A System That Warms Floors and Walls Is a Comfortable Home Heating Alternative
Isn’t it amazing that some of the wonders of the 21st century can be traced back to ancient civilizations?
Take radiant floor heat. While becoming an increasingly popular trend in modern construction, this technology has been around for centuries. From the excavated floor flues of ancient Korea and China to the hypocausts of the ancient Greeks and Romans, to Frank Lloyd Wright’s hybrid technology for his Prairie homes, this concept has undergone a global evolution that makes it relevant in contemporary homes.
In ancient Rome shows the floors raised on pillars where heat could circulate below and radiate through layers of tiles and stone. Credited with developing the first under-floor heating technology in Europe, the Romans used this system for the baths and in private houses. While by the 20th Century, Frank Lloyd Wright’s Bachman Wilson House – originally built in 1954 along the Millstone River in Millstone, NJ – was equipped with green building components, such as passive solar heat through abundant use of natural light, and in-floor hydronic radiant heat.
What Is Radiant Heating?
An alternative to traditional forced-air and hot-water-baseboard heating, radiant heating supplies heat directly to the floor or to panels in the wall or ceiling of a house from hot-water tubes or electric wires underneath the floor – directly to the people and objects in the room via infrared radiation. Once the objects absorb the heat, they radiate it to others in the room – an efficient way of transferring heat. Some radiant sources in a home are the fireplace, a wood stove, portable heaters, and radiators connected to a central boiler.
Here’s how an an in-wall radiant heat panel looks as it is installed a home under construction (courtesy of Energy.gov).
Types of Radiant Floor Heat
There are three categories of radiant floor heating systems – hydronic or water-based, electric, and air-based.
1. Hydronic Heat
The most versatile, cost-effective, energy-efficient and the best for colder climates, this option uses heated water to transfer heat to the living spaces. Hydronic systems can run with electricity, natural gas, oil, propane, wood, or solar power. A central heating unit can be used for both water and space heating to reduce total costs.
Because of its wide variety of energy sources, hydronic systems can use:
• Central Boilers that pump heated water through a network of pipes that can be fired by natural gas, propane, oil or biomass
• Electric Heat Pumps are a better alternative to electric resistance boilers since they can match the output of an equivalent resistance heater with a fraction of the energy input; and can compete with gas boilers because of their superior efficiency.
• Water heated bySolar Collectors, which have the best results when hydronic piping is embedded in a concrete slab, because it allows solar energy to be stored thermally for night time heating. A boiler or heat pump can be added – if the available solar radiation is not enough to meet the heating load.
2. Electric Heat
This system provides warmth with electric wires or coils laid directly under the floor. Manufactured with metals that have a high resistance to electricity, these electric coils are wrapped in polymer that are good conductors of heat. As the heat goes through the wires, they heat the floor, wall, or ceiling, depending on where they are installed. The best choice for this option is a thick concrete floor that will retain heat for a long time; wood or carpeted floors require more electricity to generate heat and lose it quickly.
A polymer floor heating element can be installed directly under the floor covering, making installation quicker and easier than other in-floor heating systems (courtesy of Pal N Paul Inc.).
Add warmth to the kitchen by “zoning” it for electric radiant floor heating. This lovely breakfast nook in the spacious kitchen of 2-story, 4-bedroom, 3.5-bath house plan with Craftsman touches is a perfect space for that concept (Plan #161-1067).
While electric radiant heating systems are simple and relatively inexpensive to install, there are expensive operating costs involved because of the ever-increasing price of electricity. They can be cost-effective when heating is used for only a few months each year. Because of this, electric radiant heating systems are affordable if used in small areas or sections of a home.
Get out of the warm bed in this luxurious master suite (top) of a 2-story, 4-bedroom, 3.5-bath Contemporary home … and walk straight into the master bath (bottom), which can be set up with electric radiant floor heat for the ultimate in comfort, maintenance, and affordability (Plan #161-1085).
3. Air-Heated Floors
The least efficient of all the radiant systems, air-heated floor are seldom installed in residences. They can be combined with solar air heating systems, but there are obvious problems. Foremost is the inefficiency of heating a home with a conventional furnace by pumping air through the floors at night and using solar heat during the day.
Advantages/Benefits of Radiant Heat
Just for a moment, think about radiant heat and the comfort and warmth it can provide to your home and family. You can say goodbye to noisy fans going on and off, to the countless adjustments to the thermostat, and to piling on layers of blankets.
