After some minimal spine damage I decided that yes, maybe I should make the backpack lighter, so here we are. I’m making a new frame from some square dowels and thin basswood. It’s sooo much lighter than the last one. Less than one pound I’d guess.
I put together a simple PVC reservoir and a couple pumps, as well as a small microcontroller board for some rudimentary temperature control. That and a fancy new backpacking frame and we’re ready to rock! Oh, final weight? About 22lb. Yeah- this will definitely not work in the long term. As far as performance goes, it’s very good at keeping you as cool as you want to be, assuming you are properly insulated from the outside weather. Since this unit is for cosplaying, that should be no trouble, since costumes that necessitate cooling are thoroughly insulating. Battery life is about 3-4 hours.
Well, I’ve mocked up a frame for the backpack and it’s clear this is going to be a real monster. It’s fine because I’ll lighten the whole thing later. Looks good so far though. For safety I’m going to use a LiFePO4 battery since they don’t turn into a fireball when things go wrong like LiPo’s do.
A couple years ago I started a project for a Microclimate Backpack, essentially a wearable cooling vest powered by a reservoir of icewater. It worked but was uncomfortable and the wearer risked hypothermia. I found a company online, RigidHvac, that manufactures all-in-one refrigeration units. These only weigh about 10lb or so and can be battery powered. I’d like to convert this into a wearable backpack as a proof-of-concept.
