DIY Geothermal Heat Pump. Season 3. Introduction. Fluid geothermal loop. Inverter. Free cooling.

December 8, 2021 • ☕️☕️ 10 min read

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Howdy! In this episode I do a quick introduction to the 3rd season of DIY Heat Pump project. This third season will be about a geothermal heat pump. To be precise, this is my second “Geothermal heat pump” project attempt and the fourth “DIY heat pump” in general.

This time I decided to go with fluid geothermal loop, it has a lot of benefits such as easily organazable free cooling. We’ll talk about benefits of inverter heat pumps and what happens when the heat pump is too puwerful.

Stay safe and enjoy the video!

Read the Transcript

  • Once upon a time, there lived Ivan the Fool and Elena the Fair.
  • Ivan the Fool fell in love with Elena the Fair …
  • Whether Elena the fair fell in love with Ivan the Fool is not clear.
  • Anyway, Ivan the Fool married Elena the Fair.
  • But something in their relationship went south …
  • Doesn’t want Elena the Fair to kiss Ivan the Fool, what a bummer!
  • Ivan the Fool, being unable to fix the situation,
  • on his own,
  • went for help to Koschei the Immortal.
  • “Koschei, my dude”, he said, “I need your help”.
  • And told him the whole story.
  • Koschei says: “Man, everything is simple here!“.
  • Listen to my word: “Just smash her with your fist across the head and she’s yours”.
  • Then you can kiss her as long as you wish…
  • Ivan says: “Wow, Koschei, brutally assaulting women is not really my style”.
  • Do you have more peaceful advice, maybe something that involves a little more romance?
  • Koschei like: “Well, nope. I’m afraid that’s all I can offer. Worked for me for centuries, my signature school.”
  • And in my school, we don’t beat about the bush.
  • “You can go visit my competitor - Baba Yaga, maybe she’ll give you some advice”.
  • So, went Ivan the Fool to Baba Yaga, and said: “Baba Yaga, here’s my situation, can you give me some advice here?“.
  • Baba Yaga says: “You’ve come to the right place Ivan, here’s what you have to do”.
  • Pack some snacks in your bag.
  • And go to the lands far far away.
  • Where the magic weed grows.
  • Gather it, dry it.
  • But only do it during the full moon!
  • Dry it only under the moonlight.
  • Once it dried, let it brew for a year.
  • Then dissolve it in water. First in the dead, then in live.
  • The old witch washed his brains for an hour.
  • What he should do, how he should do it.
  • “And finally”, she said, “Give this potion to Helen”.
  • Then you can kiss her as long as you want.
  • Greetings ladies and gentlemen!
  • I follow the school of Baba Yaga.
  • Therefore, this will be an introductory part.
  • Of a third season.
  • Of “DIY heat pump”.
  • And this third part will be about a geothermal heat pump.
  • As an advertisement, I want to offer you a super kitty! 🐱
  • She’s small, still without a name, but really beautiful!
  • It simply adores mice and dogs.
  • Eat mice, play with the dogs.
  • Or maybe vice versa, but mainly it plays with dogs.
  • For silly money.
  • Only 33 hryvna.
  • Or 33 EUR if you wish.
  • There’s no change, in case you pay more.
  • If you’re in Kharkov or Kharkov region, the front porch delivery is free of charge.
  • Yes, kitty?
  • It still doesn’t have a name, you can call it how you want.
  • She’s thoroughbred, three-masted.
  • Her mommy is a skilled and lethal hunter, the mice live in terror here.
  • Of course, she’s too young to hunt on her own.
  • My story with heat pumps began back in 2011.
  • Back in those days, Youtubes were not so popular.
  • Therefore, the description of my first heat pump from the external unit of the air conditioner,
  • and the internal unit, which was made by a principle “pipe in a pipe”,
  • I published it on Blogspot.
  • You’ll find a link to this first project in the description under this video.
  • That heat pump did not work for too long because the compressor died.
  • But the this led me to some conclusions and interesting thoughts.
  • The next step was to make a geothermal heat pump.
  • I bought a compressor.
