Hopefully this review is useful for other, it was hard to find real examples of use like this to get an idea of how well this unit will heat my space. I am heating a 21'x33' garage with an 11' ceiling. Walls are insulated at about an R15 but ceiling with unfinished attic above it is not insulated. Overhead garage door is insulated.Here's the data:Outside temp: 28FGarage Inside temp when heater was turned on: 40F30 minutes after heater on inside temp: 53F1 hour after heater on inside temp: 59F2 hours after heater on inside temp: 65FThe heater was able to get the temp inside the garage up to 70F after about 2.5 hours after not being used all day with an outside temp of 20F the other day as well and it keeps things very nice and comfortable.I cannot speak to reliability as I just purchased, but installation was easy (check Menards for their category 3 horizontal venting kit as it is half the price of the manufacturers kit), and the price was insanely good compared to all of the other options. I was quoted $3500 installed for other brand units from several different local HVAC companies and I was out the door installed (had a local company do part of the install) for around $900 total. I put the unit up and ran electrical but had the installer do the gas line and vent kit install.Since the unit was so inexpensive, I did add the 4 year Amazon protection plan. Hopefully it lasts a long time but if it doesn't, at least it will be easy and free to replace.All in all a good value and it gets the job done.