We installed one of these in a DIY van and it's working great. It took a good deal of research and careful installation to make it so. You'll need to swap out the fuel lines and perhaps buy a solid base for it. We also bought an exhaust extension and upgraded the air filter. The mufflers corroded out in the first year, but the unit does the job. We needed to buy this size to fit under the seat of our van. It warms the van well at cold temperatures. I believe it would bring the van up to chilly at sub zero.