I have a small wood shop 240 square.ft. The G73 as no problem keeping it comfortable 70 during our Virginia winters. I have not insulated my shop yet so the unit has to work at it & has no problems doing the job. I have my unit on a dedicated 220 controlled by a separate on off switch. The installation is very easy. You can find several good video's on YouTube showing how to install the heater. Would I recommend the G73? Absolutely. Another thing about NewAir is it's customer service. They are Outstanding. I had a unit fail shortly after I installed it, believe me I was not a happy camper. I contacted NewAir spoke with one of their techs (Dennis). I explained what happened, he assured me it was no problem. Dennis emailed me a prepaid sticker. I packed up the unit shipped it back & four days later my new heater arrived. The new unit is up and running, the shops warm again and I am not as grouchy as I use to be. Thank you NewAir. J.C. Moore Retired Navy Submariner