We live in the mountains and it can get cold in our home at night during the winter. As energy prices are climbing I have been looking for ways to cut our energy usage while still keeping our pets comfortable. I already had 2 of the 11x40, 150 Watt units that have been great; 1 for some peafowl in a barn and 1 for our indoor Blue & Gold Macaw. I purchased 2 of these smaller units for our indoor cockatiel & mini macaw. As others have said, this doesn’t put put a lot of heat. But birds like to sleep on the highest perch, so they will be close enough to this unit to feel the warmth & be comfortable. I would not recommend this for an animal that needs more heat like most reptiles.With the 2 larger units I had to let them run for about 2 weeks in a space away from the birds so the smell could dissipate. I plugged the smaller units in as soon as they arrived and there’s hardly any smell. I have to get my nose about an inch away to smell it after only a few hours and I have a good sense of smell. I’m going to pre-run it anyway to play it safe but I’m hoping I can start using this before our next cold snap in a few days. For our current needs this small unit is perfect. If you have a larger bird who can’t sit as close to the heater, go with one of the larger ones. And don’t expect a ton if heat. It’s always a balancing act between providing heat and not causing a fire.