Mitsubishi Hyper Heat System Installation Failure
Is there anyone out there that can perform an un-biased 3rd party inspection of a Mitsubishi Hyper Heat system?
I had a bad experience with the installer, the system thus far is a total failure, and Mitsubishi refuses to help.
I learned their “Diamond Contractors” receive minimal training – and no one verifies if they actually are doing the installations correctly.
I paid a lot of money for this system, and I’m currently facing having to install a new furnace since this system has been such an abysmal failure. Everyone that sees my house sees the system, knows that it’s rated for “theoretically down to -15F” and asks why I need a furnace. I keep my house at 60-65F and my energy usage is over 1300 kWh a month. I’ve owned the home for over a decade and I have had it insulated, newer windows, doors, etc. I installed ceiling fans to help move the air properly, ensured they are rotating the correct direction, etc. I’ve been monitoring in real time with a Sense monitor and the system is using 35 kWh a day when it’s 35F, for a <1300 sq. ft house. I am so desperate and no one seems able to help me. I’m worried I’m going to get stuck spending and an additional $20K on a new furnace and ductwork system, after I already spent almost that much on the Hyper Heat system.
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Replies
Do you know what your energy usage was before this system was installed?
At first blush it doesn't seem outside the realm of possibility that the system is working as designed. Usage of 35 kWh/day works out to an average of 1450 Watts. That's about 5,000 BTU/hr. Let's say the coefficient of performance is 2.5, that's 12,500 BTU/hr. That's on the high end but not out of the question for a house that size. That's why I ask about your previous bills, they would give an indication of the performance of the house, even if it was a different fuel.
What model do you have? If it's running, there's not much that can go wrong. It could have been mis-sized, or it could be low on refrigerant. If it's a ducted unit the ducts could be improperly installed.
My system is a Mitsubishi Hyper Heat Model MXZ-4C36NAHZ2 (outdoor unit). It has an interior branch box that is hooked up to 4 heads, 2 of the MSZ-GL06NA, 1 MSZ-GL18NA and 1 MSZ-GL12NA. The system was manufactured in December 2020 and installed in April 2021. It is supposed to be efficient at 35F and only see a drop in efficiency when it gets into the teens , with up to 70% efficiency at that point. However, these "Hyper Heat" systems are supposed to work down to -15F. I live in Rhode Island and 25-40F is pretty typical for winter, so I thought this system would work. I have an 80% efficiency Goodwin Gas furnace that 185,000 BTU. It was installed in 2011 by the previous home owner directly before I purchased the house and I am well aware it is both over-sized and there are some faults with the returns, ducting, etc. The Hyper Heat system was appealing for both heating and cooling and seemed like it would be a good fit. However, my home has never been flagged by my energy company inefficient- my typical gas usage was always considered average. Even though I have switched the comparisons over to Electric heat, I am constantly getting flagged saying I'm using 88% more electricity than similar homes (with electric heat) - and the 1346 kWh numbers and such.
If you're in Newport, Providence or Bristol your winter design temperature is 9F. (See https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/County%20Level%20Design%20Temperature%20Reference%20Guide%20-%202015-06-24.pdf ). That's the temperature your system should be designed for, it means that 99% of the time it's warmer than that.
If you're pulling 12,500 BTU/hr at 35F with interior temperature of 65F that equates to around 24,000 BTU/hr at 9F. Your system is rated for 30,000 BTU at 17F. They don't have a rating for colder but it's going to be less, the rating for 47F is 45,000 BTU. So it seems appropriately sized.
The rated COP is 3.95 at 47F, 2.3 at 17F and 2.0 at 5F. So my guess of 2.5 at 35F isn't far of.
I'd want to see your gas bills from previous winters before concluding anything is wrong.
New England has among the highest electric rates in the country, we've had a couple of posters here recently who installed heat pumps and found they were more expensive to run than the gas furnaces they replaced. February also had extraordinarily cold weather, February 5 was the coldest day recorded in the history of Rhode Island.
I 100% want to make it clear I'm not basing this on money. If it was about monthly bills, hands down, my gas furnace was significantly better, running around $150-$250 a month in the coldest months of the year vs the $411 a month with the electric system only. My house typically has a base-line load for gas usage of 6- 10 therm per month for hot water, cooking, etc. Winter heating use in therms was ~118 (or $144 in gas) for the same conditions that are currently running me 35 kWh per day (which would work out to ~ 1,050 kWh for a 30 day month, using $0.223 per kWh, $234.15 for electric heat only). However, the point was to switch to an efficient solution. I've been using kWh and therms, and comparing my energy comparisons to similar homes from my bills, as well as using the Sense monitor. RI Energy has a combined "Energy Units" value (combining electric kWh and therms) that makes it relatively easy to see how my energy usage has changed, dramatically increasing with the use of the Hyper Heat system). Winters in RI are getting warmer and warmer - there were a couple cold days, but many were close to 50F. I also don't use the Hyper Heat at all when it's below 20F at this point (relying on the gas furnace), because the performance is just pathetic. It struggles to heat at 35F, really drags at 30F, and gets absurd in the 20's. I was also told that the issue must be because I was turning down the heat at night (and the system in turn was struggling to make up a delta in the morning if I turned it back up). So, to avoid the issue of there ever being a delta for the system to make up, I'll run the gas furnace and the house up to temperature (then turn it off), then turn on the Hyper Heat System. So - I am turning on the Hyper Heat to a house that is already warm. The Hyper Heat system then cycles, pulling 2500 to 3000 W for about 15 minutes, dropping back to 500- 600 W, and then going back up to 2500 W, over and over. I also tried literally running no heat at all and my house doesn't drop below 50-55F. Given that I'm setting Kumo Cloud to run at 60 to 65F in a house that I've already heated to 65F with a furnace, it seems ridiculous that it would take that much energy to maintain the temperature. My general fear is that I paid a lot for this system, and if it was not installed properly (I 100% do not trust the company that did the install - they did a crappy job on the install and tried to convince me I didn't know how to read my electric bill), then the system could actually be getting damaged by trying to run it. I tried running it again to gather the data for the Sense monitor, but I am sincerely convinced something is wrong and I am doing damage every time I turn it on. The whole point of posting is to try to find someone decent that can review the installation.
