How a Heat Pump Works | This Old House

[@ndeleonn]

I taught thermodynamics at the college level for over 35 years. The molecular dynamics for the cooling and heating of gases on expansion and compression are well understood and easily explained in the classroom. However, to put these scientific principles together for the purpose of heat exchange from the outside to inside or inside to outside and make it work in real life is absolutely genius. Richard Trethewey's explanation is simple to understand and masterful. Well done!

[@bryanc531]

I have been in the hvac field for about 15 years and this is by far the best way that I have heard the refrigeration cycle explained. Richard you are awesome

[@Rpotts1999]

12 years for me and I couldn't agree more

[@michaeljames3509]

You're still an apprentice.

[@Fkidd702]

5 years and same hahs

[@michaelheery6303]

And complex formula wow

[@paulriccio5333]

I just got a heat pump and the genius of this makes me feel better about the money I spent. I ACTUALLY understand it.

[@A_J502]

This Old House for the win! In all my years as an engineering student, this is THE BEST demonstration of heating, cooling, and basic gas law I’ve ever seen!

[@michaelm7874]

I’m in HVAC field myself for ten years and this guy explains it better than I’ve ever heard it explained

[@TheSpoonyluvin]

Richard really has a talent for teaching. You can tell that he enjoys explaining it, and also understands the concept so well that he can easily dumb it down for the rest of us.

[@nursecarmen]

I have found that the people that aren't able to dumb down a subject, either don't know the subject, or are full of it.

[@oldtwinsna8347]

Richard is a certified elite grandmaster of heat pump systems.

[@sceneryj]

I’m studying 1st year engineering and you’ve just done a better job of explaining half of the thermodynamics I need to know this semester than the (very expensive) textbook. Thank you!

[@starshipgus8578]

I’ve worked automotive air conditioning all my life,but this heat pump system was somewhat complicated….until now.Thanks to you Richard,all it takes is a switching valve and some electronics.Now I can even explain it to someone else.You get the credit of course.

[@zacharywestover217]

I just graduated USF with a degree in mechanical engineering. Should have watched this before my first Thermo class. Good stuff.

[@CDinkle]

Just getting into this material in my Thermo series for Mech E., and yeah, this video really brings it home in a way that's understandable.

[@matgggg55]

I’m a mechanical engineering student now and I’m taking thermodynamics this coming semester lol good thing I’m here lol

[@warrenwiz5]

There's a joke here about which college to attend, etc. But agree, these "basics" I feel like should be a preface into what textbooks show. In only a couple of minutes they give a very good explanation of how something works. There's also a comment regarding teachers and tuition, but it would quickly arrive at the Good Will Hunting summary of “...wast[ing] $150,000 on an education you coulda got for $1.50 in late fees at the public library.”

[@JT-Works]

Go Bulls!

[@modernhustle11]

You should stay away from refrigeration then if you think this guy knows what he’s talking about.

[@EmilioPanighetti]

Like listening to a good teacher, concisely and clearly explains thermodynamics with no-nonsense. Thank you

[@johnmacward]

There is not a better explanation on KZbin for heat pumps than this one. That simple concept of ‘heat always goes to cold’ and that gases when compressed or decompressed can either get really hot (and in turn attract cold) or get really cold (and attract heat) was the little understanding piece I needed to put it all together.

[@AndrewJJ-0114]

I really enjoy Richard's cutaway models, they really clearly explain plumbing parts that I would never understand otherwise!

[@McRocket]

8:08 - Kevin O'Connor said it PERFECTLY, IMO. WOW. Thank you This Old House's Richard Trethewey .

[@kwpowell0412]

Great job Richard!! I just want to echo what a few other people have said. I have never been able to wrap my head around how a heat pump & Air conditioner work. And here in South Carolina....EVERYBODY has one. What made things so clear for me was not only did you break it down explaining it. You also had the visuals that everyone could see. Outstanding sir......you da man!

[@SLCKaled]

No fancy animations. Just pure old school wisdom!! LOVED THE EXPLANATION. Makes me realize how much real life examples like the canned air are so powerfully effective

[@ml9633]

You are amazing. I'm 64 and never understood this process, because nobody could ever explain it to me so well. Thank you so much :) Maurice

[@AD-CAN]

Man I love this channel. You save my life by explaining complex thing in human language. I am so grateful. THANK YOU!

[@Lino44]

Finally a detailed explanation and in layman terms how these things really work. Thank you!!

[@vincentdemmink4544]

Well explained! Even though English is not my native language, I could completly understand it!! (power of good explaining)

[@fernandomingo2398]

This video is pure gold. Never in my life HVAC has been so well explained. Thanks!

