posted 8 years ago
Kirk, last fall I built a well pit in Colorado to keep well equipment from freezing. Mine is 5x5x6 like you are thinking. However I put 18" of foam on top then about the same depth of dirt. Access is thru a shaft alongside with foam plug at ceiling level. Floor is gravel, walls 2x6, ceiling is 4 quad 2x6 beams. The space inside is definitely tight, I have pressure tank and carbon filter inside against back wall and I can move around to work pretty well. My pit was 50 degrees in mid winter during 5 degree period. So some things I would say, 1-hopefully your well is not going to terminate in the pit, danger of contamination and is illegal in most places. 2-I love the gravel floor, especially when I drain my irrigation lines, I just drain onto gravel ant the water drains away. 3-even though it keeps warm from ground temp, it's very humid, so concrete block walls would be better, I would be sure to compact backfill in small lifts so there is not excessive pressure on walls. I have one place where there is some bowing. 4-plan on having a catastrophic flooding event and keep that in mind during design. I had a pvc male adapter attached to the pitiless crack, and the water traveled the 10' along the pipe into the pit and filled it with water while I was away. Ruined the Franklin subdrive and blew breakers. When I got back the pit was dry, I moved the subdrive out of the pit after that. 5-not sure what batteries you are planning on using, but I think they should be vented, hydrogen released during charging?? And they probably wouldn't like being flooded. 6-if you have a shed over the pit, maybe consider insulating the floor to save ground heat in the pit. Just to be extra safe, I put a small heater in my pit plugged into one of the thermostat blocks that turns on when it senses a fixed cold temp. Mine was $12 at a big box store. 7-I have electricity run Into my pit, all in conduit In case there was flooding and had to replace burned wires. All circuits have gfci breakers back In the electrical panel. Hope this helps
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