Hi Pumpkin,
My utility does the neighbor comparison metric too - I'd be wary of drawing too many conclusions from it - it is self-reported data after all and I think the software vendor is the same for many utilities, so errors will carry over. For example, I have a heat pump with no gas furnace. I should be only compared to electric heated homes, but I'm definitely not, so I look great on gas and average on electric. The combined metric is nonsensical for my utility - it works out to 1 therm = 9 kwh.
As to the system, multi-splits have unique issues: they seem to end up being oversized every time because the product offerings aren't good enough. With the existing ductwork, you could add in a ducted unit, which can be sized much more appropriately. I have no complaints with my ducted hyper heat unit. I understand your frustration, buyers shouldn't have to be this involved in this type of decision.
That’s relatively poorly performing - my ducted Mitsubishi hyper heated house use about 1 kWh for every degree under 60. So 25kwh for a 35 degree day and that’s for the entire house’s energy use, not just the heat. I have no ceiling insulation, old windows, and more sqft. You went with ductless heads indoors?
We don't know if when he says 35-degree day that's the high temperature, low temperature or average temperature.
35 F is a typical winter temperature where I live. The system is absolutely supposed to be able to be efficient at this temperature range.
Re-posting from an earlier answer. My system is a Mitsubishi Hyper Heat Model MXZ-4C36NAHZ2 (outdoor unit). It has an interior branch box that is hooked up to 4 heads, 2 of the MSZ-GL06NA, 1 MSZ-GL18NA and 1 MSZ-GL12NA. The system was manufactured in December 2020 and installed in April 2021. It is supposed to be efficient at 35F and only see a drop in efficiency when it gets into the teens , with up to 70% efficiency at that point. However, these "Hyper Heat" systems are supposed to work down to -15F. I live in Rhode Island and 25-40F is pretty typical for winter, so I thought this system would work.
I've found 26 kWh per day is supposed to be standard for an electric heat system heating a house this size, but my Hyper Heat system only achieves that when it's about 40+ F outside.
There's just no such thing as "standard." Every house is different. Energy consumption can vary by a factor of 10 for two houses of the same size depending on how they're constructed and insulated.
Analyzing your gas bills from before the switch is the best way to determine if your energy usage is in fact up. I'll also recommend this thread from someone close to you who recently installed a heat pump and experienced higher-than-expected electricity bills:
https://www.greenbuildingadvisor.com/question/is-this-post-ashp-electricity-use-expected
The upshot was that electricity is significantly more expensive than gas there, and the efficiency of a heat pump doesn't compensate for the difference.
I'm getting the point of your username. No matter what I say, you are going to argue that I must be wrong. Pointing out that there was one day of record setting cold in RI when I live here and it's actually quite warm (we also had the warmest days ever recorded for the month of February) is problematic and tells me you are more obsessed with proving me wrong vs. helping.
I still would prefer to actually find out if there is anyone out there that can actually inspect installation.
At the end of the day, I have a garbage system I paid a lot of money for - and I would like to understand what is wrong.
I've lived in the house for over a decade, so I know the status of the drafts, the insulation, the windows, the doors, etc. I've also taken enormous lengths to insulate the home with R-value 30 insulation, fiberglass doors, new sliding glass doors with double panes and proper seals, , newer windows, etc.
The gas furnace also heats the entire house, including the basement, whereas the Hyper Heat system numbers I am quoting are for heating only the above-grade living space. The daily kWh would be even higher if I was trying to run the head in the basement (I tried that, trust me, it's a lot). So, the gas furnace therm values for prior years are not a great comparison as they are heating an even larger area and I don't have a daily meter like the Sense to pull the exact gas usage from the furnace like I can on the electric.
However, to compare apples to pears - 118 therms per month was a winter heating usage, which equated to $144. 8 therms of that was hot water/ cooking gas, so let's assume 110 was for heat, and let's assume that was heating 2000 sq. ft, since the basement is included. I know that's not efficient at all - I was aware my furnace was not efficient, installed incorrectly, and over-sized. Which, was the whole point of installing the Hyper Heat system. By contrast, running the Hyper Heat system to heat ~1300 sq ft of my house only will run me at least 1050 kWh, if not closer to 1300 kWh (based on past data). This is going to cost me at least $290 based on prior electric bills. So, it's roughly double the cost. Now, I know - Apples to Pears to Orange vs. Apples to Apples. But, still doesn't change that I have a system I need to think way too much about that doesn't seem to work all that well, and I have the giant fear it's going to malfunction dramatically due to improper installation.
