Wow! This heater is amazing. After much debating my husband and I decided to go with the Happybuy heater instead of the much more expensive espar. We were skeptical at first but figured $150 wasn't a huge investment if it didn't work out.We spent a couple days getting it installed in our t1n sprinter and have run it a handful of times now. When we first used it there was some white smoke but after running it on high for about an hour or now burns clean every time.We have this heater wire to the 12v on our goal zero lithium yeti 1000 and it works great. The power draw is not a problem for our 100amp hour system. We ran it all last night on low and it kept our van at a very comfortable sleeping temp. We could run it at a higher setting but honestly it can get to hot. We also used a high efficiency aerogel insulation in our van so depending on insulation some people might run it slightly higher.If you've been considering this heater but were worried about it not measuring up to the espar or webasto I would say this is totally worth the buy. For $150 you really can't go wrong