| An Affordable Heat-Pump Water-Heater Retrofit | | | | he also intends to use the product(from: in |
| | | | a 100-unit subdivision that is in the works. |
| The engineers at AirGenerate (previously | | | | |
| Beyond Pollution) appear to have done | | | | Skyland Falls is installing the AirTap units |
| something remarkable: create an affordable, | | | | on new, 40- and 50-gallon (150 and 190 l) |
| effective, heat-pump water heater that can be | | | | electric water heaters, set up so that the |
| retrofit onto a conventional gas or electric | | | | standard electric element provides a backup. |
| water heater, more than doubling the energy | | | | The controls on the water heater are set so |
| performance compared with a standard electric | | | | that the standard element will come on at |
| water heater. The AirTap A7 water heater has | | | | 100°F (38°C), while the AirTap is set |
| a rated output of 7,000 Btu/hour (7.4 MJ | | | | to heat water to 130°F (54°C). If the |
| hour), a first-hour rating of 42.5 gallons | | | | heat-pump module stops working for some |
| (160 l), a maximum water temperature of | | | | reason, the conventional electric-resistance |
| 135°F (57°C), an efficiency of 240% | | | | element will still keep the water warm, but |
| (coefficient of performance of 2.4), and an | | | | homeowners will notice the problem and |
| energy factor of 2.11. (Energy factor is a | | | | contact Skyland Falls. The company(from: |
| standardized measure of performance of water | | | | will go out and troubleshoot the problem-but |
| heaters; the higher the number, the better.) | | | | it probably won't be an emergency call, since |
| All this is in a unit that measures only 18" | | | | the water will remain at least warm. "Since |
| wide by 14" deep by 14" high (460 x 360 x 360 | | | | this is a new system, we wanted a backup," |
| mm), weighs only 48 pounds (22 kg), and sits | | | | Alexander told EBN. With some units in place |
| on top of a standard water heater. The list | | | | for four months, Skyland Falls has yet to |
| price is $499. The energy factor and | | | | receive a call. |
| first-hour rating of the AirTap are certified | | | | |
| by GAMA (previously the Gas Appliance | | | | Installation is fairly easy-even feasible for |
| Manufacturers Association and now a broader | | | | skilled do-it-yourselfers. According to |
| association of appliance and equipment | | | | Alexander, one of his employees can install |
| manufacturers). | | | | three AirTap units in a day. Skyland Falls |
| | | | installs the water heaters in utility closets |
| Heat-pump(from: water heaters have always | | | | with the outflow air from the AirTap heat |
| been a good idea, but most efforts to design, | | | | pump vented into the adjacent garage; this |
| build, and market them have failed. With | | | | setup provides some cooling to the garage, |
| today's high energy prices, however, | | | | which is beneficial in the summer. Of the 30 |
| consumers should be more receptive to | | | | units so far installed, only one unit has had |
| heat-pump water heaters, according to Harvey | | | | a problem-a loose bolt that Skyland Falls |
| Sachs, Ph.D., the buildings program director | | | | easily fixed. In late spring 2008, the |
| at the American Council for an | | | | all-electric homes were using less than $2 |
| Energy-Efficient Economy. "The economic | | | | per day for energy, according to Alexander, |
| savings potential is so much greater than | | | | though how much of this is for water heating |
| before, with the run-up of energy prices," | | | | is not known. |
| Sachs told EBN. | | | | |
| | | | Other heat-pump water heaters will be coming |
| AirGenerate initially produced its AirTap A7 | | | | along soon. General Electric expects to |
| water-heater(from: kit in Houston, Texas. | | | | introduce its Hybrid Electric Water Heater in |
| After selling a few hundred units in late | | | | late 2009. The model will sell for about $400 |
| 2007, the company began sourcing the product | | | | more than a standard, 50-gallon (190-l) |
| from an offshore supplier. The outsourcing of | | | | electric water heater but save an average |
| production will allow the company to | | | | family $250 per yearwith electricity(from: |
| significantly ramp up production. The first | | | | at 10 cents per kWh, the company claims. |
| of the new (offshore-manufactured) AirTap | | | | According to Sachs, a second major player is |
| units were received in January 2008, and | | | | likely to soon announce another heat-pump |
| about 200 had been sold through May 2008. Of | | | | water heater. Having major manufacturers |
| 400 units scheduled to arrive in June, almost | | | | enter the heat-pump water-heater market, |
| all were pre-sold by the end of May, | | | | according to Sachs, will give this sort of |
| according to Sunil Sinha, chief scientist at | | | | product legitimacy. "[AirTap] may be able to |
| AirGenerate. | | | | ride the wake instead of having to break |
| | | | through the ocean waves," he said. |
| Skyland Falls, a Tennessee developer, has | | | | |
| installed 30 AirTap units since January 2008 | | | | In addition to the AirTap A7 model, |
| in a 70-unit subdivision currently under | | | | AirGenerate is introducing a larger 12,000 |
| construction. Houses in the subdivision are | | | | Btu/hour model in August 2008, according to |
| 2,000 ft2 (190 m2) each and sell for an | | | | Sinha. This model will offer the same energy |
| average of $230,000. "The AirTap is doing a | | | | factor of 2.11 but will have a first-hour |
| fantastic job," according to Skyland Falls | | | | rating of 60 gallons (230 l). |
| president Gary Alexander, who told EBN that | | | | |