Saturday, December 29, 2012

black buckets

Mom's greenhouse is a passive solar greenhouse.  The goal is to grow cold tolerant greens and vegetables without a supplemental heat source.  This fall our family completed the tile floor which was the last of the insulating projects.  This allows for our first real winter of  crops.  Our goal is to keep the temperature in the greenhouse above freezing.  We are using containers of water as heat sink.  We have had the overnight temperatures drop into the 20's or lower on some nights.  The seedlings in the planters are still alive but not thriving and growing.  We are adding additional containers of water.

In an effort to improve the heat absorption quality of the water containers used for heat sink in the greenhouse the exposed sides of the containers will be covered with black duct tape.  We currently have 34 yellow cat litter boxes (thanks Lisa and Jack) and 30 new white mushroom boxes (thanks Nathan and Michelle).  Today the new white boxes were covered on three sides with the duct tape.  Each box required three wider strips and one narrower strip of the tape. 

The boxes are placed along the North wall of the greenhouse where the sun can hit them, warming up the water inside.  After the sun goes down and the greenhouse begins to cool the boxes will release their heat, slowing the cooling of the greenhouse.  The yellow boxes still need to be covered and that is a project for another day.  Thank you Caitlin for your help in covering the boxes today.


  1. Looks great! Have you noticed a temperature difference in the water in the black buckets?

  2. I took my candy thermometer out there to measure and it doesn't go low enough. I did check a black box and a yellow box that were sitting side by side and they had what appeared to be equal amounts of water and ice.