I have a Zero Breeze Mark II with two batteries and a 24v to 12v inverter to plug into a cigarette lighter or the ability to connect it directly to a 12v battery source. I live in Austin, TX and got this with the possibility to be able to camp in Texas during the summer, as temperatures are usually over a 100F. I've used it on my back porch, in my garage and in an alu-cab RTT and an iKamper X-cover. It makes the difference of sweating while you sleep or not sweating. It will only reduce the temperature by 25 degrees at most, the big difference is you can have the output pointed directly at you which will make you feel much cooler.
On the back porch when it's over 100 degrees I set it on a table next to my chair pointed directly at me, it makes it bearable to sit outside for extended time, like watching my puppy play in the kiddie pool.
In an unairconditioned garage, it will not cool down a small two car garage that is uninsulated, (I let it run overnight just to see) but it does help if you are working on a vehicle and it's pointed right at you. Much better than just having a fan pointed at you.
For the above two it's a luxury and I don't think it's worth the investment, a window a/c in the garage is much more effective and much cheaper.
In the Alu-Cab RTT with all the windows closed it will cool down the tent and keep it cool even during the day with sun bearing down on the tent, but remember, the Alu-Cab has closed cell spray foam in the top and bottom and very thick fabric walls. It doesn't just make it bearable, it makes it a great place to sleep and I don't wake up in a pile of sweat and have to air out my mattress and sheets.
In the IKamper X-Cover it is not powerful enough to cool down that much bigger tent with the sun bearing down on it, but the iKamper has much thinner fabric. At night what makes it better than just a fan with the windows down is it does an awesome job of dehumidifying the the tent, which makes higher temps manageable, again if you have it pointed directly at you, you will get cold. I recently bought iKamper's tent insulation, I will try the zero breeze out this summer with thee insulation layer installed and I have a feeling it will be working as well as it does in the Alu-Cab.
To me it's worth the high entry price, because I don't mind going on a short weekend trip in Texas during the summer, which before this, I always travelled out of state to go camping during the summer.
I realize it won't be worth it to everyone, but I'm also the guy that brings a Mr. Buddy heater along during the winter.