A "contrarian" is not someone who is always contrary. Rather, a contrarian is someone who challenges the accepted wisdom, someone who has to see things for themselves, an empiricist.
OK, 110 therms of gas a month. That's equivalent to 3200 kWh/month. If you're instead using 1050 kWh/month of electricity, that's a COP of 3.05.
I'm sorry that I'm saying things that you don't want to hear, but so far you haven't provided any evidence that your system isn't working as designed. I get that you're not happy with it. You keep saying it's "not efficient" and I have no idea what you mean by that.
Pumpkin: I'm the poster with a similar situation as you have, so believe me I'm 1000% sympathetic to your plight.
I think what the reply posters are saying is that absent any other changes (more insulation, etc.) the energy needed to heat your house should be consistent. There are of course variable in outside air temp.
To put your response in perspective, 1 therm = 29.31 kwh
Per your post you used 110 therms of gas to heat which would be 3224.1 kwh to heat the same area. But you clarified that you are not heating the same area, 35% of the area you heated with gas is your basement which you are no longer heating. I'll note that the basement should be more efficient to heat than all other areas, since the thermal mass of the earth and foundation walls will trap heat and there are usually fewer doors and window through which heat leaks out. But for simplicity, lets just go with heating 65% of the previous area heated, which would equate to:
110*.65=71.5 therms = 2095 kwh
You noted you are using 1050-1300 kwh to heat this 65%, so based on the math, it does look like the mini splits are using less energy to heat your home and are thus more efficient.
The challenge is that in your case the cost of electricity is FAR more than the cost of gas, so while your use of energy is more efficient for the same outcome, the economics are less efficient for this outcome.
Another issue to consider in your calculation is the current costs. In my area, I was heating for about $0.31/therm in the winter of 2021/2022. However for the winter of 2022/2023, the cost of gas has risen to $0.92/therm. So for any cost comparisons, I would need to almost triple the cost of gas usage.
None of the above changes the fact that there should be readily available support and trained technicians to install, troubleshoot, service or just inspect the systems that manufacturers sell. Mitsubishi has failed miserably on this front by purporting to have qualified "Diamond" service companies that have NO CLUE on multisplit systems. I too would install one:one systems if I had to do it over, but too relied on experts and have a >$20k system, and all I want is for the thing to function as efficiently as advertised, and to know there is a service company I can call if something goes wrong. So far, after dozens of phone calls, I've struck out on both counts. The most infuriating part of the entire situation is Mitsubishi is of no help at all.
OK, let's say you were using 110 therms a month with gas. Looking at the weather records, TF Green Airport reports about a thousand degree-days a month in the heating season(5600 for the year). A therm is 100,000 BTU so that's 11 million BTU/month and 11,000 BTU/degree day. That's 460 BTU/degree-hour. With a design temp of 9F, interior temp of 65F, that gives a heating load of 25,666 BTU/hr at the design temp.
In post #7 I estimated 24,000 BTU/hr based on your electricity usage. Again, nothing is inconsistent with your system working as designed.
(replying to post #19)
You really can't equate area heated to heat produced. Heat moves freely within a house. It's entirely possible that heating the basement would provide enough heat leakage to heat the rest of the house. It's also possible that heating the upstairs provides enough heat leakage to heat the basement. There's just no telling.
Following because I've got a similar situation and need a similar solution.
- had system designed by reputable designer who participates on this site, so I think the design is correct. Equipment nameplates and ducting is exactly per design
- GC's used an installer who only does new installs; absolutely no service. That ship has sailed.
- Two Mitsu Diamond installers stated they have never seen, much less installed a Mitsu ducted system.
- Mitsu is of absolutely NO help.
I'm beginning to really really really dislike Mitsubishi. They may make a good product but either the product is too complicated or their support network is entirely insufficient.
DC is one of the most helpful people on this site. It would serve you well if you took their advice.
You need to figure out the heating load on your house and share that before anyone can pass judgement on the system. Try this thread for the formula. https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler
If you search this site, you will find loads of people with multi-split issues. We took the advice of people on this board like DC and installed 4 one to one units instead of a 4 head multi.
If you want someone else to figure it out other than the free help from people on this site, your best bet is another HVAC contractor. Try calling a couple of local energy audit companies and see who they recommend
Seconded. I've seen lots of good posts from DC. And his posts in this thread are helpful, as well.
Thank you for your kind words.
HI DC - I had already reached out to a lot of people, including directly to my energy company, who had referred me back to RISE Engineering in Rhode Island. I already had one of their home energy audits years ago. I had also already met with multiple contractors as I was looking to get a furnace, as I had given up on using the Hyper Heat for heating purposes based on their performance last year (21/22). The other HVAC companies questioned why I was trying to get a new furnace when I already have the Hyper Heat system. I explained it doesn't really heat the house. One HVAC company said they weren't going to get into anything involving a system another company installed, but that I should have the original installer check the pressures and such to ensure the system was working properly. He also told me Kumo Cloud was found to waste a ton of energy, which seems very odd. I had the original installers quote my on getting a furnace and also expressed my issues with the Hyper Heat system. They told me that spending $700 a month on electric heat was normal. However, given they had quoted on not only the Hyper Heat, but also a furnace, I requested if they had a manual J calculation - they did not and could not provide that. Which seems a bit odd, as well. I went back to RISE engineering and back to Mitsubishi. I only turned to this site because I saw numerous posts of others having Heat Pump issues and thought maybe someone would know of a reputable company that could come and inspect my system.
