As an engineer and DIYer, you really speak my language!

The most comprehensive and accurate video on heat pumps. This should be available in all schools and universities as well.

Even if a MiniSplit may be less efficient at lower temperatures, it has the much greater benefit that it can cool in the Summer, where other sources can't. Definitely worth the investment. Great video.

I have a hyper Fujitsu minisplit that works minus 15 degrees. I also have cheap models that work only up to 20 degrees. One thing I’ve noticed, minisplits are good for suppliment heat. As a primary heat source, not too much. The size of the unit, size of the room and a multi zone does have an impact on its efficiency.

We used our mini split down well below zero for years and it was pretty darn cheap. Just removed it last summer and will reinstall it on a concrete pad. We had it wall mounted and that is very noisy! Real good information on this channel, keep up the good work!

I'm most impressed that you can get propane for $1.60/gallon. It's more like $3/gallon where I live.

Great info. You made me chuckle when you said "mild cold". Only up north will someone say "mild cold" when it is 20°F outside.

I did a self install on a 18k btu mini split two years ago and have been very happy with the unit and it's cost to operate. My heating costs are dramatically lower than previous years when I relied solely on my oil fired boiler which works well and is fairly efficient. Boiler efficiency aside, I wanted AC for the house which is why I chose the mini split...the added benefit of heating from the same unit was icing on the cake. I tend to not run the mini split below 20 degrees F since I feel like the unit starts to work too hard making heat and the manufacturer states it's only efficient at heat production to about 15 F.

I have 2 Mitsubishi heads in 400 sq ft cabin, 2 rooms.. power is about $75/mo at 20-30 degrees n winter and I’m here half the day and all night. 78 in the daytime, 61 at night. Love em. That’s for hot water and other electrical appliances too

Very timing and relevant video for me. I’m considering installing 2 mini splits in a northern MN cabin this summer. Thanks!

COP curves against ambient temperature would be enormously helpful.

It’s amazing how good Mini splits have gotten. Midea/Carrier has a 40seer 15eer 14.5hspf at 5f its hitting 2cop. I installed a .75ton one in the basement and have tested it at -6f with 130discharge temp and set blower on furnace in off and can maintain a 2300sf closed cell home bit excessive for the central KY environment. This home is perfect world example being a cape cod on basement.

One thing I noticed, it might be worthwhile to had additional insulation on your line set. It's evidently radiating quite a bit of heat that is cutting down on the efficiency of your unit.

Long time Benjame we truly missed you sir. Thank you for coming back 🤝

I am putting in a heat pump tomorrow here in michigan. It is presently -8 Fahrenheit. I am running it through a traditional propane furnace so that when it gets this cold, I don't have to try to pull heat out of the outdoor air! It is only costing me $1,000 above what it would be for the propane only furnace and air conditioner.

Great video! I'll be moving to an extremely cold weather environment soon, and this video answered quite a few questions I didn't even know I had! Thank you!

My 3 ton R22 HP starts to loose below 30F about 1.5 ton, but I'm in Florida where it almost never goes under 40F, and when 60F outside it's doing 36k btu+. Good tech explanation.

I dont understand a bit of this .... except , that I love what it does !! Amazing. Thanks.

Great job, Ben! We built a net zero passive solar home in East Central MN 5 years ago and use mini-splits mostly for cooling but for a little bit of heating. Ours are Mitsubishi and are rated for -19º F. I usually run them a bit in the winter to exercise the heat function. Yes, they do work! I turned one of our two units on today after watching your video. Ambient outdoor temp is currently -5º F, and the units are outputting air at about 100º F. They are pulling about 1000 watts when running. It truly is amazing technology! I really enjoyed your infrared camera shots!! Cheers!

Heat pumps spend more time in defrost when the outdoor temperature ranges from 47F to the mid 20’s especially rainy/snowy/freezing rain miserable days. For best results try to install the outdoor unit where it’s protected from the wind...use evergreen shrubs or decorative barriers at least four feet away from the unit. Lengthy defrost cycles dramatically reduce efficiency.

