The Homemade Heat Pump Manifesto

[Vlad]

Originally Posted by Ko_deZ

Vlad, I think you are mistaking customers to be properly intelligent and efficiency focused. That is not the case as any marketing person will tell you. A good design and good reputation of durability will sell a whole lot more that a small increase in efficiency. Do you know may people who are willing to have a in-door unit more than twice the size of a normal one?

You can give many examples when "good design and good reputation of durability" brought very good companies to bankruptcy. Just because somebody knew how to BS more people.

This is the point. Do you know many people who is willing to pay extra 2000-3000 $$$ for extra efficiency that is tested only in lab environment? When did you check copper prices last time? HX especially monster size like Bras_C is installing cost A LOT OF $$$.

Check the first post where AC stated the goal. He started this thread as DIY BUDGET FOCUSED. WSHP became VERY EXPENSIVE gadget for no reason just because it is "special". He broke this myth by building his GSHP from NOTHING.

[Vlad]

Originally Posted by AC_Hacker

Vlad,
I was very interested in how that part of your project played out.
So, I assume that you put in a series of 50 foot deep holes, right?
How many holed did you end up drilling?
So when you tried to do the grouting, exactly what did you try?
Did you try MIX-111?
Did you try various water-to-grout ratios to solve the problems?
Did you try some kind of tube ('tremmie tube') that you could pump grout through? If you did, what diameter(s) did you try?
If you did try to pump grout, what did you try to use as a grout pump?
As you surely know, I decided not to grout, since my holes did not pass between aquifers... so I didn't have the grouting adventures you had.
-AC_Hacker

You can read a whole story:

http://ecorenovator.org/forum/geothe...ng-gshp-6.html

Yes I tried MIX-111.

I used diaphragm trash pump Homelite 3". It has 4.5 HP gas engine(got used one for 200$). This is a great pump but it needs speed because at low rpm gas engines have no torque. Because grout is not liquid enough pump could never rev up.

I did try to add more water but it didn't help.

I used 1 1/2 clear vinyl suction hose:
http://www.princessauto.com/pal/prod....-Suction-Hose

It was very clear there was not enough pressure to push grout through the hose.

Finally I got an idea what if I use air operated diaphragm pump?. I started looking for one on eBay. One day I found one on Craigslist near Olympia in US (350 km away from my house).

It is Wilden m5 air operated dual diaphragm pump. New ones like this cost thousands of $$, but I am not rich, so I spent 150$ plus 700km in my van.

This pump requires a lot of air I mean A LOT. My air compressor is a commercial monster with real 5HP electric motor(not inflated rating but real 5HP) can't keep up. But I don't need full pumping capacity, what I need is pressure.

Long story short it looks like I finally can pump slurry-like cement bentonite clay mix. I didn't add cement because the whole point was to make sure I can pump that viscosity. Testing was fun. At one point hose came loose and blew sand/clay mix at over 100 psi pressure all over me and my house. It was like sandblaster blow. Cleaning whole side of house wasn't fun at all.

Even with pressure of about 120 psi I can only push grout through 50 feet of 1 1/2 hose. I tried 70 feet- NO GO. I had to add more water which is not too good for grout.

AC your holes were shallow and wide, so you could easy fill them with clay or sand or thermally enhanced grout (I think you should have used grout instead of just filling.)

In my case I have NO CHOICE. My holes are just 4" wide minus 2 pipes. Also the hole is full of drilling mud (easy to replace with water or even empty it) there is no way to fill it by gravity.

[AC_Hacker]

Originally Posted by Vlad

Check the first post where AC stated the goal. He started this thread as DIY BUDGET FOCUSED. WSHP became VERY EXPENSIVE gadget for no reason just because it is "special". He broke this myth by building his GSHP from NOTHING.

Thanks Vlad...

What I really had in mind was that money doesn't have to be an impediment to having a highly efficient heating system, that an efficient GSHP system no longer is the exclusive domain of the rich. And that someone who is resourceful and determined, someone like yourself, can create their own highly efficient heating system for a bargain price.