I saw that coming...your 'tude is palpable. It must be your frustration shining through, but it's never smart to argue or criticize people you are asking help from.
Try a well known energy consultant. It's going to cost you money to hire them and have them do a study and/or audit. Perhaps the local energy supplier could recommend local consultants to do a detailed analysis etc.
There are also companies all over the country that could do detailed inspections and reports for you. Spend an hour on Google looking them up.
Good luck. I"m considering the exact same install in an old house in CT this year.
There is a big difference between folks that are genuinely trying to help vs. those that are trying to prove how much they know.
Can you please elaborate "companies all over the country that could do detailed inspections and reports for me"? I am honestly curious what you are getting at here.
Yeah, we're all against you here....
Here are a few websites. Get on the phone and do some of your own homework. Maybe if you take the time to talk to some of these people, they could send you in the right direction.
https://climateactionbrookline.org/environmental-resources/building-professionals
https://zeroenergy.com/mechanical-consulting
https://jsheld.com/areas-of-expertise/property-infrastructure-damage/mechanical-electrical-plumbing-mep?gclid=Cj0KCQjwtsCgBhDEARIsAE7RYh0PSV-T3pfLdQpk9SVtiwEZyz0S2OXwPcqAJnZOhwsbIhbgL3XC_zcaAtzsEALw_wcB
https://www.ecosmartct.com/about-us/why-choose-us/
https://www.youtube.com/channel/UCI2VDyfqdsttBE0X3c-ArXg
Hello NyNick,
Trying to be civil here - I'm not here to have inflammatory discussions, and I'm too fried to deal with insults. I have, indeed, done a lot of homework and this was intended to be supplemental to that. I was hoping to get some vetted/ experienced leads vs. cold-calling companies that I found only from searching on my own.
Pumpkin, this thread has gone in a direction that you initially didn't ask for. Your original post asked for advice on getting a third party inspection of a complex system that was not acting as you expect. I will validate that frustration: traffic on this site confirms that some (many?) multi-splits don't perform as expected, and even more traffic confirms that many (most?) HVAC contractors do not competently support these installations. There are many things that can go wrong with a multi-split: bad design, bad commissioning, mixed up wiring, refrigerant leak. All of this takes serious sleuthing when you've got a complex VRF heat pump installation--you can't just look at the heads from across the room, you can't just put a gauge on the service port. Where I am in the rural midwest, I know of ZERO contractors who I could call to evaluate this system. Not trusting your installer, I hope you can find, somewhere in RI or MA, and with suggestions from this forum, an energy consultant who can study your situation and hook you up with a competent tech. It will cost you, of course, but at this point that would be money will spent.
Thank you. Nothing like getting chastised "for asking for help" when no one seems capable of answering the question I originally asked.
My recommendation would be to seek out an energy audit rather than a HVAC diagnosis. I've been favorably impressed by John Peters at Ecologic in Tiverton.
http://www.ecologicinsulation.com/services_energy.php
Long story, but a basic energy audit was conducted. Separate issue and I'll do a separate posting related to that at some point (maybe).
Thinking a lot more about the points that have been raised here, I think there are some things that will make more sense with some calculations:
This site and the calculator it links to are useful:
https://extension.okstate.edu/fact-sheets/true-cost-of-energy-comparisons-apples-to-apples.html
I downloaded the calculator and set the rates to correspond with my current rates in Rhode Island - these are from my bill that was issued today, so I know they are current. This is just the cost for energy, we are not getting into the other charges. ($0.6831/therm, $0.1778 /kHh).
Using the calculator from the site -
Notice that the gas furnace is listed as 85% efficiency (pretty sure mine is more like 80%, but I'll take it at 85%), Electric resistance is 100% efficient, and Electric Heat Pumps are listed at 300% efficient. That is important.
Using my current RI Electric rates, the cost per Million BTU comes to: $8.04 for Natural Gas, $52.17 for Electricity -Resistance, and $17.39 for Electricity - Heat Pumps. Which works out to Electric Heat pumps costing 2.16X's the cost of Natural Gas, and Electric Resistance costing 6.48x's the cost of gas.
Using the 719 kWh I used this month (I used my furnace, as well), that works out to 719 kWh x $0.17785/kWh = $127.89
If I were to convert that directly to therms, that would be 719 kwh/ 29.3 kWh/therm = 24.54 therm
If I were paying that directly with my natural gas prices, that would be (24.54 therm/ (0.85 efficiency) )x $0.6831 = $19.72
So, let's assume it would have cost me $19.72 if I had used natural gas.
Now, going back what I paid using electric heat pumps, that was $127
.89
$127.89/ $19.72 = 6.48 x's the price
My cost to heat my home using my 2021 Hyper Heat Pump is the same as if was using an Electric Resistance heater.
Oddly enough, when I run my Hyper Heat System, it pulls a very similar amount of energy as my one small baseboard heater (which is in a bathroom and only turned on for a couple of minutes at a time), even when it's' heating a house that is already at temperature (maintaining).
However, using the 300% efficiency number, that 24.54 therms equivalent should have run me less than $45. If I was paying $45 vs. $19.42, I would be happy as a clam right now.
In post #19 you said you were using 110 therms a month last year for heating.
What I'm getting is with your utilities an electric heat pump with a COP of 3.0 will cost 2.16 times as much as a gas furnace with 85% efficiency to produce the same amount of heat. So that 110 therms would cost $74, and switching to electric would raise the cost to $160.