[@bopal93]

I have seen many videos of how an air conditioner works, but this is the best explanation I have ever seen. Now it totally makes sense

[@ReverendRandy]

Great to watch two intelligent minds teaching us very important lessons on how to save energy and be comfortable. Thank you for sharing! Peace

[@RayR]

The best explanation of a heat pump I've ever seen. Great job Richard. Your a great teacher.

[@tinysand3517]

love the fact that Richard always dissect his mock ups. Make it simple to understand. Great job

[@mulimotola44]

I've been trying to understand this theory FOR YEARS! Finally a great explanation that anyone can understand! I love the examples that explain the compressor and the expansion valve with the can. Thank you so much! This is the best video on the subject by far!

[@rickcarson9423]

I live in California and just bought a new home in Florida which has a heat pump, a/c combination. I love this video because I kind of understood that it worked the opposite of a/c, which I understand how a/c works, but this really cleared it up. I'll find out how well it works when I get into my new home in two weeks! Thanks Richard! I watch ALL the This Old House line up. Have watched for decades.

[@harleyb.birdwhisperer]

How’s that working out for you? (Still in CA)

[@rickcarson9423]

We've been here one year now and there really was no prolonged period of cold last "winter". It's really like a long summer and a short mild fall. There was one week in December, I think, some rare, freak, week-long cold snap hit and it got down to 29° on two or three non consecutive days but maintained daytime temps around 60°-70°and nighttime around 40° and no problem. But we rarely use the heat. It's a Carrier unit. Electricity is cheap here (0.9 cents per kwh) and that's good because you need the a/c ALL the time! Our house is all electric. Our monthly bill averages around $180-200. Thanks for asking and good luck in California. I mean that sincerely. We're born and raised Central Valley. 60 years. We fled the lunacy. Sold our home, left our family and friends and we didn't look back lest we turn into pillars of salt! Lol! We love our new home and the people. Hope you and Pete live long and prosper...

[@bertblue9683]

A great explanation for anyone, especially for guys like me that grew up being told how awful heat pumps are. It's a hard reputation to overcome.

[@TheArfdog]

Thank you Rich for explaining the actual mechanics of how the coolant flows and what actual mechanical device allows it to change to different modes, instead of all the other videos about heat pumps simply stating "you just run it in reverse to change from cooling to heating"....

[@mikewalker344]

Finally an explanation of heat pump technology I can wrap my head around. Thank you!

[@nicolasroberge2829]

I installed a Carrier Infinity mini split heat pump last spring. It is amazingly comfortable for cooling AND heating. Amazing technology!

[@rockinrobin322]

What size house did you install this on

[@nicolasroberge2829]

@@rockinrobin322 I installed two separate 12000 BTU units on each apartment of a duplex. Each unit is 1500 square feet.

[@aprilm9551]

Another question: What's the winter weather like where you installed this? How cold can it get, and does the system work all winter to heat? I'm in Iowa, zone 5b. Probably a heat pump would not work in the very coldest months, I'm thinking.

[@nicolasroberge2829]

@@aprilm9551 Winter is harsh here. -30 in the dead of winter.

[@aprilm9551]

@@nicolasroberge2829 Nicolas, thanks so much for the reply and info! It means a lot to have real world feedback about something, so not just having to rely on advertising or general stats. OK, -30 (Celsius, I'm assuming) is a bit colder than it ever gets here, so I just may be looking into getting a mini split heat pump and will check out the Carrier brand.

[@stolas666]

That's the most brilliant video on the internet! A paroxysm of masterclass !

[@jpellet2744]

This is a truly inspired explanation of the principles and mechanics of heat pumps and hvac systems. Thanks!

[@SurferBum1002]

Best explanation I've found explaining how heat pumps work. Thank you!!

[@bulkbur6312]

king richard! being in the hvac field myself i can say that the future of comfort is exciting. i love seeing how you explain things. i want to be like you when i grow up 😀

[@VictorQuesada-bl1xk]

That was fantastic. Thank you so much for that clarity!

[@Bgkim1113]

thank you very much. you showed me a vaque understanding of heat pump of me made so clear. you are one of the best instructor who I ever have met.

[@wisconsineaglesfan7925]

Best explanation on the subject that I've ever heard. Made it really easy to understand. Thank you!

[@nomadland99]

THE best explanation I have seen for any heat pump (AC, air source, geothermal). Well done!

[@gregoryroscow5846]

Best explanation I've come across of how a heat pump works. I like the way it begins with the basic question, "How do you get heat into your house when it's cold outside?"

[@ElectricFuture]

This was an excellent video. Great explanation and demonstrations.

[@alonzogonzalez3062]

This show must never go away!

