DIY Geothermal Heat Pump. Season 3. Ep3. Heat pump design and assembly. Pt2.

G’day fellas! In this episode, you’ll see how I assembled the heat pump. I strongly recommend using the help of a professional here because it’s such a delicate process. In my case, Roman helped me remotely.

The results of the first test run were a little disappointing. Flow meters were a bit off, but most importantly, the geothermal loop did not provide the expected 30 watts per running meter.

In the next chapter, I’ll do a thorough analysis of the situation with formulas, calculations etc…

Stay safe and enjoy the video!

Read the Transcript

• Greetings, fellas!
• This is the second part of the DIY geothermal heat pump series.
• You’ll see how I assembled it.
• I will not comment on the assembly process because, by and large, in the first part I have already commented on all this.
• As for the connection of the control board to the EEV, the controller that controls the compressor, all this is supplied with the control board.
• There are corresponding instructions on how to assemble it.
• And showing how it’s wired is an absolutely pointless waste of time.
• In any case, you’ll not understand anything.
• Take the instructions and use them to connect the temperature sensors, EEV, pressure sensor, emergency high-pressure limit switch according to the scheme.
• You’ll now see how it looks in my case.
• Let’s go!
• I’m crimping under the pressure of 45 bar.
• Because for the 410th gas, the maximum should be somewhere around this number.
• Everything seems to be fine.
• It’ll stay for a while under this pressure.
• I’ll see if the arrow will drop or not.
• We’ve come to the moment of starting the heat pump.
• Here I would like to make one comment.
• If there is such an opportunity,
• I would not regret the money and paid some of the smart people,
• I used Roman’s help,
• his coordinates will be under the video,
• or some other person who understands all these nuances.
• The fact is that you need to fill the system with freon.
• This very moment, when you still need to add more, and at some point to stop, is a tricky part.
• I did it for the second time already.
• But I am sure that I will forget these nuances again because I learned how to do this using my air heat pump as an example.
• You can watch the related video.
• Everything seems to be clear.
• I remembered, started doing this one - and that’s it, I feel like I’m missing something.
• A year passed and I forgot how to do it right.
• A person who is constantly doing this, remembers how to do it correctly.
• He sees when you need to add more and when you don’t…
• In my case, Roman helped me remotely.
• He logged in remotely and saw what was happening in the system.
• I advise you to use the help of a professional here.
• And the second thing.
• I use the board and software of the “people’s heat pump”.
• Relevant links to the repository and a description of this control board will be under the video.
• Follow the links and check it out for yourself.
• Or you can call or shoot an email to Roman.
• Well, let’s move on.
• Oh! It started pumping!
• Do you hear it?
• We’re currently on the 5th hour of heat pump operation.
• At the start, there was + 10 ℃ in the geothermal loop.
• After 4 hours of work, now the 5th hour has already passed, the geothermal loop has cooled down to 4 degrees.
• I tried to turn it off for a short time.
• The temperature after 10 minutes of operation of the circulation pump rises to 4.5 ℃ and slowly goes up.
• This indicates that the pipe has been cooled along its entire length to this temperature of about 4 ℃.
• 4 - 4.5 ℃.
• As you can see, the target is now 30 ℃.
• The return flow was heated up to 30 ℃ and the compressor began to decrease the speed.
• The maximum is 45 Hz.
• So it warmed up to 30 ℃ and is now trying to maintain this temperature on the return line.
• It regulates the EEV and regulates the compressor speed.
• It should also be noted that the system now is filled with water, not a proper solution.
• I will return to the process of filling the system with a proper solution a bit later.
• Now, of course, I’m afraid to leave it for a long time in order not to freeze the evaporator.
• With all the ensuing consequences.
• Therefore, most likely I will stop it for the night.
• And tomorrow I will fill it up and run it permanently.
• The counters have not been tested, so the picture is not 100% clear here.
• The temperature sensors are working correctly.
• This is the power of the compressor.
• The total input power will be somewhere around 200 watts more.
• To be honest, I am disappointed by the results of the first few hours of operation of the heat pump.
• I was upset by the rather low temperature of the coolant that came out of the geothermal loop.
