The Truth About 2 Zone HVAC Systems Which Is Right For You

The Truth About 2 Zone HVAC Systems: Which Is Right For You?

If you have ever had the pleasure of turning on your central heating system and being blasted with a freezing blast of air, then you know that not all systems are created equal. Some systems are more user-friendly than others, so it’s essential to understand the pros and cons of different systems before purchasing your new heater or air conditioner.

Although most people think that there are only two types of HVAC systems – heat pump and conventional – there is a third type, called a 2 zone heat pump system, something you probably haven’t heard about. So what exactly does this “2 zone” designation mean? Let’s get to the point by explaining information about the 2 zone HVAC systems.

What is a Zoned HVAC System?

In a forced-air heating and cooling system, a single thermostat controls the temperature in every room. It can cause conflict among family members as they attempt to adjust the thermostat to their liking. You continue to pay for the air conditioning or heating of the basement, even if you haven’t been down there in weeks, because there is no other method to control the temperature in various rooms in the house. It can also reduce airflow, which may shorten the lifespan of the HVAC system and can be physically demanding and stressful to close vents manually. 

A professional install a zoned HVAC system using a series of dampers and separate thermostats for each home area in order. The homeowner may now setup the temperature in different areas of the house. You no longer need to heat or cool the basement or upstairs bedrooms when you are not using them.

How Zoned HVAC Systems Work?

A zoned HVAC system is composed of a series of motorized dampers placed in ducts or at the air outlet in addition to a series of motorized dampers connected to create zones. Homeowners vary in the square footage, the number of floors, the room layout, and how the rooms are used to create zones in their homes. Each zone has a temperature control that controls the heating and cooling systems. The central control panel links the HVAC system, dampers, and thermostats. The HVAC system can respond to requests from several thermostats because of this connection. 

If a particular zone requires heating or air conditioning, the damper will open, allowing airflow into that space. The damper in the rest of the house remains closed. When the damper in a particular zone needs to be opened, open the opposite damper. The opposite damper is opened. As each zone reaches the desired temperature, its damper is closed. Every room in the house is heated or cooled to the desired level when the system turns off.

What Is a Single-Zone HVAC System?

A single-zone HVAC system controls the temperature in one area or room in your home. A single-zone HVAC system operates by regulating the temperature in an area using a single heater or air conditioner. You might desire a single-zone HVAC system if:

  • Your household’s HVAC won’t be linked to the new expansion when you build. A single-zone system can cool, heat, and ventilate the expansion area.
  • Some areas of your home may be under-heated or cooled because your current HVAC system may not be able to heat or cool specific areas. A single-zone HVAC system can help you better control these spots.
  • Rather than installing a window air conditioner in their garage or workshop, some homeowners condition the air using another option, which is a single-zone HVAC system. You can still maintain the temperature and ventilation while enjoying the breeze through the windows.
  • Small cabins or other small properties might only require the installation of a single-zone heating and cooling system to stay comfortable. Your system’s capacity will determine whether you need adequate airflow with fans to distribute air throughout your home.
  • You may also experience frequent maintenance services and repair and further need a replacement. 

In choosing between the two, it is important to do research and have more info.

Good and Bad Zoned System Design

Heating and cooling every room in your home wastes electricity – just like turning on all the lights in your home when you turn on one light. When you turn off the lights in unoccupied rooms in a zoned system, you save your energy bills by lowering or halting the flow of heated or cooled air to everyone in that zone. With a zoned system, you can set the bedroom zone to 60°F during the day and 72°F at night while lowering the living room temperature to 60°F.

You can imagine how a programmable thermostat can be helpful in a zoned system. Zoning can reduce energy usage by as much as 40%. If the temperature is cold enough, a zoned system will pay for itself and start saving you money right away.

Good Zoned System Design

A zoned HVAC system reduces energy use by lowering the system’s output. To design a sound HVAC system, start with a two-stage or variable-capacity model. In systems with two stages, the system produces heat using 65% of its capacity and creates cool air using 100% of the capacity. Therefore, if you reduce the demand for heating or cooling in various areas by one-third, your home will need two-thirds (66.7%) of the system’s capacity to produce the same heat or cool air. 

The system will run at a low stage most of the time, achieving significant energy efficiency and cost reductions. It split the ductwork to serve three sections of the home. With no zoning, airflow to each section would be about 331.3%, for a total of 100% of airflow. Zoning as shown, you may use either a multi-zone thermostat or thermostats for each zone to set the thermostat so that some sections get disproportionately more heating or cooling air while reducing the total capacity.

An HVAC system with two stages or operating on a variable capacity, for instance, will provide 65% of the system’s ability rather than 100%. They might allocate it between the upstairs (20%), kitchen/family room (30%), and living/dining area (15%). 

Bad Zoned System Design

Major problem and issue exist in zoning systems.

