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Mini-split Systems the Answer to Church’s out-of-Date Heating and Cooling System

Jan. 1, 2012
Address efficiency, noise concerns of congregation

At St. Paul's United Church of Christ in Dallastown, Pa., 16 1960s-era through-the-wall hydronic-electric air-conditioning units were noisy and allowed drafts to enter the sanctuary. What's more, the hydronic coils—over several brutal winters—had endured many freeze/split/repair episodes.

"Our heating and cooling system was so inefficient that it was basically eating us alive," Pastor Russell Clark said. As contributions and tithes came in, a proposal to solve the problem was made. But as the potential costs and commitment became clearer, the property committee let the project fall by the wayside, where it stayed, year after year. Fortunately, offerings toward the project continued to accumulate.

Last year was a wild ride weatherwise. Motivated by 30 days with temperatures above 90°F, the church formed a committee to study HVAC solutions. Then came winter, with sustained record lows and more snow than the area had seen during the previous four winters combined. The church’s property committee solicited bids from several local contracting firms.

"They all had different ideas about the best way to solve the problems here," Clark said. "The key challenge, we thought, was to find a way to integrate the old with the new."

After much deliberation, the church committee invited Dave Yates, owner of F.W. Behler, a full-service mechanical contracting firm based in York, Pa., to attend a church service, after which he would be given an opportunity to present his plan to the congregation.

"Our key recommendation was the complete demolition and removal of the out-of-date system they currently had and replace it with a much greener, money-saving system that was easy on the eyes," Yates said.

Yates' plan included the sealing of 16 gaping holes left by the removal of the old units and more holes in the ceiling and floors. Adding to the challenge was the property committee's desire to preserve the architectural look of the exterior grilles.

Yates explained that the large cavities easily could be filled with high-density Dow foam board and secured and sealed with closed-cell foam. Metal pans—painted black so as not to be noticeable—could be formed to fit neatly behind the exterior grilles, while 2-by-4 frames would allow drywall and plaster to match the existing wall surface.

The congregation expressed a number of concerns:

  • The existing system was noisy. Would the new HVAC solution be noisy, too?
  • The existing system was uncomfortable year-round and drafty, too. How would that be fixed?
  • The existing system was expensive to operate, with little benefit. How would that be changed?
  • The existing units always were in need of repair, and they froze tight then leaked during winter. What would be done about that?
  • How long would the work take? Could services still be held in the sanctuary? Would Yates' crew clean up after itself?
  • What would the new equipment look like?

Yates explained that the Fujitsu mini-split systems he planned to install produce almost no sound, while their variable-speed operation ensures comfortable air motion and effortless temperature control. The smaller Fujitsu systems would go in place of the existing systems, surrounded by new insulation and trim to prevent infiltration and exfiltration.

Yates assured the congregation the Fujitsu systems virtually would be ready to go, right off the shelf. Installation would move quickly, and at the end of each day, his crew would clean up.

"I also convinced them that the new systems' appearance—compared to the battered, old fan-coil units—was glamorous, if anything," Yates said. "When I showed them photos of the new 24RULX floor console systems, there was audible appreciation."

The congregation then was called to vote.

"After the long and spirited question-and-answer period, it was a quiet, torturous wait," Yates recalled.

Finally, the votes were tallied: 97 "for," three "against," and a few impartial.

It was time for Yates' firm to get to work.

The 1964 1.4 million-Btu, natural-gas steam boiler was running nonstop all winter long.

"It was maintaining 9 to 12 lb of steam for the original part of the church, and they were maintaining heat on the hot-water side at 180°F around the clock for the sanctuary, classrooms, and offices," Yates said.

Several classrooms have mini-split comfort conditioning, while the parlor and offices enjoy variable-speed comfort via a multihead system. Yet, when Yates did a complete connected-heat-load calculation in the sanctuary, the total combined load for steam and hot water was just over 600 MBH. From previous experience, he knew that this load would be oversized and that an actual heat loss based on the structure itself was warranted for any portion that would utilize hot-water heating.

Nominal tonnage for the sanctuary was a maximum of 16 tons using the old 1-ton units, although several had ceased working over the previous few years. The Fujitsu 24RULX systems would provide up to 18.5 tons with the inverter units ramped all of the way up, which is unlikely to happen.

With the new insulation, required cooling loads are now much less, which allows the units to idle at slower speeds. While projections indicated a 35-percent reduction in power use, reality is closer to 50 percent because of the inverter variable-speed-drive energy diet.

Clark now can be heard no matter where a parishioner sits, while the Fujitsu units quietly, efficiently, and fashionably provide comfort.

"The job came in under budget, so, as an added bonus, we incorporated dual concealed inverter-driven units to quietly serve the robed choir members, lectern, and Pastor Clark's pulpit," Yates said. "Now, everyone present can worship and share fellowship in comfort while reducing energy consumption."

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