The second law of thermodynamics puts the first law into context and establishes entropy as a concept. We can simply define entropy as a state of disorder that can only increase or remain the same in natural processes. Processes in which entropy remains the same are reversible, but ones that result in an entropy […]

Note: My brother Nathan wrote this a few years back, and I only did some minor editing. A pool heat pump is essentially a water-cooled air conditioner in reverse. It usually has a large air evaporator on the outside that looks like a condenser coil and a heat exchanger (usually tube-in-tube) on the inside. A […]

We just wrote about rejecting heat to the atmosphere via radiant cooling. That’s one example of cooling without refrigerants, but there are quite a few others out there. In this article, we’ll look at some other cooling methods that don’t use refrigerants. Vortex tubes Vortex tubes swirl gas in a chamber, separating it into hot […]