Is there a type of central A/C that uses an “air intake” Several news stories about some CO deaths in NY a few months ago have mentioned this: for example, this snippet from the Baltimore Sun:
Dr. Andrei Kranz disconnected the carbon monoxide
detector in his Long Island, N.Y., home last summer because the
device kept going off for no apparent reason and waking the family.
In May, Kranz came home to find his parents, his 3-year-old
daughter, the nanny and two houseguests dead in their beds, all
victims of carbon monoxide poisoning.
Police investigators found that someone had turned on the air
conditioner without shutting off the furnace. The air conditioner’s
intake filter was clogged with leaves, so the cooling system
drew in furnace fumes instead.
I’ve been puzzling over this for awhile; never seen such a beast.