Heat Pumps: the Future of Home Heating

Hello! Here's a comment with some extra info on efficiency and the metering devices used in heat pumps. First: my wording on the efficiency drop in the cold was sloppy, and it sounds like I'm suggesting the need for defrosting is the only reason it loses efficiency. It is a reason, but not the biggest one - that's simply that as the outdoor temperature gets colder, it's harder for the refrigerant to absorb heat because the temperature difference between it and the air gets smaller. In fact, in the clip when it was -10°, it wasn't building much frost at all because it was very dry. But that was so cold that the refrigerant could barely capture any energy, which is why its output was tepid. And to be clear, its rating down to 5° doesn't mean it operates at full efficiency at that temperature. That's just the lowest temperature that it can sustain its rated heating output. Re: metering devices. I still somewhat suspect that the mini-split has a capillary tube and largely because of its cost. It was surprisingly inexpensive (this unit was about $1000, but the smallest units from this same manufacture only cost $750 and are fully capable heat pumps). If you use a thermal expansion valve or similar, you need one for each direction which adds to the system's complexity somewhat. I'd still argue that it hardly does - it is, after all, one or two small components of a large system. But simply reversing the refrigerant flow doesn't work on its own in systems that use these more complex metering devices. They'd need some additional piping and valve work (some such valves were visible in the demo rig) to accommodate two metering devices for each direction of flow.

If it's not absolute zero there's some energy. Let's steal it!

When your entire upload history is a prequel series for a single video.

This video ended up inspiring me to go into an HVAC career, I just got hired as an apprentice :) thanks for the great content!

HVAC tech from the EU here, I'm probably late to the party on this but just wanted to add, most mini splits with variable frequency compressors don't use capillary tubes or TXVs but electronic expansion valves for even more adjustability and efficiency and they're usually in the outdoor unit and not the indoor one which is why insulation of the copper piping from outside to inside is so important as well. Anyway, love your content, keep doing what you're doing!

my mother: shut the door, we ain't paying to air condition the entire neighborhood alec: ... what if you were

This video is the linchpin of the Technology Connections Cinematic Universe

We installed mini-split heat pumps on our house this year, and so far, we've noticed a significantly lower energy bill both during summer and now in winter. Your videos on heat pumps are a big reason why we did this. Thanks for making these videos. It's a small thing, but these videos are making the world a better place.

Fun to watch. I live in Sweden and close to 60 percent of all Swedish detached houses have a heat pump. The number of houses with heat pumps has also increased by almost 50 percent since 2009.

One of the perks of being hearing impaired is that I always have subtitles turned on and therefore catch things like “Coefficient of smooth jazz” and it makes me feel happy. :)

I remember subscribing when you were at around 150k subs, and I prayed that WHEN you hit 1 million, the videos would stay the same, and they have. This is honestly one of the best channels ever. You've taught me a lot more than anyone else could, and about things that are actually interesting. Thank you for staying true to edutainment. I honestly think you would make an amazing teacher.

He truly is The Engineering Guy for household appliances. I can't wait for the geothermal lecture!

I live in Australia, so it doesn't get as cold in the winter here as it does in North America, but in the winter it can get from between 0-10 degrees C. And my old house was entirely heated by heat pumps. There was like 6 split systems in the house, they worked great

When I was about ten years old, 50 years ago, I asked my father why we couldn't put the outside part of the window AC inside by flipping it around to warm the house in the winter. I didn't know the way it worked at the time but I do now.

Years of Technology Connections have prepared me for this.

If I were a science teacher, I would never do any teaching...I would just have the kids watch this channel every day. What a gem!

Thank you so much for this video, my HVAC technician and I had a disagreement today about if heat pumps can still work under 40F. He REFUSED to believe it’s possible. I was doubting my own sanity and I see now it is in fact possible!

Meanwhile in Sweden , I'm annoyed that my heat pump doesn't cool. It would have been sweet to have air conditioning in the summers!

for 20 years I've been asking sales reps to explain heat pumps, how they work, and how my cost would go down as brochures and signs say. No one could tell me. Next door got a huge carrier unit installed I asked installers, they couldn't be bothered or didn't know. Now I know. THANK YOU SOOO MUCH!

Just installed my first heat pump this winter and it's amazing. I undersized it at 12k BTU for a 1500 ft2 main floor, it's not much more powerful than a toaster and it kept 22C indoors. It's a 14 hspf rated for -26C and averaged 1.4 COP when it was -26C including the defrost (15min per hour). I'm going to install another small one for my basement now and maybe one for the pool!