How Much Energy Does MrCool Heat Pump Really Use In Winter
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- čas přidán 15. 01. 2024
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I installed a MrCool 36,000 BTU Universal Hyper Heat ducted system last summer and just ran a test measuring the energy consumption in temps down to -9F. This unit actually can maintain a 71F thermostat setting in these extremely cold temps but at what cost to total energy consumption? I will share my results so you can make an informed decision for your own home or project.
DISCLAIMER: This video and description contain affiliate links, which means that if you click on one of the product links, I’ll receive a small commission. - Jak na to + styl
Technology Connections did a great breakdown where he put these "brutal" cold days in context of when they happen and the frequency, which isn't as much as people believe they happen. It's ideal to have some backup, but even on these brutal days which last not that frequently, you can plan ahead and heat extra during the day when it is sometimes warmer or use an extra heat source. Also, heat pumps are getting even more efficient for colder climates, all the way down to -20c (-4 f) before they loose efficiency)
We are in Canada and had a Dettson central heat pump installed this past fall, configured in dual fuel mode with our 96% efficient gas furnace. We have it fall over to the furnace at -5C or colder as gas is cheaper to burn at that point. That said, we accidently ran the heat pump at -16C or so and our total kWh for that day was under 60 kWh for the entire house, not just the heat pump. Another important factor in this is how well air sealed and insulated the home is; as the air from heat pumps is not as hot as from a furnace, it takes longer to heat the home and especially leaky homes may lose heat faster than the HP can keep up. Our home is ~80 years old but we've gone to great lengths to air seal it. I also noticed that heat pumps are more comfortable as they run much longer than a furnace with cooler air (furnaces simply blast hot air to satisfy the thermostat as fast as possible and then shut off).
At this rate, the heatpump becomes a false economy. It's better to stick to propane heating. The colder outside conditions the worse the COP factor. They only do well heating water.
@@eugenehowat4505 they're great in mild climates like the PNW for old people who refuse to turn down the thermostat and thus do a lot of heating from 40 to 75ish
Need a solid backup for the cold snaps though.
How is the humidity levels inside the home with the heat pump? That's one thing I've noticed when we run our furnace a lot is that it is insanely dry in our house, like 25 percent humidity, even with a whole house humidier.
@@Eric-ii9ce well I guess I'm not doing too bad then all things considered. I was kind of hoping heat pumps kept the in house humidity a little higher.
@@Eric-ii9ce ahh fair. I'm in nothern chicago and our outside humidity is generally pretty high in the winter (almost always above 60 and generally 90s for a lot of the winter).
This is why I want a ground source heat pump. You're basically always in the most efficient zone of the heat pump regardless of the outside air temperature. This just reinforces it. Just because these new air source heat pumps CAN work well below freezing doesn't mean you should or it's efficient.
Very true. I love the idea of a vertical or horizontal ground loop but the cost can be pretty steep. Have you already priced out what you are looking at for your home?
@@everydaysolar Yeah as a retrofit it's pretty crazy. I'm planning on doing it as part of new construction, so the equipment will already be there digging the foundation/etc to dig the horizontal loops in. Combined with the additional rebates and tax incentives, it's much less of a jump. Anyway, air source still saves tons of money in the 25-60F temp zone. I love my current one even if I am running heat strips now. haha
I agree the ground source pumps are the best option, however, we all don't buy a house or land with the knowledge of the type of soil and underground utilities in the area. If my house is on ledge and there's no viable location to put in a ground loop, then the air source pumps are a relevant alternative.
I have a MR COOL 2/3 ton unit. At the moment its set to 2 ton. The most I've seen it pulls is 5.041 KW. I was very suprised it pulled so much. Im having it switched over to 3 ton when I get back home next week because its having a lot of trouble keeping the house warm at 2 ton, in a 1440 sf home. Also on most energy company apps, when you are on the daily chart, you can click on "see details" and it will break down the day by the hour. Great video.
Technology Connections has a great review of the trade-offs.
In short, even if heat pumps are--in very rare circumstances--less energy-efficient than gas or electric, they are still VASTLY more efficient over the heating season.
That’s why dual fuel systems are the ideal solution!
While they are more efficient, when I did the math on our home, whether we got multiple mini splits or central ducted with our existing ducting, the cost for the install/units/electrical versus oil costs/season meant there were no realized savings until the units were far outside of the warrantee period.
Agreed. "Below 30 degrees is not a "rare circumstance" in the Northern US@@bpdp379
Thank you 🙏 🙏 for showing the graphs and breaking it down by temperatures vs energy used.
Totally makes sense to go ground source heat pump vs air source heat pump in cold climate areas.
Ty
Really enjoyed this video! Thanks! I just (like 2 days ago) installed the same 3 ton system in my house. Looking forward to your update video when cooling vs heat.
Very good high level presentation! Absolutely true conclusion(s) for realistic cold climate installs. (Key words: realistic, cold climate.) Signed: test engineer with ductless heat pump system installed in my MA home.
Thanks for sharing this data, looking forward to seeing the summer numbers.
You bet!
You’re doing great for a DIY’er. Thanks for sharing on yt. My Fujitsu 9000 BTU 33 SEER consumes about 1920W at 100%, so four of mine would be about equal your 36000 BTU. Similar power consumption per ton.
First of all, great video and installation, everything was clear, and workmanship looks amazing. I had a couple of comments for a deeper dive, heat pump performance is sensitive to system design and what you experience will not apply across the board equally. 1) If you can better estimate your home's heat loss based on prior fuel bills or a heat loss calculation, that will go a long way to getting better insight. You mentioned your home's insulation levels but air leakage can be an even bigger variable, especially on very cold days. 2) The other side of the equation is the heat pump efficiency. Some models are better than others, but in general the efficiency is strongly dependent on the difference between the outdoor temperature and the heat pump condensing temperature (how hot the refrigerant is in your air handler coil). If you can deliver the heat into your home with a lower condensing temperature, your bills with a heat pump will be lower. For this reason, distribution system design has a big impact. In general, if you can move more air at a lower temperature, that is more efficient than moving less air at a higher temperature even if delivered BTU are equal. Since your duct design was reused from a high temperature oil boiler, it may be undersized for the best possible performance of a heat pump. Measuring your blowers air flow, static pressure, and heat pump condensing temperature would tell you where those things stand and if there is room for improvement. Maybe resizing your duct work is not practical, maybe there are some things you can do, but without measuring, we really don't know. Heat pumps are amazing, but system design is more complicated than high temp combustion furnaces unfortunately. For comparison, I have a 2000 sq ft house and it consumes roughly 25kWh (from heat pump) on days with a ~34F average temperature which is less than your system for twice the square footage.
