Rustic on the outside, high-tech radiant inside

BY STEVE SPAULDING
OF CONTRACTOR'S STAFF

SEATTLE — The "river" in the Mountain River Lodge refers to the Yakima, and the lodge overlooks a bend of the river that is famous statewide for its fly-fishing. Located outside Easton, Wash., it was the inspiring natural beauty of the locale that made the owner decide to build there.

"The owner first came to me a couple of years ago with this dream of building a lodge in the mountains as a destination point for conferences, retreats and camps," explained Buzz Burgett, president of Northwest Mechanical in Shoreline, Wash., directly north of Seattle.

The lodge owner had a long involvement with nondenominational Christian youth groups but couldn't find many places in the state that were both remote and comfortable with the capacity he needed. After more than a year in the planning stages and a trip to the bank, the owner and Northwest Mechanical finally were able to sit down in April 2005 and begin engineering a hydronic system. The 10,000-sq.-ft. lodge is now scheduled to open in early spring 2007.

"The log structure is up," Burgett said, "the mechanical systems are all in. They haven't Sheetrocked all the surfaces that are supposed to be Sheetrock. They're going to be starting the finishes shortly."

All that remains for Northwest to do is set the thermostats and do a final "spit and polish," Burgett said. The main floor, roughly 5,000 sq. ft., is all radiant. Northwest Mechanical installed nearly 8,000 linear ft. of Uponor Wirsbo PEX tubing. The second floor — consisting mostly of bedrooms and bunkrooms — is heated by Buderus radiators, one for each room. While the main floor is inslab, it is not slab-on-grade.

"It's built on a flood plain," Burgett said, "so the whole building is built 4 ft. off the ground to accommodate the potential of the river to flood."

Essentially the river could flow right through the home via the crawlspace. The main floor is all inset in Gypcrete.

The system is propane-powered, using two condensing Triangle Tube Solo 110 boilers. Designed around a -3°/-4° heat loss, the two boilers give the system 100% redundancy. The boilers work to heat two 120-gal. Triangle Tube SmartTank storage tanks.

During the installation, Burgett found the adaptability of radiant technology was able to solve some of the unique challenges involved in heating a log-built structure. For one thing, the lodge is expected to settle, perhaps as much as 8 in.

"All the piping that was going between floors had to accommodate that 8-in. flexibility," Burgett said.

Using PEX tubing was an easy way to build that flexibility right into the system. Another issue was insulation. "The R-value of the logs isn't consistent," he said. "You have various-sized logs, you have the point at which the logs meet and you have the chinking."

While logs — when assembled correctly — are excellent insulators, all the variables make it difficult to calculate what the true heat loss would be. Luckily, Northwest had finished another log home a year prior, so it was able to make some good approximations. And to ensure against any thin spots in the insulation, Northwest loaded up the perimeter with extra radiant loops.

"When all is said and done," Burgett said, "the logs make for a reasonably tight structure, and they really do look beautiful."

Northwest Mechanical billed the system at $95,000.

"As an average, you're looking at about $10 a sq. ft. for a quality radiant system," Burgett said. "Very complex systems can be more, and they can be less, but it seems to me the price is going in a higher direction because of all the cost increases."

Northwest Mechanical has been in business since 1977, and Burgett has been working there since 1985. He purchased the business in 1993.

Burgett owns and manages a full-service, 25- person shop with four design/ build crews and five service trucks. The company has a professional engineer on staff and does the up-front engineering on projects, including CAD drawings.

"We typically start with the architect and the homeowner, develop a team relationship and work through a process of engineering a system that's going to be right for their new home," Burgett explained.

Budgets are set early on and drive the engineering decisions. Installation crews then go out to work hand-inhand with the general contractor.

Northwest specializes in radiant work. Before Burgett came to Northwest he owned a small solar heating company, and the transition from solar work to radiant was not much of a leap.

"You're used to transferring heat energy using pipes, so it was a natural transition to go to radiant and then radiators," he said.

When the federal tax credits stopped the solar work dried up, but the focus on radiant remained. Back in the mid-1980s, Northwest was one of the few companies in the Pacific Northwest to use the more advanced radiant technology, such as flexible PEX tubing.

It was that combination of experience and expertise that attracted the owner of the Mountain River Lodge.