Good info...thanks! Last April, I installed a Senville LETO (18K BTU/19 SEER/3.1 COP). I live in upstate New York. So far I am very impressed with how well the unit works for both heating and cooling. Actually, I have used it more for heating than cooling. I have a small propane fireplace, but it sits idle (I haven't even lit the pilot light this year!) Today it never got above 20 and the mini-split heated my small home easily. During the colder evening hours, I wake up my wood boiler to heat the floor (yes, I love my heated floors!) I would appreciate a discussion (theory of operation) on the defrost cycle. My mini-split has 3 sensors. I am interested in how the controls uses these temperature inputs to decide when a defrost is required. I have watched the unit's entire defrost cycle...usually takes between 8-10 minutes before it goes back into heat mode. Neat watching the frosted coil thaw out! It took time to get use to the unit switching from defrost back into heat mode (WHOOOOOSH!) Regards, JT

Thank you for this video and especially for showing your calculations. This will be a great way to heat and cool my detached garage/workshop without needing to run a gas line as well as electric.

Great video buddy. Super cool heat camera shots too

I come from the AC repair in automotive and I was curious on how this system can work as a heater. This is the only video I could find that mentions the evaporator working as a condenser and vise versa. Got it. Good video. Thanks!

We have an LG Inverter V which has provided heat down to -29 C. It held a temp of +20C set at +21C. Very happy with unit. Unit is now 7 years old.

There are units that maintain full capacity down to like 0f. Capacity is more important than the cop when the backup is electric.

Thanks for putting some no nonsense facts out there. I didn't realize that they could work to that cold of a temperature. I thought that anything at 32 degrees and lower you needed a back up heat. On the point of seeing the studs from the outside. You need a thermal break in there, a newer process I would highly recommend is the use of ZIP boards. They are sheathing with a layer of foam insulation applied to the inside. It increases the efficiency of your structure.

This is going to be my first winter with MR COOL here in Minnesota. Anyone who lives here knows the crasy temps that gets.

Excellent job Ben; as an ME, I truly appreciate the level of technical detail you provide. I installed 18 Pioneer 9K BTU minis in my Assisted Living community in NE Ohio about 2 years ago. It might surprise people to learn that the only real rest that these units get, is in the summer time because seniors like it warm almost all the time. In the first six months of operation, the performance was flawless with the only exception being a bad outdoor unit control board, which was covered under warranty and relatively easy to replace. As time goes on, I'm beginning to see some little things like indoor unit fan motors becoming more noisy in a couple of the units. All in all, I am pleased with the performance and my application will be a true test of a high duty cycle scenario. I will say that about the biggest complaint I had with installation, is the flimsy drain line material. which become brittle when subjected to the elements outside. I have since installed two more of these units for other clients and I swapped out the flimsy drain line with PEX, which will save some headaches down the road I think. Also, as a closing comment that echoes yours in past videos, keep your indoor filters clean or condenser will ice up in heat mode.

Great video. Both practical and scientific. Very cool FLIR. Show this to your kids. It might inspire future scientists/engineers.

Very clear explanation of the ability of a heat pumps operation at low temps. In my case I have a steam boiler that handles the really low temps, but for much of t he winter the heat pump carries the load.

Good video, thank you for the content! I have an older heat pump i'm looking to replace, been considering the newer Mr. Cool Universal that can operate at pretty cold ambient temps. Got real tired of the old heat pump being turned off and running in 'backup heat mode' (aka toaster mode with resistance heat) during that stretch of near zero degree temps. I have my compressor cutoff around 15 degrees currently, seeing the Mr. Cool Universal able to stay fairly efficient in sub-zero temps but curious about real world experiences.

Great analysis of the mini split system using real life examples. This is one of the few videos I’ve watched to the end.

Knowing how the gas works when cycled makes all the difference in understanding why it can pull heat out of cold air or as they call heat exchange but it happens within the molecules in the gas vibrating and creating friction thus warming the condenser. Switching back and forth is very cool. I know car ac and understand house ac. But then being able to Essentially reverse the system is so cool!

Excellent presentation. Fortunately, my home has natural gas heating, and my gas bill last month (for January) was $60.00 to heat my 1850 SF house to 76 degrees F (24/7). I live in AZ in the Phoenix metro area. A heat pump would cost me much more to heat my home than using natural gas and in the summer my TOTAL gas bill (to run a gas hot water heater) averages less than $25.00 per month. My AC cooling cost on the hottest month in the summer was about $100.00. For this climate, it is the most energy efficient combination. In the winter we get temperatures that drop near to freezing (32 degrees F). My Trane gas heater rarely runs more than five minutes to maintain the temperature at night. Have a great week.

I have a Fujitsu minisplit (rated to -15F) and I live a multiunit building in Fargo, ND. Above 30F, it's all I need usually. From 0F to 30F, it's worth running with supplemental heat from electric baseboard. Below 0F, it still puts out heat, but I feel like it doesn't put out very much heat. When it's below 0, I usually shut off all the indoor units except for one, because it's really only generating enough heat for one room. And it works great as an air conditioner.

