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Multi Zone HVAC System – 2024 Essential Guide

If certain parts of your house need to be kept at different temperatures, then you might want to consider looking into multi zone HVAC system.

A multi zone HVAC system allows you to control the temperature in the different zones of your house independently; multi-zone heating and cooling units have motorized dampers and, usually, a few thermostats. Zones can be added to an existing two-stage HVAC unit to improve comfort levels and energy efficiency. 

What Is A Multi Zone HVAC System?

Such heating and cooling systems use dampers in the ductwork. This allows redirecting the cooled or heated air to specific areas.

In a nutshell, with a multi zone HVAC system, you are able to control the temperature in every room independently which is great for households where the family members have different temperature preferences. 

typical multi zone HVAC system

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How Do Multi-Zoned HVAC Systems Work?

The key components of a multi-zoned HVAC systems are motorized dampers which are placed either at the air outlet or right in the ducts. Every zone also has its own thermostat.

If you want to lower the temperature in a particular zone, you have to simply set the desired temperature on the thermostat in the corresponding area. The dampers in this particular zone will open and the HVAC system will start sending cooled air to the room (other dampers will stay closed).

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What Are The Benefits Of A Multi Zone HVAC System?

There are a few reasons why homeowners might consider getting zoned HVAC systems:


Your whole house doesn’t have to programmed to one temperature. You can change the temperature in the different areas independently. 


You wouldn’t have to heat or cool the rooms that are not in use – this will help save energy and money.

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Extended HVAC lifespan

Your heating and cooling system will not be working at full capacity all the time. It’ll ‘focus’ only on certain parts of your home and this will help reduce general wear and tear.

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What Is a 2-Zone HVAC System?

A dual-zoned HVAC system allows you to divide your home into two different temperature zones. For example, you might want to keep the upstairs cooler and the downstairs warmer.

How Does a 2-Zone HVAC System Work?

With a dual-zoned HVAC system, you’ll be able to heat and cool two areas of your home independently. Even though you’re going to have two thermostats, a single heating and cooling system will be responsible for the temperature control across the house.

A dual-unit system, in its turn, consists of two independent units that use thermostats that are disconnected from one another. Such a system might make sense if you’re planning on turning one part of your house into a rental unit.

Zoned HVAC Systems infographic

Can You Add Zones to an Existing HVAC System?

The good news is that you can add zones to an existing heating and cooling system. You would have to install a zone control panel, upgrade the thermostats, and integrate the dampers into the ducts.

The latter might become a problem if you have a single-speed blower that is always operating at 100% capacity. In such a case, the static pressure will be too intense and you would have to find a way to redirect the excess air. 

How Much Does It Cost to Add a Zone to a Heating System?

Be prepared to pay $1,700-$2,800 for adding a second zone to an existing heating system. If you’re planning on adding more zones, then each subsequent one is going to cost you up to $500.

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Best Multi Zone HVAC Systems

To find the best HVAC zoning system for your house, you would have to take your budget and the compatibility with the existing system into consideration.

Installing a zoned system is not exactly a DIY project. So, you would want to find a highly experienced professional who is going to recommend the system that is perfect for your specific case.

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Is Zoned Heating Worth It?

Before installing a zoned HVAC system, there are two things you should know:

  • The air conditioners usually required for such systems have to be two-stage units. Those are typically more expensive than single-stage air-cons, but they do have plenty of benefits.
  • Each separate zone should not be too small. At times, a single zone can include a few rooms as this allows to properly cycle the air through the house. This also means that you would have to spend quite some time plotting the zones if you want to be able to enjoy the benefits that such an HVAC system has to offer.

If you already have a single-stage unit, it is generally recommended to opt for a second separate HVAC system, rather than trying to add zones to the existing equipment. 

HVAC zoning would certainly be worth it if you’re struggling to achieve a comfortable temperature throughout your house due to high ceilings, uneven sun exposure, etc.  All in all zoned heating and cooling will help you save a lot of energy and money throughout the years (the system will pay off in around 5 years).

Of course, as with just about any system that involves extra mechanical parts, the age-old axiom is true: The more parts you have, the more parts that can break.

heat pump on pad


How Do I Know My HVAC Zone?

There are different climate zones and the right HVAC equipment for your house can be chosen by figuring out which zone you live in.

Zone 1, for example, is a hot and humid area – a heat pump is, in general, everything that you’re going to need. Zone 2 is mixed-humid and a high-performance heat pump would do well in this region, but you might need a furnace during the extra cold days.

Can a Multi Zone HVAC System Heat and Cool at the Same Time?

A single HVAC system cannot cool and heat at the same time. But you can choose to heat or cool one zone to a greater extent than the other.

Does a 2 Story House Need 2 AC Units?

In a two-story house, the upstairs is usually a lot warmer than the downstairs. Having two AC units in the house can help you keep the entire place at a comfortable temperature.

Going for a separate unit instead of zoning will make sense, if your first HVAC system is not large enough and if it is a single-stage unit.

How Many Heating Zones Should I Have?

The zones have to be proportional in size to the equipment handling them. In general, the house gets split into two zones, but if your equipment is powerful enough and the ductwork system allows you to do that, then you can go for more zones.

Does 2 Thermostats Mean 2 Zones?

Two thermostats can either mean that you have a zoned HVAC system or that you have two separate units.

Can One Thermostat Control Two Zones?

There are special multi-zone thermostats that allow you to independently control every zone in your house.

Is It Better to Put AC Upstairs or Downstairs?

It is generally recommended to put your AC downstairs as it is more energy-efficient (the downstairs is naturally cooler).

Should Upstairs Thermostat Be Higher or Lower Than Downstairs?

The upstairs thermostat should be set to around 2 degrees lower than your ideal temperature

Where Are Zone Valves Located?

If you have a hydronic heating or cooling system, then you might also have zone valves. They are usually located at the end of the zone circuit or right after the circulator and boiler.

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