The Main House

Bill Foster, vice president, Harland B. Foster Inc., Great Barrington, Mass., has been Blantyre's HVAC contractor for a long time, and he and his employees know the equipment inside and out. For years, he has been coaxing life out of Blantyre's remaining original boiler (the second boiler stopped working long ago), but last fall it became apparent that new boilers were necessary.

Fortunately for Foster, Blantyre closed down from November to May (although it now remains open year-round), so he would not have to work around guests.

"We had two separate parts to this project," said Foster. "In the main house, we replaced the existing steam system with a hot water system. The second part of the project involved installing boilers, a control system, and air conditioning for the new spa that was built in the original potting shed."

As can be imagined, the original boilers in the 14,500-square-foot main house were enormous, and it took a three-man crew a week to remove just one of the boilers from the basement. (The owner wanted to keep the second boiler in place as a display piece.)

Foster decided to replace the existing steam system with a water system due to energy savings, as well as better control. He installed two Burnham V905A two-stage natural gas boilers to meet the building's load, as well as provide some redundancy in mild weather. A Tekmar 254 four-stage control resets the water temperatures for energy control and comfort and provides warm weather shut-down for pumps and combustion damper control. The boilers have Burnham's new RTC (return temperature controls), designed to ensure boiler shock protection.

The main house already had many smaller split air conditioning systems that served the suites and other areas. A very easy way to add heat was to install hot water coils in the ducting of these units and to slightly modify the controls. In other areas, Foster uses small fan coil units or radiators.

"Aesthetics were a huge concern on this project, so we had to be inventive with the terminal units in order to blend in with the décor," noted Foster. "We used the Burnham classic radiator in some locations, because it looks as if it belongs in a period home."

Other areas, such as the main stairwell, proved to be a little trickier. This stairwell alone required over 50,000 Btu, and there was no way to put in a big enough hot water radiator to satisfy the load. Instead, Foster ended up installing two Carrier 42 Series fan coil units and building them into extensions below the sill of the window.

Due to aesthetics, the distribution piping had to be hidden, so two routes were taken to reach the existing air handlers in the attic. One easier loop goes up through the serving areas, while the west side goes up through an existing small chase.

"We ended up splitting the pipe size into two PEX tubes to go up and two back down to complete the loop, which are headered together. A higher curve circulator was used to overcome additional head," said Foster.

A triple primary-secondary pumping system was used to keep the pipe sizes down. The main 3-inch primary loop just goes around the boiler room to pick up both new boilers. The five mid-loops go out and back from the major areas of the building, and then the final terminal loops pick up the air handler coils or radiators.

The Spa

The 2,870-square-foot spa portion of the project involved the total reconstruction of the existing potting shed and the addition of a connector building to the existing carriage house. The newly renovated space includes a small gym, a hot tub, steam room, and sauna. The spa offers massages, facials, manicures, and pedicures, and an assortment of body wraps and scrubs in three private treatment rooms.

The many different activities that take place in the spa require very close control of the HVAC system. Due to the small building size, individual systems for each area was out of the question, so Carrier's CCN Building Control System was selected. Foster can monitor the system through a dial-up connection.

"We decided that Carrier's new 3V-controlled VAV (variable air volume) system would work best to keep the various rooms at different temperatures. We designed the system thinking that each area would have a terminal unit, and then we worked backwards to the 5-ton MagicAire unit which supplies the treatment rooms and gym," stated Foster.

The 5-ton air handler has two 2-1/2-ton coils in it, while a 3-ton MagicAire air handler supplies the hot tub area, and Carrier condensers are located outside. Fresh and exhaust air are provided by two Ez-Aire ventilators that are piggy-backed onto the air handlers and preheat or cool the fresh air with the exhaust air.

Two Carrier BW3 boilers provide the heating for the spa building and the connector, as well as hot water, heat for the hot tub, and some snow melt. Primary and secondary pumping is also used, and a Tekmar 262 and 665 supply the control for the boilers and snow melt, respectively.

Foster is still putting the finishing touches on Blantyre's HVAC systems, and he is proud of the work his small company managed to do in a short period of time.

"We only have five mechanics in the field, and we subbed out work to three others to get the job done. Time was the biggest concern, but we managed to finish the main areas by the time it opened in May," said Foster. And thanks to Foster and his crew, visitors to Blantyre will be cool and comfortable in the summer and warm and toasty in the winter.

Publication date: 08/29/2005