Multi-zone thermostats

Most homes in North America consist of multiple zones or spaces for different purposes. You’d have a bedroom, living room, kitchen and perhaps even an office. All these zones need to be heated (or cooled) – but not necessarily at the same time. When you get up out of bed in the morning and make your first cup of coffee, you prefer the kitchen to be warm instead of your bedroom. And similarly, when you go to bed at night you don’t need the kitchen and living room to be heated. Most people go about their daily lives living in multiple zones, but we often see people treat their home as one single heating or cooling zone, regardless of their heating setup.

There are many benefits to dividing your home into multiple zones – you can optimize for comfortable temperature when you need it, where you need it and save more energy by eliminating wasteful heating.

Homes in different regions also rely on completely different kinds of heating systems – so identifying what kind of setup your home has is the first step towards zone heating.

In this blog post we will introduce:

  • The different ways you can set up heating for multiple zones in your home
  • The impact of your heating system on your ability to create various zones
  • The best thermostats to manage multi-zone heating

Two ways to develop zones

In general, there are two ways you can divide your home into heating zones; sensor-based and system-based.

Sensor-based Zoning

With sensor-based zoning, you use separate sensors to optimize the temperature in each zone. This works particularly well if you have one central thermostat controlling the temperature of your home (central heating system). Typically, the thermostat will read the ambient temperature of the room of the room it’s in and heat/cool until it reaches the setpoint. The problem with this approach becomes more apparent when your thermostat is in one of your largest spaces – like your living room. It likely takes longer to heat your living room than it does to heat your bedroom.

Consider this simplified example:

  • It takes 30 minutes to increase the temperature by one degree in your living room.
  • In your bedroom, it only takes 15 minutes to raise the temperature by one degree.
  • If you want to heat your living room by 1 degree, your bedroom will have warmed up by 2 degrees.

With sensor-based zoning, you place sensors in each zone you want to create. These sensors will measure the temperature of each specific zone, optimizing it for your comfort.

System-based Zoning

By design, system-based zoning is a simple concept to grasp: you have multiple heating zones in your home because you have multiple heating systems you can control individually. This means you have more than one thermostat; in fact, you’ll likely have at least one thermostat per living zone. This is by far the most efficient way of achieving energy savings through zoning – although, depending on the heating system you use, it may be more expensive to install.

Heating Systems

The most significant factor in determining how you can divide your home into multiple zones is your HVAC system. It’s a lot easier to change thermostats than it is to change HVAC systems, which might involve hiring more electricians or contractors. Generally, the voltage output of your system is the most important factor in determining compatibility with heating systems and the ability to create zones. Homes in North America typically run on one of two standards: Low voltage and High or Line voltage systems.

Low Voltage Heating

The Common Scenario

If you have low voltage heating (furnace, radiator etc), you more than likely have a central heating system with one thermostat. This means a sensor-based system is likely your best option. If you want to move towards a system-based zoning system, it probably means a good deal of construction – new circuits and fixtures will be required.

The Uncommon Scenario

Sometimes, low voltage heating systems are broken up into multiple zones (through duplication of heat sources or usage of dampers and ducts). Each of those circuits will require their own dedicated thermostat. If this is the case, we would recommend a separate learning thermostat for each zone. With this setup, you can save energy more efficiently without having to spend much time changing setpoints and temperatures for each zone.

Line Voltage Heating

The Common Scenario

If you have line voltage heating (120-240V), you likely have multiple thermostats – as many as one per room. In that case, you’re already well on your way to having a system-based zoning system. Just replace these thermostats with WiFi or smart options that having zoning options and manually set your zones.

The Uncommon Scenario

Even though a decentralized heating system is more common for high voltage situations, there are exceptions. Fan coil thermostats are a type of central line voltage heating system, and unfortunately, there is no smart thermostat that exists for fan coil systems. This system would require a sensor-based thermostat as there is only one thermostat controlling the entire home. Once Mysa is successfully launched, one of our next steps will be to build a fan coil compatible smart thermostat. If you are interested in staying up to date on those developments, sign up for a notification.

Best Multi-zone Thermostat

Rather than doing an elaborate write-up of why each thermostat would be the best option for different scenarios, we’ll keep it simple. Use this decision tree to make your decision – it considers everything discussed above.  If you’d like to know more about the smart thermostats included, check out this article for a comparison of thermostats per heating system (low and line voltage).

Top Zoning Thermostats


Ecobee4

The ecobee4 is best for when you have a central low voltage heating system with only one thermostat. You can connect sensors to the thermostat and Ecobee will then make sure the rooms you are occupying are heated to your comfort. The downside of this is that it won’t necessarily maximize energy savings, but it will maximize comfort.


Nest Thermostat-E

If you have more than one thermostat for your low voltage system (for example, one upstairs and one downstairs), Nest’s Thermostat-E makes the most sense. Your home is already divided into two zones; with the Nest’s learning features this will save energy and ensure comfort.

2018 Update: Nest has launched a temperature sensor. If functionality is up to par with Ecobee’s sensor technology, the Nest Thermostat E is the most economical option for your home, unless you are are building your entire smart home ecosystem around Amazon Alexa.


Mysa

The Mysa Smart Thermostat works with all electric baseboard and electric fan-forced heaters – those on a Line Voltage system. Typically, homes with this type of heating system have multiple thermostats, as many as one per room. Mysa allows you to control each room or zone individually, but also has the unique functionality of grouping thermostats into zones together for ease of use. This is the optimal way to maximize energy savings and comfort.

Mini Split Heat Pumps

We didn’t want to write this article without mentioning mini-split heat pumps. If you’re not sure what they are, make sure to check out this article. These heat pumps move heat, but they don’t create it, making them efficient parts of many modern homes and a great way to build zones.  It is, however, quite expensive: depending on the structure of your home, the placement you choose and the quality of the heat pump but you are looking at few thousand dollars per heat pump. If you do have mini-split heat pumps (or are considering some), make sure to check out Sensibo or Tado – they’re currently the only smart thermostat systems that work with heat pumps.