If your habits are like those of most homeowners, you have at least a single portable gas furnace or air conditioner being stored in the garage, attic, or cellar. The people I was with and I all purchase such heaters or a/c units for temporary use and then want to keep them, “just in case”. The issue with storing them in these places comes when time, temperature, and even pests invade them without our knowledge or permission. If you store a window air conditioner, for example, in the cellar, you may end up with mice, feral cats, and other pests using it as a place to live. The layers of insulation make for a cozy place the hang out and the casing keeps them safe from others who want to harm them. You may suppose that all is fine, take it out and plug it in, and find that it doesn’t operate like it should or that the electrical components have been all mangled up, making it a fire hazard. You have no way of knowing that it has been used as a residence for these inhabitants. If you do keep these items for years it is pressing that you have them inspected ahead of time before assuming that all is well, and your local Heating and Air Conditioning contractor often offers a service that enables you to drop off portable units and have them cleaned and checked out to make sure they can be safely used. You should understand, though, that these fees can be a hundred dollars or more. In some cases you many just decide to go get a new one. Either way you choose to handle the issue, the few bucks you need to spend are insignificant when compared to the safety and comfort of your lake house and family.