Invisible, Clean, Quiet, Efficient and Dependable – Living With Radiant Floor Heating is One of Life’s Simple Pleasures
In Ontario, forced air heat is still the most popular because of its low installation costs. However, it is the most expensive type of heat to operate and the least comfortable.
When a forced air furnace comes on, a blast of warm air blows into the room for a short time, spreads through the room, carrying dust, pollen, and other air-born pollutants with it.
It continues until the thermostat is satisfied. The warmer air rises to the ceiling, leaving cooler air below. As the room cools, the thermostat calls for the cycle to repeat.
Living in a house with radiant floor heating can almost make you forget that it’s winter outside.
There is no other heating system as comfortable. Heated floors deliver warmth to the skin and clothing without overheating and drying out the surrounding air.
Radiant floor heating heats objects, not air, to provide superior comfort. People are surrounded by radiant warmth, and the air temperature is uniform from floor to ceiling.
Many radiant heating systems operate by heating up a mass, commonly the floor. By pumping heated water through tubing or pipes in, or attached to the floor, heat is conducted from the tubing to the floor.
The floor then becomes a heated mass, which radiates its heat to warm all bodies and objects above it. These objects, in turn, re-radiate the heat, heating other bodies in the room.
Since radiant floor heating warms bodies first; less energy is needed than with heating systems that heat the air to warm the bodies.
The temperature of the floor, in most cases, is dictated by the outdoor temperature. If you wanted to maintain a room temperature of 70 degrees F, the floor surfaces temperature can range from 72 degrees F on a mild day to 85 degrees F on a cold day. The colder it gets outside, the warmer the floor will become.
The floor should never feel hot. When a lot of heat is not needed the floor will feel “neutral” – neither cold nor warm. On cold days, the floors will feel warmer, the colder it gets outside.
With radiant floor heat, you can put the heavy socks and slippers away in the middle of winter. However, the floor never becomes so warm, that it would be uncomfortable to wear shoes.
History – Even Old Romans Knew What Was Good For Them:
During the days of the Roman Empire, a sophisticated system of fires were built under the great stone floors of their bathhouses. This kept the floors and the rooms warm so the patrons could lounge in luxury beside the pool.
The Koreans have done the same for thousands of years with their homes. They have a fire pit under one end of the house and direct the heated air and smoke under the floor of the house and up a chimney on the other side.
Great stones placed under the house in the path of the heated air retain the heat and continue to keep the floor warm throughout the night after the fire has gone out.
In North America radiant floor systems have continued to be used over the years on a limited basis, it was not until the advent of synthetic rubber and plastic tubing suitable for the job that there began a renewed interest in radiant floor heating.
Since the interest was rekindled in the late seventies and early eighties, a new industry has grown up around radiant floor heating. People are rediscovering the extreme comfort and energy efficiency of this type of heat.
When Does it Make Sense?
The cost-effectiveness of new technologies and construction techniques has made the comfort of radiant heating affordable and adaptable to almost any situation.
- It especially makes sense in houses and small commercial buildings with conventional levels of insulation and standard insulated glass windows—especially those in climates with minimal cooling loads—where the extra comfort of radiant heat is desired, and the budget allows.
- In buildings with large open spaces and tall ceilings.
- In buildings where air-flushing is common, such as garages, fire stations, airplane hangars, and industrial areas (because the large-area radiant floor allows quick recovery).
- When cost is not an issue and satisfying most or all of the heating load with solar energy is a high priority.
- When building occupants have an acute chemical sensitivity or allergies—in which case there may be concern that dust could be distributed through a forced-air system or that high surface temperatures from a gas burner or electric heating element will burn dust particles and cause health problems.
Comfort – You Will Find Yourself Laying On the Floor More Often:
By far, the biggest selling point for radiant-floor heating is the comfort. The large radiant surface means that most of the heat will be delivered by radiation—heating occupants directly—rather than by convection.
Warmer surfaces in a living space result in a higher mean radiant temperature (a measure of surface temperatures in an area that influences the rate of radiant heat loss from occupants). With higher mean radiant temperatures, most people are comfortable even at lower air temperatures.
Studies conducted by the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) indicate that with radiant heating systems people can be comfortable at temperatures 2Â°C to 4Â°C lower than with convective systems.
Energy savings – Money in the Bank:
There is potential for saving energy with radiant-floor heating through several mechanisms, including lower thermostat settings, lower-temperature boiler configuration, and reduced infiltration.
Homeowners with radiant-floor heating are likely to be comfortable at lower air temperatures because of the elevated mean radiant temperature in such homes, the lack of significant airflow, and the delivery of heat at floor level.
The second opportunity for energy savings with radiant-floor heating is through keeping the boiler temperature lower than is necessary with conventional baseboard hot water distribution.
The third opportunity for energy savings (over forced-air heat) is that radiant-floor systems do not increase the rate of air infiltration.
Standard forced-air heating systems can significantly increase or decrease the air pressure in different parts of a building, which in turn can increase air infiltration/exfiltration rates—at least in a conventional, leaky building. With radiant floor heating, as with hydronic baseboard heating, this will not happen.
Potential for use of solar energy.
The relatively low temperature required for circulation water in a radiant-floor heating system provides an opportunity to utilize solar hot water.
This approach works best with concrete-slab systems; higher-temperature water is required when the tubing is attached to the underside of wooden floors.
While such systems are somewhat complex and expensive, radiant slabs offer one of the best ways to make use of solar energy for heating portions of a building without direct access to sunlight.
Backup heat is still required and can be provided with a wood stove, through-the-wall-vented gas heater, electric resistance heat, or backup heating element in the solar storage tank.
Quiet Operation – You Can Hear Yourself Think:
Radiant hydronic floor heating is soundless. Unlike forced-air heat, there is no noise from a fan or airflow through ducts; and unlike hydronic baseboard heat, there is usually no gurgle of water through baseboard radiators or creaking from expansion and contraction.
The primary noise will be the sound of circulating pumps and the fan used in power-venting the boiler. With radiant-floor systems that have tubing attached to the underside of wood flooring, there may also be some creaking from expansion and contraction.
Humidification is unnecessary with a radiant system because radiant heat does not alter residential air moisture content, which is adequate if the air isn’t dried out by combustion or by increased infiltration of cold, dry outside air.
Flexible Room Layout – Put Your Furniture Anywhere You Please
Because there are no baseboard radiators or air registers with radiant-floor heating, there is much greater freedom as to where furniture can be placed. Radiant-floor heating systems are “invisible.”
Improved Air Quality:
Houses with radiant-floor heat boast improved air quality. Compared with a conventional forced-air distribution system, there is likely to be less dust circulating the room.
And unlike electric baseboard or forced-air heat, there will be no surfaces hot enough to burn dust particles—which could introduce volatile chemicals or toxic particulates into house air (even passing through filters).
This concern would be greatest for people with allergies and acute chemical sensitivities.
It’s hard to express doubts about something that’s popular. Like ground-source heat pumps, radiant floor heating has a loyal and zealous following of builders, designers, and homeowners who consider it to be the best heating option around—and appropriate in almost any situation.
Until you’ve lived with this form of heat, it’s hard to judge how comfortable it is. However, once lived in radiant floor heated home most people report they would never go back to living in a house without it.