Radiant On A Grand Scale
Best Of Show
American HeatingContractor John Mills started small -- repairing solar panels. His interest eventually shifted to comfort systems in general, then to radiant in particular.
Sun Valley Residence
When Mills founded American Heating in 1985, he was installing about 5 percent radiant. Today, he works on two radiant jobs for each forced air job. 16 years ago, American Heating consisted of John Mills. Today, the company has 14 employees and last year, hit $1.5 million in sales -- most of which is radiant.
At least some of the credit for American Heating's success lies in their location. "We are very fortunate to be in a market that serves people with higher incomes who demand quality -- they will pay money for the value."
Mills got the job that won Best of Show because he was the only contractor bidding on it who lives in the area and he has experience with both sheet metal and radiant installations on large houses.
The setting for the job is a residence near Sun Valley, Idaho. This humble abode weighs in at about 23,500 sq. ft. -- all of which is radiant heated with secondary, forced air for backup. It also has a radiant snowmelt system built to service 16,000 sq. ft. The home has a main living area on the first floor and the second floor has guest bedrooms and a caretaker's apartment. As you might imagine, this job took a great deal of planning. "Our philosophy for a project of this scope was that there had to be an organized plan before the first screw went in," says Mills.
Another challenge of the job was planning the way to use the mechanical room. There were several other trades who were using this space for their work. The requirements of the other trades had to be considered and the space had to be arranged so there was room for everyone. Mills set four 4-by-4 steel posts into the slab floor and overhead framing. A primary, high-temperature panel is supported by one pair of posts. The second pair of posts supports the low-temperature panel. The two panels are tied together by an injection system. The architect designated a vent chase, which determined where the boilers (plumbed primary/secondary) would be set. The system has a primary pump -- even thought each high-temperature zone is individually pumped. The high-temperature panel is the primary loop. "We know that we have enough flow to move the heat where it's needed," says Mills.
Among the home's unique features is a basement that houses two separate mechanical rooms (as well as a billiards room, a theater, a powder room and a darkroom for photography). One of the mechanical rooms is for the space heating system (as well as equipment for the other trades). The other services the snow melt equipment. It was critical that planning the use of the mechanical rooms be exact and thorough, because there simply wasn't room for error. If one trade botched its job, it would affect the others.
A Lutron whole house management system ties everything from the stereo to the comfort system together. Mills says one of the most challenging and fulfilling aspects of this particular job was researching and developing an understanding of whole house automation systems. Mills designed his system to be compatible with the Lutron system, but operate independently if the Lutron system collapses. This stand-alone setup is essential for technicians who know radiant, but don't know whole house automation systems, to be able to service the home's comfort controls. "Our main concern for this project was that the control package be as simple as possible," says Mills.
The house has 25 independent heating zones. From these 25 zones come 10 second-stage zones -- in case there is a need for additional heat. They all have Enerzone "Enerstats" thermostats, because Enerzone specializes in making equipment compatible with whole house automation systems. Each radiant zone is individually pumped as well as each second-stage zone. The spa and indirect-fired water heating system each has its own pump. Taco switching relay controls and Taco zone controls were used to operate the zone valves.
The heating zones are all run off two, multistage, Lochinvar CHN boilers, just in case one goes out of service. A tekmar 262 staging control employs each boiler as needed and balances the work between the twin Lochinvar CHN boilers, so at the year's end, both boilers will have performed the same amount of work.
The snowmelting system was designed to serve 16,000-sq. ft. of driveways, courtyard, front stairs and terrace, multiple patios, second-floor bedroom decks and two large mechanical equipment areas. There is a second mechanical room that was set aside just for this system. Two Lochinvar CBN2065, high/low-fired boilers are plumbed primary/secondary using Grundfos Versaflo pumps and staged through aquastats. A frame was built around the pumps to support a noise-dampening curtain. There are several exterior manifold locations and all exterior trunk lines are HDPE. The grid tubing is 3/4-inch ID cross-linked polyethylene. An Environmental Technologies ASP snowmelt control system keeps everything fully automatic.
The house has 10 air handling systems to provide second-stage heat/air conditioning and keep air quality reasonable. The condensing unit and ventilation fans are placed in a hidden, snowmelted area on the roof.
Mills was impressed with the workmanship of the other trades working on the house. "All work was neat, organized and accessible," says Mills. He is most proud of the pre-installation footwork that happened during the planning stages of this project. There were many trades competing for a relatively small space and it could not have worked if the pre-installation planning was not superior.