Rhode Island snow melt is steaming

Special to CONTRACTOR NEWPORT, R.I. The snow melt works so well you can see steam coming off of it, said Charlie McCarthy, the radiant heating guru for contractor Donovan & Sons, Middletown, R.I., about his firms latest job at an upscale residence in Newport. The house includes radiant floors in its 612 bathrooms and lap swimming pool, multiple hydro-air zones and snow melting in the circular driveway.

Special to CONTRACTOR

NEWPORT, R.I. — “The snow melt works so well you can see steam coming off of it,” said Charlie McCarthy, the radiant heating guru for contractor Donovan & Sons, Middletown, R.I., about his firm’s latest job at an upscale residence in Newport.

The house includes radiant floors in its 612 bathrooms and lap swimming pool, multiple hydro-air zones and snow melting in the circular driveway. A prominent Rhode Island citizen, who wishes to remain anonymous, owns the three-floor house. The house has two bedrooms on the third floor and four on the second floor, including the master suite.

McCarthy selected four Viessmann boilers and a 120-gal. VertiCell domestic hot water tank, all controlled by a tekmar Model 254 four-stage boiler/domestic hot water controller. The boilers feed 10 hydro-air zones. A separate air conditioning subcontractor placed the First Co. air handlers, but Donovan & Sons piped to them and wired the controls, including Taco relays.

“Two boilers would do the house,” McCarthy told CONTRACTOR. “That’s 600,000 Btuh, and two are there for the snow melt, but they’re all wired together.”

Donovan & Sons was hired on a time-and-material basis to finish the job after the original contractor was dismissed. Because construction had already started, McCarthy said he was forced to make some compromises.

For example, the lap pool area was supposed to be heated electrically until the electrical inspector said no. The slab, however, had already been poured. McCarthy put aluminum heat transfer plates on the floor, put down a mat and tied Stadler-Viega 516-in. tubing to the mat in 200-ft. loops. The tile contractor put bluestone tile down on top of the tubing. Donovan & Sons also installed the makeup water system and the Teledyne Laars power-vented heaters for the pool.

For the snow-melt system, McCarthy said he would have preferred to have placed his manifolds in the garage, but he had to put them outside in a pit.

“If I had known that they were going to do this, I would have put the manifold in the garage, but it was an add-on after the job was started because the driveway is so steep,” he noted.

The contractor ran 40 ft. of insulated 114-in. Type K copper tube out to the manifold. McCarthy put 6,000 ft. of Stadler-Viega tubing into the ground — mostly 25 mm and some 19 mm — in 500-ft. loops on top of Styrofoam insulation board. The snow-melt system is controlled by injection rather than a mixing valve. The driveway is concrete that’s stamped so it looks like cobblestone.

Donovan also installed the plumbing for the job, which Dan Donovan described as “pretty much standard.” The job was piped in copper.

The bathrooms, including children’s and guest bathrooms, contain Kohler fixtures, Porcher toilets and Grohe fittings. Some of the baths have whirlpool tubs. Donovan said he liked the flexibility of the Grohe fittings to provide different configurations of showerheads and body sprays.

The kitchen includes two under-mount Blanco stainless steel sinks and Grohe fittings.