Forced-air heating works by sending furnace-heated air through ductwork and into the living spaces. The catch? Hot air doesn't always go where you want it to go. In fact, as you remember from school, warm air rises. This means that soon after entering a room, warm air floats up to the ceiling, leaving the temperature as chilly as ever down below. What does the homeowner do in response? She turns up the heat, of course—and in doing so, drives up the energy bill. Fortunately, not every heating system relies on the movement of air. Radiant floor heating, for instance, operates via thermal radiation, which concentrates warmth not way up by the ceiling where you can't feel it, but instead right where you need comfort the most.
Location, Location, Location
In a home with forced air, your comfort often depends on your location. It's warmest—too warm—directly next to the vent. But as you travel farther and farther away, it gets cooler and cooler, until you find yourself reaching either for a sweater or the thermostat. At the same time, with conditioned warm air always rising, upper floors tend to feel overly warm and lower floors not warm enough. Simply put, by heating the home unevenly, forced air makes the homeowner choose between enduring discomfort (thriftily) or turning up the heat (at a cost). With radiant heating, it's a whole different story, because the technology delivers from-the-ground-up warmth across every square of floor space, ensuring that from wall to wall, room to room, and bottom level to top story, the temperature doesn't waver.
On Again, Off Again
Forced air only compounds the problem of uneven heating by operating cyclically—that is, by stopping and starting over and over. If you've ever set foot in a home heated by forced air, you know the routine. When the system kicks on, warm air roars into the space—for a while—then suddenly halts. Later, once the home has cooled to a threshold point, the heat starts up again. The result? Intermittent, dramatic temperature swings that send the homeowner back to the thermostat again and again. One of the great appeals of radiant heating is that it operates continuously—and silently—delivering comfort that doesn't come and go, but remains cost-effectively consistent.
Leakage and Loss
Ductwork plays an integral role in the operation of any forced-air system. That may not be a bad thing on paper, but in practice, air ducts very often prove leaky, particularly when they run through uninsulated space or when gaps form at the joints between two sections. Believe it or not, in the process of transmitting heat throughout the home, ducts can lose enough of it to reduce the system's overall efficiency by 20 percent or more. No other heating system suffers the same fate. For instance, with radiant heat—the Warmboard system, for example—minimal heat loss translates into maximum savings. Meaning, you pay only for the heat you feel, and not for heat lost to a ductwork design flaw.
If you've ever stepped barefoot onto a cold tile floor, you know that comfort partly depends on the temperature of the surfaces, furnishings, and objects you come into contact with. That's another reason why forced air underwhelms homeowners: If it warms anything else besides the air, it does so only to a modest degree. In pursuit of greater comfort, therefore, you turn the thermostat up higher and higher, risking unpleasant consequences for your household budget. That's why, for all-encompassing, "everywhere" warmth, industry experts increasingly recommend radiant heating. It's a technology that doesn't stop at warming the occupants of the home—it also warms everything else.
All or Nothing
In a conventional forced-air system, one thermostat controls the temperature of the entire home. If you want to heat ANY room, in other words, you must heat EVERY room. Next-generation options like radiant heating enable you to reject the all-or-nothing approach and all the energy that it wastes. Instead, the technology lends itself with surpassing ease to a zoned setup, in which you can target different temperatures to different parts of the house. That way, you can turn up the heat in the space you're in, while turning it down everywhere else. Not only does zoning save you significant sums of money, but it also saves you from the stress of family infighting over the thermostat setting. At last, different household members with different temperature preferences can all be comfortable at the same time.
The Radiant Solution
Given these considerations, it's no surprise that studies have found radiant heat to perform at least 25 percent more efficiently than forced air. Whether or not a radiant system provides any further savings usually depends on its design. The traditional design hinges on gypsum concrete, which has a significant downside: it takes a long time to heat up and cool off. That's why industry leader Warmboard swaps concrete for aluminum, a material that's 232 times more conductive. In fact, aluminum transfers heat so effectively that it enables Warmboard to achieve the target temperature with less energy than would be required by any other system. In fact, with Warmboard, you save 10 to 20 percent on top of what you'd already be saving simply by having chosen hydronic radiant heating in the first place!
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