By Samantha Bresler | Thu, September 25, 14
The ability of an Air Source Heat Pump (ASHP) to heat homes in the dead of winter may seem too good to be true. This technology is no figment of your imagination - it has us quite excited because it promises to deliver heat in subzero weather. ASHPs warm our houses by extracting heat from the outdoor air. But, if you live in a cold climate, it’s hard to extract warmth from temperatures near or below freezing. Fortunately we are seeing heat pump technology advance in recent years to the point where ASHPs offer a legitimate space heating alternative in the Northeast and Mid-Atlantic region.
One of the key strategies that came out of the Northeast/Mid-Atlantic ASHP Strategy Report, published in December of last year, was the need for improved performance metrics for ASHPs when providing heat in cold conditions. A sub-committee made up of regional stakeholders convened over the summer to develop an initial proposal for what a cold-climate specification should include.
The voluntary “Cold-climate Air-source Heat Pump Specification”, currently in development, will identify ASHPs that are best suited to heat efficiently in cold climates. The specification is intended to be used broadly by energy efficiency program administrators as a model equipment and performance requirement specification. It also is intended for engineers, contractors, and other practitioners who need assurance that the equipment they select will have the required heating capacity at certain temperatures without unnecessary oversizing, and will serve the load efficiently throughout the ambient temperature range.
Efficiency programs in extremely cold regions that currently incentivize ASHPs without the specification mainly rely on the Heating Seasonal Performance Factor (HSPF) metric. But with the specification, they can identify the best units based on a variety of parameters, not just the HSPF. With the specification, other programs in the region will expand so the incumbent and inefficient units will be replaced sooner.
Simply phasing out incumbent electric resistance heaters could provide annual energy savings of approximately $1.2 Billion and avoid over 7 million metric tons of annual carbon emissions – or roughly 3,000 kWh and $459 annually per home. Developing cold climate specification is timely, as more regional stakeholders are promoting ASHP technology and need a better way to identify those products that perform efficiently. Regardless of the technology, the comfort, the cost savings, or the reduction in carbon emissions, ASHPs can play a major role in revolutionizing household heating across the region. The ASHP magic trick never ceases to amaze – especially when it creates heat from cold air.