EcoRenovator  

Go Back   EcoRenovator > Improvements > Geothermal & Heat Pumps
Advanced Search
 


Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 08-08-11, 05:57 PM   #871
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts
Default

Quote:
Originally Posted by RickHeid View Post
I just love reading the stuff on this forum and this is my first post. I have been kicking around an idea and just wanted to see what you guys thought. I have a well that is 6" in diamater and down 180'. The water level is always at the 45' level and the pump is 10' from the bottom of the well. I was thinking of pulling the pump back up and putting a copper coil in the 10' at the bottom with a plastic pipe feed and return to my heat pump. Then put the pump back down the well. We don't use a lot of water from the well however it seems to me this would work even better than a 180 ft hole filled with grout, as every time I use water, cold water will come into the shaft. Oh and I live in central TN.
I think the issue will be how fast the water comes back into the well shaft.

If you really know how fast the water comes into the well shaft on a sustained basis, you are on your way to knowing how much heating or cooling you can expect from your well.

-AC_Hacker

__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 08-08-11, 08:08 PM   #872
RickHeid
Lurking Renovator
 
Join Date: Aug 2011
Location: TN
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Default

It comes in as fast as we use water. It seems to me though that I would be doing the same thing as a hole down 120' or so filed with grout, with the benifit of chilled water replacing whatever we use on a daily basis for laundry, bathing, drinking exc. Rick
RickHeid is offline   Reply With Quote
Old 08-08-11, 10:14 PM   #873
Xringer
Lex Parsimoniae
 
Xringer's Avatar
 
Join Date: Feb 2009
Location: Woburn, MA
Posts: 4,918
Thanks: 114
Thanked 250 Times in 230 Posts
Default

Quote:
Originally Posted by RickHeid View Post
I just love reading the stuff on this forum and this is my first post. I have been kicking around an idea and just wanted to see what you guys thought. I have a well that is 6" in diamater and down 180'. The water level is always at the 45' level and the pump is 10' from the bottom of the well. I was thinking of pulling the pump back up and putting a copper coil in the 10' at the bottom with a plastic pipe feed and return to my heat pump. Then put the pump back down the well. We don't use a lot of water from the well however it seems to me this would work even better than a 180 ft hole filled with grout, as every time I use water, cold water will come into the shaft. Oh and I live in central TN.
I think you mean the water level at 45', is saying the water is 135 feet deep.?. (71.6 gallons)

Therefore, if the pump is only 10' from the bottom, and you have 125' of water above it,
why not hang the copper coil above the pump?


Or, instead of a coil, What would be wrong with using 200' of copper to make a 100' long loop?
Xringer is offline   Reply With Quote
Old 08-08-11, 11:35 PM   #874
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts
Default

Quote:
Originally Posted by RickHeid View Post
It comes in as fast as we use water.
Didn't you say that you were interested in using this well for cooling?

Do you already have an air conditioner?

Do you know what your air conditioner is rated at? If you bought a whole house unit, it would be rated in Tons (12,000 BTU/hr) if you use window air conditioners, they will have a rating sticker on the side.

This would give you some idea how much cooling you will need from your well.

If you put a loop in your well and grouted it, you would probably get around 9600 BTU/hr or about 8/10 of a Ton cooling.

Yes, you are right that you might be able to do better by extracting cold water from the well. But if the sustained water flow is below a certain amount, you would be better off to make a loop and grout it.

Physics is involved.

-AC_Hacker
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Old 08-09-11, 03:33 PM   #875
RickHeid
Lurking Renovator
 
Join Date: Aug 2011
Location: TN
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I have a 3 ton heat pump and it works fine as it is, but I would like to reduce my electric usage as I have already put a 3 kw solar electric system on my house. I put the heat pump in myself and it is only 3 years old. I was thinking I could use it and put a plate heat exchanger in line with the evaporator. My theory being I would first cool the freon with air and then further cool it with the water being pumped through the plate heat exchanger. In my mind this would then reduce the temperature rise of the well water.
RickHeid is offline   Reply With Quote
Old 08-09-11, 03:47 PM   #876
RickHeid
Lurking Renovator
 
