How Radiant Heating Works
If you're looking into the purchase of a radiant heating or radiant floor heating system, then you should know the fundamentals of how they work. Fortunately, the basics behind how a radiant heating system works are easy to grasp. You've likely been using radiant heating in some form or another your entire life without even realizing it.
Radiant Heating Throughout History
Once they'd mastered the basics of building and maintaining a fire, early humans also noticed that the rocks lying next to the fire stayed hot longer than the air and would continue to radiate heat long after the fire died and the air cooled. In that way, mankind drew comfort from radiant heating before we could even speak.
These early experiments with radiant heating lead to the use of blocks of masonry heated by fire as well as specially-built masonry heaters. The invention of the fireplace added the effect of convection by drawing cold air up and out of a room as well.
One of the earliest examples of radiant heating came from the ever-industrious Romans. The sophisticated and costly Roman hypocaust used the principle of convection to spread hot air through a building by conveying it from a furnace room through hollow tubes built into the structure. The brick and stone walls and floors heated by the hypocaust then emitted infrared radiation to warm the whole room. Artifacts indicating the use of under-floor radiant heating date back to around 5,000 B.C.
The same basic principle is in use today, but modern radiant heating systems typically use more effective heating elements than air thanks to the availability of electricity and natural gas in the household.
How Does Modern Radiant Heating Work?
If you have a furnace, you know that it heats up air and uses a fan to blow that hot air into the various rooms of your home through a series of ducts. Radiant heating, on the other hand, works without the use of ductwork or a fan by applying heat directly to specially-designed panels in the walls or ceiling. Radiant floor heating, unsurprisingly, eschews ductwork and a fan by applying heat directly to your floors.
Both forms of radiant heating can be adapted to use any common fuel source already present in a house, including boilers, heat pumps, active solar heat, and electric heating. That adaptability is due to the variety of methods by which radiant heating can be implemented.
The primary division among radiant heating methods lies in the use of either water-filled tubing or an electric thermal mass heater. Beyond that, the differences mostly relate to where the devices are installed, i.e. in the floor, walls, or ceiling. Traditional radiant heating and radiant floor heating are considered distinct from one another.
A purely electric system, which uses plates or conductive mesh embedded in a heat-retaining material such as concrete or tile, is simple and effective, but can be more expensive to implement and maintain. The cheaper solution is an hydronic system, which uses hot water pumped through tubes.
An air-heated radiant floor is also an option, as well, but it's important to note that they are generally considered both inefficient and impractical. Air-heated radiant floors are occasionally used in conjunction with solar power systems and solar air heaters. However, if you're planning to install a radiant floor heating system, it's best to opt for an electrical or hydronic system.
The correct radiant heating system for your home mostly depends on your budget and the fuel source you already use.
Before you set out to install and implement a radiant heating system in your home, you'll want to take into account a few factors that extend beyond the type of radiant heating system you're looking for.
When you do install a radiant heating system of any kind, it's important to understand the potential for error over the course of this complicated process. First, it's strongly recommended that you use a specialized contractor to properly install your radiant heating or radiant floor heating system, so that it doesn't break down due to installation error. Failure on the part of any one of the many specialized tradesmen required for the job -- from a carpenter to a concrete mixer -- can contribute to the eventual breakdown of the whole system. For example, an improperly sealed connection among the pipes could show no warning signs until after the system is completely installed and pressurized.
Since hydronic radiant heating systems use pipes and pumps, it's crucial to have them inspected for leaks simultaneously with your yearly inspection and maintenance of boilers and other equipment. One leaking connection can cause your system to lose pressure, decreasing energy efficiency. The leaked water, in turn, can lead to corrosion and further damage, and the air introduced into the system can make noise, too. If you have a preventative maintenance contract with your HVAC service provider, be sure to check it for radiant heating system coverage.
Another consideration before selecting a radiant heating or cooling system is the climate. Hot air being pumped in from a furnace can really dry out a room, but radiant systems have a much lesser drying effect on the air. If you live in a cold and wet climate, this could contribute to moisture control issues you experience in your home.
Finally, no matter what type of radiant heating system you employ, the installation can be an expensive and lengthy process, because it is embedded within the structure itself, and should ideally be done during construction or a massive remodel. Old houses can, with some effort, be retrofitted with radiant heating, which adds value in the long run, and can save on energy, especially for homeowners who only need to heat a few rooms at a time. If radiant heating sounds like the right choice for you, let us help you get started by choosing a contractor.