# Ah, sweet mystery of air conditioning (dead animal division) **URL:** \ **Category:** Factual Questions\ **Created:** [October 17, 2007, 6:46pm UTC](https://boards.straightdope.com/t/ah-sweet-mystery-of-air-conditioning-dead-animal-division/423063 "2007-10-17T18:46:21Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [October 17, 2007, 6:46pm UTC](https://boards.straightdope.com/t/ah-sweet-mystery-of-air-conditioning-dead-animal-division/423063/1 "2007-10-17T18:46:21Z")
We have heat pumps for both AC and heat. Around the house are several grills covering the intakes, near the floor. They go straight down about 5 feet into the slab and to the units. Outgoing air comes in from grills up high. It is obvious we have some dead animal down there, as the stench started about a week ago and is getting steadily stronger all the time. It must be near the dining room intake, as that is where the smell is the worst. I’ve called a duct cleaning outfit due tomorrow on the recommendation of my AC service guy. I asked both how in the hell any animal could possibly get into this completely closed system. Both had no idea, but said it is not uncommon. Anybody know how any animal larger than an insect could possibly get through the louvers on the grills into the ducts? Judging from the smell, it must be about the size of a horse. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [October 17, 2007, 6:51pm UTC](https://boards.straightdope.com/t/ah-sweet-mystery-of-air-conditioning-dead-animal-division/423063/2 "2007-10-17T18:51:37Z")
I would start by making sure all the grates ARE on and that the system IS sealed. Check around the furnace and by the filter for any openings. Remember, something like a mouse only needs an opening the size of a quarter to get in. ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [October 17, 2007, 7:03pm UTC](https://boards.straightdope.com/t/ah-sweet-mystery-of-air-conditioning-dead-animal-division/423063/3 "2007-10-17T19:03:05Z")
Geoff, check this out: [an episode of DIY Network’s “Finders Fixers”](http://www.diynetwork.com/diy/shows_dffx/episode/0,3110,DIY_27277_45913,00.html) They “fixed” a similar problem last week, but it wasn’t a dead animal, it was sewage > [@](#): > > After a thorough inspection, home inspector Wally Conway finds that the cause of the mysterious smell in Kate Woods and James Donaldson’s home is a leaky sewage pipe in the crawlspace. > > The pipe connection where Kate and her dad tied in during the bathroom remodel has failed and is dripping gray water from the kitchen sink onto the return air ducts. The ductwork has sagged to the ground. Now, whenever the AC system is turned on, return air is sucked across the standing sewage water in the sagging, rotting duct. The end result: the nasty, yucky smell is filtered throughout the house. ---
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [October 17, 2007, 8:21pm UTC](https://boards.straightdope.com/t/ah-sweet-mystery-of-air-conditioning-dead-animal-division/423063/4 "2007-10-17T20:21:14Z")
Thanks, **ZipperJJ** , that’s interesting, and makes me realize I’m lucky, I guess. Having a house on a poured slab is a pain when I want to run wires, cables, etc, but in this case, it is a good thing. All the AC ductwork is put in place, and then the cement is poured around and over all the pipes, conduits, sewer lines and ductwork. Thus, as everything is embedded in solid concrete, it is almost impossible to have the disaster you linked to happen here. In any case, I hope they can recover the animal remains when the get here.