Join Date: Aug 2011
Location: TN
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Xringer, I was thinking I would get more than enough thermal transfer in a coil of copper in 10' of my well and the coldest water will be at the bottom. As the copper coil heats the water it will rise and also as we use the pump for domestic water use it wil be replaced with cold water that comes into the pipe at 45 feet. I also would like the coil below the pump so if I have a pump failure it would not be any harder to pull than it is now. Rick
RickHeid is offline   Reply With Quote
Old 08-09-11, 06:10 PM   #877
Drake
DIY Guy
 
Join Date: Jan 2011
Location: Mpls,MN
Posts: 315
Thanks: 2
Thanked 17 Times in 17 Posts
Default

Interesting concept. As AC points out calculating output won't be easy. If well is used for potable water any feed back line to well may not be allowed or desired because of possible contamination.
Drake is offline   Reply With Quote
Old 08-09-11, 06:15 PM   #878
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts
Default

Quote:
Originally Posted by RickHeid View Post
I have a 3 ton heat pump and it works fine as it is, but I would like to reduce my electric usage as I have already put a 3 kw solar electric system on my house. I put the heat pump in myself and it is only 3 years old. I was thinking I could use it and put a plate heat exchanger in line with the evaporator. My theory being I would first cool the freon with air and then further cool it with the water being pumped through the plate heat exchanger. In my mind this would then reduce the temperature rise of the well water.
A 3 Ton heat pump...

That would be 3 x 12,000 = 36,000 BTU/hr

I don't know what the SEER rating is of your unit, but I would guess that your unit consumes somewhere around around 5 KW/hr, or 160% of your solar system's peak output.

If you were to compare your AC heat output to your well's ability to absorb heat, if it were a closed-loop grouted borehole, it might be able to absorb about 9,600 BTU/hr or about 25% of your heat. And as you suggested, it might be able to do somewhat more, depending on your water flow rate. (This is where it is important to know your continuous flow rate.)

Be mindful that if you wish to use an open water source, the inexhaustible particulate supply in the water will eventually cause fouling in a plate style heat exchanger. Usually, tube-in-tube or tube-in-shell exchangers are used in this application because the spaces between the plates in a plate exchanger is pretty small, and therefore easily fouled.

There would be a bonus for you in that the cooling water, which would get warm, could be utilized as part of your domestic hot water, if you had a preheater tank ahead of your hot water heater.

So, there are plate collectors (or tube-in-tube collectors) that are called de-superheaters that are placed as you suggested in the condenser part of the circuit, and are for pre-heating water.

If you are wary about all this DIY, you might contact the company that installed your heat pump and ask what they would charge you to install a de-superheater.

Here's a link to a site from Alabama that discusses this technique.

-AC_Hacker
__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...

Last edited by AC_Hacker; 08-09-11 at 06:23 PM..
AC_Hacker is offline   Reply With Quote
Old 08-09-11, 06:27 PM   #879
RickHeid
Lurking Renovator
 
Join Date: Aug 2011
Location: TN
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Default

AC Hacker, I am a DIY guy. What is a contractor? I put my own heat pump in. This one was easy as it is a package outside unit. My first house and heat pump installation was a split unit. I am an electrician by trade but have yet to find anything I couldn't do myself and I am 56 years old. However, I do research and try to learn all I can about a job before I do it. It was harder pre-internet. I can't tell you all the times someone has thought my stuff wouldn't work only to be wrong. Only thing is, I can't defy the laws of physics. I am prety sure my idea would at least improve my HP efficency.
RickHeid is offline   Reply With Quote
Old 08-09-11, 08:59 PM   #880
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts
Default

Quote:
Originally Posted by RickHeid View Post
AC Hacker, I am a DIY guy. What is a contractor?...
OK, full speed ahead!

So my 9,600 BTU/hr (minimum) would be a reasonable starting place for sizing the de-superheating heat exchanger.

If you start hunting heat exchangers on ebay, many of them are specified for water-to-water. So you'll need to find out what the refrigerant-to-water heat transfer rate will be... it will be substantially less, because water has an amazingly high ability to transfer heat. This means that the HXs will need to be bigger. You can find tables that specify refrigerant-to-water transfer rates this will make your task easier.

I don't know if you've ever worked with refrigeration, but I strongly advise you to start with something smaller, much smaller... to get your bearings. There are many air conditioners and de-humidifiers around, and you could hack one or two of them to get your tool set and skill set together before you hack into your home system.

Best of luck,

-AC_Hacker

__________________
I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote
Reply


Tags
air conditioner, diy, gshp, heat pump, homemade

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:02 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design