I'm looking at these in the UK and was back converting the temperatures to °C and our average Winter low is 37°F, even in 2010 when we had a really cold Winter it went down to -16°C (3.2°F). England's record lowest recorded temperature was in January 1982 when we hit -27.2°C (-17°F).

I'm a auto HVAC guy have used mini splits, love them,I think if we line the rear grate with a heat rope for pipes the mini split would pull heat off of that to increase efficiency and less defrost cycles with better heating.

I've heater my house with a 36 thousand BTU and 2 heads (1 up stairs 1 down stairs) .. My power rate is 16 cents per KWH .. I've had this pump since 2012 and I record the power meter readings approx. twice a week every week since 2012 .. .. I also have electric heat but it's NEVER on , I only heat with the heat pumps .. In winter (here in Canada) when the temps are -10 to -20 it costs anywhere from $8 - 10.50 per day depending when the clothes dryer etc. are on ...

I currently heat and cool with two Senville 12k BTU 26 SEER units. They perform amazingly without heat strips when it's well below 0° F. with blowing snow. I installed the units myself and really like them!

I love this video. Please next time include conversion to celcius. You will gain lots of subscribers from the rest of the world by doing this.

Thinking about getting one of these. It is great that it can go down so low. I live in Michigan, it can actually get down to -10 or -20 below zero at times.

Also have to figure in duct loses as well with a traditional split system

Phenomenal information young man. Thank you for all this information.

Finally someone talking about heat pumps in MN climates. Thanks for the video!

Thanks Ben! I tried your site and discovered w wealth of information! Man, I have to say the web is lifting mankind out of it's the lower way of thinking. I'm 78 with 4 heat pumps, that I personally installed in my home; and I continually am amazed of the knowledge on the web.😇 I just sign on to your site!!

One of the best videos ive ever seen thank you!

Very informative video !! Thanks !!

Very smart video. Full of concise facts. Very helpful for costing out energy sources

I wish my propane cost were that low. I live in Arkansas currently and the last time we got a delivery it was about $2.19 a gallon. Lol the flip side is our electricity averages about $0.09 per kilowatt-hour.

We have 5 Fujitsu units in our home and there are a huge improvement of the radiant heat ceiling. I run 4 of them year round, the 5th is for the guest room. Our extreme cold is -14 and they have no problem. The only gotcha is you have to clean the filters every month on the blowers. Outside unit needs to be washed down every 2 to 3 yrs.

Great video! Very good explanations and the thermal camera portion said it all.

This is exactly the video I was looking for. I’m in Minnesota and looking to size a mini split for a very small passive house.

Dude super helpful information for a new homeowner like myself living in Canada. Thanks a million, saving this information preciously!

After seeing those infrared shots, I believe I would consider taking steps to place the inside unit and the outside unit as close as possible on future installations. Clearly, there is energy being wasted with longer runs.

Those work great for places like Seattle, we spend most of the winter with rain around 38-42 degrees. Maybe 1 week or less with snow on the ground and even then it's in the 20s.

Here is W TX inverter heat pumps work well, especially if you oversize. Problems with oversize don't exist here in summer as our humidity is nil. We can upsize by 50% without issue and have heat down to the lowest it gets to be here in winter. These work great.

Well done vid, Ben. Unlike your tropical southern Minnesota temperatures, I had -33F yesterday morning as I cruised by the Mississippi River. I think the standard heat pump(non-minisplit) units that most HVAC guys install have a cut off temp that hovers in the 20F range. This mini-split unit would be a good option for those over garage bonus rooms that tend to be outfitted with baseboard electric.

Nice video. But missing from all this conversation is, how many btu/hr do you need? I saw the infrared camera pick up your framing (thermal bridges for heat loss from inside to outside). Anyone building new or renovating really should run the numbers on insulation vs fuel cost, and try to strike a balance. I'd encourage people to familiarize themselves with the Passive House Standard, which includes super insulation, quality glazing, eliminating air infiltration and thermal bridges, and use of ERV. If you do these things first, you can reduce the size and operating cost of your heating and cooling equipment. Full passive house certification is more difficult and costly, but the base principles can be applied to any structure.

I agree with all of the comments, you do a great job explaining the COP, I would really like to see you analyze a air to water heat pump for several climate zones like a Noraire with a single heat pump central system, or an Apollo or Spacepak Monoblock type system.

Great job! Earned a subscription. Will refer others to this!

