Radiant floor heating is best known for its ability to keep floors warm, but is it limited to floors? Is radiant heat sufficient to warm the air and possibly even heat the entire house? We investigated how radiant heat warms the air to provide you with these answers so you can decide if radiant heat flooring is right for your home.
Radiant heat transfers warmth through the floors to raise the air temperature in a room to the desired temperature. Under the floor, electric wires or tubes containing hot water are installed to warm the floor first. The heat then spreads evenly throughout the room, providing a consistent and comfortable air temperature.
Continue reading to learn more about radiant heat. We’ll talk about how it works, how it compares to forced-air systems, whether it can only be installed beneath floors, and whether it can be used as a whole-house heating system.
How Does Radiant Heat Work?
When radiant heat is installed, the heat-carrying tubes are either placed within a concrete slab or subfloor (called a wet install) or directly beneath the subfloor (dry install). Because of its density, concrete retains heat well, making a wet installation the most efficient for heating.
As the subfloor warms, it begins to radiate heat into the room. Radiation waves rise to heat the objects and people in the room. Technically, the air is not heated directly, but it is warmed by heat transfer. This is a major reason why radiant heat is thought to be so energy efficient. Instead of wasting energy heating the air for the indirect comfort of those in the room, the people in the room are directly heated.
Is Radiant Heat Electric Or Gas?
Radiant heat is generated by electricity or water.
Heat is transferred through the floor into a room in electric systems via a series of electric wires installed beneath the floor.
It can run on 120 or 240 volts. This is the simplest option for do-it-yourself projects.
Hydronic, or water, systems operate by pushing hot water through a piping system. The water is heated by a boiler, which can be either gas or electric. Either one works equally well, and you can use whatever you have on hand. If you don’t have a boiler and need to install one, it’s worth noting that gas is less expensive to run.
Which Is More Effective, Forced Hot Air Or Radiant Heat?
Once installed, radiant heat systems outperform forced hot air systems in almost every way imaginable. Nonetheless, most homes use forced hot air for practical reasons: the cost, time, and difficulty of installing radiant heat. To compare the distinctions:
Radiant Heat Advantages
- Radiant heating systems use far less energy. Leaky ducts in a forced-air system waste 20-30% of the warm air intended to heat your home, resulting in higher energy bills. Radiant heat can save you 15% on your energy bills on average.
- Radiant heat systems heat the entire floor surface, allowing air to rise evenly throughout the space for warm, consistent temperatures. There are no hot and cold spots caused by air movement and radiator or vent placement, as in forced-air systems.
- Radiant systems are known to reduce allergies. The blowing of hot air through the ducts of a forced-air system also blows dust and other allergens around. This does not happen in radiant systems, which tend to reduce allergy symptoms and suffering.
- Radiant heat requires very little maintenance. Systems can last up to 35 years and are frequently backed by a 25-year warranty. A service call is uncommon in radiant systems; forced-air systems typically require furnace replacement in half the time.
- Radiant heat is quieter than forced-air heat because there is no noisy furnace kicking on and off all the time.
Forced Air Advantages
- Forced-air systems are less expensive to install. While radiant heat systems last longer, require less maintenance, and save money on your monthly bills, they can be twice as expensive to install as a forced-air system. Radiant systems typically cost between $10 and $20 per square foot.
- Forced-air installation is much easier. A readily accessible furnace can be kept in the basement. Radiant systems, on the other hand, may necessitate the removal of the floors for installation (and again if any repairs are needed).
- Forced-air systems are relatively compatible with home cooling because the same ducts can serve both functions. It’s not always easy to provide cooling power through the same system as radiant floor heating. If you require whole-house air conditioning, ducts must be installed.
Is Radiant Heat Flooring Capable of Heating An Entire House?
Radiant heat flooring is capable of heating an entire house. The actual success of heating will be determined by a number of factors, including the house’s airtightness and insulation. Houses with a lot of carpet may not get the full benefit of radiant heat flooring because carpet can act as an insulator and keep heat from entering the room.
Existing homes are often too difficult for a whole-house retrofit, so new homes in construction or homes already in major remodeling projects are the easiest for adding a whole-house system. The floor would have to be removed and replaced, which would deter many homeowners unless they were already planning extensive home renovations.
The hydronic system is more efficient and cost-effective if you need a whole-house system. Electric systems are typically more expensive to operate (but easier to install) and are best when heat is only required in a specific area (such as a bathroom).
Floor Installation Alternatives
Is there a way to enjoy radiant heat without pulling up the floors for people who want radiant floor heating but it’s too late to do anything other than a difficult retrofit into their existing home? A radiant heat ceiling is a lesser-known alternative.
The same basic method is used in the ceiling of a radiant heat ceiling. Tubes, either electric or hydronic, are installed, and heat radiates down from the ceiling.
The first question that this system frequently raises is efficiency – how can the room be warmed from above if heat rises? Technically, it is hot air, not heat, that rises.
Because the air is not directly heated (warming is a secondary effect as heat transfers to people/objects in the room), this is still an efficient way to heat with little energy loss. It’s similar to how the sun or a heat lamp can emit heat waves to objects on the ground.
This method has the following advantages:
- Installation is less expensive (about half the cost of radiant flooring).
- It is easier to retrofit and causes less disruption in the home.
- Floor coverings have no effect on or limit the output of a room.
- Can heat to a higher temperature without risk of damage or discomfort, as in flooring systems (walking on a too-hot floor, even if the temperature is safe). No one has to worry about touching the ceiling.
- Warm-up times are reduced when compared to floor systems, which can take an hour or two to reach the desired temperature.
What Is The Best Floor Covering For Radiant Heat Flooring?
When radiant heat flooring is used, ceramic tile conducts and stores heat well and covers the floors. Vinyl or linoleum can also be used, but the best results will come from thinner vinyl with dense padding.
If carpeting, such as vinyl, is used, avoid thick carpets and choose dense padding. Avoid carpet whenever possible because it can prevent heat from entering the room.
Because heat can cause wood to dry out, it is best to use selected laminated wood flooring if wood floors are desired.
How High Should Radiant Heat Be Set?
A radiant heat system can provide two types of temperature readings. Thermostats can give you either an air temperature or a floor temperature reading. In general, floor temperature readings are about 5 degrees warmer than air temperature. Set the floor temperature to 75 degrees if you are comfortable at 70 degrees.
Overheating the floors can cause damage, so keep them below 85 degrees Fahrenheit. Finished wood floors are especially vulnerable to heat damage.
Radiant heating heats the air by heating hot water or electric wires beneath the floor (or, less commonly, in the ceiling). Heat moves from the floor to the objects and people in the room, and then to the air. This ensures that the temperature remains constant and even. Radiant heating can be used as an energy-efficient and comfortable heat source in a single room or throughout the house.