[@evakaral1647]

Richard, thank you for explaining the operation so aptly; even I, a non-techi can understand it. Brilliant!

[@99andycat]

Great explanation...First time I've got close to understanding how these things really work and are controlled.

[@Jimmyjimjimjim]

Hands down one of the best explanations.

[@impsquared]

Richard best teacher on this planet by a long mile!

[@tannernewton8543]

Sometimes when i'm sad I come find this video for the 1000000th time, its that good

[@lkw5699]

I love watching these explanations. Love this show. Richard and Tom are the best.

[@mikepurewal5816]

Hi from Canada. This video and audio explanation of Heat Pump/AC was amazing. The concept was explained very well. Thanks to great mentors like him.👍

[@HrdRockFan]

Best explanation I’ve heard… and not likely to forget again. Thanks!

[@TheDataMaestro]

I might have to watch this a dozen times before it sinks in.

[@donchiva2222]

I agree, the explanation wasn't very good. He talks too fast and skips too much by not giving context.

[@jakefromstatefarm142]

Which brings me to my next point dont do drugs

[@AlecDinkleshit-yo5np]

@@donchiva2222he was making a joke cause it uses heat sink technology.

[@DizzyDeeds66]

He lost me in a couple of places but I was able to get the overall gist and this was really helpful. I'm in the process of trying to figure out how to bring an almost 100-year-old house that still has no air conditioning and an oil burner heat and hot water system into the 21st century. The consultants that I've had come to the house have suggested this type of system (natural gas is not available where I am to convert to and I'm trying to get off the fossil fuels anyway). This was all new to me and this video was really helpful in my understanding of how a system like that would work in the house. Thank you!

[@treeskier58]

An old house, you would be better off spray foaming the place to seal up all leaks. The kicker with heat pumps in the winter is that they are still making heat with electricity by compressing the gas. The industry wide coefficient of performance (COP) usually given as 200 to 300% gives the general public the idea that they are getting free energy. Is this more efficient than resistance heating, yes a little. But a wood stove or a gas heater is more efficient in the overall scheme

[@davidreis6431]

What a good explanation. Nothing like someone who knows what they are talking about, and able to communicate it for the average person. Thanks.

[@scott.howell]

Finally, after a week of runaround and sophisticated jargon, I heard just what I needed. Thanks, and I believe I am now a "This Old House" super fan.

[@bb57365]

Outstanding explanation of a complicated subject.

[@andrewl8251]

This explanation is simply priceless.

[@randydogs61]

Am getting a heat pump in Nov, thanks to Richard , When you need it explained the This Old House professionals. its that simple.

[@TheresNoAntidote]

This is something we take for granted daily. This process is insane! Human being invented this? Mind blowing

[@joshuasmith1215]

That was probably an easier and better explanation than like anything I've been watching to learn about this stuff. I think I truly understand the fundamentals of these systems now.

[@ronhamm]

Great explanation of a complicated system.

[@mondavou9408]

Thanks for taking the time to build that model, it made it very easy to understand. Well Done!

[@ceeemm1901]

Fantastic explanation and so simple, just following basic laws of physics.Thanks.

[@bkohatl]

Thanks Richard and Kevin, you make the mysterious understandable.

[@simonslocombe5942]

Brilliant video Richard... the workshop, presenter and you my friend should be given an award for creating this one. Taking the simple principal of a air conditioning unit and reversing it to create a heat pump... Please do your best to get sponsored/funding/support to create more videos on heat pumps... by far the most effective and efficient is the ground source heat pump giving out over 400%... so for every 1KWh of electricity used, you get 4KW of heat... Just let you know there are massive incentive's by the UK Government to install and develop these thermodynamic systems... Not only are you helping out us electronics engineers and technicians, you are helping to save this planet...

[@johnmurphy8083]

I have a ground source pump here in Massachusetts, and it's simply brilliant! At the push on a display, switch from heat to cooling. No fuss, no muss

[@kszatmary]

This is the best explanation for the layman. Other videos I've seen on this topic were too technical for my non-mechanically inclined brain. This video was perfect. Thanks.

[@ktyoung67]

Holy Moly I always wondered how that worked! I need a new heating/cooling system for my home wanted to try and demystify the whole heat pump thing. Excellent explanation I am not mechanically or engineered minded at all and I understood this.

[@modernhustle11]

To be honest, you still don’t understand it because he has no idea what he’s talking about 😆. He is a meme to us legit hvac guys

[@oisinofthefianna3246]

When in heating mode you will always be constrained by the amount of latent heat in the ambient air, regardless how advanced the control system is. When needs outstrips available sensible heat in the air back up must kick in (electric usually).

