Tips for Electrifying Everything
December 5, 2020
Discusses heat pumps for HVAC at 14:50.
Also touches on induction cooking, heat pump for water heater, etc..
This guy says newer air source heat pumps work well in cold climates, and he’s in Cleveland, so that’s very good news if true.
Climate Denial Crock of the Week 
December 5, 2020 at 6:25 pm
Our air source heat pumps work fine in Winter and Summer.
One thing, though. We were early adopters, and we caught a bit of pain from being on The Bleeding Edge, as they say in high tech.
Our ‘splits were installed in 2014. The prime contractor was a mess, and, as it turned out, their back office was in worse of a mess, but we did not know that at the time. Eventually (2 years later) they went bankrupt. But, little did we know, that they were paying their subcontractors margins that were next to nothing. This affected the quality of their installations.
We had 3 Fujitsu units installed. One unit was spec’d and installed with a run of tubing that, after the fact, proved to be too long. Either somewhere on the run, or the stress it posed on the compressor caused it to leak. This meant it was running low. We were not happy about this, but could not complained to the prime because, well, they were out of business. We found another dealer but, as it turned out, their service wasn’t great because they felt they didn’t install the system so ….
Anyway, they nursed the long run unit along, feeding it R410 repeatedly. We did not like this at all because that’s a potent greenhouse gas, or becomes it. But because they did not do a root cause analysis and kept this up, costing us a pretty penny, we fired them. And we found someone else who was competent. They tried to fix it, working with Fujitsu, but eventually the compressor failed. Fujitsu replaced the compressor (for free to us), and that failed, too. The recommendation of the new contractor was we needed to replace the unit. We did, buying a completely different unit, a Mitsubishi. That’s worked great, but it’s only been since 2018.
At this point we would have only gotten Mitsubishi units and not Fujitsu, but we did not know and at the time (in 2014) didn’t have much of a choice.
Interestingly, the unit that failed was a copy of a Fujitsu unit we still have but is operating fine.
The space now is filled with contractors who will do these units and our systems are now under the care of someone who does nothing else.
December 5, 2020 at 6:27 pm
[…] update is overdue, but I was writing up elsewhere so I thought I’d drop it in here as […]
December 5, 2020 at 7:00 pm
Same experience between Fujitsu and Mitsubishi. Got the Fujitsu first, somehow was not very happy with it. Always felt a bit fragile. Another local dealer showed up one day and offered to exchange the F. For Mitsubishi . I think he had bought a truckload of Mitsubishis and needed to sell them and had a client he could sell the Now second hand Fujitsu to.? Very small population here and odd things happen like that.
So I went along with it. Very happy with the Mitsubishi and the dealer later told me that when he reinstalled the Fujitsu unit it never worked again! Meanwhile for a very modest charge the Mitsubishi has been very satisfactory for now more than four years.
December 5, 2020 at 7:03 pm
Interesting video.
On the hot-water heater he misses one point: It’s not only a convenience to place one closer to the faucet, giving you warm water faster. For things like a kitchen sink, where you typically use hot water often but not gallons at a time, not having to warm 12 metres of piping every time you want some warm water can save you half the energy.
By the way, the (German) Miele dryer he refers to.
Miele is considered the gold standard for washing machines/appliances in Europe, top of the bill (and price range).
December 5, 2020 at 8:56 pm
Bought present house 30 years ago with 4 reverse cycle, heat pumps, none new at that time. One is still functioning. Another cooling system is the evaporative AC. Referred to as ‘swamp ..’ in the USA. Not as convenient or effective as conventional AC, but are way cheaper and generally way more energy efficient. Work brilliantly in hot DRY climates.
Note. Pumping heat out of sub zero air can be done but the laws of thermodynamics are ROTFLTAO. Wear a sweater.
December 5, 2020 at 9:03 pm
We have never have had to wear sweaters. Mitsubishis are better than Fugitsu but both simple say “Can’t do it any more” when it gets too expensive, and shut off.
December 5, 2020 at 10:40 pm
Actually we prefer a sweater to synthetic heat, This has brought a thought to mind, didn’t hurt much. The 80s, another house, this city, was heated by a potbelly stove. Heat so beautiful it overcame my Nordic to the bone desire for efficiency. Less than 40 years later we only heat an individual room for some minutes (and wear more clothes). And the world warms!
December 6, 2020 at 12:24 am
Not clear what the trade-off between 10 degrees cooler with sweaters and saved electrical energy are. There is no doubt some.
We never require any supplemental heating, until it is too cold outside for the heat pumps to operate. That is rate, and it is increasingly getting rarer. Indeed, heat pumps are a bet on global warming being real in cold climes.
We do shut down and not heat rooms we do not use, such as a guest room.
I have measured marginal electrical consumption from reducing temperatures in rooms 4 degrees Fahrenheit using our Sense installed electricity monitoring device, and I find little statistically detectable difference, at least at 40 degrees Fahrenheit outside temperature. It might be more at 20 degrees Fahrenheit. I intend to do that measurement some day.
