Boiling over: Zones help a Maryland waterfront residence combat chilly breezes
There are quite a few perks to having a backyard that ends in the Chesapeake Bay.
The fishing can be great, the views are wonderful and the fresh, salty breeze is unbeatable in the summer. But in the winter, that pleasant breeze turns wild, howling across open water and onto land.
While Stevensville, Maryland, enjoys a climate with fewer heating degree-days than much of hydronic country, the wind off the bay is enough to turn the tides in favor of a hot water system. Wilfre Co. Inc. was referred to the owner of a 4,500-square-foot, bayside home whose existing heating system wasn’t sufficient when the wind kicked up.
Air-to-air heat pumps were the primary source of heat, with hydro-air coils and a large condensing boiler as a second stage.
“The boiler was programmed to take over at 30°F,” said Martin Harrison, owner of Wilfre Co., based in Hebron, Maryland. “The main problem, though, is that the original near-boiler piping wasn’t up to snuff. The home couldn’t get near enough flow to satisfy the thermostat.”
Because the project involved airside equipment, ductwork, controls and hydronics, Wilfre’s do-it-all approach made them the perfect outfit for the job. The full-service HVAC construction company, with 30 trucks, even has its own sheet metal shop. It has a long history.
“My father and uncle started the company in 1970 as a backhoe rental, got into plumbing two years later, and opened a mechanical division six years after that,” Harrison said. “Fifteen years ago, my brother, Bill and I took over, and the rest is history.”
Just a few pumps short
When Harrison arrived at the seaside home last fall, a 250,000-British thermal unit condensing boiler was supplying hot water to two air handlers — one upstairs and one downstairs. The hydronic coils in the ductwork couldn’t get adequate flow.
Amidst the spaghetti bowl of near-boiler piping, there were only two circulators on the whole system. One pump served the indirect water heater, while the other, located on the return side of the boiler, was attempting to provide all other circulation. There were no zone valves.
Steve Kidwell (left) the president-CEO of manufacturer’s representative firm ROI Marketing and Martin Harrison, owner of Wilfre Co., worked on the Maryland house project.
Wilfre’s HVAC technicians completed residential load calculations following the Air Conditioning Contractors of America’s Manual J. Figures come in at 180,000 Btuh with a 10°F outdoor design temperature. This confirmed what they already suspected: the boiler was big enough — and then some.
“I suggested replacing the 12-year-old boiler with a new Burnham Alpine and re-piping the mechanical room,” Harrison said. “At first, they didn’t want hot water again. Understandably, the old system left a bad flavor. But they came around after seeing the numbers and learning that the near-boiler piping was the problem.”
Sitting on Chesapeake Bay, winter winds blowing across the yard and into the back of the house made heating difficult.
Wilfre disassembled the existing system in September, when the heat pumps would have no trouble satisfying any call for heat. The new, 210,000-Btuh Alpine condensing boiler was hung on the wall, along with a U.S. Boiler Co. Sage zone control and a Grundfos electronically commutated motor circulator for each of the two zones.
“We built a primary/secondary system so that the zones operate independently of each other now,” Harrison said. “The Alpine installed easily, and even field-converted from natural gas to LP (liquid petroleum) without swapping orifice plates.”
Wilfre Co. HVAC technicians installed a 210,000-Btuh Burnham Alpine in the home’s garage with well-insulated primary/secondary piping.
Shortly before the project started, Steve Kidwell, a manufacturer representative from ROI Marketing, had introduced Harrison to the Burnham Alpine and U.S. Boiler K2 high-efficiency lines. The first experience Wilfre had with the boilers was during construction of ROI’s live-fire, mobile training laboratory. After installing them in the trailer, Harrison wanted to put one in the field. Since the bayside home needed a large capacity, the Alpine was a perfect fit.
With eight models between 80 and 80,000 Btuh, the high-efficiency Alpine fits nearly any residential and light-commercial application, officials said.
“The fact that we could hang a boiler of this capacity on the garage wall, instead of setting it on the floor, was a plus,” Harrison said. “The free, three-year parts warranty was a big advantage too.
“The only challenge on this project was keeping ample domestic hot water available while the system was down,” he added. “The master bedroom has an 80-gallon tub that gets used almost daily.”
To keep hot water flowing, they put in a temporary 50-gallon electric tank. Once the new boiler was up and running, the existing 60-gallon tank was left in service. With the Alpine’s big capacity and the water heater set to priority, there hasn’t been any trouble getting enough hot water to the bathtub.
Martin Harrison, owner of Wilfre Co., poses with the piping installation.
Throughout the project, the homeowner noticed the quality of work that Wilfre was providing. The front of the garage was no longer occupied by a massive copper octopus. Instead, a wall-hung boiler is now joined by new circulators, clearly marked piping, and a well-insulated primary/secondary system.
While the family didn’t keep track of their propane use, they have commented that the boiler runs far less often and longer per cycle.
This article and its images were supplied by U.S. Boiler Co.