Next home upgrade - better insulation !
Not knowing your insulation situation, you have oversized your unit by 50%. In a very well insulated home a 2 ton unit should be sufficient.
Not that an oversized unit is terrible in the heating months but in the summer it would cool the house so fast that you would loose the ability to remove humidity effectively.
Then again maybe you don’t have a humidity problem like we do here in Texas !😅
It definitely gets unpleasantly humid in IL in the summer. Sure, not as bad as Houston or Baton Rouge (most days) but still uncomfortable.
Wow! I like the graph and table. Good details too. You got to up the R-values on that home!
This little house is tough the R18 roof is actually rigid foam on top of the flat roof decking under a membrane roof. Kind of limited without an attic space.
I live in Manitoba Canada and building code in my area is R30 walls, including basement, and R50 in the ceiling. You're basically heating 2-2.5x the actual square footage. You are mis-representing the efficiency gains by heat pumps... plug these numbers into a heat loss calculator and make another video. Apples to apples not apples to pineapples...
Very good video. Do you have stats that show the cycle times for the condenser? Curious to see how often it is turning on, ramping up and then turning off.
Hello sir, thanks so much for the great videos.
I have 1 question how does this unit do for dehumidification in the summer ?
That sounds about right. They work great in milder weather, but not in very cold weather. A wood stove isn't a very expensive backup option. My stove is my primary source with baseboard heaters as backup.
It's really convenient to compare against gas but in my area I don't have gas available so I have to compare it to propane and my split system is greatly cheaper than my previous system and I was surprised when it got to minus five and my units kept us comfortable, I couldn't be happier with my new units!
Excellent information on the cold temps when a Heat Pump looses it efficiency and a home should have gas or oil heat source to take over when it is very cold -- (looked to me like the lines on your chart cross at about 20F) where a person would probably want a furnace to take over the heating chores. I have a Carrier furnace that is about 6 years old and i'm contiplating going to a (dual fuel hybrid Heatpump/Furnace combo) unit when I replace the Carrier furnace.
Yeah, depending on your location you need some alternative heat source for the below 20F days where the energy consumption really starts to slip. A dual fuel is an option and I also know Mr Cool has started to do some geothermal but the installation of the closed loop would really drive some labor cost and take it away from a DIY setup.
I remember years ago when Mr. Cool intalled that heat pump in an older home in an icebox state and crowed about how it kept the house at 70, even when it was -29 out. They later did a follow-up video and proudly showed off the power bill which read at 2200 kw-hrs. 2.2 megawatt hours?!? Maybe electricity is cheaper there but compared to Michigan natural gas prices, my electric bill would be $300 a month. So thank you for lending real world perspective and real numbers behind running a heat pump in the cold. I do plan to replace our aging gas wall furnace in the addition with a cheap mini-split, but that's for supplemental heating and cooling, not our main source. Currently, like it or not, our single stage 92% AFUE natgas furnace works in this old metro Detroit home...
Where I live in North Dakota (same state as that Mr Cool video) our submetered electric heat works out to 5.5 cents per kWh- among the cheapest in the US
Things to consider:
1) 1000 sqft home has a higher surface area per volume than a 3500 sqft home. So it will naturally have a greater heat loss due to the increase surface are per volume.
2) That 1000 sqft home is not very well insulated - at least by newer standard.
quick listen.. quick off the cuff response... I plan to listen again..
Spot on - I was sold that my air to air heat pump would be all I needed in my zero energy ready tiny home. A couple of years ago three months at almost $200.00 a month to heat a 230 sq ft home seemed too high. Committed to all electric and planning to rely on solar, a passive home design expert suggested increasing in ground insulated thermal mass and an oil filled resistance heater-for sub 20F temps. It has made a significant difference with bills the past two years being lower, under $120 for the worst month so far. If I had known options and needs I would have insisted on more thermal storage, even a 24 hour storage system.
I installed a Tosot 12K mini split into a 10 X 16 Greenhouse, all insulated except for the 45 degree slanted roof solar windows, single pane, total exposed, 8' X 12' area. It was installed mostly to allow my freeze sensitive plants (citrus) to winter through the North Texas cold spells, seldom going below zero, but always at least once a year, for a few days in the singles and teens. Had such an event last week, ran it at 61, the lowest it would go, but with Turbo fan to insure no cold corners, and was surprised to see it was handling 7 degrees outside and 61-62 inside. Also, the Condenser was running about a 35 to 50 percent duty cycle, which was even more surprising. It is a 240V unit and did not seem to be working very hard at all, but I am curious what the power draw was on that unit alone. I'll have a better idea once the bill comes around as I normally have an 80 to 120 buck bill in the winter (Gas Heat in the house), and we'll see the change when it shows.
Second year heating with a 4/5 Universal set at 4 ton heating 1400 sqft in central Wisconsin. Last year had -18 and this year -11. No issues keeping warm. I am all electric and my last bill was $120. I don't have the breakdown for that but that is for everything.
For the author of this video if you are in ComEd territory go on the real time pricing program. My other home is in Illinois using a geothermal heat pump. The real time pricing has saved me thousands over the last fifteen years.
I have a 2000 sq ft home (heated space) that is heated by a gas furnace/ and cooled with a air conditioner. The garage has a Mr Cool DIY mini split 24K unit for 1000 sq ft. This is my first winter using this unit. It keeps the 3 car garage heated at 65 degrees using about 6KW hours per day, and peak power use when the temps were in the teens at 17KW hours when it never got above freezing. I'm very happy with the Mr Cool mini split.
