• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • r ranson
  • Nicole Alderman
  • Pearl Sutton
  • Anne Miller
  • Burra Maluca
  • Joylynn Hardesty
  • Mike Haasl
stewards:
  • James Freyr
  • paul wheaton
  • Jocelyn Campbell
master gardeners:
  • Steve Thorn
gardeners:
  • thomas rubino
  • Carla Burke
  • Greg Martin

Cooling a tiny house with well water

 
pollinator
Posts: 260
Location: OK High Plains Prairie, 23" rain avg
45
homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The cost of getting electricity to my 20' shipping container is prohibitive - $15000. 95F seems to be the summer temperature for about 3-1/2 months. I can insulate the outside of the container with spray foam insulation and a radiant barrier and cladding. I can face the container East with it's back to the West or North so there is less wall exposed to the afternoon and sunset heat. I can put it on an East or Northeast facing slope to give some protection from the western sun. Possibly I could dig down into the hill a few feet to also protect from the west sun. The well will have to be overhauled but the other well on the property is 200' deep so the water is cool or cold in summer. Would it be very complicated to use the well water for radiant cooling in the floor and perhaps in a wall? How would this be done? After I get the cool out of the water I can run it into a tank below me for livestock.
 
gardener
Posts: 3063
Location: latitude 47 N.W. montana zone 6A
701
cat pig rocket stoves
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Denise;
Well, I like all your ideas of insulating , cladding , partial bury, using slopes to protect from the hot sun. Adding porches to keep the sun off the container. Planting trees for future shade.

What I wonder about is, cooling with water.   I believe you are in a high humidity area?  A swamp cooler comes to mind , I know they work great here with 20% humidity, but I do not know how well they work in high humidity.

Myself I would look at Solar panels. Enough panels with a pair of 6 volt battery,s on a sunny day, will run a small A/C wall unit. And lights , charging station, music, tv ...   can you tell I've been off grid for 37 years...

Here is a link for solar panels.      https://www.ebay.com/itm/1-180-Watt-12-Volt-Battery-Charger-Solar-Panel-Off-Grid-RV-Boat-180-watt-total/272812576939?ssPageName=STRK%3AMEBIDX%
That is less than a dollar a watt. I've bought numerous panels from this supplier.
 
Posts: 61
Location: Northwest Missouri
21
forest garden fungi gear trees plumbing chicken cooking ungarbage
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
In this case I think you'd actually do your radiant cooling in the ceiling. Heat rises, transfers energy into the cold water flowing through your coils, and that is whisked away. Tricky to time your flow rate, pumping, and then determine tank size and where the overflow would go, if any. You're on the outskirts of practice and theory here I believe. There are more established technologies like swamp coolers, but I'm curious what others have to say on the subject of radiant cooling!

Digging your home into the ground, growing shade plants like trees or annual vines, things like that will be more reliable with no moving parts.  
 
Posts: 608
72
duck forest garden fish fungi trees food preservation bee woodworking
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Depending on where you are, (in temperate areas), your ground water is somewhere between 45 and 55 degrees (F).  Water takes a lot of energy to heat up, so, yes you could use your well water to cool your house, depending on the size of the house, how tight it is, and how much water you can pump up.  

First you have to get the water up from the bottom of the well (solar or wind, I'm guessing).  Once you do that, if you just run it in a long looping route in the house and it should suck up heat.  It would probably cool more effectively if you mount it up higher than the floor.  Heat rises, cold sinks.  If you cool the floor, your feet may well be cold before your head stops sweating.  Cool at ceiling height and you cool the whole room.

The main things to consider are surface area and air flow past the cold line.  The greater the surface area, the better the cold can absorb heat.  The greater the air flow, also, the beter the cold can suck up heat.  (think of a car radiator, lots of air flow, lots of surface area, except with a car, it's doing the opposite, the water is giving heat up to the atmosphere).  

You could get some scrap radiators, stacked one in front of the other, with a fan moving air through them.  (using what you can find, Automobile, Old drained A/C units, fridge radiators).  The cold water should feed into the radiator furthest from the fan, then feed the others.  Another alternative might be mounting them a few inches below the ceiling, parallel with the ceiling.  That way as air cools, it will drop down and make a natural air convection.  

POSSIBLE PROBLEM WITH THIS SUGGESTION:  People used to poisoned when unscrupulous bootleggers in the 30's used car radiators to make whiskey, but I'm pretty sure that was because the alcohol and maybe some small percentages of acid leached lead out of the radiators and put it in the whiskey.  I'm 85% sure water would be ok, once the radiator is well flushed out. Might not hurt to double check on that, if you're going to drink it)

Now that I think of it, it may be easier to break down and buying as many finned hot water radiators made for a house as you think you'll need.  (the kind that are behind a baseboard on the wall).  Only, since you want them to cool instead of heat, I would mount them up high, and maybe a few inches from the wall (condensation on the wall might be a problem (otherwise).  My WAG (wild assed guess) is that you might want a little more to cool than you would use to heat a house of similar size, if you were using hot water heating).

