In this issue

All-climate heat pump promises energy-saving alternative

Jammie Sabin (left) of Aspen Homes discusses the advantages of the all-climate, air-source heat pump with Energy Services Representative Linda Swails and Mike McCoy of Tri-State G&T.

Homebuyers visiting Enchantment Ridge, a new subdivision in Loveland, Colo., will find curb appeal, scenic location, custom design and many unexpected features—such as a heating guarantee—that are of interest to area utilities, as well.

Recognized for energy-efficient housing

Enchantment Ridge is the latest project by Aspen Homes, a Colorado-based builder that prides itself on building to, and often exceeding, Energy Star and Built Green Colorado standards. The company has been an Energy Star Partner since 2003 and earned the 2006 Partner of the Year award for building energy-efficient homes.

Built Green gave its 2006 Built Green Home of the Year award to the builder's net-zero-energy house in Fort Collins. The custom home combined a ground-source heat pump system and solar panels with a net-metering agreement with Xcel Energy to eliminate the owner's utility bill. "We take the 'systems approach' to building our houses," said Jammie Sabin, vice president of Aspen Homes. "All the components have to act together to positively impact the house's energy and water use."

A highly insulated building envelope, low-e windows, mechanical ventilation and sealed-combustion water heaters are standard features on all Aspen Homes. At Enchantment Ridge, an innovative all-climate, air-source heat pump provides heating. The efficiency of the heat pump, combined with the design of the homes, is so effective in lowering the amount of fuel needed to heat the home that Aspen Homes offers buyers a space heating consumption guarantee.

Tri-State conducts tests

Manufactured by Hallowell International, the heat pump is the next generation of the cold-climate heat pump that has been around for the last eight years, said Sabin. "This all-electric unit works to -30 degrees F, so it eliminates the need for dual-fuel back-up systems," he observed. That makes it both economical and environmentally friendly, he added, because, "The price of electricity is much more stable than heating oil or natural gas, and it can be produced from renewable resources."

Tri-State Generation and Transmission Association is watching Enchantment Ridge closely because the power wholesaler is currently involved in its own multi-year demonstration of the air-source heat pump. Although Tri-State's demonstration is not associated with the subdivision, Tri-State Senior Engineer Mike McCoy has teamed up with Sabin to give tours of the system in Enchantment Ridge show homes.  "It's good to have a large-scale project on the Front Range, to compare with data from other parts of the state," said McCoy.

Poudre Valley Rural Electric Association is the only Tri-State member in the area to install a heat pump so far, and that was in June of this year. Starting with Delta Montrose Energy Association in 2006, Tri-State member co-ops have installed 10 systems since the heat pump hit the market. Tri-State and the National Rural Electric Cooperative Association are funding a study by the Cooperative Research Network, NRECA's research arm, to collect data on the heat pumps' operation through phone line hook-ups. "It is a promising technology, but we want to verify manufacturer claims before we promote it to consumers," McCoy said, "See how it performs in the real world."

Two co-ops are testing the heat pump's performance in the harsher climate of the Rocky Mountain's Western Slope. In Telluride, San Miguel Power Association installed a system at a commercial property. DMEA retrofitted a home that had a conventional air-source heat pump and the back-up gas furnace those systems require. The homeowner will be able to compare heating bills from his old dual-fuel system with the new model.

Highline Electric Association and Y-W Electric Association are testing units on the eastern plains. More members have expressed interest in joining the demonstration, which Tri-State would welcome. Several others, including Empire Electric Association in southwestern Colorado and United Power northeast of Denver, are looking into it, said McCoy. "Some want to see data first, others were waiting for funding or figuring out how to structure an incentive," he explained. "Our goal is to get the heat pumps spread around the region to test them in all sorts of conditions."

Affordable alternative to ground-source

Coming from a utility that has shown such strong support for the geothermal, or ground-source, version of the heat pump, Tri-State's enthusiasm for the all-climate, air-source system might seem surprising. Not at all, McCoy insists. "Ground-source is still the Cadillac of heating systems—in performance and price," he pointed out. "If there is an option that will give some consumers a bigger bang for the buck, we want our members to have the data on it."
 
Sabin agreed that while ground-source heat pumps are still more efficient, its air-source counterpart offers other advantages. "Any contractor who knows how to install a forced-air furnace can put in an air-source heat pump," Sabin said. "It's just new engineering of off-the-shelf components. For instance, the air handler is a York—a standard application."

Although the heat pump's cost is similar to a ground-source unit, installation is much less expensive because the air-source equipment is all above ground. The compressor sits on a slab outside the house, the air handler is inside and some piping connects the two units to each other and to the indoor ducts. "There is no loop field," said Sabin. "That makes it perfect for retrofits and production settings. In subdivisions with small lots, there usually isn't room to dig a big loop field."

And the all-climate heat pump outperforms conventional heating systems—it is 300-percent efficient, compared to the 95-percent efficiency rate of the best natural gas furnaces. The manufacturer claims the heat pump can heat a house for $2.40 for 24 hours, based on $0.10/kWh.

Heat pump set to reach wider audience

If Sabin seems unusually well-versed in the advantages of the air-source heat pump, it is because he is more than just a customer. He is also head of Lorax Energy Conservation, LLC, a distributor for the Hallowell all-climate heat pump and other energy-efficient systems. "We couldn't find support for the technologies we wanted to use in our houses, so we started our own company," he explained.

Backers are ready for the all-climate heat pump to become commercially available, said Sabin, and Lorax's plan to train local contractors to install the unit would increase its marketability. Utilities offering incentives would help, too, but Tri-State leaves that up to its members, McCoy stated. "We provide a menu of incentives, and our members decide which ones suit their customers' needs," he said. "This is one a lot of them are already considering seriously."

Homebuyers—utility customers—are looking for ways to reduce their dependence of fossil fuels, said Sabin. Combining highly efficient electrical systems, like the air-source heat pump, with on-site generation, like solar panels, reduces the homeowner's carbon footprint, and it makes renewable energy more economical.

For his part, Sabin would like to make the all-climate heat pump standard in Aspen Homes' next subdivision. "We are always looking for ways to do more and better on each project," he said.