Dang, that is not bad at all. Assuming you have at least a reasonable amount of insulation in the garage?
EXCELLENT video! I wonder what effect on total energy consumption heater strips would make? My system has them and switches over automatically. I don't have natural gas or propane at my house so all electric is my only option.
I’m running 3.5 Tons of 16 and 20 SEER central hp systems. I was doing fine above 30F. Below that or more three cloudy days and the wood burner got lit 1/2/24…and I have 32kWp, 168kWh LFP! My 80 gal hwh consumes 15-20 kWh and total for my all electric home is 50-80kWh per day. I’m going to build a heat pump water heater for next winter.
Maybe another topic for another day, If the air handling unit can be located in a conditioned space in the house, and the ducting well insulated (and/or buried in blown-in insulation) it may be possible to get a smaller unit that accomplishes the same heating and cooling as a larger one. I was able to do this while doing an energy upgrade remodel. By reducing air leakage and increasing insulation in the attic, exterior walls and crawlspace. I was able to downsize the new design from 3 to 2 tons. This will save me money on energy costs for heating and cooling as long as we own our home. Possible savings are dependent on your starting point, construction type and the relative ease or difficulty of air sealing and insulating your building envelop, choice of equipment (with attention to life-cycle location of equipment and ducting.
Thanks for the video. A recommendation, overlay the internal room temperature on the graph.
For this test the room temp was set to 71F and the unit was able to keep up 👍
It would be interesting to see if improving the R values for the insulation would significantly drop the power usage. Looking up charts, it seems like attics/roofs are recommended to have at least R38 up to R60 insulation, R18 seems rather insufficient. Obviously redoing insulation would be a bigger project. Understanding how to determine sources of heat losses would make a good video, perhaps seeing if there is a way to prove significant heat loss via the roof's poor insulation.
i watched your other video where you showed the heat pump putting out 90+ degrees at the floor register on a super cold day - my new carrier seer 16 heat pump is only putting out 70+ heat on a day with temps in the mid 20s!
Hmmm, do you know what they claim for the lowest operating temp? The Mr Cool Hyper Heat I think calls out -26F.
What was your indoor temperature? If it was 50° in the house, then that makes sense. Most standard 10 through 14 seer central heat pump systems will put out anywhere from 80 to 95° supply temperature without the electric resistance heat energized, depending on the outdoor temperature, of course. Most mini split heat pumps between 18 and 33 seer will put out 100 to 124°F supply air temperature.
Most likely, because the system is oversized for a 1000 sq ft home. Unless his home is poorly insulated.....
Awesome video, so great to see numbers. We are off grid in Alaska powered by solar and just installed a one ton Mitsubishi Hyper Heat this last fall (everything installed except the line set). So we'll have it connected in the Spring fingers crossed. Very interested in how much power it's going to require!
Our numbers for our 1200 square foot cabin are:
Floor insulation: R-53.7
Wall/door insulation: R-24.0
Ceiling: R-59.4
Windows: U-0.26
Window SHGC: .21
Window to Wall Ratio: 12.3%
Air leakage: 1.05 Air Changes Per Hour at 50 Pascals
Heating Design Load: 11,964 BTU/hr
With you using 40KW around freezing and 120KW at -5F, we're really hoping our extra insulation and smaller heat pump will bring that energy usage down! In the darkest month of the winter we'll be lucky to bring in 20KW of power with our solar on a good day (but outside of December our production goes way up). But we'll have a diesel DC generator as a backup, so even without sun we can either use diesel or use the wood stove.
Eagerly awaiting the performance of our heat pump next winter... Thanks for sharing your numbers, great video!
Nice work on the R-values 🙌 I think you will do much better but at the temps below 20F it would most likely be wise to have a supplement the need for heat with some type of fuel source. Wood burning stove or pellet stove would probably help to cut off the crazy ramp in energy consumption.
@@everydaysolar absolutely. We have a wood stove for heat now. We've been at this for just over five years now and this past summer we added a ton more insulation since our walls were still not closed up yet. This summer we hope to install the floor and start on interior walls and counter tops and such. Every inch out here feels like a mile. But we could tell the insulation did wonders because we now hear an echo inside the cabin and because the stove burns so much less wood. We were thinking about getting a Webasto diesel heater too, but decided instead to use diesel to charge the batteries to run the heat pump since that would burn less diesel to heat the cabin due to the COP even during the cold temps.
Good presentation on equipment usage. You need to consider getting your insulation R values up to code. Air sealing is also critical. Give your equipment an optimal environment to work in to really see the value. Poor insulation and a leaky structure will always equal higher energy costs no matter how efficient your equipment is.
The absolute energy demand will be significant where your energy supply is limited but in most situations the important piece of information is the Coefficient of Performance. Even in these cold temperatures if the CoP is advantageous then larger solar/battery capacity might still be more cost effective than installing alternative heat sources. Of course only a site-specific analysis is going to answer whether that could be the case.
Here in Charlotte NC where it is not too cold, we use the heat pump for most of the load, firewood in an enclosed fireplace to supplement during temps below 35 degrees ( 15 days a year ) . We do have electric strip heaters within the heat pump for back up, but I have the breaker off and only use them for extended cold. ( maybe one day per year ) Here is a question for you, if you trick the outdoor unit to think it is warmer out would that improve your efficiency, such as use the heat from the firewood pushed into and around the outdoor unit coil ?
My 36,000 BTU Mr. Cool unit heating my workshop used 80 Kilowatt-hours on my coldest day with a low of -6 and high of 4. Crazy amount of energy usage. I just installed some propane heaters for these below freezing times.
I need to get my detached garage insulated so I have a hope of heating and cooling it. I dream of the day with a huge workshop on in-floor heat 👍
What’s your cost per KWh for electricity? Where is live that would be $4.40 worth of electricity (5.5 cents/kWh submetered winter heating). That is the same cost as 2.5 gal of propane in my area ($1.70 per gal summer fill)
@dustinsnyder3483 my electricity is $0.15 per kwhour.
