Opening windows can bring in pollen, dust, humidity, noise, and a lot of energy loss during cold winters and hot summers.

In a bedroom it might be worse than the elevated CO2 problem.

That’s a bit of a dramatic way to describe opening a window.

	▲	joezydeco an hour ago \| parent [-]
		I've been designing my own ERV system for the house and have been weighing all the options, so I had this list in my head. Nothing dramatic, just the reality. We have allergies and like sleeping in a cooler bedroom.