Excerpt from: = Will Utilities Warm Up to Low-Temperature Heat Pumps? = 2.3.06 Jay Stein, Managing Director, E Source Research, Plattshttp://www.energypulse.net/centers/article/article_print.cfm?a_id=1199 What Is a Low-Temperature Heat Pump? We have defined the low-temperature heat pump (LTHP) as an air-source unit, capable of providing both heating and cooling, that:
- Operates down to an outdoor temperature below –10°F. It’s rare for a conventional air-source unit to operate below this temperature.
- Meets or exceeds its rated capacity at 0°F. Conventional heat pumps typically put out roughly half of their rated capacity at this temperature.
- Exhibits a coefficient of performance (COP) of at least 2 at 0°F. Conventional heat pumps typically exhibit COPs of 1.7 or less under these conditions.
LTHPs incorporate several recent technological innovations in order to achieve this performance. The most significant one is a sophisticated microprocessor control system that until recently would have been far too expensive to include in a mass-produced residential air-conditioning product. These control systems, working in concert with other features, enable LTHPs to solve some persistent problems for northern electric utilities by:
- Improving on the efficiency of electric-resistance and conventional heat pump space heaters,
- Reducing the peak loads imposed on transmission and distribution systems when large stocks of conventional heat pumps simultaneously call for backup electric-resistance heating,
- Competing more-effectively with natural gas and other fossil fuel–burning furnaces for space-heating load, and
- Providing a less costly and less complex alternative to GSHPs.
Low-temperature heat pump technology clearly has much to offer to the electric utility industry. The Playing Field
David Shaw, who used to work for Carrier Corp., started conceptualizing the first LTHP in 1995. He set up his own research laboratory—Shaw Engineering—to create an air-source heat pump for cold climates that would eliminate the need for electric-resistance backup heating in very cold weather. After a few years, he received strong interest from Northeast Utilities, which was working with Nyle Special Products (a small specialist heat pump company based in Bangor, Maine
) to develop a heat pump water heater. Shaw then licensed the technology to Nyle, allowing it to develop a product based on his work. Nyle built four prototypes that were tested over the winter of 2002–2003. Nyle dubbed its product the Cold Climate Heat Pump, and we estimate that somewhere between 150 and 200 units have been delivered to customers to date—with around 20 of the installations located in Canada
and the rest in the U.S. The performance of these units was decidedly mixed, with some operating demonstrably well and others experiencing problems due to inadequate installation, poor quality control, and flawed control strategies. In early 2005, Shaw decided not to renew Nyle’s license to the technology, and he began negotiating with other manufacturing partners. Nyle, however, retains the trademark to the Cold Climate Heat Pump name and claims that it will develop a similar product that can be manufactured without violating any of Shaw’s patents. In July 2005, Duane Hallowell, a former Nyle employee who led that company’s efforts to commercialize the Cold Climate Heat Pump, acquired the rights to the patent for David Shaw’s LTHP technology. Hallowell says that his company, Hallowell International, will spend the rest of 2005 perfecting the product and begin releasing 2,000 beta units for a pilot study in the third quarter of 2006. A hallowell heat pump (or All Climate Heat Pump) is a heat pump designed specifically for heating while still providing high efficiency cooling. This product was invented in 1995 by a former carrier corp engineer. Now commercially available ( see www.gotohallowell.com ). It has been studied though several organizations to show much greater comfort, significantly reduced defrosts compared to traditional systems, and can maintain high heating capacities in northern climates at temperatures as low as 30 below zero while keeping efficiencies above 200%. There are three new studies coming out in the coming months showing the results of an 8 state cooperative research study by the national rural electric cooperative association. The system is only released as air to air for about $6500.00 and installs like a central air conditioner. My wife and I were considering a geothermal but the price to install ran about 30k for a 3.5 ton system for our 2500sf home. We called Hallowell and asked for references and spoke with a customer of theirs on Cape Cod. They heated 3000sf home for about $700.00 for 2006 / 2007, with an electric rate of 17 cents per kwh. This could be a very disruptive technology finally offering an alternative to fossil fuel