Oh, that reminds me of the largest dust bunny nest I have ever encountered.
Apparently, back in November when my son lost a calculator behind the dryer, his successful efforts to retrieve it with a broom knocked loose the dryer vent. Our clothes dryer has been venting heat and lint behind the dryer for months!
The dryer began to cycle its thermal overload circuitry, today so I had to pull it out to check things out. I found more than a grocery bagful of compressed laundry lint wedged behind the dryer. We are talking - Major Fire Hazard! The whole area had become so plugged with lint that the unit was no longer vented at all.
I see now why the clothes were taking so long to dry and why the dryer, which vents into a corner of the garage, did not seem to heat the garage during the winter.