These systems are great for small square footage area's and more milder winter areas..My minisplit is smaller but combined with a very efficient wood burner, and some diesel heaters for extreme temps and redundancy..My place is only 600 square feet..My garage is 800 square feet, but I heat that with a separate wood burner and propane heater..But my solar handles all of my electricity..
Yeah, that is a much more practical setup and let alternative heat sources handle the heavy lifting. Thanks for the feedback.
Our carrier Mini-split can go to -22f but very little heat is moved at that temp. It's ok down to about -5f. We supplement with a pellet stove and the old electric baseboard in the bedrooms. Over the year the bills are pretty decent.
I’m planning a renovation using a carrier mini split as my primary heating source in NY. I’m trying to figure out if carrier has a graph showing at what temp the efficiency declines at a given load. The mfr’s are cute saying they can maintain 100% heating capacity down to -22F but obviously at a tremendous cost. Would you say your carrier is still very efficient at 15F?
@@greg03811 yes, the COP scale is right in the manual as I recall. Pull it off their website. Mine does fine at 15degF and we are in SE MN.
It would have been nice to have a comparison in this home. Without that, it is hard to undestand if there is a benefit to having a heat pump at a given temperature.
Love the data on the heat pump and how you laid it out vs. temperature though!
Yeah, I wish I could have compared the old system with similar insulation but since this house was recently rehabbed I didn't have baseline data from a gas furnace or oil burner.
Great discussion, thanks. I've had a lot of experience watching the power consumption numbers on my 4/5-ton Universal (not hyper heat). I've had average temps in the teens and pulled up to 70 kWh for a day to heat 3200 sq ft, insulated a bit better than yours. I'm amazed when I see the condensing unit pulling almost 8000W on its own on very cold days - far higher than I would have expected! I've made some tweaks that have helped a little, would be interested to compare some of your settings for airflow, and the few settings available on the condensing unit.
dear god, get a wood stove or pellet stove for the cold days. Any efficiency will be lost once that breaks and you have no heat and a $500 bill.
These numbers seem pretty high, which probably indicates that your heat loss is a bit higher
In second week of January we had similar temps in Europe (-7C low/0C high) and my 14kw heat pump was using up to 50kwh per day, but for a 185 sqm house.
Have in mind, my heat insulation is better, but my windows are 20 year old wooden double glazed.
We worry too much about heat pump efficiency, but in the end, if your heat loss is high, heat pump needs to use a lot of power to compensate.
Yes, very good bottom line point on heat pumps and heat loss. Efficiency is a double edged term in this case. Efficiency: 1 (manufacturer choice use) - does the system provide heat/cooling in all conditions, 2 (operating cost) - energy consumed and operating cost. Manufacturers aren't always as clear as they ought to be about efficiency. Operating cost is also connected to electricity unit cost in your area. MA has highest national cost per unit of electrical energy (except for Hawaii). In my case, i am forced to use pellet stoves for heating and the heat pumps for AC. Be very careful, Scott's graph temp. vs electrical consumption is spot on.
Very important for potential conversions to heat pumps: 1. have an accurate heat loss (manual J) assessment done by very reliable professional, 2. If heat pump(s) is/are still a good option, select very reliable heat pump/home system professionals. I found this is a very difficult effort. There are very few reliable professionals in this field, 3. Have the professionals go over the project in detail and make certain you understand those details. Don't go with 'trust us, you will be very happy with the system and the savings'. 4. Select the best system on the market, emphasis - do your homeowrk.
If 50A circuits have to be added to run the system, this is a huge flag that a lot of electricity will be used to operate and lots of $$$$ for that electricity.
Don't be fooled!
I thought the same thing . Usually a 3 ton heat pump requires only a 30 amp breaker
Thanks for your work
You bet!
Have you done a "Heat load analysis" of your house? I would love to compare it to mine.
I wish we could do an exact apples to apples comparison between your's and mine but there's too many variables. I have a bosch 4 ton, 2500 sq ft house built in 1965, its built very well but still old standards, especially with the insulation, most windows are new but still got 4 to replace, duct work needs redone because its apparently undersized so I'm still supplementing the upstairs with the baseboard heaters that used to be the primary heat, we're in IL as well ontop of a hill with no cover and really strong winds, my unit is a 20.5 seer and 13 hspf vs the mr cool appears to be a 16 seer and 9.5 hspf. My system has had to kick on the aux 10kw resistant heat grid from time to time but for the most part the heat pump has done well to keep the house at or near 70°.
Awesome video. Great data.
Thanks for the feedback!
Im not keen on putting outdoor units direct on the base especially in colder climates as the regular defrosting promotes ice build up as it runs off.
Really the outdoor should have a minimum of one foot clear space below it to clear the water. It also helps to get the cold air away and promotes better air flow circulation
My heat pump spent more time in "Defrost" mode (where it runs but isolates the air handlers to de-ice the outdoor coils) than heating the living space!
I use my 98% efficient gas furnace in winter and the heat pump the rest of the year.
That's a very good study and I was surprised at the electricity used. Pushing 40 KWh at 30 degrees is a bit high and confirms what I thought about heat pumps. They might be a descent option if the temps don't stay in the 30's for long. Better options would be wood stove, nat gas, propane and geography. My furnace is using about 1.3 KWh/day plus natural gas which was $22 for 1 Dthm of use last month (furnace, stove, water heater). Helps living in NM but does get cold at night. Heater actual runtime up to 2 hours a day. I too lived in IL, time to leave Scott, weather and taxes are killers there.
Yes, I would think that attic insulation as being insufficient at those temperatures. Probably a more comprehensive test would include heat loss on the outside or through the attic.
Wow, that consumption on the cold days is nuts. Very eye opening. My model Y uses about 350 kwh driving it for an entire month. At least it's able to heat in below 0 temperatures.
Have you looked into heat pump clothes dryers? GE makes a compelling model that use a lot less energy than an electric ducted dryer.
