How It Works

The Kool Fire is said to produce hot and cold water simultaneously. This is achieved by using two separate circuits within the machine, so the unit acts a chiller and a boiler. It also includes circulating pumps and controls.

The system starts up when the thermostat calls for either (or both) hot or cold fluid. The fan coil unit's control valves open according to room demand, allowing for multiple different temperature settings at the same time. This arrangement can be beneficial in a home or building where one side may be cool and the other warm.

Systems are installed outdoors and can be matched to any hydronic design (e.g., radiant) or air system (e.g., fan coil units), or a combination of the two. A number of hydronic accessories are available, including ice-melting systems, patio slab warmers, indirect-fired hot water tanks, pool and spa heaters, etc.

The unit is atmospheric, which means it is a low-pressure system. "The machine has been designed so that any solid HVAC technician can install and service it. Except for one part, every other component can be replaced with off-the-shelf items available at any HVAC wholesaler. This make it very friendly to service people," noted Michael Scharing, chief executive officer, Kool Fire.

The renovation of the Beverly Hills home involved a 100-percent conversion from a forced-air system to the hydronic heating-cooling system. The system was chosen by general contractor Michael Grosswendt of All Coast Construction, Westlake Village, Calif., after speaking with Kool Fire president Robert Donnell at a party.

"I told him about the system, and he liked the idea of it," said Donnell. "He knew this particular project was going to be challenging just because of the design. Mike [Grosswendt] does a lot of work on these kinds of homes, and he really wanted to deliver the most comfortable system he could for his client."

Grosswendt stated that he was intrigued by the concept of one gas-burning boiler providing heated air, heated potable water, radiant heating, and pool heating. "The energy-saving characteristics were immediately evident. That heating paired with the cooling, the versatility of the individual fan coils, the healthy characteristics of ambient humidity and the exceptional quietness all appealed to my aesthetic sensibilities," he noted.

The House

It wasn't too difficult to sell the homeowners on the system. The concept of moist heat versus dry heat was very appealing to them, and they wanted a radiant floor in the bathroom anyway. Donnell also explained to them that zoning the system would save money and that the equipment would be installed in parallel.

"That configuration allows them to have redundancy, so essentially they have a backup," noted Donnell. "If they went with a traditional system and zoned it with multiple units and one of those units went down, that part of the house would have no heating or cooling. With our system, all the equipment is on the same circuit, so there's redundancy."

The house was previously cooled by four heat pumps, the outdoor units of which were on the home's flat roof. The roof was replaced as part of the retrofit, and the City of Beverly Hills mandated that the new equipment could not be visible on the rebuilt roof.

Instead, the three new hydronic units were installed on the roof of the carport. A parapet wall was constructed to hide them from view. The fan coil units were placed directly on the roof of the house and connected to each room by way of short duct runs (each room has a supply and return). Stucco/roofed boxes were constructed over each fan coil unit and the roof was built over the top of the boxes. Pop-off hatches facilitate their service.

"The equipment had to go on the roof due to the total lack of attic space," said Donnell. "The interstitial spaces were 6 to 8 inches, as opposed to 20 inches in a regular house, and there was very little space to run piping and install fan coil units."

The house has 11 zones and almost every room has a thermostat. The hydronic system also heats the domestic water, swimming pool (through an indirect-fired titanium pool heater), and spa. Donnell said indoor air quality is less of a concern with this system because there is not a lot of ductwork. "In addition, we don't have a common return, so we're minimizing the risk of moving contaminants from one part of the house to another."

The estimated cost of the equipment for the Beverly Hills home was in the neighborhood of $27,000. As Donnell noted, "It is more expensive, and it's geared toward a higher-end home, but it does things that you can't do with a traditional system."

For more information on Kool Fire, visit www.koolfireusa.com.

Publication date: 06/27/2005