Temporarily Convert a "high Tunnel" Greenhouse to "Chinese Solar Greenhouse" for the Winter to Extend Your Season! and Use Less Heating Fuel.

This is my idea to temporarily convert high tunnel greenhouses into "mini" chinese solar greenhouses for the winter season. Then in summer they revert to high tunnels so we can get the best of both worlds.

Supplies

High tunnel greenhouse, aligned east west, reflective greenhouse tarp, straw bales and polystyrene sheets.

Step 1: Start With Your High Tunnel Aligned East West

A high tunnel is normally aligned north south optimized to make best use of the summer sun, the sun rises and for the whole morning it shines on the east side of the greenhouse and then for the afternoon and evening, it shines on the west side so every plant gets a similar amount of sunlight. But for 4 seasons use, it is much better to align it east west, so that although the light won't be so even in Summer, it is easy to insulate the north wall and make it reflective for the winter when produce prices are much higher.

Step 2: East West Alignment Is Better for Year Round Use Because?

In Summer the sun rises in the northern half of the sky. I live at 48.5 degrees north and it spends about 3.5 hours north of east in the morning in June and about 3.5 hours north of west in the evening. But from 22 September to 22 March, the sun spends all its time south of the east west line. So if you put in a temporary insulated reflective wall in a northern part of your greenhouse, you both save heat loss at night and reflect light into your greenhouse during the day. Result? Much warmer climate in the greenhouse! It might not be best to insulate the entire north of the greenhouse, so I see nothing wrong with putting the insulated reflective wall 1/3 or 1/4 way along. Remember, its inside the greenhouse so it doesn't have to be sturdy like outside. It might be as simple as reflective silvery tarp with rows of straw bales behind them!

Step 3: Lots of Reflected Light at North Wall, So Why Not Put in a High Bench?

I don't have a high tunnel, I just have a little greenhouse with a reflective north wall, and a shelf on the north wall. It works! There is lots of light (and reflected light) for the shelf and even reflected light under the bench for the plants below it! So you will get a nice sheltered warm spot both on the bench and below it for the plants to grow great in winter! Lucky plants!

Step 4: Night Blanket and Night Curtains.

Chinese solar greenhouses have night blankets and night curtains. So if possible, you should have these too. leave them open in the daytime then close them to keep in the heat at night.