While in principle heat pumps work harder when there is a bigger gradient they need to fight against to transfer energy, I have studied both the specifications of our newer Mitsubishi heat pump and its practical characteristics, and it’s clear it has been designed to use different strategies in specific heat ranges, because the cost of electricity consumption for maintaining temperature at a fixed target as a function of outside temperature is not continuous. Moreover, it is not even true that maintaining it monotonically increases with temperature. It seems the design switches to a different pattern or protocol at 20-40 degrees Fahrenheit than above that, and the per unit cost is actually higher in the 40-60 degree Fahrenheit range.
I will admit, I don’t know what that’s about, but I’d read it and observed it.
Anyway, I’m happy for the advances no matter what they are.
In our case, pre-heat pumps, most of our electricity during the year was being spent to power an air conditioning unit which operated on several really hot days. Now, we hardly spend any electricity during Summer, and most during Winter for these purposes. As more frequent hot days occur during Summer, this will be a win.
I should also say that the trade-off here depends upon one’s opinion regarding the ethics of electron hoarding. We also have a handsome PV array on our roof, one which sets us, at October-November with a deep deficit that the electric company owes us. That deficit is exhausted typically about February-March, but we are building another come April. This is all possible because we have the so-called “net metering”, and we do make an effort to economize so neighbors can take advantage of our free electricity. However, were the utility manage to convince state authorities to make the net metering less favorable, we would immediately stop being neighborly, and hoard electrons wherever possible, including probably installing house batteries and diverting energy to our hot water heater during days when generation is high. (BTW, that hot water heater is capable of heat pump operation, too.)
In a pinch, we have an orphaned oil furnace providing heat and hot water. But, in fact, nearly the only time we run it is for 15 minutes monthly to make sure it still works.
December 13, 2020 at 5:03 pm
Bear in mind the possibility of increasing your rooms’ latent heat retention. Even something as silly-sounding as vases full of water mean your rooms don’t have as fast temperature swings from mere heating of the air. (Of course, this means it takes longer to heat up your room/house in the first place—unless you fill the containers with pre-heated water—but it adds to the normal heat retention provided by rugs, furniture, stuffed trout, etc.)
December 13, 2020 at 5:09 pm
Good thought!
I do wash my woolen socks, sweaters, hats, and dry them downstairs, where there’s one heat pump. And we minimize use of a standard dryer, even if it is pretty efficient (ElectroLux), at all seasons. In fair ones, all gets dried outdoors.
So maybe there’s a model of drying the clothes upstairs instead.
Thank you for the suggestion!
December 6, 2020 at 11:53 am
Near Hanover New Hampshire, we have Mitsubishi heat pumps that have done a great job of keeping the house warm for two years now. The units will use a lot of electricity when it is cold (and it gets down to -20F on rare occasions), but the cost of that electricity is still less than when we heated the house with oil. And while the electricity in the New England pool is still fossil fuel heavy, it’s much cleaner and more efficient to heat our house this way–especially since we have solar panels which offset some of the electricity used.
To give a general idea of the use (I have detailed records), our average summer electricity use is about 25kWh/day (kids, pool, busy house). In November, we average 45 kWh/day, running the heat pumps to keep the house at 68F. In the coldest days of last winter, our usage was 100 kWh/day, but the January average last year (pretty cold winter) was more like 85 kWh/day.
Sounds like a lot of juice, but assuming our normal non-heating electricity use is around 20kWh/day, we are at about +60-65 to keep us warm in January. At $.17 per kWh, that’s $11.05 a day. Yes the electric bill went up a lot, but now there’s no oil bill. Last winter we saved more than $2000.
I would have been happy to break even–we’re using much less fossil fuel.
December 13, 2020 at 6:18 pm
Can I ask you a question about your Mitsubishi offline some time? We have one MXZ-3C24NA2 for our dining and living rooms.
One of my email addresses is ecoquant -at- letterboxes -dot- org
December 13, 2020 at 5:15 pm
Good basic intro to electrification options, but (and you knew there’d be a “but”):
– I didn’t like that he still pushed buying hybrids (video from 2019), and I pouted a bit when he mentioned Tesla but ignored my lovely Leaf. 😉
– He went to heat pump water heaters, but neglected tankless as a space-saving option.
One thing clear from the video: Building gasless means lower construction cost, and builders love cheap.
December 13, 2020 at 5:22 pm
Yes, the Leaf and, if it were now, the Bolt should definitely be mentioned.
On the other hand, because of (e.g.) Massachusetts incentive structures, we have this.
My friend and engineer neighbor dislikes heat pumps in favor of solar thermal for that.
I can understand those for a fresh start, but heat pumps have the advantage — as in our case — of being dropped into a home with existing fossil fuel heating which, in our case was oil and has been more-or-less orphaned. “More-or-less” means I test it once per month, and we use it in the rare cases temperature drops below -15F or the utility company’s power goes offline and we drop back to our propane backup generator. These are rare cases.
Yes, we have solar PV but in Massachusetts the rules are if you want net metering or SRECs you need to be grid tied, and that means, if the grid goes down, your panels go down.