The Future of Home Heating: Why Heat Pumps are Taking Over
Heat Pumps use air conditioning technology (‘refrigeration’ to be precise) to heat and cool your home. It’s almost as simple as that. It acts like taking an air conditioner out of your window in the Fall, turning it around, and sending the heat flow into your house all winter. But no reinstallation is needed!
How it works: The outside unit looks just like (and is) a conventional central air conditioner, except it has a ‘reversing valve’ which allows the refrigeration fluid to flow in the opposite direction when switched from “cool” to “heat”. This allows heat to be captured from outside (even when it is quite cold) and released inside, warming your home. Electricity runs the compressor and fans that do this work – and these now run more cheaply with variable speed motors. A thermostat is your control.
How it saves money: Gas heaters and other combustion boilers create heat by burning fossil fuel. Heat loss is about 15-25%; and CO2, carbon monoxide and particulate are exhausted into the air. Heat Pumps do what your fridge does, moving heat from one side of a wall to another. They move 3-4 times more heat energy than they use in grid energy. Here is an estimate of annual operating cost savings. Heat Pumps should last 15-20 years or more.
Shifting away from greenhouse gases: As grid electricity gets to be a greater mix of solar, wind and hydropower, fossil fuel use for electricity is reduced, without further expense by each homeowner or tenant. PA is targeting 100% fossil-free electricity by 2050, up from 8% in 2021. As this shift occurs, heat pump households switch off gas dependency. US Department of Energy concludes that “heat pumps reduce emissions in the average household in every state when compared against the highest efficiency gas-fired equipment available.”¹ NREL estimates 1.1 tons of annual carbon reduction per heat pump household vs. high-efficiency natural gas.²
Installation Concepts: What you install depends on what you have now in your home. Existing ductwork can be kept and attached to a heat pump. If the home has no existing air ducts, then “mini-splits” are used. These air conditioner-sized units pull in room air and expel cooled or warm air. These are connected to the outside units by a 3” bundle of supply lines.
Heat Pump Installations:
*typically vary, based on existing heating/AC system
Will these work in Pennsylvania: Oh, yes! Finland, Norway, South Korea, and other cold places use these extensively. They work well in Maine and Minnesota. This latest generation of heat pumps works well as a defrost cycle has become standard, so ice does not build up on outside coils on cold moist days. Around the world, new tech heat pumps have been heating and cooling for a decade.
Incentives: These systems are a bit more expensive upfront than a central AC unit, but they replace your existing heating and air-conditioning systems and are cheaper to operate. If you have new systems, a switch now may not be economical. But if your existing systems are old, unreliable, and inefficient to maintain: Prepare, price, and switch! Plan well ahead of the failure of your existing systems to get a contractor with heat pump experience and guidance. Not all AC installers have made the switch or can help guide incentive capture. These are the current Federal incentives:
Low-and moderate-income households: The Inflation Reduction Act offers instant rebates up to $8,000 for heat pumps. “Moderate income” here means less than 150 percent above the area median income. Use this calculator to check.
All households: Tax credits are available for heat pumps up to $2,000 per household per year, up to 30 percent of the project’s cost. Other tax breaks for home electrification are available, up to $1,200 per year if your electrical system needs an upgrade. These incentives have been conveniently indexed here based on Zip Code and income.
One more thing: These are ‘air-sourced’ heat pumps, as heat is exchanged with outside air. Another style is a ‘ground source’ heat pump, sometimes called ‘geothermal’.³ These are generally less suitable for retrofitting into Philadelphia homes, due to higher initial cost and space required.
For more information:
https://www.rewiringamerica.org
https://www.washingtonpost.com/climate-solutions/2023/04/27/heat-pump-name-air-conditioning/
https://www.washingtonpost.com/climate-environment/2023/02/28/how-to-get-heat-pump-home/
¹ “…heat pumps reduce emissions in the average household in every state when compared against the highest efficiency gas-fired equipment available. Even under conservative DOE minimum efficiency standards and a 100-year global warming potential of methane, 98% of U.S. households would cut their carbon emissions by installing a heat pump today, based on their combination of climate, electricity generation mix, physical housing characteristics, and heating demand profile”. https://www.rewiringamerica.org/circuit-breakers/heat-pumps
² https://carbonswitch.com/heat-pump-savings/
³ This article is about ‘Air-sourced’ heat pumps; heat is exchanged with outside air. A ‘ground source’ heat pump, sometimes called ‘geothermal’, where heat is exchanged with the earth via hundreds of feet of buried plastic pipes and circulating water. New air-sourced heat pumps are much simpler and cheaper to install, and easier to maintain, but may have higher operating costs. The case for ground-source heat pumps is better when electricity is very expensive, extended very cold weather is common, and the site has enough land is available to dig up and place heat-exchange piping. New buildings and commercial scale building are better candidates for ground-source systems due to scale and complexity.