  1. Because single-stage systems operate at 100% capacity and the blower runs at full speed, you cannot reduce energy consumption when the system is on. Secondly, working at total capacity always prevents you from lowering the energy consumed.
  2. A blower exhausting 100% of its airflow must either exhaust it all or divert it to other zones, either not being cooled or heated or being cooled or heated at less than their maximum extent. If you open one zone while leaving the others shut, too much either heated or cooled air can result in the open zone. Because of this, the system will run in short, frequent bursts, which can result in temperature swings and mechanical problems. The rooms will be either hot or cold due to all the airflow. Sensors can help to regulate this.

Finally, you might hear rushing or whistling noises in the ducts, which may be damaged or leak due to all that airflow.

  1. They do not recommend a bypass duct and damper. A bypass duct and damper are usually associated with zoned systems. It connects to the trunk of the system, which supplies air to the zoned branches at one end, and the return air plenum at the other. It must be closed to prevent air from flowing through it, at least in theory. When one or more zones are closed, the damper opens partially or fully, resulting in a build-up of air pressure. 

When the damper is partially or fully open due to one or more zones being closed, the excess air is forced back into the return air plenum through the bypass. As a result, the air does not gush through open zones.

Using bypass ducts anywhere in the system is not recommended because:

  • The coil may become clogged or freeze when the AC is on, and cold air is forced into the air handler. 
  • The AC is a single-stage system that runs at 100% capacity, so there are no energy savings. 
  • There is no energy saving when the AC is running. 
  • The more air pressure there is within the air handler, the more air is forced through the bypass damper, and the wider it opens. 
  • Even when all zones are open, air will enter the bypass duct and will waste the energy used to cool or heat it. 
  • Electronic bypass zone dampers partially address this concern. Bypass dampers may collect humidity and consequently develop mold.

Leading HVAC pros concur that this is a professional opinion, and they back it.

The Benefits of Zoned HVAC

With zoned HVAC systems, you can focus on your cooling and heating exactly where needed, rather than throughout the entire house. It has many advantages, like lowering your energy consumption, reducing your monthly bills, minimizing wear and tear on your system, and may even increasing its longevity. It keeps the higher floor in your house cool without blasting the air conditioner by keeping the basement cool and unoccupied.

Choosing the Right Kind of Zoned HVAC System for Your Home

A two-zone HVAC system can provide comfort for most homes and decrease utility costs by up to 30%. Every family member can enjoy guaranteed comfort with this system.

Take it a Step Further by Going Ductless

It is possible with a ductless HVAC system to heat and cool beyond what you have ever experienced before. Unlike conventional systems, there are no ducts in a ductless system. Outdoor units, which are connected to up to four indoor air handlers that can be wall-mounted in the various rooms of your house, are used instead. Ductless systems reduce the risk of poor indoor air quality and issues that frequently plague central air conditioners and furnaces-such as uneven heating and cooling in the home due to damage and leaks in the ducts. 

You can control each air handler individually with a zoned HVAC system. You may set one air handler to cool the room down to 78° in the summer while cooling another to 68°. These types of HVAC systems are ideal for large homes with a lot of rooms, as well as homes with two or more floors, since heat rises and gives cooling and heating requirements distinct. 

Limitations of Zoned HVAC Systems

It is impossible to create zones that are too small. The system cannot provide enough air to a restricted area, so that the equipment won’t operate properly. For example, you’d prefer to have the toilet as a component of the master bathroom zone rather than as a separate zone. You require a two-stage air conditioner and a variable-speed blower on the furnace or air handler. These devices are more costly than single-phase models, but reduced operating expenses frequently offset higher initial costs.


It is less expensive to install zoning equipment during the construction of a home than to retrofit it because installing it is easier; regarding this, you may call your chosen company for your HVAC. The 2-zone HVAC is an ideal solution when you’re in dire need of cooling or heating but have no room for multiple systems. While this may seem a little unconventional, it’s a great way to keep your room at the right temperature without wasting energy on cooling or heating areas that aren’t being used. 

With thoughtful planning, you can save space and money with this ingenious system. You can also seek an HVAC team to answer your questions and for more details.


Can you have 2 zones with one AC unit?

A zoned system allows one unit to heat and cool multiple rooms in your home. A dual-unit system consists of two independent units, each controlling a separate temperature zone with independent, unconnected thermostats.

Do I need 2 thermostats for 2 zones?

If you have two zones in your home, you will need two thermostats to control the temperature in each zone. It will allow you to set different temperatures for each zone and maintain a comfortable environment in your home.

Is dual-zone HVAC more efficient?

There are a few factors to consider when determining whether dual-zone HVAC is more efficient. For example, if you have a large home with many rooms, dual-zone HVAC can help to save on energy costs by allowing you to control the temperature in different areas of the house separately. Additionally, dual-zone HVAC systems typically have higher SEER ratings, which means they are more efficient at converting energy into heating and cooling.