Where Does The Heat Come From In Radiant Heating For Homes?

Q:

When you have radiant heat as the main source of heat in a home where does the heat actually come from?

A:

There are two types of radiant heat that typically are available on the market for residential homes, one is electric floor heat and the other is hot water floor heat.

ELECTRIC HEAT

Electric in-floor heating is most commonly seen in bathroom floors but there are times when people install them in all floors of a home to help heat the home. In colder climates it’s usually not enough to heat an entire home all by its self; you usually require baseboard heaters or a main forced air heating system like a furnace.

Electric heating are heat lines or “mats” that are installed on top of the sub-floor and then are hooked to a thermostat on the wall. They are powered solely by electricity. As the heat lines warm up so does the finished flooring on top of them. Electric heat is predominantly placed under tile on floors, this helps give it thermal mass. When the electric heat warms up the thermal mass of the tile and mortar that is underneath it then it starts to radiate heat outward in the air. Because the air above the tile is colder then the heat rises up towards the ceiling of the home constantly. The tile will continue to radiate heat to a limited extent even after the heat lines have stopped producing heat. Electric heating lines are limited in the amount of heat that they can create; they also require a lot of electricity to do so depending on the amount of heat that you want out of them.

HOTWATER HEAT

Hot water in-floor heating is exactly what it sounds like, it is hot water that can be made from several different kinds of sources, and it is then circulated through piping that is placed under the finished flooring of your home to heat it. Hot water heat produces enough heat for you entire home no matter how cold a climate you live in. You will not require any extra heating sources like electric in-floor.

The hot water is circulated from a central location and fed into the piping, the area’s are usually broken down into zones so that you are able to control the temperature of the zones depending on the area’s use and also depending on how warm or cold the room is because of other forces such as sunlight through windows or heat making units like fireplaces.

Hot water in-floor usually is installed in 1.5 inches of “gypcrete” a concrete product that is designed to be installed over heat lines to create thermal mass. Because it is imbedded in the gypcrete hot water in-floor is extremely efficient in its heating. Long after hot water has stopped circulating through the lines the floor will continue to radiate heat, hot water in-floor takes a while to come up to temperature from completely cold but it also takes a long time to cool down as well.

Hot water in-floor heating is one of the most efficient ways to heat your home regardless of what fuel source it comes from.

Rob Abbott
Village Builders Inc.