Six Myths of Eichler Radiant Heating - Page 2

Six myths tied to your radiant heat system: surviving winter by warming up to reality

Steel pipes do not rust from the inside if the system is leak free and well maintained. That's a big 'if.' Steel pipes are very unforgiving, and even a minor leak left unattended can cause irreversible damage by allowing oxygen to be drawn in to the closed loop that can corrode the system. Wet conditions in the slab from poor drainage, roof leaks, or plumbing leaks can do serious damage to the outside of the steel pipes.

While steel pipes can be repaired, great care must be taken in the method and materials used. There are some good additives that can help extend steel pipe life, but unlike copper tube, total failures happen far more frequently.

Myth #4: Baseboard heating is the only practical replacement solution for a defunct radiant system.

It all depends. How does one define 'practical'? Typically, baseboard systems found in Eichler homes are replacement units comprised of long, fin-tube radiators with sheet metal enclosures that are positioned along walls in each of the heated rooms. Hydronic baseboards are hooked up to the existing boiler, if still operable, or a replacement.

While baseboards are perhaps the least expensive replacement option, they take up a lot of wall space and may be an aesthetic concern. Also, since they collect dust within their unit housing, they need to be cleaned periodically.

European-style flat panel radiators and towel warmers have many more design options; and fan convectors (which give instant heat and can be tucked under cabinets) can also be used in conjunction with the existing boiler and combined in the same system. An installer can assist in understanding and choosing from the many types and brands of products available for a whole-house hydronic heating system.

It is also possible to completely replace the radiant floor tubing without jackhammering out the slab. Using hydronic tubing, this is typically accomplished with an overlay of insulation and a poured cement-type material. However, this option raises the floor height by one-and-one-half inches or more, requiring changes to all of the door openings. The efficiency gained is significant, and so is the cost. But on a major renovation, it's worth considering.

Other heating alternatives usually involve rooftop forced air with multiple register holes cut through the roof, and heat blowing down from the ceiling. Roofing replacement is usually scheduled at the same time to seal in penetrations. These can be big-ticket items.

There are also moderately priced mini-split systems that combine air-conditioning with heat capabilities (as do the roof-top forced air systems), but do not require roof penetration, extensive ducting, and re-roofing.

Electric systems are available, but like the other options already discussed, they have special features that must be carefully weighed against the three rules of practicality: space, aesthetics, and cost (installation, long-term energy use, and maintenance).

Myth #5: Installing quality wall-to-wall carpet and pad will help keep heat in the house and increase overall comfort.

Absolutely not true. Carpeting and pad defeat most of the advantages of radiant heating, since they heat the wrong side of the floor.

When wall-to-wall carpeting with a pad are in place, the heating output per square foot could drop by 50 percent or more. In addition, the carpet certainly will add to the slow response time already required to heat the house and have an impact on utility bills.

Concrete, tile, and stone give the best output, followed by other hard floor coverings. If one must live with carpeting, there is a low 'R-value' pad available, but it still will not come close to matching the heat performance of the proper materials.

Myth #6: The original wall thermostat is inaccurate, but since it is line voltage, it can't be replaced with a programmable model without costly wiring changes.

Not these days. Programmable thermostats are required by code on all new houses for energy conservation, and are especially important on radiant systems, which typically have long response times.

Accurate, programmable setback thermostats that suit the very special single-pole, line voltage requirements of Eichlers are available, and can replace the existing thermostats with no extra wiring. These models should not be confused with double-pole or low-voltage models.

Even if the programmable features are not used, these modern thermostat models are far more accurate in a simple on/off mode than the old type of thermostat.

It is also possible to add controls that sense outdoor as well as indoor temperature. Common in Europe, on the East Coast, and in commercial applications where energy conservation is important, they anticipate and adjust for rapid changes in outside temperature to maintain an even heat in the house. They do cost more.

Guest 'House Doc' Jerry Rothfeld is a radiant heat maintenance expert who operates Jerry Rothfeld's Hydronic Heating Service (800-478-3060) - email, serving Marin, San Francisco, and the East Bay.