NOTE: We hit the limit for number of posts in a single thread. Continued in Subterranean Heating/Cooling System - Continued. Waterstar, good news about the water pipe. I have been trying different layouts on paper. Below is my latest draft showing a single level of pipes. There are two systems for each greenhouse, one for the internal heat sink and one for the outside. The outside system is intended for greenhouse cooling when the inside heat sink has reached capacity. Both return the air to the original greenhouse. The intake plenums are now in the north corners farthest from the doors. The outside systems each have a single exit from the greenhouse through the lowest level of the greenhouse foundation wall and two return entries. There will be underground plenums on each side of the holes in the foundation wall to facilitate tubing attachments at the different levels. We are planning on using plastic totes for the underground plenums. Estimated tube lengths is 16 feet. 6x16=96 feet. The inside systems will have three tubes on each level with a tube under each growing bed and one under the walkway. These will continue into the central shed area and loop back to exit on the north side of the greenhouse near the door. Since the foundation wall under the greenhouse doors does not need to support much, multiple levels can have sideways blocks. Estimated tube lengths is 22 feet. 9x22=198 feet. 96 + 198 = 294 feet of tubing per greenhouse. The estimate from the SHCS calculator was 120 feet of 4" tubing for each greenhouse. I will use 4" for the outside systems and maybe 3" for the inside since the space is limited and the length is exceeded. The pipe levels for the east and west greenhouses will probably be offset by 6 inches in the central shed area. However, there are three places where the pipes for a single greenhouse cross. Should I put an air block between the pipes where the pipes are too close? How close is too close? Thanks in advance for your feedback. Anna NOTE: We hit the limit for number of posts in a single thread. Continued in Subterranean Heating/Cooling System - Continued. This post was edited by Annalog on Thu, Apr 3, 14 at 7:27

RE: THIS ENTIRE THREAD Maybe Obama will rescue our economic and social quarrels for 'everything' LOL... An economics professor at a local college made a statement that he had never failed a single student before, but had once failed an entire class. That class had insisted that Obama's socialism worked and that no one would be poor and no one would be rich, a great equalizer. The professor then said, "OK, we will have an experiment in this class on Obama's plan". All grades would be averaged and everyone would receive the same grade so no one would fail and no one would receive an A... After the first test, the grades were averaged and everyone got a B. The students who studied hard were upset and the students who studied little were happy. As the second test rolled around, the students who studied little had studied even less and the ones who studied hard decided they wanted a free ride too so they studied little. The second test average was a D! No one was happy. When the 3rd test rolled around, the average was an F. As the tests proceeded, the scores never increased as bickering, blame and name-calling all resulted in hard feelings and no one would study for the benefit of anyone else. All failed, to their great surprise, and the professor told them that socialism would also ultimately fail because when the reward is great, the effort to succeed is great but when government takes all the reward away, no one will try or want to succeed. Could not be any simpler than that. =========================================================== (I'll write to him tomorrow, cough). Is it just me, or does this sound very familiar to the tune of this entire thread? Dax

Thanks Dandylioness! I'm not the best person to ask about "wicks" but I can give you a simple (non scientific explanation,lol...) I use a piece of yarn although I'm sure anything similar will work like a piece of cotton string, an old shoe lace. I insert it through one of the hole in the pot and it helps remove the excess water (perched water) that always seems to pool on the very bottom of the pot. This way, when we get a lot of rain, it helps drain it...Hope that made some sense :o) Here is a link that might be useful: Here's a picture...I believe it belongs to AL

All the air has gone to the third floor. If you are able, hook a garden hose to the purge valve for that return line and put the end of the hose out a window which is higher than the top floor. Purge until all the air comes out. This is a simple way to do it. Also, make sure your pressure is at least 13#.