  • Started to think over the scheme of the new heat pump.
  • How to design a geothermal loop …
  • And then it dawned on me that the geothermal loop needs to be made cheap and serious.
  • And then I remembered thermal siphons.
  • And then it hit me.
  • If you’re interested how, you can watch the first season of “DIY Heat Pump” series on my channel.
  • A link to the video will appear here, or here.
  • So, … I started to improvise.
  • Well, as a result, this heat pump can be said to have started up.
  • But output from this heat pump was very small.
  • And it didn’t work great.
  • Therefore, it was decided to quickly,
  • since almost the whole summer I fiddled with this geothermal pump,
  • to quickly build an air-water heat pump.
  • This story is documented in the second season
  • of “DIY heat pump”.
  • The link will also be somewhere at the top.
  • This project worked out better.
  • There are no special complaints about it’s operation.
  • It just works.
  • The only thing I don’t like about it
  • is that it’s operation becomes questionable either near zero temperatures, or below zero.
  • It freezes quickly, because the gaps between the lamellas are very small.
  • And naturally defrosting is needed.
  • And it freezes over very quickly if the humidity is high.
  • If the air is dry, it can work for 3 hours without freezing.
  • And our winters here are usually quite wet.
  • Therefore, it freezes 90% of the time.
  • In just about 20 minutes.
  • Then it thaws.
  • And also my defrosting was done by the heat of the compressor.
  • It takes quite some time to thaw it back.
  • You can see all this in my videos.
  • In history.
  • Therefore, I will not dwell too much on it now.
  • And yet …
  • This spring I’ve finally decided that I will drill wells and insert geo probes.
  • I figured that I need about 6 kW of heat from the ground,
  • in order to get about +/- 8 kW of heat.
  • The figures were obtained from the results of the operation of the air-water heat pump.
  • It has exit counters.
  • I could quite clearly trace how much heat it consumes per day.
  • You can calculate this with a gas boiler, knowing the calorific value of the gas.
  • Knowing the efficiency of these gas boilers.
  • You can get all these numbers quite good and fast enough.
  • But I had the exact numbers already.
  • Therefore, 6 kW from earth + 2 kW of electrical energy that the compressor itself consumes.
  • 8 kW.
  • This will be enough for me 98% of the operating time of this heat pump.
  • As for that 2%, well, the gas boiler doesn’t go anywhere.
  • If there happens to be -30 ℃ one day, which may or may not happen every 3 years.
  • Then I will use gas heating.
  • Thing is, a highly powerful heat pump is not needed,
  • because the results of the operation of the air-water heat pump clearly show that
  • when the heat pump is excessive in terms of thermal power - this is also bad.
  • It’s bad why? Because it turns on, pumps up the required temperature in these 10 minutes.
  • Heats everything up …
  • If you estimate the heat consumption of the house,
  • then you need, for example, that all batteries are 32 ℃.
  • Then the heat losses will be compensated.
  • But when the pump is too powerful, what happens?
  • It heats up to 40 ℃, then stops, waits until the temperature of the coolant drops to 29 ℃, and reheats it all to 40 ℃.
  • So, what do we see here?
  • As we know, COP is highly dependent on the temperature difference between the outside air and the house.
  • More precisely, not so much temperature of the house as the temperature of the coolant.
  • The water that heats the house (30 ℃) has COP 4, at some outside air temperature.
  • And when the temperature almost reaches 40 ℃, we have COP 3 there.
  • We lose at least 25% of energy.
  • Well, we don’t lose it, we consume more electrical energy and less from the geothermal loop or from the outside air.
  • Therefore, the heat pump must be close enough to its limit.
  • If a house needs 10 kW of heat, then a 10 kW heat pump is needed.
  • That extra demand that happens very rarely, it is better to heat it up with gas.
  • Or use some other heater.
