Is a heat pump worth it? Online calculators are a hugely mixed bag with obvious biases on many of them, and installers all want to sell their favorite gizmos so it's hard to get a straight answer from them. [more inside]
posted by maxwelton on Dec 8, 2012 - 10 answers

What type of pump do I need to buy to remove air from an animal cage and deliver it at a controlled rate to an experimental setup? [more inside]
posted by keelyellenmarie on Apr 10, 2012 - 4 answers