By my own example I tried to show that it wouldn't be easy and that many unseen problems would have to be solved, but it is still possible.

This is all not at all to say that people with resources shouldn't attempt to do it too, but I have intended from the beginning that, since there is no place else that I am aware of, in the entire universe of the Internet, for DIY of heat pumps and most especially GSHP, that this thread should be that place.

You have admirably risen to the challenge, and you should know that you are an inspiration to many and I hope that you tell the full story of your project, so that even more people will understand that they can do it too. So far, no one else has done quite what you have done.

BradC is doing some tremendously interesting work, too. He, no less than you, is pushing out the fronter of DIY heat pump and GSHP knowledge. His focus, though not like your, is not wrong, but it is different. His work is worthy of respect, no less than yours. So far, no one else has done quite what BradC has done.

So, this space on the web is quite unusual, quite valuable, quite worth respecting and protecting. In a curious way, it is kind of like a home. We are all learning from each other here.

-AC_Hacker

[Vlad]

To be reasonable or Follow your goals

For DIY projects it is very important to set your goals and keep them in mind. Your goals must be reasonable. If your priority is budget then think about pay back. Many "efficiency benefits" have pay back period of 20-50 years.

Here is my example. Few years ago I got professional heat loss calculation for my house (4200 sqft) It is over 54000 BTU. Again, it was done by professionals using very sophisticated software. Everything was taken into consideration (type of windows and area, wall insulation, roof insulation.... you name it)

Last fall I was getting ready for winter and wanted to start using radiant floor heat in a portion of my house (3000 sqft). All my calculations were based on that darn 54000 BTU heat loss. After reading this thread and many others and my drilling straggle I realized that I can't go geothermal. So I gave up (but because I am stubborn I just gave in...).

At one point I started thinking what if I go air source HP? But after reading about floor temperature required (adding floor TD, HX TD) I realized It is impossible to have that much temperature rise especially when your demand at max and outside is at low.

I have HWT which is natural gas power vented 50 gal 34000 BTU input. Considering its efficiency of I guess 70% the real useful heat output is in 24000 area or 2 ton. I knew it was kind of small for domestic HW (after long shower sometimes I can see temperature decline) and heating at the same time. So I made some changes:

1. added mixing valve. It allows to raise temperature without compromising safety (we have 2 small boys and safety is a highest priority)

2. I added second electric HWT (80 gal monster) which is used only as a storage tank. It does have one 4.5 KW heater that can be used in case of emergency.

I have good control system for radiant floor: outside temperature reset variable speed pump control few temperature sensors 12 zone manifold. This system helps keeping temperature in comfort range also it adopts to outside temperature.

Now some observations:

1. Only on coldest days HWT runs 1-3 hours at the time and takes a break !!!!!

2. I calculated gas usage based on 3 year data. Now we use even more hot water and gas drier(60000 BTU unit) (with 2 years old and 6 month old you need a lot of water)

3. On warm days HWT does nothing like before.

4. Water temperature in underfloor loop most of the time in 82F-85F range (return 5F degree lower). Only on coldest days I saw temperature going up to 92F-95F.

5. This is very cool one: our gas bill went up by about 100$ a month !!!!! For 3000 sqft it is not bad at all (remember 70% efficiency)

6. Radiant floor pump most of the time runs in low RPM range(it is controlled by speed control). Many suggestions largely oversize pump.

7. I saw many people were complaining about air problem in radiant floor. My manifold is located in basement and top floor is 20 feet higher. System runs absolutely noise free (except some humming from pumps in basement). Absolutely no problem with air (I did added air scoop and air eliminator)

Now having all this data I need to make many corrections.