If you are pumping fresh well water through the system, a radiator may eventually clog up with mineral deposits.  (warming and cooling water changes it's carrying capacity for different substances, and I'm not sure off the top of my head if heating it up would increase or decrease it's capacity.  If it decreases it, it may lead to mineralization.  You might check on that.).

Where are you at?  If you're in a humid area, cooling the air might lead to mildew and mold issues.  You will at least get water dripping off of you radiators, which is simply a problem to be solved.  In a very dry area, as was mentioned above, some kind of swamp cooling system might works well.  (If you have a hot, dry breeze blowing through a window, pumping water up and letting it trickle through a loose mat or something the breeze blows through in front of a window will give you a very creditable swamp cooler imitation).
 
gardener
Posts: 3048
Location: Central Texas zone 8a
665
cattle chicken bee sheep
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I wonder how effective it would be to just run a sprinkler on the building itself. This would require the foam to be inside, not out. That along with shade might go a long way
 
pollinator
Posts: 3479
Location: Kansas Zone 6a
58
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have done some research, I am planning something similar-but I have springs I can use.

Radiant cooling can be done in the floor or ceiling, but ceiling is more efficient for cooling. Floor can be used for heating, though.  Suppliers say to use twice as much tubing for cooling as for heating, with shorter runs per loop or bigger tubes. This is to keep the temperature even.

NEVER let a floor get below dew point! Commercial buildings use fancy thermometers or internet weather apps to control this.  I was planning on never really cooling the floor enough for that to be a problem.

I am going to have a two stage system, the spring water going into an insulated holding tank with heat exchanger to keep the loop water separate.  That is so I can run enough water through the loops to keep the temperature even, that pump will just run all the time, and the amount of spring water brought into the tank can be adjusted to control the temperate.

There are rules on returning well water back to the aquafir, food grade and failsafess and such, but I wouldn't mess with it.  

There are now solar AC solutions that could cool a well insulated container for less power than a 200' well pump.  I would look into those first if I were you.  I am probably going to use them because I need a dehumidifier.
 
pollinator
Posts: 2721
Location: Massachusetts, Zone:6/7, AHS:4, Rainfall:48in even Soil:SandyLoam pH6 Flat
221
forest garden solar
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
60F well water will cool you 95F house to a comfortable 75F. You just won.
Unfortunately 95F with 70F humidity has a dew point of 83F so at 75F all the water in the air will condense on your floor/walls/ceiling (imagine the outside of a tall glass of icewater). This condensate equal mold and rotted/ruined clothes/furniture/etc. This is why AC units have drain pan or why window unit AC always have water dripping.  

Personally I would make a fan-coil unit (fan+radiator) and a drain pan to catch the water than condensate out of the air.
 
denise ra
pollinator
Posts: 260
Location: OK High Plains Prairie, 23" rain avg
45
homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thomas Rubino Could I bypass the solar panels for now and just used charged batteries? What type of AC runs on batteries? It only has to cool 160 sf.
 
denise ra
pollinator
Posts: 260
Location: OK High Plains Prairie, 23" rain avg
45
homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Here is the humidity chart for the area, perhaps someone can tell me if this is too much humidity for a radiant cooling system or for a radiator/fan system to be effective? In the night I too wondered about dealing with condensation.
humidityx.png
[Thumbnail for humidityx.png]
 
R Scott
pollinator
Posts: 3479
Location: Kansas Zone 6a
58
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
On average you are good, you will have a dozen days a year you have to be careful about condensation.  That also means you are dry enough for an evaporative / swamp cooler to work-much cheaper and lower water requirement.

If I were building a shipping container in the high plains I would insulate well, put it under an RV carport to shade ( isolates from radiant heat better than an attached roof) and build both a swamp cooler and a roof sprinkler system  
 
thomas rubino
gardener
Posts: 3063
Location: latitude 47 N.W. montana zone 6A
701
cat pig rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Denise;   You would need a small inverter to make the A/C power. Harbor freight should sell a small unit that would work for you. Make sure your wall A/C unit  uses less watts than the inverter you chose.
And yes, you could start with a charged battery and no solar input. But your going to work that battery awful hard, it won't last long.
Even one panel, smaller than the ebay model I showed you would help. But your better off with a bigger one.  
 
denise ra
pollinator
Posts: 260
Location: OK High Plains Prairie, 23" rain avg
45
homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thomas Rubino what size AC are you running? Can you suggest a brand or a link please? How many 12 volt batteries do you need? How long will this run the AC?
 
thomas rubino
gardener
Posts: 3063
Location: latitude 47 N.W. montana zone 6A
701
cat pig rocket stoves
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Denise;
I'm not running A/C at all.  We open the house up all night and shut it tight during the day.
A quick check showed window units for cooling as small as 150 Sq FT .
As far as battery's.  Minimum 2, 6 volt deep cycle. The bigger the better. They will need full charging every day to run an A/C unit.  That is why I showed you the ebay solar panels.
How were you thinking of charging them ?
 
 
 
denise ra
pollinator
Posts: 260
Location: OK High Plains Prairie, 23" rain avg
45
homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thomas Rubino, I will charge them with solar panels.
 
I don't like that guy. The tiny ad agrees with me.
Learn Permaculture through a little hard work
https://wheaton-labs.com/bootcamp
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!