Clinton’s retrofit job of an elderly care facility proved as difficult as balancing the budget (or, for you Republicans, escaping impeachment). The same could be said for two more jobs — one by Jim Patterson in Massachusetts of a B&B, and another by Clay Thornton in Utah of a historic military post. These three cases illustrate the variety of radiant heating retrofit jobs sprouting up in the United States.

Hayes Valley Elderly Care Facility Bay Hydronic San Francisco, Calif.

Clinton, of California-based Bay Hydronic, stepped into the gutted 93-year-old building down the block from the San Francisco Civic Center and realized multiple zones (37 to be exact) were the most important factor in designing this building’s radiant heating system.

Only the exterior walls, interior floor and ceiling was left in the two-story building, says Clinton, who has been in the trade since 1971, and exclusively installing radiant heat since 1986. “This design was fun to work out,” he says. “We wanted to keep the individual residents satisfied, but didn’t want to create a complicated system.”

The biggest challenge the structure presented, Clinton says, was the lack of space to run supply and return mains. There wasn’t a basement or an attic, so his company threaded the mains through the original roof truss.

The control system was solved in a slick way. Bay Hydronic installed non-electric, wall-mounted thermostatic valves. (The wall-mounted steel boxes were eventually covered with white enamel plates for aesthetics.) “In contrast to the ‘bang, bang’ on-off operation of thermostats, these valves continuously modulate water flow, precisely matching heat delivered to the heat needed,” adds Clinton. “No overshoot, no undershoot.”

Bay Hydronic determined a continuous flow circulator best suited the elderly care facility. “It made the pump control easy,” Clinton explains. “We wired a pigtail on each of the two circulators, and simply plugged them in.” Two condensing water heaters were set to maintain 120 degrees F.

The combination of thermostatic valves with constant circulation in an environment where no setback was required meant that constant temperature was maintained, says Clinton. The valve provides modulation of flow rate, which in turn modulates temperature drop across the floor. “It’s an ideal thermal environment all the time,” he says. “The average radiant temperature is fully modulated.”

Clinton combined radiant floor, ceiling and wall panel heat to craft a system with 94 percent efficiency. Most of the rooms are radiant floor heat, although it wasn’t possible for a couple of the bathrooms, so radiant ceiling heat was installed instead. PEX tubing (the 1/2-inch variety) was used throughout and in a counterflow spiral pattern.

The system oversees heat for 23 carpeted bedrooms, six tiled bathrooms, three sitting rooms, two dining rooms and a kitchen, entertainment room and reception area. “It’s silent, draft free and avoids possibly transferring germs from one room to another in heating ventilation ducts,” Clinton says. “Good health is aided by good heating. “No other system we can dream of would provide the comfort, individualized control, health benefits and efficiency in this system,” adds Clinton. “No other system so exactly meets the needs of the application. And it’s simple to service.”

The Saltbox Orchard Valley Technology Northampton, Mass.

“Mechanically, it was a tough building to fit our things into,” says Patterson, general manager of Orchard Valley Technology in Haydenville, Mass. “There were a lot of crawl spaces and low ceilings with no attics.” The 2,300 sq. ft. structure, more than 200 years old, resides near Smith College.

Not only did Patterson need to create a system where everyone could control his own temperature, but he also needed to be detailed oriented to keep his customer happy. “She was trying to bring the house back to the era that it was built,” he says. “She wanted something that was going to aesthetically blend in.” (The aesthetics ruled out baseboard, which the homeowner thought would detract from her targeted environment.)

The system covers the front portion of the bed-and-breakfast, two entertainment rooms, a large kitchen and the owner’s wing. This radiant system streamlined the previous heating system, which used three grossly oversized boilers, Patterson says.

He eventually designed a system with 27 zones that used a variety of radiant wall panels as the primary heat source in a majority of the house. The white powder-finished units, which rise out of the floor, sit only 3 inches from the wall. The units were a cost upgrade, but provide superior comfort levels, according to Patterson.

Orchard Valley Technology snaked PEX tubing through the walls and crawl spaces to each panel. One gas-fired boiler with a horizontal indirect water heater and a microprocessor were used to help complete the system. “Because of the medium temperature operating range of these panels, the radiant heat broadcasted by the large surface areas can be felt several feet away,” explains Patterson, who has been installing radiant heat since 1995. “Their clients always comment about it.”

Towel warmers serve as the primary heat source in the bathroom. Patterson says the towel warmers worked out perfect for the owner. When people walk into the bathroom it’s the first thing they see, he says. “It turned into a real neat feature for a bed-and-breakfast,” adds Patterson. “It’s something different. It’s more expensive, but there’s only five or six of them in the house. Patterson sells towl warmers as a long-term investment.

“The homeowner laughs because when couples come over the guys are in the basement looking at the boiler and the women are in the bathroom looking at the towel warmers.”

Patterson now points out his once thought of nightmare is a dream come true. “The bed-and-breakfast scenario has provided us with a constant supply of interested, potential clients,” says Patterson, who has seen a spurt of radiant jobs in the last two years. “The owners have served as an excellent source of referrals for similar jobs. We just sold another job off of it. People are willing to invest in a much better heating system.”

Camp Floyd Stagecoach Inn State Park Thornton Plumbing & Heating Fairfield, Utah

“One hundred forty years of winter have been hard on the interior of the building,” says Thornton, who co-owns Thornton Plumbing & Heating with Ken Barney. “The park wanted radiant heating because it is an invisible system. They didn’t want anything modern coming out of the house.”

The history of the Camp Floyd Stagecoach Inn State Park is decisively documented in plaques around the site. The former military post quartered the largest troop concentration in the United States from 1858 to 1861. The nearby 2,000-sq.-ft. Stage-coach Inn was originally used by visiting officers of Camp Floyd, and later on as an overnight stop for the pony express.

“Normally, if it’s a new construction you just staple the tubing down to the sub-floor and pour gypcrete over it,” says Thornton. “That really wasn’t an option here. This was very difficult to install.”

Thornton says 2 inches of foam were inserted between the floor joists where 1/2-inch PEX tubing was anchor-ed with auger clips. The warped, rounded plank floor was reinstalled into its original location.

Several modern mechanical pieces dot the structure, but none can be seen by the public. A wall-hung, cast-iron boiler resides in a closet where only the staff has access. A remote sensor thermostat keeps things comfy from on top a door jam. There’s also a vent that comes out the side wall. “There was no place to run a vertical flue,” Thornton explains. “They didn’t want to vent it out the side wall, but we didn’t have another option.”

The job only took about two months to complete, says Thornton. The two-story building was then restored with original period furnishings.