Historic Structures Present Challenges
Buildings constructed during the turn of the century were not built with large mechanical HVAC systems in mind. But today, with many older buildings undergoing renovations to become either museums or vacation getaways, cooling is now essential.
Contractors have a variety of options when it comes to providing cooling, but space and design are serious considerations with many of these older buildings. That is why in some applications a water-cooled chiller system can be the way to go.
Historic LodgingThe Marigold Lodge, built in 1913 and located in Holland on the banks of Lake Macatawa, is a summer escape for corporate VIPs of Herman Miller Inc. The 34-room home has been described as an architectural masterpiece, and it was added to the National State Registry of Historic Sites in 1984. But one thing that was missing from the lodge was a method to provide cooling during the summer months.
(Coincidentally, the lodge was built by Egbert H. Gold. Gold’s father invented a method of heating homes through the use of a steam boiler.)
A firm proposed to help out the owners of the lodge and suggested the installation of a central air system. There would have been several drawbacks to this approach, including the installation of a duct system that would have interfered with the original design of the lodge. Herman Miller decided to scrap the plans and turned to a local contractor for help.
“Structurally, that just wouldn’t work,” said Brian Holt, owner of Mast Heating and Cooling in Zeeland, Mich. “That’s when they came to us, looking for a system that could cool that spacious lodge efficiently without infringing on the aesthetics of the building.”
For the Marigold Lodge, Holt proposed using two five-ton Unichillers, manufactured by Unico, along with seven Unico air handlers. At the time, the Unichiller had just been introduced to the market. It was designed for residential and light commercial applications. Unlike other chillers that run in large tonnages for commercial and industrial projects, the Unichillers are available in three-ton, four-ton, and five-ton models.
Holt said that the design choice had several benefits. First, the Unichiller allowed installers to hook up seven air handlers to one condensing unit. A regular system would have required seven DX condensing units. The system also alleviated the issue of installing obtrusive ductwork. The piping ran from the condensing units to a number of air handlers in the attic.
There were challenges associated with the project, including equipment installations that needed to be done within the small attic space. But Holt said that the results far outweigh the installation challenges. Each air-conditioned room has its own thermostat and filtered grill, which provides comfort on an individual basis.
Chiller BenefitsAccording to Tom Taylor, marketing manager for Unico, the Unichiller, and water-cooled chillers in general, are very beneficial. “The biggest benefit is the coolant medium,” explained Taylor. “With chilled water, you don’t have to worry about refrigerant and pipes leaking. Also, it’s more environmentally friendly.”
Taylor added that by using chilled water, the piping system can be extended out to greater lengths. This can provide more flexibility with the outdoor units. The units can be located right next to the building or placed further away where they can be hidden from view. It also provides more options in cooling individual spaces.
For example, the Unichiller was used to cool the nine-story Orrington Hotel in Chicago. The hotel also has a rich history, opening back in 1923. Taylor said that 11 condensing units were placed on the roof of the hotel. An unobtrusive duct system was tied in with the Unichillers, making it possible to cool multiple floors and areas of the hotel.
The benefits are the same as in a retrofit application, but Taylor explained that water-cooled chillers along with an air-handling system can create better control for larger homes.
He said that in homes that are anywhere from 5,000 to 20,000 square feet, a central heating and cooling system won’t do. By using a number of air handlers, the homeowner will have more control over cooling and will save energy in the long run by delivering those temperatures to specific zones in the home.
Publication date: 07/14/2003