Great job breaking it all down. Should bust out your decoder ring and do one on SEER ratings.

Good job, Ben. I have been unable to find COP tables for any brand of mini splits including the brand you promote. Why is this information so hard to find?

As a hvac tech of 18 years I’ll tell you that I love ductless splits, they break down all the time and I make tons of money off them.. I’ll take ductwork and natural gas any day , refrigerant leaks are so common with ductless due to stupid flare fittings also control boards , blower motors and condensate leaks are always inevitable

So I live in Vegas , I got about 2,5 cop .. and solar on top of my house , I love my heat pump

I'm new into heat pumps owning two and I've realized one important thing. The amount of insulation your home has is crucial to a comfortably heated home with a heat pump. 3-4 tons/36-48k btu of heating is simply not enough for you average midwest 2000sq 1960-70s home unless it has had replacement windows, doors and upgraded attic, crawl space and even exterior wall insulation.

Can't say more. Very clear👍👍👍

Smart guy . I m going to replace my central ac next week . So i was looking for information about heat pump . how it works in in our Minnesota's winter . To me looks like paying upfront for heat pump wont return in savings . May be later more and more advenced technologyes will be able to heat house in extreme winter.

Great vid, you are outstanding in explaining heat pump and your system must be far superior to my Daikin DZ17VSA intalled for my 2400 sq. ft. house in May 2020 here in Michigan down in the lower thumb area. I keep records for DTE billing for years so here is my findings using AIR TO AIR HEAT PUMP. DTE bills, Dec. 2018 173.00/ Jan. 2019 188.00/ Dec. 2019 144.00/Jan. 2020 198.00. Pump installed In May so air conitioning bill for Jun 2020 168.00 ( GOOD ) Now the big suprise Dec. 2020 297.00/ Jan. 2021 361.00/ Feb. 2021 406.00. Made phone call to HVAC installers and had adjust made that anything below 35 degrees and AIR TO AIR IS SHUT OFF AND RUN ON PROPANE.

Where I live, in Southern Ontario (Canada), the temperatures run around -20C (-4F) for two months of the winter. and -10C (14F) for another 2 months of the winter. That would give a COP of around 1.9 for the winter. The main problem is that we get around 2 weeks of -40C/F temps and Mini Splits just won't work in those temps, so that's why we use an oil burner furnace to heat our house (won't don't have A/C, it does not get hot enough to need A/C). Sometimes the temperature falls below -45C and the neighbours propane furnace won't work since the propane liquifies at -42C.

Very smart, I've learned a lot. Heating cost is much more than cooling here in Long Island, NY. I have a cottage I'm planning on putting it in.

Daikin has a cold weather unit

Another very handy video, thanks.

Great video. And you are correct and accurate, however; respectfully, I debate that compression of refrigerant is "creating" most of the heat being used. There's so much to be said about how heat is transfered that it's hard for people to wrap their head around, so scripting your video to be easy to understand was a good call. I think we can agree that "temperature" is a construct developed to more easily understand the release and transfer of energy. I'm impressed how far things have come since wet blankets and ice boxes

Thank You Ben !!! Great Info !!

We install hundreds of these units. There is a lot of misinformation going around. I will try to make this short and simple. First if you are going to use these units to heat with you must do a heat loss in each area you plan to heat using the design day in your area (design day is the coldest expected day of the season) in mid eastern PA we use 9 degrees. Second you must use a unit capable of providing these BTUs at that design temperature. Just because your unit says it works to -22 means very little because it does not tell you the diminishing BTU output. You must look for this info in the charts. Most inverters are only putting a little more than half capacity at 0 degrees. For instance, you have a room that requires 12000 BTUs on a zero degree day, you can not use a 12000 BTU unit. In order to get 12000 BTUs on a 0 degree day you will need to look at the charts and you will find you will need a 18000 or 24000 BTU unit to get the 12000 on a zero degree day then the units will be to large to properly dehumidify when using them for A/C. You must use HIGH HEAT units. Different companies call them different names. Hyper Heat, High Heat, etc. These units use a two stage compressor and will put out full BTU capacity below zero although there is still a drop in efficiency they still provide full BTUs. The industry itself has caused this confusion because they got into this competition about how cold the units would operate to without explaining the diminishing output.

Thanks for the video. My generation had to deal with "early" models in the 70's & 80's. They were terrible and made me really wary to get back into type of HVAC system.

Thanks Benjamin! Very helpful, especially with the fuel cost comparison! I'm in MN too.

Great explanation on mini split

If you could in another series talk about seer Ratings and what it means at a higher seer

Very informative!