[@MikeInPlano]

Ask yourself if you really want to be running your air conditioning compressor year-round. Keep in mind how high your electric bill is in the months when your A/C is running. Do you really want that to be your electric bill 12 months of the year? There's a reason why the vast majority of homes use some form of fossil fuel (gas, oil) to heat them. It's much less expensive, and as others point out in the comments, much more efficient than a heat pump. Even electric heat will cost you less than a heat pump. No thank you!

[@TheBoomtown4]

In all my years of teaching thermo heat value stochiometric binary engineering, this is by far the best carrot diaper tuna carburetor camera suspension banana! Thanks!

[@efficientmewithsomto8020]

You’ve got it perfectly explained, I love the the enthusiasm

[@dharmawanindrathaher5989]

Wow. Just wow. You brought this mystery down to an easily understandable treat!

[@CMRHM]

Sir, you guys have just made a best demonstration regarding refrigeration cycle, thank you!

[@garywright8846]

Great video I’ve been in HVAC many years and this guys explains it all so well. Brilliant well done.

[@fessit]

Thanks. I studied refrigeration in college over 4 decades ago. Things have come a long way since then.

[@candidone8544]

I've been a longtime fan of TOH and this segment is as good as any they've had...excellent! My personal surmise is how the use of known gas compression/expansion effects are used much like mechanical gearing, which can upgear or downgear by design. It's the reversibility where full spectrum versatility of heat pump tech resides. Awesome!

[@surendersingal9122]

Great demo on showing us expansion n reversing valve mystry demo.

[@TheNephilim101]

WOW ! 😱 What an amazing explanation and illustration ! Thank you 🙏

[@chris-vn6sw]

Came across the video by chance. The guy explained it really well ! 👏👏

[@davidmurray6070]

Incredibly well explained. I definitely learned something new today. Also, love the passion with which Richard shares the knowledge.

[@MatthewWilliams-b1m]

Thankyou for explaining this in such a understanding presentation .

[@UberKrispy]

i have a 12k/16k unit installation on Thurday in my rental. this was so informative.

[@StarWarsCosplay]

This is brilliant. I have never understood this until now.

[@waltervasquez1488]

Best video ever about heat pumps.

[@woodtool2882]

Thanks Richard, you're the best.

[@victoriabilenko9289]

Fantastic! All clear, thank you so much for showing the "guts" of the device and explaining so well. I am an Arts degree and was always afraid to come near these incomprehensible devices, but turns out brilliant and simple.

[@GunnyPhillips]

Those who intimately know their craft can impart it to others in easily understood terms. Great job and many thanks!

[@shangobunni5]

What a great explanation! THANK YOU for this very informative video. I’m looking into getting a heat pump, and this really helps me to understand more about how they work.

[@georgejones5431]

Very true very good on every explanation

[@erlanisy4481]

Awesome demonstration of how it works. Great and easy to think. Thank you.

[@paularubina3778]

I love this, thanks !!

[@neverbyluck]

This is an amazing and simple explanation. For the first time this concept makes sense! Thanks very much!

[@ltcameron1]

The best explanation I have ever seen. Really well explained. Thanks

[@appastewart]

Awesome job explaining that!

[@aprilm9551]

What a fantastic explanation. Thorough and detailed, and I was able to understand everything. Not that I remember it all, but it certainly makes sense to me now. And, previously I was confused -- as are many people -- as to how a heat pump can cool, but now I see it is all just a matter of moving heat around, in one way it heats a space, and move it the other way and it cools.

[@carguy1312]

I understand how an a/c system works. I never realized you could simply reverse flow and get the opposite effect. Great description!

[@chickenpasta7359]

i dont work in or study the hvac field but this is just super cool and fun to watch

[@mikefanelli545]

Excellent, Richard.

[@dwaynekoblitz6032]

I'm right dead center of having to make an expensive decision and this is helpful. Thank you.

[@christianiantosca5008]

Great explanation of a mysterious principal

[@tylornunn1447]

That is by far the best explanation I have every seen on the refrigeration cycle. I have a question though, does this increase the amount of condensation being produced in the evap coil?

[@ffgoldsmith246]

Studying thermodynamics and since we begin I didn't understand the whole process Only in this video. This is an amazing explanation of how does heat pump works. thank you so much for this useful video. gonna check what else in your channel.

[@swessel75]

Thank you !!! Excellent production !!!

[@sonklam2304]

Man, I just finished the fundamentals of Thermodynamics course ( mechanical engineering major) but didn't really understand much about this until now. Wow, exceptional well explanations.

[@GHOOGLEMALE]

What an excellent explanation Richard - First class demonstration. 👏👏