1. Energy-Efficient and Cost-Effective
Radiant heat systems can reduce energy costs and deliver exceptional comfort. Unlike traditional radiators that emit uneven temperatures across the living spaces, radiant heat is generated from underneath the floor and – because hot air rises – all the way up to the ceiling and throughout the room, providing just the right temperature with the adjustment of a wall thermostat. Because of the improved perception of heat – and comfort level – you may be able to turn down your thermostat a bit. Radiant heat may provide homeowners an average saving of up to 15 percent on heating bills.
2. Simple to Run and Maintain
Once the system is installed, you can make sure that heating runs efficiently by using an automatic thermostat that works with a smart phone – or a programmable one that allows you to schedule when you want the heat to come on and switch off.
Here’s a look at the various choices for floor heating thermostats that ensure the systems works smoothly (courtesy of Warmup).
Radiant heat allows you to design your dream home to your specifications – and choose a floor covering that suits your lifestyle. The system works with all floor coverings such as wood, laminate, tile, concrete, carpet, etc.
4. Safe and Comfortable
With the heating system installed under the floors, everyone in the home is safe from sharp edges or hot surfaces. And because heat radiates from the floor, there is an even distribution of heat in the living spaces. This translates into more comfortable rooms throughout the home.
5. Clean and Better Indoor Air Quality
In contrast to forced-air heating and its tendency to circulate dust, allergens, odors, and germs, radiant heat results in slow and gentle air circulation that prevents allergens from being airborne for a long time. The improved indoor air quality is an important consideration for children and adults with allergies, asthma and other conditions that can be exacerbated by indoor pollution.
6. Quiet and Out-of-Sight
What’s more wonderful than a system that just keeps you warm and comfortable – without the noise of clanging pipes? With radiant heat completely hidden under the floor, walls and rooms are uncluttered with radiators, air vents, and baseboards.
7. More Space and Design Freedom
No wall radiators means less constraints on furniture placement as well as additional space within the living areas – and clean walls that you can adorn with simple décor accents or more elaborate touches.
8. Easy to Localize or Zone
Radiant heat systems provide the potential for more energy savings because they are designed for room-by-room zoning. Homeowners have the ability to group rooms together and create their own zone. With zoning, different rooms can have different temperatures at different times – thus saving energy and maximizing comfort for all family members.
This Great Room – living, kitchen, dining areas and breakfast nook – in a 4-bedroom, 3.5-bath Craftsman style home can be created as one heating zone within the luxurious home (Plan #161-1067).
Disadvantages of Radiant Floor Heat
While radiant floor heat has obvious benefits, there are also a number of disadvantages to think about.
1. High Installation Cost
Experts provide costs of $10 to $20 per square foot – depending on the type of radiant floor heating you choose and the location and layout of the home. Look to add between $200 and $250 for a qualified electrician to connect your electric system to the power supply. Based on this range, the total cost of heating a 1,500 square foot house can run a homeowner $15,000 to $30,000. Keep in mind that hydronic systems may cost two to three times more than the electric type. It is also worth noting that in the long run, radiant floor heat systems may pay for themselves because of the lower utility bills.
2. Installation Time
If you’re opting for electric systems, factor in the time to apply a self-leveling compound – and allow it to dry – before the floor covering is installed. A good estimate is one to two days. Hydronic systems usually take about a week to be completed.
3. Longer to Heat
While it may take a radiant floor system a bit longer to heat an indoor space, there is a silver lining provided by modern technology. A Smart thermostat can be programmed to preheat rooms when the lowest electricity rates are being applied.
4. Difficult to Repair
Because most of the wiring or piping is installed under floors or in walls, repair work can be expensive and inconvenient.
Is Radiant Heat an Option for You?
While not all popular trends make sense for everyone, there’s something to be said for the benefits of radiant heat. Yes, it’s more expensive to install – especially in older homes – but if you are willing – and able – to take on the substantial upfront cost and the length of installation, radiant heat may be an option worth considering. Remind yourself of the potential energy savings down the read, plus the flexibility to create “zones” within the home – instead of doing a whole-house radiant floor heating.
Forget about the cold floors and the hot-cold temperature fluctuations in your home . . . and think about the warm, comfortable, and luxurious alternative of radiant floor systems.
Footnote: The lead image in this article is the spectacular, light-filled living room of a two-story, three-bedroom, 2.5-bath Contemporary style home. For more details, click here (Plan #126-1190).