If you’re looking for ways to improve your home comfort, upgrading to a zoned HVAC system is one of the best options. With a zoned HVAC system, you’ll generally never need to worry about any parts of your house being too hot during the summer or too cold during the winter. In this article, we’ll explain everything you should know about HVAC zoning and why a zoned system is such a great investment.
What Is a Zoned HVAC System?
Most residential central HVAC systems have just a single zone. That means when the HVAC system is running, it always supplies hot or cold air to every part of the house. It also means there is only one thermostat in a central part of the house that controls the temperature for the entire home. In a zoned HVAC system, the house is split up into two or more smaller areas, each of which has a thermostat that controls the temperature only for that zone.
The way it works is that there are metal gates called dampers installed within various parts of the ductwork system. These dampers can open and close to allow air to start flowing into a zone or to block off the airflow to that zone. When the thermostat in any zone senses that the temperature is higher or lower than you want it to be, it will signal the HVAC system to start running. At the same time, it will also signal the damper for that zone to open so that air starts flowing out of every vent in that zone. If the HVAC system is still running and another zone gets too cool or too hot, that zone’s thermostat will also signal a damper to open so that the HVAC system starts supplying heating or cooling to both zones. As soon as one zone reaches the correct temperature, its thermostat will then signal the damper to close so that air stops flowing to that zone. Nonetheless, the HVAC system will continue running until every zone is finally at the right temperature.
One other thing to note about zoning is that it can generally only work if you have a variable-speed HVAC system. That’s because the system needs to be able to constantly adjust the volume of airflow based on how many zones are currently open and how much heating or cooling it needs to put out at any given time. If you had a standard single-stage HVAC system, you’d encounter major issues any time not all of the zones were open. For instance, a furnace would quickly start overheating if any zones were closed since it would produce much more heat than needed, resulting in much of the hot air backing up. The system would also have major issues with short cycling, which is when it repeatedly turns on and off in a short period of time.
Benefits of HVAC Zoning
Although installing a zoned HVAC system costs more than a standard single-zone system, it will provide major benefits in terms of improving your comfort and helping reduce your heating and cooling costs. One reason a zoned HVAC system can lower your energy bills is that you can set the thermostat in each zone to a different temperature. There are even smart thermostats that can adjust automatically based on your habits. That means you don’t need to heat or cool unoccupied zones as much, which in turn reduces how much your HVAC has to run. Variable-speed HVAC systems in general are always far more efficient and use much less energy since they can run at a lower speed instead of always being on full power.
In terms of improving your comfort, one of the biggest benefits is that you can easily eliminate hot and cold spots on different floors or different parts of your home. You can also ensure that the room you’re currently occupying is exactly at whatever temperature you want, which isn’t always the case with a single-zone HVAC system. That’s especially useful for multi-story homes where you often end up with the basement or lower floor sometimes being too cold and the upper floor often being too hot.
One last advantage of a zoned system is that your HVAC units will often have a longer lifespan than they otherwise would. That’s partly because variable-speed HVAC units in general tend to last longer since they don’t experience near the amount of wear and tear when operating on a lower speed. In a zoned system, your HVAC units also typically won’t run as much as they would in a single-zone system since there will rarely be times when you need to heat or cool every zone at one time.
Understanding the Basics of Designing a Zoned HVAC System
To enjoy all of the benefits a zoned HVAC system can provide, the system must be designed properly in terms of the size and layout of all of the zones. In most cases, you never want to have more than four zones. That’s because a variable-speed HVAC system can only slow down to where it produces around 25% of its total heating or cooling capacity. If you had more than four zones and only one zone was currently open, you’d still often end up with issues like overheating and short cycling.
You can design a cooling and heating system with more than four zones if you want, but it will create some issues with zones being warmer or cooler than you want at times. The reason is that not every zone in this type of setup can be a “control” zone, which is one that can signal the HVAC system to turn on and off. That means all the thermostats in the other zones can do is open and close their zone’s damper.
To illustrate the potential problems you may encounter, let’s say you have three bedrooms in one part of your house and want them all to be a separate zone. The master bedroom would normally be your control zone, and its thermostat would signal your HVAC to run when the bedroom was too hot or too cold. Even if the other two bedrooms were too hot or too cold, the only time they’d start receiving air is if the master bedroom was also too hot or too cold since their dampers would be located further along in the same duct branch. As soon as the master bedroom reached the right temperature, its zone damper would close so that air also stopped flowing to the other bedrooms even if they hadn’t yet reached the right temperature.
In most situations, you’re best to design a zoned system so that each floor of your house is on a single zone or create separate zones for your sleeping areas and the other living areas you use more often. That way you can save energy by heating or cooling the unoccupied zones less. You’ll also improve your comfort by ensuring each floor or part of the house always stays exactly as warm or cool as you want.
Air Control Home Services is a family-owned company that’s been providing honest, reliable HVAC, electrical and plumbing services in the Lake Havasu, AZ, area since 1990. Our expert technicians specialize in all aspects of air conditioning and heating systems. We’re ready to help if you’re looking to upgrade to a zoned HVAC system or need to install a new heat pump, air conditioner or furnace.
To set up a consultation with one of our comfort specialists and learn if a zoned HVAC system is right for your home, contact us today.