I haven't looked at the clothes dryers yet but I am eyeing a comparison between a standard electric water heater and a heat pump unit. Would be interested to see the difference in power consumption.
@@everydaysolar If you have a space that can maintain >50F the heat pump water heater works quite well. They do make a little more noise, more like a buzzing noise, also. Mine was installed in may 2021. Annual usage has been: 571kwh (7 months) / 1094kwh / 1257 kwh with 2A, 1C household. I would say the biggest change in the last 2 years, has been more frequent baths/showers for the kid. I'm not sure how much I was using before the change, but I do recall immediately seeing a significant drop in usage after it was installed. We also had a change in washing machine in late 2022, from a front load HE machine to a top load less efficient machine.
There is no comparison. My 50 gallon rheem used 870 kilowatts last year. A straight electric one would have been 3-4x that number. @@everydaysolar
Thanks for the insight. Next video, Geothermal Heat pump :)
Just need to rent a excavator to dig the loop 🤔
Mr cool should not be used in cold climate heat situations. This was the issue with early heat pumps. Mr. cools are only full heat rated down to 17 degrees. Where as cold climate heat pumps today are rated output down to -5 to -15 F.
It would be more of an apples to apples comparison if you converted the gas used to BTU's and for the same period convert the Kwh to BTU's or for equal time at various temperatures with both systems. More for those on grid looking to see which is more cost effective. I know oil where I live is over $4.00/gal while a kwh is about $.14. I have been running mini-splits in my shop, (14000 cu ft), home (8000 cu ft) up and 8000 cu. ft. down. for four to five years. When it gets below the mid twenties F I notice it is spending a lot of time defrosting itself (very inefficient). Which brings up a problem with modern mini-splits, how to know when they are running at top efficiency and how to know when they are not. Older systems just required a gauge applied to see if coolant was up to snuff where as a mini-split requires a full pulldown of the system and weighing the charge. A process not everyone is equipted to do (I have all the equipment and even so it is a job I put off when I am not sure it is needed). The insulation that comes on the linesets are only minimally insulated (the R value of that foam jacket is around R5) and because they are installed back to back the efficiency of that delivery system is degrading the systems considerably. You just can not run a hot line immediately adjacent to a cold line and expect good results. I added several inches of insulation when I installed mine but looking back I probably should have scrapped the factory foam and installed the lines several inches apart for an ideal installation. Then you can super insulate each line keeping them isolated from one another. With up to forty feet of lineset out in ambient temps, it can be a source of energy loss in the best of circumstances. Another source of energy loss is having to heat tape the drain lines to keep the condensate from backing up into the unit case. I am always wondering if I should turn my oil boiler (baseboard heat) back on and at what temperatures it becomes more cost effective. I installed KWH meters from china on each unit but the meters like much of chinesium turned out to be disfunctional crap. Nice looking lineset covers that were large enough to separate the lines and hold adequate insulation as well would be a much needed aftermarket offering. Nothing in todays world is even close to that standard.
Hmm. I'm inspired to do this on my Mitsubishi multizone split heat pump with two central air handlers.
Do you know if manufacturers publish the coefficient of performance vs outside temperature instead of just the seer rating?
I would be interested in seeing if a radiant floor system such as “Warm Board Radiant Floor” that does offer a heat pump as one heating source vs the forced air system that you are using, would be any more efficient.
That 36,000 BTU spec caught my eye (see below, for pointless anecdote.)
Energy consumption only has relevance over time, never on any one month's bills! Scott, your other video about its ability to maintain 70 in below-average outside temps is all that matters ... because it seldom reaches that cold in Illinois or stays very long.
And since the "emergency heat" option wasn't needed, neither would other supplemental heat be helpful UNLESS that other alternative is known to have lower costs than running the compressors 24/7 (all else being equal, but it never is with wood, gas or oil.)
That is why, "being off the grid" is romance, not practical for homeowners and not helpful to *neighbors* who have to shoulder infrastructure costs the "off grid" citizen does not contribute to. Another hat tip to Alec at Technology Connections for mentioning the un-obvious.
Fun fact: I once heated most of a 1600 sq ft house with one small, 36,000 BTU ventless gas stove in the basement, the kind that sell for less than $500 and look like an old fashioned wood stove. The basement (800 sq ft) was too warm and the upstairs could get cold, but we made it through for a year like that. But the IAQ did suck, to say nothing of depending on a gas pipeline.
As far as I can tell, those heatpumps are still using R410A Refrigerant? That's being phased out completely here in Europe for a while now, all replaced with R32, which in turn is now being replaced with R290 - much better performance in cold weather compared to R32 - and R32 is already much more efficient than R410A.
I see lot of heat pumps these days being rated for up to -25C, i wonder what is the performance in the -7 to -15C. In the area where i live there are like 7days when it reaches that temperature during the night, most of the time is 5 to 8C high and 0 to -5C low. My parents have 2 with R32, but never use them in the winter.
@@ristekostadinov2820 Heat pumps in general are huge here in Finland, which regularly experiences temperatures like yours for extended periods of time. The main type used to be ground source, but with improved air source heat pumps and refrigerants, air source heat pumps are extremely popular. Based on the discussions I follow online (especially now that we have the coldest winter in 20 years) they seem to work fine for most people.
I was seeing power numbers like that during the same cold spell, except my air handler draws less. My heating and cooling seems more even than it was with gas, conventional AC and single speed blower. It might allow me to get away with a lower temp on the thermostat. We had a bit of snow with our cold, just enough to wipe out solar, so all we'd need to go off-grid is an entire basement of batteries. :)
can you please provide the model of the condenser?
It looks like the day with a high of 20 degrees resulted in 2x the energy consumption. Not sure if watching the high or the average is more representative/predictive of energy usage. However I suspect switching to electric resistance heat at that point or almost certainly for the 111kwh day would be a cost savings. 70kwh of electric heat would be a lot in a 1000sqft space. That's roughly the same as two 1500w space heaters running an entire 24 hours. 111kwh is roughly three 1500w heaters all running for 24 hours. Would be an interesting experiment.
