The Washington Post takes on one of my favorite questions today: Why don't we use more heat pumps here in the United States?
There are two kinds of heat pumps, and I love them both. The first type should really be called "a cheap air conditioner," because that's what it is: an air conditioner that uses better technology than the one you have now. In summer it pumps heat out of your house and in winter it pumps heat into your house. And it does so for about half the cost of traditional heating and cooling.
The units are more expensive than standard air conditioners—and some climates are more favorable for heat pumps than others—but they don't cost that much more. And they save a lot of money in the long run:
In the United States, about 16,000 air conditioning units are installed daily on average. Researchers from CLASP and Harvard University predicted that if over the remaining decade, all houses installing central air conditioners bought a subsidized heat pump instead, consumers would save approximately $27 billion on heating and cooling bills, while decreasing greenhouse gas emissions by 49 million tons of carbon dioxide by 2032.
Hell, I had to replace our central air conditioner a few years ago and it cost somewhere around $10,000. The heat pump alternative might be a little more expensive than that, but only a little.
The second type of heat pump is geothermal, and it's a practical option only when you're building a new house. It looks like this:
A geothermal heat pump takes advantage of the fact that once you dig down about six or seven feet, the temperature of the soil stays the same all year round, usually around 55° or so. In winter that's hot water that can be used to heat a house. In summer it's cold water that can be used to cool a house. That's super-efficient.
However, it also requires a whole bunch of piping to be installed underground, and that's a lot easier to do when a house is being built. Once the house is finished it's a lot harder to find the space to install the ground loops, though it's usually not impossible.
So this is a no-brainer. If you're building a house in a favorable area, it should include the piping for a geothermal heat pump. If you're replacing a central AC unit, it should be replaced with a heat pump. The Post story, sadly, doesn't really explain why heat pumps aren't more popular in the United States:
Estimates show that 90 percent of Japanese households use heat pumps to heat and cool homes, contributing to a 40 percent drop in the country’s electricity consumption over the past decade. In Italy, the government effectively pays citizens to use the technology; homeowners can get 110 percent of their heat pump cost reimbursed.
But the devices lack popularity in parts of the United States and Europe....Energy experts point to a couple of reasons heat pumps haven’t entered the mainstream. First is the name, which makes it difficult for people to recognize that it heats and cools. “It is confusing,” said Corinne Schneider, the chief communications officer for CLASP, an energy nonprofit. The high price of installation — systems can cost upward of $10,000 to buy and install — is also a hurdle for many users.
Well . . . maybe. But is it really that confusing? And aftermarket heat pumps aren't way more expensive than conventional AC compressors. I honestly don't understand why both of these aren't mandated technologies wherever they can be used.
UPDATE: I was writing sort of casually here and should have been more careful. Heat pumps really are great technology, and Japanese manufacturers have made them even better over the past decade. However, not every American should literally have one. They work better in some climates than others, so there are plenty of places where they don't do a very good job.
Just generally, though, we should use them more than we do. That's especially true for geothermal heat pumps, but their high installation cost keeps them from being more widespread. However, geothermal systems would mostly be installed by home developers, and a government mandate/assistance program aimed at developers could probably go a long way toward making them more popular.
Chicago is far enough nouth that every time the jetstream weakens we get cold, days and days of cold. I don't know if a heatpump would be a good solution (it should work as advertised during the summer, especially if you live next to the lake); I would advise anyone in the upper Midwest contemplating such a refit to take a good hard look at the numbers before buying.
'North'.
We installed a geothermal heat pump in our house near Madison WI and it worked great. The sit above ground type is going to have a hard time in an extended cold snap.
For ours, the drillers came and went over 100" down in 2-3 loops. After that, air conditioning in particular was a breeze. It's like hooking your house up to a cave. In winter, you can also harvest a lot of heat from the 55F ground temperature (once you get below the frost line).
It would be better to call them ground-loop heat pumps. And it is possible, at least in theory, to add them to an existing home. I came "that close" to doing so. The thing which trips you up is you end-up needing to go vertical with the bores rather than trenching, and to get deep enough you have to use essentially a well drilling rig. And that can mean $$$. Assuming you can even get someone. 'Round these parts (California) they are all booked through the end of the year drilling actual wells.
So, I will end-up with an air-source heat pump. Sigh.
Heat pumps were touted in the 70s. Only trouble was, back then they were not all that adept at actually heating when it got very cold and they would fall-back on electric resistive heating. Jacking-up the owner's electricity bill.
I honestly think one of the problems has been the confusing name. I have a phd in chemistry and care about environmental issues but I just didn’t understand what these were for a long time. I obviously didn’t do much research but the name just did not make me think it was anything interesting.
The longterm (~500 years) average temperature of an area is found at about 2 m in the soil with small deviations from that number as one goes deeper. Warming or cooling potential can be estimated relative to that average number. So heating with a heat pump in Alaska is infeasible but cooling southeastern state housing would save tons of energy and money.
