[login]

WHAT IS RADIANT HEAT?

Radiant heat is widely regarded as the most comfortable, healthiest and most natural heating form available.

It is based in principle on the primary source of heat we know - the warmth of the sun. It warms you and the objects around you instead of the air that you breathe.

The warmth felt from the suns rays is not warm air but actually infra-red energy.

HOW DOES RADIANT HEAT WORK?

Like the sun, radiant heat moves in straight lines, warming all the objects in it´s path which in turn act as small heat convertors, giving off their own gentle heat thus preventing people losing warmth to cold objects such as walls, floors, tables, chairs, etc.
The key aspect of radiant heat is its transmission by electromagnetic waves.

Air is transparent to the transfer of energy, which occurs directly from warmer to cooler objects.

Return to top

WHAT ARE THE ADVANTAGES AND DIFFERENCES AGAINST OTHER FORMS OF HEATING?

The biggest difference between radiant heating and conventional heating systems (hot air) is that, radiant heat controls the rate at which your body loses heat. Hot air systems just put air into the room without heating the objects.

The air quality of your home is cleaner because dust and other air pollutants such as mould, fungi, bacterium and viruses are not blown as with conventional "forced air" systems. The absence of air vents also creates a quiet and peaceful atmosphere in your home.

Radiant heaters are safer, more durable and more cost effective than all other forms of heating available.

During tests in the United States carried out by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), a room was built containing every form of heating commercially available. Test subjects invited to participate were exposed to the different types of heating and asked to set their own comfort levels using thermostats marked only with numbers and showing no temperature settings. The results showed that when exposed to radiant heat, the test subjects selected temperature levels on average 5.6ºC lower than any other form of heating.
Radiant heat is clean - fabrics and painted surfaces stay brighter and fresher because radiant heat carries no grimy fumes and dust to soil them as with systems that heat the air. Cold surfaces such as walls and floors attract grime and dust more readily than warm surfaces.

Thermostatically controlled high consumption oil-filled radiators (1200W-1500W) switch themselves off when the room reaches its desired temperature. Most people budget that they will be on standby for approximately 50% of the time, however, in general they run for at least 75% making them an expensive heating alternative.

Conventional heaters allow the heat to collect unevenly where it is most likely to escape - the ceiling and along walls. Because the temperature with radiant heat in a room remains relatively constant, heat loss can be reduced by up to 25%.
Rooms heated by fan heaters lose heat as soon as they are switched off because they only heat the air, not the objects, which in turn heat the air.

The lower temperature required for a radiant heat system helps to maintain natural humidity and lower static electricity levels. Humidification is unnecessary with a radiant system because radiant heat does not alter residential air moisture content, which is generally adequate if the air is not dried out by combustion or by increased infiltration of cold, dry outside air.

Return to top

HOW DOES RADIANT HEAT AFFECT US AND OUR BODY?

No heat is as healthful and safe as radiant heat, which produces no chemicals, dust particles, odours or fumes, thus making it more appropriate for asthmatics, arthritis sufferers, persons with allergies or chemical sensitivities.

People actually accept radiant heat better than any other form of heating which is why the principle is used in incubators for keeping babies and chickens warm.

Your body has its own heating system which helps sustain life. Marvellous though it is, the human heating system alone can't keep you comfortable. For while the body generates heat, it also loses heat. Body heat is given off in winter by radiation, convection, and in a minor way, evaporation.

Radiation is the transfer of heat by direct rays from your body to cooler objects around you. Place your hand next to a block of ice and you'll feel a chill as rays of heat leave your hand. Similarly, cold walls and floors draw heat from your body.
Convection is the transfer of heat from your body caused by the movement of air around you. A fan cools you because the draft pulls heat from your body. Even warm air will chill you if it moves rapidly around you.
Evaporation is the transfer of heat from your body caused by water drying on your skin, as when you step from the bath.
This only plays a minor part in body's the heat loss.

Your body acts like a radiator - when you are not doing any work, your body produces about 400 BTU´s /hr. You give up about 100 BTU´s /hr by expiration (perspiration and breathing). Another 200 BTU's are lost by radiating towards cooler objects around you.

The rate of heat emission from the human body is influenced by the air temperature, the air velocity and the mean radiant temperature to which the body is exposed. Low air temperature has the effect of increasing body heat loss giving rise to the sensation of cold. Conversely, the body feels warm when mean radiant temperature and air temperature are increased and the air velocity is reduced. In terms of achieving comfortable warmth, experiments show that increasing the mean radiant temperature has approximately twice the impact of raising the air temperature.

This explains why radiant heat is so effective in providing comfortable warmth. Therefore, your surroundings affect the rate at which you give off body heat. If the body is properly balanced with the environment, you feel comfortable. Several things influence this such as drafts, cold walls and floors, losing as much as 50% of a bodies heat - a bare foot on a cold floor or an arm brushing against a cold wall.

With radiant heat, surfaces are not prone to loosing heat, so it is not necessary to overheat your home to maintain a comfortable temperature. When the objects in a room are warm, the comfortable temperature remains with a lower expenditure of energy. As the heat is distributed evenly throughout the room - radiant heat provides true comfort.

Return to top