And I'm so glad I did! I've been experimenting a little. It was on our deck. the night that I moved it - the temp on the deck was 31 degrees. I moved the unit into the coop (it's at the end of a roost, so same level as the girls), and the coop temp that night only got down to 42 degrees! Perfect! So, last night was about the same temperature wise. But, when I went out to open the pop door this morning, I noticed that I had forgotten to close the window last night. So even with the window open all night, the temp didn't go below 40 degrees! (It remembers the high and low temps over a 24 hour period). This is good for 2 reasons. I don't need a heat lamp on cold nights, AND it tells me that there isn't a draft on them (cuz the temp would have dropped sometime during the night). So when I open the big vent for the summer (I have a panel screwed over the big vent for winter), I think I'm good - it's even higher than the window - and bigger.