That appears to be a 4-5 ton unit. I have a 2-3 ton unit running 2000 sq ft main and basement levels. I have it set on 2 ton, and it has drawn a max of 4500 watts when it is 10 degrees outside.
I installed a 60k Mr Cool Hyper Heat Pump and notice that the overall cost to heat my home this winter is already significantly higher than my previous 65% efficient 1989 gas furnace it replaced. This comparison is limited in that it is only for the past two years, through the relatively warm December this past year. If I remember correctly, early winter last year was a bit cooler (or at least we had more snow). I am not sure I would recommend the heat pump for Michigan winters yet, at least not until the utility provides some sort of reduced rate for heat pump electricity. I would be interested to know what the financial breakeven point is for installing a heat pump vs a more traditional gas furnace. I know there are a lot of variables, but I think a thorough analysis would be helpful for many making this consideration. Thanks for the videos!
You would need to factor in the cost of gas that you saved not having a gas furnace anymore. Of course, you will use way more electricity by heating with electricity than heating with gas but that doesn't tell the whole story. However, I think everyone knows that typically gas heating is still cheaper than electric heat pumps. If your electricity comes from solar panels then heat pumps can be cheaper.
HVAC business here. Totally off grid going on two years. 32kWp, 168kWh LFP. 3.5 tons of 16 and 20 seer HP’s on house, Fujitsu 9k 33 Seer on power shed. All electric home, 1960 sq ft. I made it until 1/2/24, then had to light the wood burner. I would recommend running most heat pumps down to 10-20F, depending on COP and HSPF of hp, then switch to gas/wood/oil. I still run blowers at times to circulate heat better.
Is it because it is "working harder" or is it because it is running for longer duration over the given day?
I was shocked at how much your baseline power usage is. I only used ~10kwh a day last week (laundry day was 20kwh)
Because heat pump COP drops as dT (inside vs outside) increases .. for the same total kwh of heat inside the space , a heat pump would use less kwh of electricity (keeping COP higher) if one gathers that inside kwh of heat when the outside temperature is warmer (daytime) .. instead of waiting for night time when the dT is larger and heat pump COP would be lower .. such an approach would need enough thermal storage available to last for that over night time period.
What is the cost comparison to the oil or gas and entire home electric/heat combined vs going all heat pump? I want to know if is worth switching to the heat pump and the main reason to switch if your total cost was lower. I have too many neighboring trees to get solar to offset.
I know you are testing the concept. So in future videos, your net cost would be interesting to see compared to what you were using prior to switching to heat pump would be interesting to see since you are tracking. It's less important if you're using a lot of electric on super cold days. If overall, it averages out to using less energy or a less expensive energy over the season. But you didn't address that yet.
Mr Cool also has a gas furnace, would have been awesome if you had that and compared usage of the heat pump alone vs the gas furnace alone in the same space.
How insulated are these houses, and have you done a blower door test if so what is the air change rate?
I was thinking the same thing. One therm of gas is equivalent to about 30 kwh of electricity. So worst case Mr. cool used the equivalent of about four therms of gas. Need a cost comparison of gas vs. electricity where he is. Where I live that one high day would have cost $40 in electricity but only $10 in gas. However he is talking about trying to go off grid. It would be possible but you would need a couple hundred kwh of battery storage, maybe 30kw of solar and lots of sun on those ice cold frigid winter days.
two questions: 1. Why haven't you taped up your ductwork seams with foil tape? 2. If you live in an area where it gets to -5, why didn't you opt for the heater kit? The power usage might have been less if the heater coils would just need to kick in for a short while to get the living space up to temp, and then the heat pump could work to try and maintain that temp.
I need to seal up the duct work but wasn't too concerned as I actually wanted a bit of heat for the basement. I didn't get the additional heat kit because I wanted to see what the heat pump could do in this exact instance so I could record the data and share it with the viewers. If I was just installing in my house without taking data I would probably have went with the 5kW heat kit for a little backup in the brutally cold days.
Sound high, first thing I would check is if the gas load has been optimised for your current system. When you get below 32 degrees with heat pumps the correct amount of refrigerant become a critical factor. They will work fine in warmer weather but when you start poking at the edges of the curve efficiency drops like a rock. Your graph is suggesting that may be the case. Living in ILL i would have it optimised for heating.
There are two types of HAVC guys working the field that know what they are doing. One can follow the instructions and give a good system and then there is a heat geek who can tweek every BTU out of the system. and it is not all compressor work, duct placement and sizing and type makes a huge difference in comfort level. I had a system installed 20 years ago and it was meh, this guy was down visiting a friend and volunteered to, take a peek at my system, He looked around , did a lot of mumbling to himself. sat down and did some math (Math?) and gave me a list of things to get changed /checked. The system was hugely better in comfort level.He keep saying "that will work but this is better way to do it"
I have a 3 ton hp by Amana and I'm curious why the me cool is less efficient. My hp on a 40 degree day or even 30 degree day never used more than 30 kwh.
Those numbers are horrible for a house that small, I have a mrcool universal and it’s set to 2 ton by dip switch’s but can do 3 ton aswell, can yours do the same? My best guess is you would half those numbers if you can switch it and air seal and add more insulation, I also have a blueridge 38 seer 9000 btu mini split in my living room that will heat my whole 1500 sq home to 72 the lowest temp so far we have had for that is 36 outdoor temp, I use that one all day except at night when all the bedroom doors are closed then i switch to the mrcool ducted.
after -15c There is no comparrison to wood heat for effiency and carbon footprint. It just works!
In Alberta, Canada, -30c our power grid is under alert as we do not have enough power. 30-50KW in one day is just mental at $0.28/kwh you would spend $14 to barley heat your home. Or you could spend $6 on a bag of pellets.
Thanks for including your rate it helps to see the range of rates across the US and Canada. We are lucky in my area to have a flat rate of $0.08 / kWh.
What is your COP ?