  • Or, the second way is to use a variable setup.
  • The so-called inverter heat pump.
  • An inverter heat pump allows adjustment in a certain range.
  • For example, rotors allow adjustment from about 15% (15 Hz) to 90 Hz.
  • The difference in heat output is colossal.
  • Judy! Get out of here! 🐕
  • The difference in heat output is very large.
  • The pump will work continuously and will heat the water not up to 40 ℃ or 42 ℃, but up to 30 ℃ and keep it there.
  • And at the same time, it will work at the maximum COP.
  • Naturally, it will consume minimal electricity.
  • Therefore, this season is going to be about an inverter heat pump.
  • And geothermal loop.
  • Geothermal loop, based on my calculations (6 kW of heat is needed), I took 30 W from the running meter of the loop.
  • All experts speak about this number.
  • There is no point in not believing them.
  • My geothermal loop is going to be about 200 running meters.
  • 4 inclined wells 50 meters each at an angle of 45 ° to the horizon.
  • They all capture an angle of about 100 °.
  • This time everything will be on 410th freon.
  • Why 410th? Because my compressor is for 410th freon.
  • The math here is pretty simple. If it were for 404, I’d use 404.
  • What attracts me is precisely the fluid geothermal loop, when the fluid is pumped by a circulation pump.
  • The fact that you can easily organize free cooling.
  • When I thought about the geothermal loop based on thermal siphons, I deliberately made this sacrifice.
  • Sacrificed free cooling for the sake of the fact that it will be cheap, fast, simple, and reliable.
  • But the trick failed.
  • And then I did not bother with thermal siphons anymore for the simple reason that plastic is not suitable for them, or some specific plastic is needed.
  • Using copper will be expensive and will be similar with the water geothermal loop.
  • Therefore, it can be cheaper only on well drilling.
  • Copper itself will be expensive.
  • In general, you need to plan quite thoroughly and still need to check how it will work.
  • How much heat can be taken from the geothermal loop on copper, how to plug this well.
  • Therefore, in this part, the water geothermal loop will be used.
  • I’m also putting into plan diverts the for free cooling.
  • There will be a separate plate heat exchanger.
  • In which the heating water will enter from the geothermal loop.
  • And which will heat the water through this plate heat exchanger, which in turn heats the house.
  • Of course, the circulating pumps will be installed too …
  • So, sometime later you can expect a report on free cooling.
  • That’s all I wanted to say in this episode.
  • After this one, the episodes will go one by one.
  • The spacing between them will depend mainly on my free time for editing.
  • Because a lot of material was filmed.
  • What to include, what not to include, I need to revise everything, edit it, cut off the excess, add what was missing.
  • There will be some inserts in videos because I was filming everything without too much preparation.
  • And now all this needs to be sorted, and the content made clear for a simple viewer.
  • One part will be about the geothermal loop.
  • There will be a part about heat pump assembly.
  • And there will be at least 2 bonus videos.
  • How I started this whole thing, the problems …
  • I definitely stepped on a rake a few times…😂
  • No wonder I adhere Baba Yaga’s school 🧙‍♀️
  • I will not hide anything because I am not a specialist in heat pumps.
  • It’s the specialists who hide their skeletons in the closets.
  • And my skeletons are all on display, you can clearly see them: 🦴💀🦴🦴💀🦴🦴💀🦴🦴💀🦴
  • I don’t make money on this.
  • On the heat pump manufacturing and installation.
  • So I am allowed to be wrong.
  • But this will be interesting for you to watch, and, hopefully, you will not repeat my mistakes.
  • Ok, give me a thumbs up 👍, comment, but do not rush ahead of the locomotive.
  • It’ll be fun and interesting, let’s go !! 👍
  • Kitty-kitty🐈
  • Come on, show yourself …
  • Say, “New owner, where are you?”
  • Where is my new owner?
  • And this is her beloved doggo🐕.