Radiant Heating-What You Need to Know

Whether you want to remodel your bathroom, put in new flooring, countertops and cabinets or do a complete overhaul, remodeling your home can be an exiting and enjoyable experience. Sure there could be a few snags along the way, but if you do your research and plan ahead the end result will be well worth the trouble. You don't necessarily have to give an arm and a leg to enjoy a few luxuries; a few thoughtful changes will make your home the envy of many.

One such option is to install radiant heating. Radiant heating has been in use for a very long time, going as far back as the Roman Empire. Radiant floor heating is a way of keeping your home warm by generating heat underneath or within the floor. This type of heating warms the floor's surface rather than merely raising the temperature of the air in the room.

There are three types of radiant floor heating: hydronic, electric and air. In these pages we will talk about the advantages and disadvantages of hydronic (water) radiant floor heating.

A network of metal or plastic tubing carrying hot water is laid within a floor or underneath a sub floor. These tubes carry hot water into specific rooms or "zones", dispersing the heat through the floor surface. Since the floor is heated throughout there will not be any hot spots or cold spots and your living-space will be evenly heated. The cooler water returns to the heat source where it is reheated and sent out again in what is known as a "closed-loop system". The heat output is determined by pipe spacing, water temperature, flow rate and floor covering.

There are three components to this heating system: a heat source, a distribution piping system and controls. The heat source in hydronic radiant floor heating is usually a boiler or a hot water heater, but other heat sources can be used too. The energy used to heat the hot water can be natural gas, oil, electricity, propane, wood or solar hot water collection. A properly designed radiant floor system will not exceed 29ºC (85ºF).

Radiant heating systems can be easily designed and installed in new constructions. You may also incorporate a radiant heating system in your next remodeling project as long as the following requirements are met.

• The building structure can support the additional weight of the concrete/cement overpour
• The underside of the existing sub-floor is accessible
• There is enough height in the basement for a concrete overpour above the existing floor

You may either install radiant floor heating throughout the house or in selected rooms. Since most of your time is spent in the kitchen, living-room and bathroom it is a popular choice to install radiant heating in these areas. However, if you decide to install radiant heating in only selected areas the rest of the house will need a separate heating and ventilation system.

Pros and Cons of Radiant Heating

PRO: Humidification is unnecessary with a radiant heating system because radiant heat does not alter residential air moisture content and allows your home to maintain a comfortable humidity level. If your home is properly insulated and outside air doesn't often enter your home during winter, room humidity will be kept at an ideal level. The lack of fans or blowers to circulate the air means that particles of dust, pet dander and other unhealthy allergens will remain on the floor for easy cleaning instead of circulating constantly all over your home.

PRO: Costs for radiant heating vary from $600 to $800 for approximately 100 square feet. This cost will increase or decrease depending on specific heating requirements and energy efficiency results. In addition to the heating system, a mechanical ventilation system is required in the house. On average it is calculated that you can save up to 30% in fuel costs with a radiant heating system, so the significant initial investment will save money in the long term.

PRO: With proper maintenance of the mechanical parts such as the circulation pump, water heater and controls, your radiant heating system will last for well over 40 years. With certain types of tubing the lifespan of radiant heating systems can be significantly increased.

CON: Be advised that radiant heating is NOT a "do it yourself" project and requires the services of a qualified technician.

CON: Radiant heating systems may be slower to respond to temperature changes. Overheating can occur in poorly controlled or zoned systems. The system is not designed to have the temperature frequently adjusted. Night setbacks are not practical in most situations as the system is slow to react.

CON: Ventilation must be done separately. As air conditioning cannot be used in ventilation-sized ducts, window/wall air conditioning can be installed or room-by-room split systems can be used. Additionally, high-velocity air conditioning systems that use small outlets in ceiling or walls have proven very compatible with radiant floor heating operation.

CON: Extra support may be needed for the weight of thermal mass topping on a wood floor. If the building structure can't support the weight, then the dry plate system can be considered.