[Vlad]

I found the answer to pumping stubborn grout:

Concrete countertops: How cement particles are like socks. - YouTube

Concrete countertops: Using superplasticizer to increase workability without decreasing strength - YouTube

Superplasticizers: the wonder of fluid concrete - YouTube

http://fritzpak.com/pdfs/pb115_supercizer7.pdf

This can be very handy for many DIY projects. Now concrete jobs look to me more attractive.
It is not expensive, which is good. 2.5 lb bag costs 20 CAD. It is enough for 1 cubic meter of concrete.

[AC_Hacker]

Originally Posted by Vlad

I found the answer to pumping stubborn grout.

I have a hunch that there is another piece to the puzzle.

Here is a picture of a hand grout pump, I got this picture because it so clearly shows the principle...

I think that the missing piece is that a pump with a fairly small diameter piston is used to overcome the tremendous fluid friction of the grout.

If you have access to a lathe, you could probably build a motorized one. Commercial grout pumps are horribly expensive.

-AC

[Xringer]

That kinda reminds me of my hydraulic car jack..

I wonder if it would be possible to use compressed air (HPA) at 3,000 to 4,000 PSI to push the grout?

If you only needed 900 PSI, you could use cheap CO2..

[Vlad]

Originally Posted by AC_Hacker

I have a hunch that there is another piece to the puzzle.

Here is a picture of a hand grout pump, I got this picture because it so clearly shows the principle...

I think that the missing piece is that a pump with a fairly small diameter piston is used to overcome the tremendous fluid friction of the grout.

If you have access to a lathe, you could probably build a motorized one. Commercial grout pumps are horribly expensive.

-AC

It only costs about 1000 $$. If I could find used one for 200-300$$. There are other ones using the same idea(They used for concrete Mudjacking). But they all in 1000$$ range. I want to keep price affordable for DIY person. If I was doing this for a living no problem 4-5k pump will pay back.

[Vlad]

Originally Posted by Xringer

That kinda reminds me of my hydraulic car jack..

I wonder if it would be possible to use compressed air (HPA) at 3,000 to 4,000 PSI to push the grout?

If you only needed 900 PSI, you could use cheap CO2..

So, you need some kind of reservoir that has big opening for filling grout. It must be big enough to hold enough grout otherwise you will get voids. Also it must be strong enough otherwise you will be a local terrorist .

I don't think pushing grout with just gas pressure is a good idea. You need pump.

[Ko_deZ]

Originally Posted by Vlad

You can give many examples when "good design and good reputation of durability" brought very good companies to bankruptcy. Just because somebody knew how to BS more people.

True, but that would be screwing up your reputation. I was talking about the loads of companies that has a good reputation, and keeps it by delivering good quality systems. They do consider aesthetics as well as efficiency as they know that a huge ugly thing will not sell as much as a small neat thing. This is also why the in-door units have a centrifugal fans, they are more noisy than a normal fan, but they take up a lot less space, and fits the purpose of having a long and thin heat exchanger, and thus sell more. Most of us DIY guys do not have that requirement to the same extent.

Originally Posted by Vlad

This is the point. Do you know many people who is willing to pay extra 2000-3000 $$$ for extra efficiency that is tested only in lab environment? When did you check copper prices last time? HX especially monster size like Bras_C is installing cost A LOT OF $$$.

2000$ extra for slightly larger heat exchangers? I don't think so. Example:
air cooled condenser with aluminum plate fin foil and can custom made products, buy air cooled condenser with aluminum plate fin foil and can custom made products from alibaba.com
And I can guarantee that the heat pump producers get a whole different price than we do. Of course, the price would be increased more than the cost, but still, they will not do it, not because of efficiency but because of aesthetics.

Originally Posted by Vlad

Check the first post where AC stated the goal. He started this thread as DIY BUDGET FOCUSED. WSHP became VERY EXPENSIVE gadget for no reason just because it is "special". He broke this myth by building his GSHP from NOTHING.

You are missing my point. My point was not bang for the buck, it was that it will always be better with larger heat exchangers when it comes to efficiency. Yes, they get more expensive, but when you DIY, you can often get hold of some used parts cheaply or free. As long as you set up your system correctly, having larger heat exchangers will be more efficient.