"The SHCS relies on a hybrid earthtube and rock bed latent
heat storage system. The system uses a matrix of four inch
slotted pipe buried in a rock bed that is constructed under
the greenhouse structure. The total volume of greenhouse air
is circulated through the pipe matrix 5 times per hour
at a flow rate of 2 to 4 feet per second and latent
heat is stored in the rockbed. This is a very innovative
process in that it uses additional heat energy released
during the phase change from water vapor to liquid.
The SHCS will be used year round to help maintain a more
constant temperature in the greenhouse.
If a temperature differential in the 20-30F range is
maintained between the rock bed and the water vapor
saturated greenhouse air, phase change occurs and heat
energy is released and stored in the greenhouse rockbed
foundation. The SHSC system pays for itself by
significantly reducing the amount of fossil fuel derived
heat used in cold weather crop production."