UNEXPECTED RETROFIT

One such individual was considering buying a large, 12-year-old house in Tulsa, Oklahoma, but he first wanted to make sure its eight original furnaces and air conditioners were in good shape. He reached out to Tom Boyce, owner, Airco Service Inc., Tulsa, Oklahoma, to assess the equipment and was more than a little surprised when Tom Boyce told him it would be best to remove the existing systems, fix the ductwork, better insulate the house, and then install smaller, high-efficiency furnaces and air conditioners.

“He thought we were just going to suggest minor repairs, and, instead, he ended up buying eight ultimate comfort systems that consisted of 21-plus-SEER air conditioners with 98 percent AFUE furnaces,” said Tom Boyce.

Aside from a few refrigerant leaks and condensate problems, the home’s original furnaces and air conditioners still worked; however, some of the ductwork was in poor condition, and the returns were not large enough. In addition, the insulation was lacking, and the equipment was near the end of its normal life expectancy. The homeowner made clear that comfort was his No. 1 priority followed by problem-free equipment, so, Austin Boyce, sales and marketing manager, explained how Lennox’s XC25 variable-speed air conditioners with 98 percent variable-speed furnaces could solve both issues.

“We changed out the eight systems, brought the insulation up to snuff, and then fixed and sealed all the ductwork in the house,” said Austin. “Thanks to a tighter building envelope, we were able to downsize the equipment to three 5-ton units, two 4-ton units, two 3-ton units, and one 2-ton unit, each with a MERV-16 filter. We also installed four humidifiers in closets that were accessible and semi-conditioned, rather than in the attic, where freezing becomes a concern.”

A Lennox iComfort system allows the homeowner to control the environmental settings in his or her home from an iPad. Even though it cost $160,000 to replace the HVAC systems, the homeowner is pleased with the retrofit, said Tom Boyce. “He said changing out the systems was the smartest thing he ever did — he’s very happy.”

THE GROUND ATTACK

When a builder in Tarrytown, New York, considered using a geothermal system to heat and cool a new 15,000-square-foot home, he asked Geothermal Energy Options, Lagrangeville, New York, to help determine whether that was the best option for the house. The builder was concerned about the cost of the system, as well as operating costs and comfort, but, through energy modeling, Christopher Ryan, the owner of the company, was able to show that a geothermal system would make the most sense.

Originally, the project called for a gas-fired boiler with hydronic heating coils for forced-air heating and air-cooled condensers for cooling. “But, in our area, fossil fuel prices are very unstable, and the annual costs to operate this type of system is extraordinary compared to geothermal,” said Ryan. “Therefore, it was primarily the return on investment that encouraged the builder to choose a geothermal system.”

Comfort was also an issue, as the builder wanted the forced-air heating system to be able to maintain an interior temperature of 70°F at an outdoor temperature of 7°. To meet those specifications, an 18-ton EarthLinked geothermal system was installed to provide forced-air heating and cooling as well as radiant floor warming. To address any IAQ issues, energy recovery ventilators (ERVs) were specified to provide mechanical ventilation to interior areas that did not have operable openings.

There were several challenges Ryan faced on this project, including a smaller-than-normal mechanical room that could not easily accommodate the number of compressors necessary for the application. To solve this problem, he mounted a frame to the mechanical room wall so that the compressors could be stacked, thus saving valuable floor space.

A second, much larger challenge involved the house itself, which was a modular design that was delivered to the site in 48 pieces. The air distribution system was designed six months prior to the house being delivered, but, because there were so many pieces, numerous logistical and design changes had to be made on-site. “All of the ductwork layouts we had so carefully planned in advance had to be changed almost completely,” said Ryan.

The total cost for the geothermal system, ductwork, ERVs, hot water package, and radiant equipment totaled $196,000. Ryan is relieved to know that the rest of the homes in the subdivision will be stick built, which should reduce the number of on-site changes that need to be made.

