Radiant Water Heat - Hot Water Warmth
Typically, radiant water heat is called hydronic radiant heat in the construction industry. This is a very versatile and efficient way to heat a structure. Factories, commercial buildings, and homes all can use water to heat their space. The pictures shows a cutout of a radiant floor with PEX radiant tubing embedded into the subfloor.
You can also embed hydronic radiant systems outside in concrete driveways or sidewalks. This is used in colder climates so the warmed concrete melts away ice and snow. It also is common to embed the PEX radiant tubing in the concrete floor in basements or in a concrete floor of a home that doesn't have a basement. The finish flooring can be placed right above this radiant source of heat.
The best way to incorporate radiant water heat is to install it into a new structure. Retro fitting radiant heat is impossible for concrete, but it can be done under pre-existing subfloors. Almost any flooring can use hydronic radiant heat. It can heat concrete, wood floors, tile, laminate, linoleum, and even some types of carpeting.
First, you have to lay down all the tubing for the water to run through. Hydronic systems traditionally use PEX (cross-linked polyethylene) tubing. PEX is wrapped all around below where the finished floor will be placed. Then the tubes are connected to a water heater or a boiler. You also can generate hot water with solar heat.
Then you finish the flooring of your type. With concrete, you lay down a metal grid and the tubing. The concrete is poured over this, embedding the heating system within the concrete slab. With other floor types, the tubing lies underneath or within the subfloor. The floor is then placed on top of the tubes. You should insulate the below a radiant water heated floor to ensure the heat radiates up into the floor.
A Review of Radiant Water Heat
Using hydronic radiant heat is steadily gaining popularity in North America. It has been the preferred heating choice in Europe for decades. There are two main reasons why this system is used.
First, radiant heat produces a wonderful warm floor. In the dead of winter, you can walk around barefoot on a floor heated with a hydronic system. The whole floor is one large comfortable heater. Because you are using a large area as a radiator, it also produces a nice, even heat.
With furnaces that push out forced heated air, you get an uneven heat. Hot air rises, as cold air falls. As soon as the heat comes out of a vent in a home with forced air, it goes right to the ceiling. With radiant floor heat, the heated floor radiates throughout the whole room, from the bottom up.
The second huge benefit of heated water systems is it’s efficient. Radiant hydronic heat can reduce heating bills by up to 40%. There is two reasons for this. For one, it is cheaper to use heated water because water hold heat better than air. When you heat up the water, the water retains that energy for a longer period of time. Also, people who use radiant heat set their thermostat between two to four degrees lower than with heated forced air. This isn’t because the users are trying to save money either. With a heated floor, the warm air stays lower instead of gathering on the ceiling with forced air. The heat is where the people are with a radiant water heat. You feel warmer, because it is warmer where you are. I guess if you are really tall, and you are standing all the time, radiant heat might not be ideal.
The big reason radiant water heat isn’t used more often, especially in the United States, is because its more expensive to install than a furnace. Instead of one heater and a bunch of duct work, a radiant water heat system needs hundreds of feet of PEX tubing to be layed out. This tubing then has to be embedded into the floor with concrete, or by insulating beneath the subfloor. The start up costs will eventually pay for themselves when compared to a furnace, but many people don’t consider this when building a home or new structure.
There is also a lag time when you activate this heating system. Since the whole floor is the radiator, it takes a bit of time to heat up all this thermal mass. If the room is much colder than you desire, it will take longer to heat than a forced air system. Also, this system takes longer to cool off.
Advantages of Radiant Water Warmed Flooring
It can be used for numerous different floor types. If the radiant system is embedded into concrete, you can still add tile, laminate, carpet, and some types of engineered wood over the top. If the radiant water heat is installed as a part of the subfloor, you can add virtually any floor covering of your choice. Carpet for radiant floor heat can be tricky, so make sure you choose the right carpet pad and carpeting.
Concrete driveways and walkways can use radiant heat to melt snow and ice. Imagine "clearing" the drive and walkway by simply switching on your radiant heat system.
The floors are warm. This is more comfortable than using heated forced air. Every person who owns a system will swear by this. Once they have lived in a home with radiant floor heat, they don't even consider moving to a new one without it.
Water holds heat better which means it heats your home more efficiently than hot air. Think about the temperature of a pool. When it has been warm outside for an extended period of time, and then the air gets cool, the water stays warmer than the air.
Disadvantages of Radiant Water Heat
There are some homes where it might just not be practical to install radiant floor heating throughout the home. In that case you'll want an energy efficient furnace.
Installing it is more expensive than putting in a furnace. You have to live in a home for a number of years before radiant water heat will pay itself off.
It’s much harder to retro fit, and can’t be installed in pre-existing concrete slabs. You have to install it right away in new construction for concrete.
The large thermal mass of a radiant floor takes longer to heat up and cool down a room compared to heating the air from a furnace. Some systems heat up faster than others, but overall, the response time is slower than forced air. A system like Warmboard would be the fastest, and a concrete system is the slowest to heat up.
Radiant Water Heat - Should it be a heating option for you?
No matter what type of project you are planning, radiant water heat should be considered. Looking for more information is the first step in the process. There is one thing you should keep in mind. The smaller the area that needs to be heated, the less likely a hydronic radiant heat system is the right answer. You can still use radiant heat, but using electric is ideal in situations where you want to heat a small space like a bathroom. I suggest looking into hydronic systems for large jobs, and for new construction. See who can install a system like this in your area, and start comparing prices!
Hydronic Radiant Heat for Floors in a Forclosed Home
Hydronic Radiant Floor Heating in Concrete or a Subfloor
Hydronic Radiant Floor Heating System Explained
Radiant Hardwood Floors
Outdoor Radiant Heating
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