Cool Your Greenhouse With Enthalpy: Part 4

[Jeremiah Robinson]

This post first appeared on coldweatheraquaponics.com

In this final post on cooling, we let you in on a trick that can make a big difference in your summer greenhouse temperatures by getting the sisters - Ventilation and Evaporation - to work together.

The thing to know about them is that they both like hate enthalpy, and want it gone!

Ventilation and Evaporation work together to reduce enthalpy using something called a "climate battery" or a subterranean heating and cooling system. The climate battery fans draw the warm moist air from the greenhouse into pipes buried in the ground under the greenhouse.  Once there, the cool sides of the tubing cause moisture to condense. This dries out the air in the same way that a dehumidifier does.

Check out the video below for a demonstration.

Once dry, the air is primed to absorb more moisture from the water, further reducing greenhouse air and water temperatures.

The magic of the climate battery is that the earth has a near-infinite ability to absorb heat.  This is the principle that ground-source (geothermal) heating and cooling is based on.

At night, if the air temperature drops below the ground temperature then some of that condensed water re-evaporates and the climate battery is recharged.

As a bonus, the system works in reverse in winter, saving you energy then too!

[Jeremiah Robinson]

Hey Jim, I'm with you.  If it were me I'd build it myself.

Agreed that bigger is better, but even a million gallons of water heat up eventually under constant thermal load.  At some point you have to push back.

[Jim Fisk]

Ideal ain't always affordable! That crew and pipes in the first pic don't come cheap. It is ideal however. Penn and Cord just rely on the 50 or so 55g barrels for the battery. A much cheaper approach. On the other hand if I win the lottery I may call that crew in. On the other hand my 2400g system water is close to those 50 barrels in storage volume. AP does have that advantage. Bigger is better in terms of water volume in so many ways.