Tweet
There are two types of heating and cooling systems:
- Single-stage systems
- Multi-stage systems
Single-stage systems
They are mainly described as 0N-OFF systems which either run at full capacity (hot/ cold) or they fully in OFF state. Most of them constitute old HVAC models that serve smaller homes. They are the cheapest and easiest to install but highly inefficient in consumption.
How can they be identified?
- Conventional systems will have a single wire for heating (W/W1 connector) and another one for cooling (Y/Y1) connector.
- Single-stage systems have a Y1 connector with a single wire for both heating and cooling.
Multi-stage systems
Mostly comprise of systems used in new bigger homes. These 2- stage (most common), 3-stage and 4-stage systems allow home users to set desired temperatures. They are expensive to install but provide even room temperature. They have features such as room occupancy sensing and geofencing which all help to save energy.
How can they be identified?
Heating wires lead into terminals labeled W while cooling wires lead into terminals labeled Y.
- 2-stage conventional heating systems have wires going into W1 and W2/ W and W1 terminals
- 2-stage conventional cooling systems have wires going into Y1 and Y2/ Y and Y1 terminals
- 3-stage conventional heating systems have wires going into W1, W2, and W3/ W, W1, and W2 terminals
Smart thermostats work with multi-stage heating and cooling systems since the majority support up to 2 heating and cooling stages.
Here are some popular smart thermostats.
For guidance on the selection of HVAC controllers including retrofitting old systems, please feel free to contact our HVAC experts.
More information on HVAC Systems is found on our Controls website.