We use the WHO-175 heater mainly on construction sites and have not had any issues within the last 2 months. The device works perfectly. It has proven especially beneficial during construction outside on the scaffolding. We place it under the scaffolding so that heat can move evenly from below and heat the entire side of the building. In the construction of private houses, we use it to keep the interior warm during interior finishing works. At first, our biggest fear was the construction dust which could ruin the device, but experience has shown us that if you clean it with compressed air in a dusty environment more often, then it works perfectly in those conditions. Very economic, especially compared to a diesel cannon, and emits more warmth without creating a draft in the room.
We use the heater on construction sites and move it to different rooms when necessary. Dusty conditions have not proven to be a problem if you clean the device once in a while. We purchased the Weltem WHO-115 model, because at first we wanted a device that was not too big and one that would be easy to move. The WHO-115 model does its job well, but we have understood that in our conditions we could actually use an even bigger and more powerful model.