Wednesday, March 24, 2010

Juwel 1000 Cold Frame: Temperature Testing Research Part 1

A while back I was given a Juwel 1000 and this spring I finally got around to testing it out. The current temperatures over the last couple of days have ranged from about 20F to 55F.

To start with I've placed the Juwel 1000 on my back porch. It is a wood deck type porch that is currently surrounded by snow and has ventilation through the floor. With this setup the cold frame is not sealed on the bottom. Over the last couple of days I placed one of my Thermachron sensors inside and one outside and created the temperature graph above. The maximum temperature difference was 21.6F and the minimum was 0F. The maximum temperature inside was 83.3 and the maximum outside was 63.5. Minimum inside and outside temperatures were 23 and 21.2 respectively.

I have plans to put it on top of a simple plywood box that will house some containers or hydroponic systems, some water containers as a heat sink/stabilizer, and a light bulb or a small heater hooked up to a thermostat. I'll post the info when I get it set up.


Greenhouses Kits said...

Nice review on Juwel 1000, thanks for sharing this information, it is very useful to me.
But I don't understand to read the picture. Would you please give a little explanation of what that picture means?

Aaron said...

The blue on the bottom of the graph shows the difference between the inside and outside temperatures. Whereas the red and green lines show the actual temperatures. Basically it shows that without any heat sink the cold frame cannot maintain a warmer temperature.

When the outside temperature gets above 40 or 50 degrees the temperature inside the cold frame increases significantly.