Your math is off a bit:
"Using the 719 kWh I used this month (I used my furnace, as well), that works out to 719 kWh x $0.17785/kWh = $127.89
If I were to convert that directly to therms, that would be 719 kwh/ 29.3 kWh/therm = 24.54 therm"
That is correct.
"If I were paying that directly with my natural gas prices, that would be (24.54 therm/ (0.85 efficiency) )x $0.6831 = $19.72"
This is wrong. Your heat pump put out about 3x the heat of the electricity you used. So even though you used 24.5 therms of electricity, it produced 143 therms of heat.
So if you now look at that in a furnace, it would cost you:
143 therm/ (0.85 efficiency) )x $0.6831 = $114
So not that far off.
The only question that remains is if your heat pump is running at COP3 or less. The only way to check that is by installing a power monitor on the unit and measuring temperature delta on each indoor head.
Akos, your math is off too. You wrote: "Your heat pump put out about 3x the heat of the electricity you used. So even though you used 24.5 therms of electricity, it produced 143 therms of heat."
Three times 24.5 is 73.5. That would cost $59.07 to produce with gas.
So producing the same amount of heat costs $127.89 with a heat pump and $59.07 with gas. It's the same 2.16 ratio.
"The only question that remains is if your heat pump is running at COP3 or less. "
Bingo. That is the key question.
Since you have an energy monitor connected have you done any tests to check the performance of the unit? Have you measured the delta t's across the coil.
One of the easiest tests you can do it is set your unit to max heat by setting the fan to high and the temp to like 82 on every head. When you confirm its at max capacity with your energy monitor go outside and measure the temperature of the larger pipe going to each indoor unit from the outside condenser. You should see 125-140 degrees. If your seeing significantly less than that your unit is most likely low on charge.
You can also calculate the cop and btu output of each indoor head very easily as well. There was a recent post about measuring the cfm on the same topic.
Pumpkin,
I’m 72, so I am old enough to remember what happened in the late 60’s, the last time the electric utilities convinced lots of people to build all electric houses and retrofit lots of electric baseboard heat with the “incentive” of an electric heat rate. “All of a sudden”, demand for electric power outstripped demand, and the poor, innocent, wittle electric utilities that never anticipated what would happen, had to run to state PUCS to get higher rates and eliminate the electric heat rates. Electric energy has always been the absolutely most expensive way to heat a house. Here in New England, electric rates are among the most expensive in the country. Why? Because every New England State is dependent on electric power from the massive Québec utility Hydro Québec, imported by high tension lines (not too cheap build in mountains) that run all the way into central Québec, several hundred miles above Vermont’s northern boarder with Québec. And why is that, you ask? Because too many of your neighbors are afraid. Some are afraid of the dark. Some are afraid of mice. Some are afraid of snakes. Some are afraid of the boogey man. And some are afraid of nuclear power plants. We had a nuke here in Vermont. It aged out and had to be decommissioned. I suppose it supplied cheap power to other New England states as well as a substantial portion of Vermont’s needs.
Here in Vermont, our wise state Senate just passed the “Clean Heat Act”. It will cause fossil fuel importers (bad, dirty, naughty, evil) to buy carbon credits. This will increase the price of propane and heating oil (bad, dirty, naughty, evil). This, at least in theory, will force at least some people to switch to electricity (good, clean, obedient, and wholesome). There is of course, no provision for incentivizing internal power production beyond hoping that if we cover the entire landscape with solar panels that everything will be ok, we hope? And of course HydroQuebec could always take pity on us because so many of us are afraid, and reduce our rates, maybe?
At least one local large dairy farmer went into the electric generating business. He paid about $1 million cash for his first digester and recovered his investment in a year selling power to his neighbors. He is still buying digesters and adding generators. He now makes way more money selling electricity than he does selling milk. Somehow, our entire illustrious state Senate has missed all the local press has gotten. We have a little hydro here, not really enough to do anything. The state has spent a substantial amount of money taking out old dams. Is it possible that some of those could have been small power stations, like the dairy farmer?
And the $64,000 question is what about a new nuke? Apparently our politicians would prefer to hope for a miracle than plan for the future. After all when the the afraid people get really afraid they awful noises. Clearly we have no leaders with the intestinal fortitude to risk educating the afraid.
There are already in place extremely generous rebates for heat pumps, heat pump water heaters, and all manner of other electricity-consuming gegaws and dodads, like heat pump washers and so on. Better to feed the consumer demand than plan, too, I guess.
It has been 63 years since 1960. So I guess that is the length of the stupidity cycle. Congratulations! You have been had by your state government. Suck it up spend the money you need to in order to dig yourself out of the hole you dug for yourself. Also in the 60’s my engineer father taught me about perpetual motion machines. He also taught me that there ain’t no free lunch and life ain’t fair. I taught my daughters those things and added that if it sounds too good to be true, it probably is. The people pushing this stuff make over-broad generalizations about things that in reality are tied to a multiplicity of design factors unique to each job. Has anybody suggested trying to find out how massive the backup electric resistant coils are? They could be 7500 W or more. If they are coming on too soon as the outside temp drops, they will eat you alive.
Give me A Weil-McLain Gv90 cast iron condensing boiler, a conventionally vented propane hot water heater and some ducted min-splints for cooling and back-up heat, with a standby generator. May not be politically correct, but I won’t have to go to the warmup center in the firehall. Some of the locals are calling them woke up centers, but that would be mean to the afraid.
