I am building a set of greenhouses. they will be 2700 sq.ft. each. I intend to grow year round in one and extend the season in the other two with them being dormant for 6 weeks mid winter. We will be using underbed pex tubing under the grow beds and perhaps may run two separate layers, one deep and the other below it to supercharge the soil with increased temperature, beginning in late summer.the goal is to maintain growing bed temperature at 5 - 15 degrees above the air temperature in the greenhouse to facilitate continued growth and production.
I see three individual systems working for each greenhouse with an optional "super tank" filled and heated if feasible and needed to satisfy demand. I realize that heat stored in tanks leads to stratification so I am hoping to position a set of heat exchangers in the tanks to facilitate temperature rise from various sources.
there will be a long solar hot water collector, about 600 sqft oriented S. there will be a number of biochar retorts in a row using common flues for exhaust with a heat exchanger in the flue. there will be wood stoves with water jackets and air heat exchangers for quick warm up and use of available resources. and there will be a ceiling header running the length of each green house to collect and preheat water in this heat cycle.
With multiple retort biomass barrel type processors, and the wide range of temperatures that a heat exchanger will experience inside of the exhaust flue from pyrolysis to wood degassing and combusting those products, what would be a simple way to capture these product of combustion temperatures and put them to good use?
I intend to use 3/4" pex in the under bed systems of less than 400 feet per run. I intend to run the return from each return header in each house to its own tank for pumping. I am at 37 Degrees North Latitude in Missouri. thank you for your thoughtful consideration.