A number of states have tax credits associated with heat pumps. I know people in Midwestern states who have installed them on new builds (with added wood heating), and they absolutely love them for the cost savings. They also say that they get better humidity/moisture control. I plan to install on my next house.
I just replaced my gas furnace and AC -- the biggest issue was everybody wants to sell what their father's sold -- no one pushes heat pumps and they're difficult to find if gas is available. Meanwhile, everybody love mini splits because they're cheap, and they can charge outrageous prices to install them. Plus, utilities and government subsidies for heat pumps and are pretty lackluster. If you look at prices for heat pumps in cold climates, prices go through the roof.
Technology Connection has done a set on YouTube by somebody based near Chicago on heat pumps:
Heat Pumps: the Future of Home Heating - https://youtu.be/7J52mDjZzto
Ground Source / Geothermal Heat Pumps and Other Info - https://youtu.be/7zrx-b2sLUs
How to calculate when heat pumps make financial sense (and other heat pump follow-up thoughts) - https://youtu.be/BRdq2ExLJns
Why Heat Pumps are Immensely Important Right Now - https://youtu.be/MFEHFsO-XSI
Heat Pumps are Not Hard: Here's what it will take to start pumping - https://youtu.be/43XKfuptnik
Heat pumps are great. We just built a new house (almost done) and we put in a Mitsubishi split system for heating and cooling and we got a Sanden heat pump water heater.
I'll give people a pass on this in very cold climates, but everyone else should get one. You have a unit outdoors that produces a hot or cold liquid as needed and pumps it to heat exchangers in the house. You don't need any air ducts which saves space. You only heat or cool the rooms you are using which saves energy. And these are quite efficient; you get roughly 3 units of heat for 1 unit of electrical energy (in a moderate climate). The same unit can heat or cool so if you were just thinking of replacing your furnace you get an air conditioner as a bonus.
These are good down to about 40°F ambient temperature.
The Sanden water heater is even better. It is quieter and uses something called EcoCute technology.
https://en.wikipedia.org/wiki/EcoCute
This uses supercritical CO2 as the refrigerant (R744) instead of a halogen based gas. It is somewhat more efficient. It should produce about 4 units of heat for one unit of electrical energy (depending on outdoor temperature). It is said to operate down to -14°F. Below that a resistive heater turns on.
You can also get a solar water heater booster. This is a panel about two or three square meters in size. It has a glass cover separated from some piping by an air gap. Cold water goes into a pattern of piping behind this. It heats and stores some water. The outlet goes to your water heater. This can boost ground temperature water of about 60°F to maybe 90°F or more. Nice idea, but the ones I've seen are far too expensive.
I think heat pumps are not popular for two reasons. First, they cost a bit more up front, but save you money in the long run. This is familiar human behavior, we put much more weight on a small loss than a large potential gain. My wife is like this. She will buy any old junk if it comes with a coupon. Sometimes I tell her I will pay her $10 to get the better one but she refuses.
The other reason it is not popular is that it is not promoted. If the government got its act together and advertised this, if the Feds harangued localities to zone for this, if they subsidized it, then it would get used more.
It would also be useful if cities or states could figure out a way to warranty these. They are more complicated and sometimes break. Maybe if we all had to carry some sort of insurance on these for a few dollars a month, then people who are strapped for cash would feel more secure about getting one.
In California many cities are banning natural gas in new homes so people are switching to heat pumps.
The State of California may ban natural gas for heating air and water by next year.
https://www.bdcnetwork.com/california-considers-statewide-ban-natural-gas-heat-hot-water-new-homes
Once CA shows that it works others should follow. Also, increased volume will lower prices. Once builders and installers get more experience that will make adoption easier.
Might I suggest that EVERY article of this sort be a little more careful with geography.
America is a big country. The right tech for LA is very different from the right tech for NYC, and it doesn't help anyone that we get an endless stream of articles that all claim (solar/wind/heat pumps/...) are some sort of universal solution.
The primary effect such claims have is that people will look to their circumstances ("clearly tech X does NOT work for me in Phoenix") and conclude that the people selling these stories are no different from the sorts of scam artist liars who have been selling other universal American solutions since for forever – silver bullets for school reform, for medical reform, for housing etc etc.
It's great to promote solar in AZ, or heat pumps in Seattle; it's not helpful to pretend that either is a generic "American" solution!
Had a home built for me in the Finger Lakes in 1982. On six acres, it had a geothermal heat pump, using the same well as the drinking water, with the well and pump/pipe spec'd for the extra volume. Water was returned by a shallow drain under the side lawn, to a wooded declivity.
When I downsized 13 years later the new owner replaced it -said it was too noisy. (well, it was really loud).
I never did figure out if I saved money, just the electric bill seemed reasonable.
It does beg the question if drilling and installation of groundwater wells can be combined with the drilling and installation of an open loop groundwater heat pump system for homes that are completely off-grid.