My system in Boston ran 1450 kwh in February for a 2400sf house, well-insulated, tight, nice triple pane windows. I'm in my 3rd winter of a similar but larger system that has had a lot of issues. Depending on how well sealed and insulated your house one thing to consider is your system is oversized. My understanding, I'm no engineer, is that the large Hyperheats ramp up to high energy usage when they first turn on and then theoretically operate at a efficient ratio. When they are oversized, as mine are, they turn on every 15 mins or less and ramp way up to the 1.5 kwh and then turn off after 5 or 6 minutes, then repeat the process. The units that are in relative draftier spots (i.e. my basement unit) kick on more often. My solution, which unfortunately doesn't apply to you, is to set the units on my 2nd smaller condenser to 68 and the units on the larger condenser to 63. Not really a solution, I'm just trying to make the best of an oversized system that I'm apparently stuck with. If I was going to do it over again, I would use smaller heads in the bedrooms and have 3 single condensers instead of a single and double hyperheat. I've heard good things about Zero Energy Design, but haven't worked with them myself. They are closer to Boston, but maybe able to consult with you. https://zeroenergy.com/mechanical-consulting
Just to put it in perspective - I'm heating about ~1300 sq ft and I never set the mini-splits (in the winter) above 65F. Most of the time, the 1350 kWh number is for keeping the house at just over 60F. It typically drops below 59F overnight. To put it in perspective, if I had no heat running at all, the house would be 55F overnight. Which seems to indicate the system doesn't do a whole lot. And yes, I am really cold. My basement hangs out around 50-55F. It's a flagstone foundation that I've done a lot to seal, but it's not ideal. It also has full size windows (newer windows, but I want to correct an earlier poster about the idea that basements are going to hold heat better than the rest of the house). The furnace can heat the basement adequately, but there is only 1 head down there for the mini-split and it's in a room that is separate from the rest of the basement.
> Just to put it in perspective - I'm heating about ~1300 sq ft and I never set the mini-splits (in the winter) above 65F.
Wait, why are you not setting them above 65F?
Sorry I do not have any answers to help Pumpkin. But it is discouraging to hear about folks having issues with such an expensive product.
I think this thread highlights how difficult it will be to convert a large segment of the housing units in America to electric heat using mini splits/ heat pumps. Granted, people who have existing ductwork can merely replace a central AC/furnace unit with a high efficiency heat pump. But heat pumps in general, and mini splits in particular, are complicated machinery compared to most furnaces and boilers. They will require a large, well trained army of HVAC technicians to install the numbers that will be needed. Most existing HVAC companies seem to know how to install them, but few seem interested in carefully calculating size and air flow or dealing with repairs (I learned this the hard way when a mother board fried in my dad's 36kBTU multi split and the local HAVC companies wanted to replace the entire unit for $7000. I bought a board online for $300 and did it myself in one hour).
Mini split units are also very expensive installed, probably too expensive for the market that needs to develop. I believe that the price per btu or per unit is much lower in Europe and Asia, as units are sold by retailers like appliances. I assume that when they go bad, they are just replaced cheaply.
I am not sure what will occur here. Perhaps a hybrid between what we have now and what exists in Asia and Europe. Perhaps the market will change as volumes grow. Utility companies or other large companies (maybe the manufacturers themselves?) may sell and install large numbers of these units at a discount using technicians trained solely to install mini splits. Sizing will be done via sophisticated AI programs based on prior gas or electricity usage. More senior/experienced technicians would be on call to handle problems that arise.
The thing is, he hasn't presented any evidence at all that the product is not working as designed. It's clearly not working to his satisfaction, but it might just be a poor design. It might also just be that his location is a poor choice for the technology because electricity isn't price competitive.
Yes...
I was just musing about the market in general and how we get from here to a (mostly) electric future. If we want to induce huge numbers of folks to transition from relatively simple time tested fossil fuel furnaces and boilers, we are going to have to solve for a host of issues related to product design, sizing, installation, electricity delivery and price and maintenance...
"It might also just be that his location is a poor choice for the technology because electricity isn't price competitive."
This brings up an interesting question. At what price point DOES HP technology provide a competitive choice?
My electric rate was .24/kWH and .22/kWH for delivery last month, totaling $.46/kWH.
I could stay with oil or switch to propane (no natural gas nearby) or Hyper Heat when I do my renovation. I know HP's are more "efficient", but if they're double the monthly cost it certainly seems considering that the payback isn't worth it. My GC has been making this argument for a year.
At Pumpkin's .68/kWH it seems not to be.
Wow. I am amazed...My rural electric cooperative charges me 11 cents per kwh and a $30 month general fee. And 70% of my electricity comes from non fossil fuel sources.
If they have hydro that's generally incredibly cheap.
It becomes competitive when the price per BTU is cheaper. Being more efficient doesn't do much for you if the underlying fuel is more expensive.
The only complication I would see is trying to look into the future, HVAC equipment lasts decades, what's true today may not be true in the future. But trying to predict future energy prices is a mug's game.
Thank you. How do I compare HP btu's cost to propane or oil btu's cost?
Sorry if this is an elementary question.
As to increased fuel costs in the future, they all are subject to unknown increases. I'm happy just trying to figure out today's costs and running with it.
In post #32 Pumpkin gives a good description of how to price compare different fuels and a link to a calculator.