• What’s this? Why it behaves like this?
• This question has yet to be answered.
• Here I am making an announcement for a future video, where I will show how and with what I filled the geothermal loop.
• It will be a little later. A link will appear here after some time when that video will be released.
• Therefore, follow the link and see how I did this.
• Now I will show the result of the work a day after filling the geothermal loop.
• And in the end, I will comment on this whole situation.
• After the first night of work.
• The heat pump worked for a little more than a day.
• Practically without turning off.
• And now we have such an interesting picture.
• Well, firstly, there is some kind of error with the flow meters, so one of the power readings is wrong.
• Most likely the second one is wrong.
• And the input power seems to be correct.
• But I’m not sure.
• Over the course of a day, the geothermal loop temperature fell from 11 ℃ to almost 2 ℃.
• This is 200 running meters of the loop, we actually worked it out with 3 kilowatts.
• It’s kind of sad.
• It’s about a little more than 15 watts per running meter.
• Clay.
• The clay is quite heavy, loamy.
• There is no sand.
• We did not go into the water.
• Maybe the top of the water layer has been snagged a little.
• Maybe this is due to the fact that we have 2 dry years in a row and very dry soil?
• What this is connected with is not clear.
• Well, that’s what we have here. I need more time to analyze this situation in greater detail.
• First, I’ll need to check the flow numbers.
• And then everything else.
• Another interesting observation.
• I stopped the heat pump for the night.
• Somewhere around 10 PM yesterday.
• This morning there was already around 8 ℃ in the loop.
• And at 10 o’clock in the morning, I started up the heat pump.
• There was almost 8.5 ℃ of heat in the geothermal loop.
• The whole loop warmed up quickly enough.
• After an hour of operation of the heat pump, the loop again dropped to 1 ℃.
• The input is 1 ℃, and 3.2 ℃ comes out of the loop.
• I don’t know what this indicates yet.
• I think that we will draw conclusions a little later.
• Approximately 10 days of operation of the heat pump on the geothermal loop without shutdowns.
• As you can see, the geothermal loop has already dropped down to - 1.6 ℃.
• For a long time, it held about - 1 ℃.
• But when it held - 1 ℃ it was on 67 Hz.
• I cranked it up to 72 Hz.
• It dropped to such temperatures.
• And, in principle, it keeps this temperature fairly stable.
• Of course, I would like to have an output temperature not - 1.5 ℃, but still at least + 3, + 2 ℃.
• But something is wrong with the geothermal loop, I’ll need to figure it out.
• Now the outside temperature has dropped.
• Naturally, the heat transfer agent temperature dropped too.
• I had it more than 40 ℃ before, but now there is not enough power to hold it there.
• I also cannot increase the frequency because there is not enough evaporator.
• In general, I’ll need to modify it.
• Up to - 5 ℃, - 7 ℃ it works fine, and after that, it’s not enough.
• Now, the outside temperature at night is - 15 ℃, and in the daytime around - 11, - 12 ℃.
• So, I think we can summarize the first results.
• Today we have programmed problems.
• This is an insufficient heat exchange area (PHE).
• But this was to be expected because these PHEs were designed for a compressor of lower capacity.
• There was an offer to install an inverter, which I could not resist, but there was no PHE for it.
• Therefore, I put on a smaller PHE.
• Therefore, PHEs have been ordered, they are being delivered right now, most likely I will change them next year.
• Next season.
• Second little problem.
• Can you figure it out for yourself?
• You have seen the design of the heat pump.
• But there is an error.
• In the design.
• Comment under the video. In the next video, I will tell what this error was.
• And the third problem, the biggest problem, is that the geothermal loop does not provide the expected 30 watts per meter.
• Which I was counting on.
• I now get a little less than 20 W per running meter, while the circuit drops down to - 1.5 - 2 ℃.
• However, in this case, it stabilizes at this temperature.
• But it’s still sad.
• This caused me to get less output power.
• I expected that the temperature at the output from the geothermal loop at 30 W would be about 0 ℃, maybe a bit more.
• In this case, I would receive 20% more heat output than I receive now.
• Well…
• In the next video, I would like to return to the analysis of the situation.
• What’s going on down there underground.
• Calculate with formulas, with thermal conductivity, and try to simulate the situation.
• So …
• On this sad note.
• I say goodbye to you until the next video.
• Subscribe, hit that bell, give me a comforting like.
• Bye! Have a nice day.