Water-based or glycol-based radiant flooring: what is the difference?

Water-based radiant floor heating

The water system uses heated water that circulates through pipes. This is the most common option for residential installations.

Advantages:

• Energy efficiency: Water is an excellent heat conductor, allowing heat to be transferred very efficiently throughout the room.
• Less maintenance: This system is fairly simple, with no need to add chemicals, which reduces long-term maintenance costs.
• Lower initial cost: Compared to glycol, a water system is generally less expensive to install.

Disadvantages:

• Risk of freezing: Water in the pipes can freeze if the temperature drops too low, which could damage the system (although this problem is rare if the installation is done correctly, with antifreeze or a thermostat that protects against this risk).
• Limited to warmer temperatures: Water must be heated to a higher temperature than glycol, which may result in slightly higher energy consumption in some cases.

Glycol radiant floor heating

The glycol system uses a mixture of water and glycol (a type of antifreeze) as the heat transfer fluid. This type of system is often used in places where the temperature can drop below freezing, such as in cold areas or unheated basements.

Advantages:

• Frost protection: Glycol prevents the fluid from freezing, even if the outside temperature becomes very low, allowing this system to be used in colder environments (e.g., under unheated floors or in country homes).
• Maintains heat at lower temperatures: Glycol can transport heat more efficiently at relatively lower temperatures, making it ideal for low-temperature heating systems, such as those powered by a heat pump.

Disadvantages:

• Higher initial cost: Glycol systems tend to be slightly more expensive to install due to the additional materials and equipment required.
• Maintenance and inspection: Glycol requires more regular maintenance. It must be checked to ensure that it is not contaminated or degraded and that it retains its antifreeze properties. If glycol deteriorates, it can lose its effectiveness and cause damage to the system.

In summary:

• Water system: Less expensive to install, simpler and more efficient, but a little more limited if you are at risk of very low temperatures. It can freeze if not properly protected.
• Glycol system: Ideal for very cold environments, as glycol prevents freezing. However, it requires more regular maintenance and is a little more expensive to install.

If you live in a cold region and don't have heating in your basement, a glycol system may be a better option. On the other hand, if you live in an area where temperatures don't drop too low, a water system will probably suffice, with lower maintenance costs.