What you care about is cost per unit of delivered heat. The inputs are cost per sales unit, unit of heat per sales unit, and installed efficiency.
It's very area dependent. My parents were looking to replace their propane furnace with a heat pump. We took their electric bills and propane bills to calculate it out. Turns out... Propane is more expensive than resistance electric heat. Their propane was costing $3.48 and their electric at $0.13/kwh. At those prices, it's within a few btus/$, but propane never runs at 100%, while electric is 100%.
This is exactly what keeps me up at night these days. Someone suggests (comment #38, below) that hopefully the IRA credits will kickstart the market and provide more techs and support, and HVAC companies will rise to the challenge. But as you point out, even IF companies can staff up and tool up and myths can be debunked, we have a housing stock that is broadly unsuited to an easy conversion. The manufacturers aren't helping themselves--their glossy brochures show minisplit heads mounted in every room as smiling families lounge about, and the salespeople push hard on the multisplit solutions with no mention of the various other measures required to adequately update an older house. I'm not as optimistic about the market moving in wise directions--federal IRA credits are attractive but relatively small, and they are only tied to basic equipment efficiency ratings rather than design standards or post-installation measured performance.
I agree with what you are saying and your projections. As you say, commissioning is a nightmare, sometimes taking over 24 hours, or 6 MD. Except for the larger outfits that put in ground to water geothermal systems in a few very high end houses, but mostly in public buildings, I know a few HVAC guys who have put in one air to water heat pump but only one who puts in a lot of them. He is a distributor for and installs Arctic air to water heat pumps, which sre made in Ontario. There is a one year parts and labor warranty. So that gets a big red X from me. And the air to water is really the Holy Grail here, because you can easily do so much more with hydronic than you can sort of half do with forced air. And you can use a chiller, a more mature technology.
And the market conditions in Asia and Europe are different. Most of the houses have been built since the end of WWIi and the Korean War to building codes way more strict than our own. The people are obsessed with high efficiency buildings and heating appliances. The build quality is better and cheaper to heat. The typical German house has lots of poured concrete, covered with flat clay tile and layers of various kinds of foam. The roof is tile, not asphalt shingles. Except for the foam, it pretty much the same building that would been built for rich people or the Roman state.
Most of the countries have very little coal and no oil, so they have a tradition of outrageously expensive imported motor and heating fuel. They all have way more nukes than we do, so electricity is cheap. The countries are small and the cities are close together with way much higher population densities than us, so the transmission lines are short. Japan’s population is graying and shrinking. So electricity really works for them, and all they have to do to lmake it cheaper is to educate their afraids about nukes.
In this country, we have out of repair transmission lines, ancient substations with transformers leaking PCBs into the soil, and rolling brownouts and blackouts in major metro areas all summer long.
I live on a major highway about 30 miles from Burlington, the largest city in the state. The roadside transmission lines look great with lots of new transformers from the last cyclone winter storm that took out 6 or so power poles across the road. The power company guys are great and hard working. We only lost power for six hours. Before that storm, our UPS’s clicked and beeped several times/hours and the lights flickered. I hardly ever had to do a full computer shutdown, but I bought a few new UPSs. And after that storm, absolutely nothing has changed with the clicking and beeping and replacing UPSs.
A recent CBS piece said Vermont has one of the worst transmission grids in the country. Small state, small tax base, almost 0 internal - not hard to figure out.
So I agree with your projections about what has to happen, but without mountains of cash and way less magical thinking from our politicians at all levels, I think it could take way longer than any time soon, because our distribution infrastructure sucks and needs to be fixed before we can do any of that stuff., and I doubt if it much different in other rural areas. . Our leaders would have us believe that because this new technology works in new, electro-centric societies with highly efficient houses, it will work in 50 to 150 year- old farm houses with no insulation and ancient windows that rattle when the wind blows. That is a fantasy and that is a lie.
In terms of the reasons not to use the ductwork that existed in my home - I 100% wanted to do that, but I was told the ductwork in the house was a nightmare. I will say that a lot of this comes from the fact this was a house that originally had woodstoves, then had an oversize oil furnace, then an oversized gas furnace, and who knows who installed the ductwork and when. There was also potential risk that the ductwork had, at one point, been wrapped in asbestos. In addition, 2 "trained HVAC professionals" are the ones that set-up the current system - My furnace was nicknamed Cthulu by more than one person during an energy audit. There was the argument over soft vs. rigid ductwork, as well. Aforementioned "trained professionals" thought it was appropriate to only have intakes coming in from the basement, which results in dirty air being brought into the furnace from the floor of the basement in a house from the 1890's. I use proper filters and swap them out regularly, but it's still problematic. In addition, there is some CO risk as the furnace is near a gas hot water heater. Once again, this was all done by 'trained HVAC professionals.' I have CO monitors linked to a Nest system all over the house and in the basement. After a lot of consultations and quotes from 4 separate companies, I was advised to go the ductless mini split system - and told it would work for my heating needs. If the efficiency levels really were similar to number in the calculator, then it would be all good with the Hyper Heat and I would not be concerned. However, given all the issues with my current gas furnace and the issues with the Heat Pumps, I will need to replace the furnace and the ductwork, which is looking like a massive chunk of change.
"If the efficiency levels really were similar to number in the calculator, then it would be all good with the Hyper Heat and I would not be concerned. "
Can you talk more about that? Because everything we've seen so far is that the efficiency you're experiencing is about what you should have expected. In particular, it was entirely predictable that your cost of heating would have more than doubled, given the relative costs of gas and electricity.
