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