A SYSTEM FOR THE (GILDED) AGES

Originally built as a residence in 1912, the 50,000-square-foot Hempstead House — part of the Guggenheim Estate on Long Island, New York — is now a venue for weddings and other events. The home has a long and storied past, but, more recently, Hollywood producers have shot a number of movies and shows in the mansion, including “Scent of a Woman” and “Boardwalk Empire.”

Designated a Nassau County Park in 1967, its trustees recently decided to upgrade the heating and cooling systems in the mansion’s 4,000-square-foot bridal and groom suites. The original idea was to replace the existing steam heat system, but there was concern as to how new duct-work could be installed without ruining the aesthetics of the historical building. Since it was important to protect the integrity of the architecture, Brian Gelber, partner, Stan Gelber & Sons, Uniondale, New York, recommended the small-duct, high-velocity Unico System.

“We installed two Unico Green Series variable-speed air handlers with heat pump coils and two Carrier heat pump condensing units,” said Gelber. “The Unico System allows them to have zone control for this area rather than depending on a tremendous steam boiler hundreds of feet away in the basement. The high-efficiency system conserves energy, which is important here on Long Island, seeing as we have the fifth highest electric rate in the country. It’s also a quiet system because of insulation in the ducting that works as sound attenuation; you barely hear it operating.”

The installation was tricky because Gelber needed to find a place to mount the condensing units where they could not be seen. He found the perfect spot on the roof of the back porch, where the equipment is invisible from the backyard and the street. Because the mansion is made of stone, a core drill was used to penetrate the building in order to run the piping.

“Snaking the Unico ductwork through the ceiling was also an intricate process,” said Gelber. “Fortunately, the third-floor servants’ quarters haven’t been used since World War II, so we could use that area as a mechanical room. We were able to open up the floors and lace the flexible ductwork across the ceilings in voids that we found above arches and domed ceilings without any damage to the original plaster work and moldings. It worked out better than I imagined.”

The $40,000 system was installed last fall, and the trustees are very pleased with how it works. Gelber enjoyed the project as well, noting, “It was fun doing something so historic. I’m fascinated with the ‘Great Gatsby’ era, so it was kind of cool to see how extremely wealthy people lived 100 years ago.”

A COASTAL RETREAT

Chris Norton, general manager, ABM Mechanical Inc., Bangor, Maine, is no stranger to working with discerning customers on their high-end homes. The firm features an in-house mechanical design engineering department, pipe pre-fabrication facility, HVAC service departments that cover most of the state, and installation crews for both high-end residential and commercial applications. Recently, the company was asked to install an efficient, reliable HVAC system in a large home within a tight timeline and with little to no disruption to the aesthetics of the interior.

The large seasonal residence was built on the rugged coast of Maine in the late 1980s and had virtually no HVAC systems in place. Space heating was accomplished through electric baseboard and permanently mounted resistance unit heaters, but even though the owners only occupied the home in the summer, it lacked air conditioning.

Norton was asked to install a system that not only provided air conditioning and dehumidification, but that was aesthetically pleasing and would not disrupt the design of the home. To that end, he installed an AirStage variable refrigerant flow (VRF) heat pump system with seven ducted terminal units and three wall-hung evaporators to condition the bedrooms and several staff areas.

Given the homeowners’ concerns over aesthetics, duct and refrigerant lineset routing was carefully selected to minimize the disruption to the pristine building, said Norton. “The finished look of the entire project had to be seamless, so the condenser was installed behind a privacy fence that is located 180 feet from the home in order to remove it from the line of sight. From the client’s perspective, the only signs of the installation are the linear diffusers and the thermostats on the wall. In the staff areas, traditional wall-hung evaporators were used.”

Norton relishes working with discriminating homeowners, noting: “all these types of projects are unique in their own ways and present new and exciting challenges. There is no single answer for every high-end home — each one has its special qualities and challenges that require the contractor and engineer to look at all the possible equipment and delivery options. Next to technical proficiency, attention to detail is the most important aspect, and there is no margin for error when working for clients of this magnitude. It keeps us on our toes every day.”

Publication date: 6/22/2015

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