Heat Pump Resources

Renewable juneau’s heat pump brochure

We’ve put together a quick brochure outlining many of the basic facts that relate to the use of heat pumps in Juneau. Download it here. We’ll soon be updating many of the details of our brochure to accurately reflect the rapid increase in heat pump adoption presently occurring in Juneau.

Heat Pump 101 Guide

Clean Technica has a 7-part series available via their website entitled, “Dragon’s Guide to a 100% Renewable Home.” Part 4 is all about heat pumps and more, a very thorough resource covering costs, installations, energy calculations and more.

Sanden Heat Pump Water Heater with CO2 Refrigerant

Keep your eyes open for new efficient air to water heaters. We know of two installations of these high efficiency hot water heaters in Juneau and some local installers are experimenting with them for radiant space heating.

Standard heat pumps use hydrofluorocarbon (HFC) refrigerants such as R410a, which has a 100-year global warming potential (GWP) greater than 1,700. Though they work well, these refrigerants also typically do not create water temperatures high enough for hydronic (electric resistence) heating. Sanden is now offering a residential heat-pump water heater that uses CO2 (GWP of 1) as the refrigerant and can deliver water hot enough for domestic hot water, and even for hydronic heating in energy-efficient homes.

Available in Japan for several years, Sanden’s CO2-based heat pump is just now making it to the U.S. Using low-GWP CO2 as a refrigerant, this 4.5 kW model produces high-temperature water with very efficient heat transfer, very little pump energy, and good cold-weather performance. It is capable of delivering approximately 16,000 Btu/hr and can produce 149°F water with outdoor temperatures as low as –15°F.

Compared with other heat pump water heaters, the Sanden water heater is a split system, so it doesn’t lower the air temperature in the space where it is located.

The outdoor unit is paired with storage tanks of different sizes for different applications, including an 80-gallon stainless steel tank that can supply domestic hot water, and even space heating in efficient homes (a larger 11 kW version better-suited for space heating is in the works). Because of the significantly higher operating pressure of CO2 refrigerant (compared with HFCs), the piping and connections with this product must be more rugged than that used for standard heat pump water heaters.

Read more about Sanden’s CO2-based heat pump here.

Ductless Heat Pump Installation Considerations

This page from Efficiency Maine, addresses major factors such as goals,  budget, indoor unit location, indoor unit types, outdoor unit locations. “Goals: It’s important to know up front what you’re looking to get from your heat pump. Some common reasons people switch to heat pumps are cost savings, comfort, reduced environmental impact, convenience, and aesthetics. Be sure to share your goals with your installer. It’s also helpful to know if the heat pump will be the only heating system, the primary system, or a supplemental system.”

Another valuable resource is this page on system sizing from Fine Homebuilding. No matter what type of heating and cooling equipment you ultimately pick — heat pump, furnace, boiler, or something else — it should be sized correctly for the space in which it’s installed. That’s basic advice, but what does “sized correctly” really mean?

What Do The Acronyms EER, COP, SEER, and HSPF Mean?

Heat pumps are all about efficiency and with them come many efficient uses of the alphabet, acronyms that detail numerous aspects of a heat pump’s ability to heat, cool and save you money by avoiding the burning of fossil fuels or the use of baseboard electric resistance heating. Here is a website that defines these terms and explores heat pump efficiencies in depth.

Air source heat pump potential in Alaska

A bit dated, but a Cold Climate Housing Research Center paper on the heating potential of heat pumps in Alaska.