Snowmelt System Enhances Appeal of Bed and Breakfast
Running a bed and breakfast was a dream come true for Pennsylvania entrepreneur Jim Winner and his wife, Donna. Winner is the inventor of "The Club" automotive security device. The century-old gothic mansion and accompanying estate that Winner purchased had previously been used as a private residence. Renovations updated the four-story mansion to allow it to accommodate 20 guests in pampered style while maintaining its Old World charm. Elsewhere on the estate, a carriage house was converted into an art gallery and museum, and an 1,800-sq.-ft. greenhouse was upgraded to stage garden parties year-round.
While inquiring about the potential of radiant floor heating to increase guest comfort, Winner learned of the broader role radiant heating could play in upgrading the property. With a network of snowmelting equipment, the snow, ice and potholes that plagued the parking lot and courtyard could be eliminated. While indoor heating was upgraded throughout the estate for increased guest comfort, the most visible heating upgrade was the snowmelt system.
Winner dealt with a single manufacturer's representative, Rep-Line Sales of Greenock, PA, to cover virtually all aspects of the hydronic heating upgrades. The rep was able to recommend systems utilizing a mix of snowmelting, radiant floor heating, baseboard heating, single boilers, modular boilers and controls from a single manufacturer, Slant/Fin, for use throughout the estate. Using the Slant/Fin Terra Therma system design software in their offices, Rep-Line was able to quickly create and modify system layouts and equipment specifications.
Outdoor HeatingThe primary function of the snowmelt system was to keep the 150-foot circular driveway and parking area clear of snow and ice. The system was extended to include a courtyard adjacent to the museum entrance and several sidewalks and a foot bridge linking the buildings. In all, the system covered a total of about 9,000 square feet.
For the driveway and parking area, 5/8-inch Slant/Fin Terra Therma PEX tubing was embedded in a 6-inch concrete pour over a gravel base. Tubing was secured with nylon ties to wire mesh at a depth of 3 inches. A special curing agent and color dies were added to the concrete so that a simulated cobblestone texture could be stamped into the surface.
The entire snowmelt system is fed by a 1.2 million Btu Slant/Fin Caravan gas modular boiler located in the museum building. Supply water from the three-module boiler system is directed to six manifolds. Each manifold feeds six PEX tubing runs of up to 250 feet each. A separate 1 1/2-inch PEX main travels 120 feet under the driveway to the foot bridge. A remote manifold housed in the mansion basement feeds the six snowmelting loops on the bridge.
Assembly of the manifolds went smoothly due to the modular construction of the Terra Therma manifold components. Manifold modules were stocked in bulk at the wholesaler, Sparmon, Inc., and delivered to the job as needed for assembly. Fiberglass reinforced modules were joined to each other by hand with a simple twisting action, with one module per loop and up to 14 loops per manifold. Zone valves and balancing valves were built into each return module to precisely control flow. Terra Therma design software actually specified balancing valve settings loop by loop. As a result, few adjustments were required after start up.
The use of modular boilers and Tekmar 662 reset controls permitted the snowmelt system to operate at high efficiency regardless of the load. Snowmelting is performed automatically. The system is activated when the outdoor temperature drops to near freezing and a moisture sensor on the driveway detects ice or snow. At the outdoor trigger temperature of 36?F, plus moisture detection, the Caravan boilers begin to circulate boiler water throughout the system. As the outside temperature drops, the boiler supply water temperature increases in steps to a maximum of 145?F. A four-way mixing valve protects the outdoor slabs and the boiler from extremely rapid temperature swings. For example, if the driveway temperature is 10?F when moisture is first detected, circulating 145?F supply water could crack the slab. In addition, the extremely cold glycol solution coming back from the system upon start-up could shock the boiler unless tempered with the four-way valve.
System efficiency was also important to Winner. The Caravan modular boilers save energy by step-firing only the number of boilers necessary to match the snowmelt load. At milder temperatures, it's likely that just one boiler module will be capable of maintaining the required output.
Rep-Line Sales was able to keep system costs lower by specifying Slant/Fin's 399 MBH gas module, the largest permitted by code under the "modular" designation. With an input of 399 MBH per module, the Slant/Fin Caravan system was able to meet the 1 million Btu load using three modules, saving the extra cost and space that would have been required if four or five lower capacity modular boilers had been used.
Indoor HeatingOf the indoor heating upgrades, it was especially challenging to convert the 1,800-square-foot greenhouse from a habitat for plants to one that's comfortable for entertaining. While there is considerable solar heating during the day with the building's 2,300 square feet of glass surface area, the heat loss at night jumped dramatically. To satisfy the load, Terra Therma PEX tubing was buried in a new concrete greenhouse floor. Baseboard heaters were installed in the utility room. The heat source for the entire greenhouse system is a dedicated 275 MBH Slant/Fin Galaxy gas boiler.
The formerly unheated carriage house, now an art gallery, was heated with five loops of 1/2-inch PEX tubing and a separate baseboard zone. The system utilizes a 60 MBH Slant/Fin Sentry gas boiler.
While most of the existing radiation heating in the mansion itself was left intact, Terra Therma radiant floor heating was installed throughout a new spa area. The objective was to provide an added degree of comfort for guests utilizing the steam room, sauna, whirlpool and showers.
Supply water temperature for those areas was increased to provide extra comfort for bare feet and wet bodies. A 90 MBH Slant/Fin Victory gas boiler was installed adjacent to the spa. The power-vented Victory boiler was chosen because the location is not near the building's chimney.
The bed and breakfast may still look Old World, but its heating is definitely 21st century.