20100526
Posted to the Yahoo SolaRoof Forum
Hi John,
There is no misconception. You have the right understanding - a Sola Roof with both the Bubble Tech and Liquid Solar processes operating in the Cavity Space of a DIY Tunnel Greenhouse will keep the environment under control for both temperature and humidity. This is because the inner cover will be held at the Liquid Film temperature, which holds the peak mid-day temperature at a steady state that is at maximum about 25F over the source temperature of the Soap Liquid Tank (and thermally coupled Liquid Thermal Mass). Therefore, a 50F start temperature can limit maximum greenhouse temperature to 75F to 80F.
I operated several full scale test units in the Lab, small scale Back Yard Project or two, and more than a couple large scale operational field projects that incorporated both the Bubble Tech and Liquid Solar processes. At the Sola Roof Yahoo Forum you can check out the file in the Photos section: Nelson Thermal Data
Trickle cooling with low temperature well water is extremely effective as can be seen in the slide showing "summer data". This stuff is as interesting and unexpected as the results with dynamic Bubble Tech. Larger liquid thermal mass systems and night chilling would enable low-energy cooling in the hottest and most solar intense climates. You can join a deeper discussion of the Liquid Solar process of heat capture, removal, storage, use or rejection at the Sola Roof Wiki. For technical people you could look at the page: Hot Roof Problem.
All conventional roofs get hot in the sun. A transparent roof also is hot - especially a double glazed system (120F or more) - so, without our dynamic "water working" methods a solaroof would also be hot. Plants grow best under a "cool sky" temperature - so the water cooling of the Sola Roof is a powerful mechanism - keeping the apparent "sky temperature" at about 70F - same as tropical sky temperature. Therefore the Sola Roof is a heat sink and all heat transfer mechanisms flow the solar thermal energy (radiative, conductive and phase change of condensation) to the cooled inner skin. Again, it is not rocket science any more than the Bubble Tech - we are just sprinking the relatively cool soap solution liquid up into the roof cavity space. During the winter day this same system cools and captures the solar warmth (at low temperature) but the Bubble Tech can make good use of this low temperature energy over a cold winter night.
I expect that with a bit of collaboration we can share a great DIY Kit and many of our members could build at multiple sites this summer. Lets put our heads together.
DIY Food - its radical - thanks for believing, Rick (Sola Roof Guy)