I’m not looking at going off grid so my takeaway here is that you can have a heat pump as your only heating source even if it’s really cold. Yes it’s costly to run at -9F, but the VAST majority of days here in Ohio are nowhere near that cold
Yep, worth considering one with a "heat kit" or gas backup so if the heat pump goes down you have a Plan B for heat.
How often do you need to run the auxiliary heat if your lows are in the 20-30F range? We are heat now and love the warm temps. Decades ago, we had a heat pump and had to run our auxiliary electric quite often and that added greatly to the bill. Hopefully the heat pumps are more efficient now.
This unit doesn't have the additional heat kit but that is an option. For these results all of the heating was just from the heat pump. The tech has come a long way but when temps get below 20F it would be nice to have an alternative heat source like propane or natural gas to lessen the energy consumption.
In Northern California the new electric rate for 2024 is $0.525/KWh. So that really cold day would have cost $59.85 just to heat the house here, suggesting that heat pumps would be foolish to install in the Sierra Nevada.
Holy lord! That is insane. That rate is about 7X what we are paying in Illinois. Thanks for the feedback 👍
can you compare setting your tstat lower during the night vs keeping the temperature constant
Yeah, that would be a nice test. I will see if we get another cold snap. I wanted to push the unit a bit for this test but setting the termostat to 65F would have gone a long way.
Do you think these deep freeze days would even out or consume less overall energy with assistance from the heat strip kit?
Yeah, I think with those extreme days heat strips would be a little more efficient. They would still consume a good amount of energy daily but my guess is it would not be as bad as the heat pump.
can you add any insulation to the ceiling? those are min. wall r values and 1/3 to 1/4 the recommended r value for the ceilings.
Unfortunately without a ton of work I am pretty much stuck with the low R-value for the roof. Not an overly efficient house for sure.
Are you able to share what your set temperature was on these coldest days ? Was it set at one temp to maintain all day ? Heat pumps arent as effective at massive set temp changes (ex above 3 degrees), which is why so many recommended leaving them set at one temp and running all day
One thing I love about having an ecobee, is that there is a website called beestat that help you determine at what temp your heat pump pump is unable to keep up with heating your home and the outskde temp. Definitely check that out
The thermostat was set to 71F and held constant. That beestat page looks interesting, thanks for the heads up.
Due to the thermal inertia of the buidling one should expect a higher energy consumption in the case of longer lasting cold temperatures.
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how much gas did your other property use ? thanks for those videos!!!
Since I am only paying $0.08 per kWh in my area at a flat rate not including any of the delivery fees This power bill will be $150 without fees. Bit of a guess but my gas bill for the 3500 sq ft home will most likely be around $350 for the same time period.
That makes me curious as to how much energy an additional resistive heater in the air handler would use and whether that's a viable option, or if using a dual-fuel system would be best.
I bet a 5kW heat kit might be the same daily use or maybe even a little lower. It would most likely heat up the temp coming out of the register, give the heat pump a rest, and possibly not run constantly. Also if the heat pump fails you can limp along with some heat from the heat kit until you get it fixed.
@@everydaysolar Heat strips really get that electric meter spinning ! I have a 5 ton Bosch Heat pump central ducted system in a 20 year old 3400 square foot home in middle CT. The system is energy star rated, and is rated to produce full heat down to 5F, so not quite a cold climate unit. I had it installed with 2 x 10KW heat heat strips in the air handler, mainly as backup in case the outdoor unit goes down. On the week they installed the system it went down to 4F and they had the configuration set as dual fuel (!) and the system kept turning off the outdoor unit and switching to the heat strips below 40F. Beyond stupid. I used 2000KW in a day or two. My electric bill for that month was huge. The system was reconfigured correctly after that. I also tweaked the setup to minimize the heat strips. They will never come on if outside temp is over a set point of 35 (adjustable setting). The heat strips will also not come on while the system is in defrost mode (every 80 minutes when its cold) - This does not cause any discomfort but some people will say it lets the blower blow unheated air during defrost. I don't mind that. The heat strips (as third stage heat) will come on if the outdoor unit cannot get to the set point on the thermostats in 60 minutes run time. That has not yet happened. This system produces 60,000 btu per hour on a mild day. It replaced an oil furnace that supplied 85,000 BTU and burned a lot of oil.
I also had each 10KW heat strip on its own 60 Watt breaker. I turn off one of those breakers. If I foresee incredibly low temps or am planning to be out of the house for a trip I might turn both breakers on to keep the house from freezing the pipes if the outdoor unit fails but then when i got home I would have to kill myself when the electric bill came.....
Using a heat pump means setting the thermostat and essentially leaving it alone. Little to no setbacks. With the heat strips off, it may take me a bit longer to raise temps but that hasn't been the case as daily winter temps seem to average 29-32 or so.
I keep the house at about 60-63F most Winter days because I'm British, and I'm cheap.....I wear extra layers.
Electric Costs (total house electric load including heat) Nov-December-Jan-Feb cost me $400-500 per month. Sept-Oct and March-April $300 per month. $150 per month for May thru August. I don't use A/C my house stays cool. I also have a heat pump water heater that cut my electric bill a bit.
If the power fails, I have wood burning fireplace that will be a pain in the ass to use, but better than nothing. I also previously installed a 1.5 Ton Mitsubishi Hyper Heat in the family room while I was bored during Covid. I could run that on generator power if I had to. I will take the chill of the big family room, and is very efficient down to very low temps.
I'm 74 years old and trying to decide whether to add solar to offset the electric use. My roof is not suitable for panels, I would need a big ground mount system and my property might be troublesome for an install. I may build a DIY solar small system as an experiment for fun.
Sorry for writing so much but I watch all your great videos and wanted to contribute. Thanks.
We have a 2 ton air heat pump system on a 1400sqft home that is 16 years old. During the cold snap with a high of 3F, we used almost 200kWh. Sounds like this system isn’t much more efficient in low temperatures.
heat pump is the future. Great video!
We would like to see cycle time compared to 30s to bitter cold, does your thermostat keep track. Unit maybe consuming same energy but running nonstop since house can not maintain the heat.
