You guys may or may not be interested in this. I'm currently tweaking a prototype thermoelectric heat pump I designed and built from basic HVAC components and a thermoelectric chip (TEC). In the world of off-grid living, we can only afford to run a costly (power-wise) window air conditioner or conventional dehumidifier on a very sunny or windy day, and even when trying hard to keep the window opening sealed, it's often self-defeating. I needed something that could run almost continuously if necessary and maintain the integrity of our tight building envelope. The primary goal is dehumidification with cooling secondary. For efficiency and reliability, DC is highly preferred. And for self-reliance, simplicity and minimal moving parts is highly preferred. A thermoelectric chip fits the bill perfectly. It is a solid-state device kind of like an LED which uses the Peltier Effect to cool one side and heat the other. But there are no commercial thermoelectric air conditioners, so I had to build my own. This is the prototype. It contains extra sensors, controls, and visibility for testing purposes. My production model will be opaque from the outside, will be controlled by a remote thermostat, will contain a larger TEC, and will be better insulated. Now that the proof-of-concept is complete, I'll be fitting my house for the necessary wires and ducts to install several production models in different rooms. By way of comparison, the smallest window air conditioner you can find in Walmart/Sears/Home Depot/etc puts out about 5000 BTU (nominally, anyway, but much of it may be wasted), draws about 500 W (EER of 10), runs on AC current (which ups the total wattage due to inverter losses), uses a compressor and refrigerant, leaks air around the window opening, and is a security hazard. My thermoelectric air conditioner puts out perhaps 100-200 BTU (the demo/prototype model here wastes some through the plexiglass window), draws 82 W (although the demo/prototype model here is wasting some for the flashy lights and sensors), runs on DC current (efficient from the house batteries), uses solid-state components with minimal moving parts (only DC computer fans), exhausts air efficiently though vents, preserves security, and requires almost no maintenance. That's a pretty poor EER (around 2), but the advantages outweigh the disadvantages. Now, 82W of cooling won't do diddly squat for most homes -- it would conventionally cool about 4 sqft. But for a very tight and well-insulated one, this is sufficient to make a bedroom or office comfortable. I'm installing my prototype unit in my utility room to keep the moisture down and to keep the heating system from over-heating the computer servers. I'll also be using my experience in creating these units to design my walk-in refrigerator's cooling system. It will have R-50+ insulation and require minimal cooling.