or heating cycles will typically be shorter resulting in the system using less energy.
Instead of needing to run for around 15 minutes twice or three times an hour, the system may only run for a few minutes any time it only needs to heat or cool just a couple of zones. This is simply because all of the hot or cold air the system produces will be directed only to those zones that need it so that they are heated or cooled to the desired temperature much more quickly than they’d be if the system was supplying air to every room.
The fact that your HVAC system typically won’t need to run as much or work as hard also leads to it suffering less wear and tear. This reduced wear and tear means that your furnace or AC will be less likely to break down and need repairs. A multi-zone system can also increase the life of your HVAC units for the same reason.
Designing the Ideal Multi-Zone System for Your Home
When designing and installing a multi-zone system, the number and location of the zones can depend partly on the layout of the home and the existing ductwork system. To understand why this is, it’s necessary to look at how most ductwork systems are designed. The part of the duct system where the hot air from the furnace and cold air from the AC flow into is known as the supply plenum. The supply plenum connects to one or more trunks, which are the larger ducts that bring hot and cold air to different parts of the home. There are then smaller sections of ductwork known as branches, and these connect or “branch off” the trunks and supply air to each of the rooms.
In a multi-zone HVAC system, the dampers are installed where each branch meets the trunk. When a damper is closed, it blocks off that particular branch so air no longer flows into it. In many homes, the ductwork is set up in a way where a single duct branch supplies air to more than one room. For instance, if you have two or three bedrooms located next to each other along the same hallway, they may all be supplied by the same branch. In this case, all of those rooms would have to be in the same zone and controlled by a single thermostat.
However, you could split those rooms up and make each one its own zone simply by installing and connecting additional branches to the trunk that supply air to each room individually. While this would obviously increase the installation cost, it would also provide the benefit of allowing each person to independently control the temperature of their bedroom. If one person always prefers their bedroom much warmer or cooler, they can adjust the temperature on the thermostat in their room so that it receives more or less heating or air conditioning.
San Antonio’s HVAC Experts
Air Authority, A Riteway Service Company is a locally owned and operated HVAC contractor, and we have more than 30 years of experience providing exceptional heating and cooling services throughout the San Antonio area. Our certified technicians can help if you’re looking to upgrade to a multi-zone system, and we can also expertly handle all of your HVAC installation, maintenance and repair needs. To learn more about the benefits of multi-zone systems or to schedule a consultation to see if this type of system is right for your home, give us a call today.