Yeah, that would be a good look. The thermostat does not track that but I could pull it from the EcoFlow Smart Panel 2. From a high level it is pretty much running non-stop and also running at a higher power draw. Let me see what I can pull and integrate that into a pinned comment on this video at the top of the comments section.
I bet your loving your solar when you see those figures.....imagine the bill without it!
I aint producing that much Solar on this property 😕
I wonder how much power a geothermal heat pump system would use in this same situation???
Is your sheet metal ductwork insulated on the inside? You need to insulate your refrigerant lines all the way to the cabinet.
No insulation on the ductwork in the basement. Getting a bit of heat loss for sure. Yeah, I agree I need a bit more insulation on the indoor and outdoor units. Thanks for the feedback!
Looking good. Thanks for the details. Long time HVAC business here, totally off grid, but only 5 mini splits under my belt. I really like them for very small well insulated rooms or homes and only down to 30F odb for us off gridders. Below that, it’s okay to run on sunny days, but wood/gas/oil needed to supplement.
That's a lot of power usage. Thank you for the video. Really illustrates our need to keep using the gas furnace for heating even though we have 5 tons worth of mini splits (3 units, 5 zones).
Yeah, there is definitely a cross over point where the efficiency slips away.
Not sure where you're located, but R18 in the attic? Seems like a change there would make a big difference.
Yeah, it would be nice to up the insulation but unfortunately it is a flat roof and no attic space.
Whoa. That spike in consumption is wild. I was looking into this as a solution here in KC. After an entire week in the negatives, it seems that this isn't a viable option.
Yeah, it would be nice to have an alternative heat source during the cold dips to avoid the dramatic ramp in energy consumption.
Basing a 15 to 20 year investment in a heating / cooling system on one week of exceptionally cold temperatures is probably not the way to go. Look at long term averages. I can almost guarantee that a low temp capable heat pump will save you significant money in the long run, even if the energy usage shoots up with occasional sub-zero temps. Now if sub-zero is your norm during winter, then that’s a different story.
It depends on what your backup heat is and what you have now. I had an electric resistance furnace that was consuming that crazy amount for the ENTIRE heating season. Now it just does when the temp dips below 20F/-6C and the heat strips kick in, which for most people is a small fraction of the season.
I have never heard a recommendation for Mr. Cool in a low temp area (other than from Mr. Cool), there are makes/models that are better for sub -0F performance.
Those other brands/models are just heat pumps or a hybrid system?
Question....isn't 3 tons a but large for your 1000 square foot home? I can see oversized for heat in winter months. However, wouldn't a 3 ton unit be too big for only 1000 square feet create a humidity issue in summer when cooling?
Since my R-value is low I think the unit will work well for the 1,000 sq ft. If I had a higher R-value in the ceiling that might make a 2 ton a better match.
FYI: A new 92% 90000 btu, single stage, constant torque blower motor, Airtemp gas furnace I just installed is consuming 456W. Temp rise 51F! It would take three of those 3 ton hp’s at 25-30F to put out this kind of heat.
The gas is providing heat equivalent to 24,267 watts while it is burning. (that is counting it as the 92% efficient specified - in reality it is likely not operating at peak efficiency much of the time)
@@Sylvan_dB yes, you are correct for heat exchanger output. Maybe 150 more watts of heat from blower motor, transformer losses.
I thought the 2/3 ton unit only had the single outdoor unit, not the double-stacked thing?
The Hyper Heat version of the Mr Cool Universal starts to double up at 36,000 btu (3 ton).
Did it keep you warm at the -5?
Yep, maintained the 71F thermostat set point.
My Mr. Cool system has failed to provide heat. Multiple HVAC technicians to my house have complained about the vague trouble codes fm the unit, and extended wait times on hold trying to speak with a Mr. cool expert technician. HELP!
Did the HVAC tech have experience with Mr Cool? Here is an installer map which you might be able to find an experience HVAC company in your area mrcool.com/installer-map/.
You appear to have 2 things going on with your 36kbtu heatpump on your 1000 sq.ft. home -- The first (which you acknowledged in the video) is the poor insulation in your roof. R-18 is mediocre for your area of the country. I suspect it should be more like R-50 for proper insulation. This would definitely retain more heat and work your heaters less. The second is the the COP of your MrCool units. I had trouble coming up with numbers, but it looks like the 36kbtu MrCool units have a COP47 value of 2.8; or rather, for each 1kw you put in, you get 2.8 kw out (@ 47F) -- Naturally, this COP number drops dramatically as outside temps get really low (eg. -5 F). In comparison, modern Fujitsu minisplit heatpumps have a COP47 of 4.0+! As much as I like the idea of DIY heatpump installs (go MrCool!), their lower efficiency numbers compared to their competition make me wonder if it is worthwhile for colder regions of the country. Anyway, thanks for the video. Nice presentation.
Both your wall and ceiling insulation are only 1/3rd of the recommended levels. In a northern climate zone, your walls should be R40 with at least half of it continuous insulation as opposed to cavity insulation between studs. Your ceiling/roof insulation should be R60 with at least half as continuous on the exterior. There is a 4000sf Passiv house in Canada that uses only 1500w average winter load on its heat pump, because it was properly insulated. Your insulation levels might be "typical" for a lot of older homes, but I don't think it is rational to expect an inefficient home to get some sort of miracle out of even a COP5 heat pump. Also, have you had a blower door test to see how badly the home leaks ?
Time to improve your insulation and weather stripping. A 1000 sq ft house heat load at 0 deg F should be about 15,000 BTU. If you had insulated first you could have installed a much smaller unit.
Thanks so much. I guess that I was totally confused in that heat pumps saved energy. I almost went that route.
This unit does a good job and honestly pretty reasonable on the energy consumption until you get 20F or below. Then it kind of falls of a cliff for efficiency.
Heat pumps are only more efficient than a electric heat unit until you need the electric heat to kick in. Overall in the winter below 20*F a gas furnace will beat it everytime.
I still haven't figured out why our Government is trying to do away with gas knowing darn well that the power grids are maxed out during freezing spells.