As noted in this video these heat pumps "do work in winter cold" however, it's less efficient as the temps drop below 30 degrees which means this information is much more important in calculating which source of energy to use, NG, LPG, wood, or electric. The common denominator to all of this is cost of fuel.power and as we all know, prices vary much from area to area. That's the big problem to figure...why is electric priced so differently from area to area, state to state? Generating power in CA vs. TX isn't that much different yet the price to the users is by 6 times in some cases.

Thank you for the hard work you put into your videos. You really helped me have a better understanding of how they work. I'm in the process of deciding if I should replace my old central AC or install mini splits. Would you recommend a 3 zone CH unit? Wondering if one head unit stops working do you need to replace the whole thing? Thank you again. I really enjoy your material.

Excellent video. I'm planning on installing mini splits in my house next year. I only have electric heat so at the moment I'm learning. Thank you!

Ben. What an Excellent and informative class. Well done and thanks from Florida ps you can wear shorts here

Mini split tech has improved since this was made as well, keep that in mind..

I will be moving to the Twin Cities soon. No central cooling in the house. Radiator heat so retro-fitting ducting isn't smart. I was thinking mini-splits in the two upstairs bedrooms would be the way to go. Nice to know that these hyper heat systems exist.

Thanks for crunching the numbers. Very helpful an and very well done.

Probably adding insulation to lines would be good idea

As far as I can tell, there's no such thing as "heat pump mode", there's just a heat pump used in an aircon to provide heating or cooling inside. I would say an aircon is always in "heat pump mode," because the heat is always pumped (either to the inside for heating inside or to the outside for cooling inside).

My Carrier heat pump was still putting out heat at -18F the other morning. Not full btu's though. Supposed to shut down around -22. If I was in northern MN it wouldn't be enough. -40 and colder up there this week. I am in SE part of the state. Suspect my unit is same manufacturer as yours. Looks the same.

Interesting information. My Napoleon mini split was not at all effective in warming my small space at -20F . My gas fireplace unfortunately stopped working and I had to wait a month for the part. Had to resort to space heaters for a month to keep from freezing. I am quite disappointed as I added this unit as a back up heat source which failed miserably when I needed it most. It does a good job of cooling in the summer.

I have a three zone Halcyon DC inverter minisplit system. While the air condition mode is efficient. I would not recommend a minisplit system as a sole source of heat, The heating performance is poor. With an outside temperature in the mid 40's, the minisplit unit got my upstairs room to 61.6 degrees (with my oil burner system set at 60 degrees downstairs), during the night when it is colder outside, that of course eventually drops. I have contacted the contractor twice for the poor performance, but they insist it works properly.

Awesome video, helps me make an informed decision. I am thinking about installing a Mini-Split system. I have a situation in my house where back in the 50's there was a system installed by Coleman in which they ran a 3" takeoff to each room, the living room received 2 since it was a little larger. The furnace I have now (25+ Years Old) the unit shuts off on high temperature because the furnace can not expel the heat within the unit through the 3" lines. My furnace technician told me that this will be an issue with a new furnace and will only let this happen 3 times before it shuts the furnace off and requires a technician to come and investigate, a safety feature. My dilemma is now installing basically all new larger duct work throughout the 2 story house or look at other options like a mini-split. It's a smaller house, 1250 Sq. Ft. so I have no real internal walls to run duct work up to the second floor and tearing out walls and ceilings to make this all happen is going to run the replacement bill through the roof. Even if the Mini-Split is more expensive than a normal furnace replacement I still think it's going to be the way to go when the time come's, it's going to be much cheaper and less intrusive than trying to replace duct work and I will probably be able to do it all mostly myself, or at least a big chunk of it. Thoughts?

Thank you for the breakdown.

Excellent video, well thought out and presented!

That Flir is a great stud finder for exterior. Heat pumps are amazing how it pulls heat out of cold air.

I had a hot air oil burner in the house when I bought it 4 yrs ago I do not use it because of the dust it blows bothers me. I added mini splits to my living area, master bed rm and addition of the house. I keep a propane wall unit in the living space and 1 of the bath rms. and a propane stove. I have solar put on the house when I moved in and sell power back to PPL. I also have a fire place and keep some wood around but no longer use it.

Great video and really helpful. I will be using a mini split for my shop (16x24 insulated garage). We are on propane which I knew would be much more expensive to run vs the mini

Looking at the line set via thermal imaging - I bet you wish you had located the unit higher and closer to the indoor unit.