@Pumpkin - as a longtime and frequent reader and poster here at GBA, I'm saddened and disappointed by the reception you have received. You have asked a reasonable question and even though we as a group don't seem to have a good simple answer, we should support you in finding a solution. For my own situation, my answer is simply to wait, hoping that within a year or so the Inflation Reduction Act will give rise to qualified techs who can troubleshoot mini splits. Multiple possibilities exist for this to come about
- work directly for the mfg (best option in my opinion, as they will be easiest to locate and hopefully will work hourly, troubleshooting, rather than trying to sell something or defend something they already sold)
- be a separate industry that springs us, much like roofing inspectors
- work directly for the current installers but just be FAR more competent and interested in solving problems.
For those questioning Pumpkin,
re: System Design - Pumpkin can use the guides previously posted here to calculate his/her home's heat load, and check that against the actual equipment installed. That will answer if the equipment is theoretically appropriate for Pumpkin's install. The homeowner should not have to do this, but unfortunately in the current environment we live in the US, the homeowner either needs to do this themselves or hire a consultant dedicated to this work, and cannot rely on most installing subs.
If Pumpkin verifies the equipment is theoretically proper for the situation, that leave a non- functioning install that still needs troubleshooting (similar to my issue).
Troubleshooting these systems is very complex and time consuming, and at present ridiculously expensive.
Most HVAC installers, as @nickdefabrizio reported above, have a one size fits all solution to simply replace the system. They don't 'want to troubleshoot.
There are no third party consultants I'm aware of who have the technical skill to troubleshoot technical details of Mitsu (or other specific mfg) system installs.
Mitsu is useless. They just want to refer customers to improperly trained "Diamond Elite" dealers. That program need considerable reworking.
Pumpkin, although I don't have an idea for a company you can call to pay to solve this, here are some ideas based on the additional info you posted, all of which, by the way, I've learned about by reading this site.
1. People often report that ductless mini-splits short cycle due to how close the t-stat is to the unit. If your units do not have remote t-stats, consider investing in at least one to see if that helps. Also you posted that you have a Nest system. I presume that is NOT connected to the ductless units, but in case it is, my understanding is Mitsu minis do not work with Nests.
2. You probably know this, but in case not, ductless units need additional maintenance. They have filters inside and coils need to be cleaned. There was an article on here about this a while back but it is behind a paywall. You mentioned having a system with "Intakes" coming from the basement which results in dirty air. Not sure what system that is since ductless minis do not have intakes, but maybe you also have some ducted units. In any case ductless units need maintenance.
3. These units need EXACT refrigerant charges. They just don't work if they have too much or too little. Ask your installer for their calculations on lineset length and refrigerant charge and poke around to calculate if the lbs of refrigerant is proper for the install.
4. These units have ALOT of variables, settings, control wiring (especially if you have a branch box) all of which can make the units not function properly. Apparently putting an electricity sensor on the minisplit circuit can give alot of info - minisplits are supposed to just hum along and not have big spikes. The spikes are what use so much power. But also be forewarned that no all energy monitors will get you the data you need for a minisplit. There are separate threads about this also.
5. The units are not supposed to be set back when you are not home or are sleeping like a Nest or programmable thermostat does, because they work most efficiently humming along within 1-2 degree variation instead of running at full speed. You also noted you only set them to 65 - can you try setting to 70 and keeping them there and see how that does? Does your utility let you check daily or hourly usage? That is a start at evaluating usage if you don't have an energy monitor system.
6. Lastly, you posted several issues - initially I understood the problem was the units are using far more power than you expected; more recently you posted they unit cannot heat your home past 60 degrees - ie they can't meet setpoint. What has your installing sub stated about the inability to meet setpoint? While I can certainly see an installer ignoring complaints about higher than expected power usage, not meeting setpoint seems like an issue they should be willing to address.
I disagree. Pumpkin has not produced one scintilla of evidence that his system is not working as designed. Rather, the evidence so far is overwhelmingly consistent with the conclusion that it's working exactly as designed -- it was just a poor match for his needs.
The math seems to lead that way, that's for sure.
HVAC contractors would seriously benefit themselves by taking the time to perform proper Manual J calculations on homes and appropriately size systems. With Heat pumps, it seems there is a constant stream of people unsatisfied by poorly sized systems or unexpected costs because the definition of "average" home is meaningless. The reputation is falling back to the heat pumps rather than the system designer. With average HDD and a Manual J in hand, a contractor should be able to say "this system will cost roughly X dollars/year to operate."
Pumpkin,
One other random thought, not in answer to your question:
Are you monitoring the temperature of the house with remote sensors besides the heat pumps? If you are having comfort issues with the pumps, it's good to know whether they are not running because they think they've hit their target temp, or if they just can't 'keep up.'
It seems pretty common for heat pumps to need to be set 'for comfort' rather than a given temperature, especially if the temp sensors are in the heads.
Hey Pumpkin, where are you in Rhode Island? There is a wide range in quality from the free Rise Engineering / utility sponsored audit.
Pumpkin,
I would follow AKOS post #39 and bfw577 #43's suggestions. Sometimes the best way to solve problems is to do it yourself. This way you'd have solid performance data.
You've got me scared to death about putting HYPER HEAT units into my 1850's full blown restoration.