PAC 4" to 3" exhaust

[dantheman]

hi all.. will i have a problem running the 4" exhaust from the Portable Air Conditioner (dripless) through a 3" inch hole in the outside wall, about 12" length, using a 4" to 3" adapter?

There are no windows in this cold cellar and the intake pipe on the other side is a 3" ABS through the outside wall with an identical 3" ABS the opposite outside wall (that i plan on using for exhaust of said PAC).

Thanks, Dan

[Steve]

Gotta love ethnic engineering

[Real Pisser]

Don't hold back; SAY it like you WANT to :

supposed to be healthy for the USA, he says

[Stormin Mormon]

Yes, it will reduce the air flow.

[dantheman]

Hey--good to hear from you again.. been a while :)

I know the airflow will be reduced; my question should have read "would the amount of airflow restriction make a significant difference?" Or.. will it still work just not 100% effecient? More like 95%? It's such a tiny space and i only really need it to be cooler and drier during the summer which, up here in Toronto, is quite short. But brutally Hot and Humid (and beer affecting) for those two weeks.

Okay i don't feel like taking it all apart and drilling those two holes an inch bigger etc. Ya Ya i'm getting lazy.

So.. big difference or negligible?

Thanks, Dan

[dantheman]

The Cellar is located under the front landing and is 10ft x 5ft with an extra 4ft x 4ft (with sloped ceiling) under the front steps.

Two 3" ABS pipes through the masonary walls, one at each long end of the 10ft x 5ft part. One ABS pipe extends down near the floor. This design came from an article written by some "expert" in home renos and was supposed to provide airflow for the little cellar and bring cool air in (from the pipe that goes near the floor). I even installed the more expensive wire-shelving so that air could "flow" through the shelves.

There is no "wind". In fact, so little air flowed that i installed a bathroom fan vented out one ABS pipe (the one with the opening near the ceiling) to encourage airflow (I had some mould growing before i did this last year and since it has not returned. However, the little space is at least 75%-85% humidity during this hot spell and 21 deg C.

It's 66 sq ft. Low ceiling. Fully insulated on the basement side with a proper heavy, insulated exterior door with all the weatherstripping. I just want to cool and dehumidify the tiny space during the summer. The wine likes it better that way.

Does any company make a tiny little PAC with 3" exhaust? I can't find one--just a 7500BTU unit with 4" venting. I already tried a regular dehumidifier but that creates a lot of heat.

It's just a closet.

Thanks, Dan

[Stormin Mormon]

My guess is negligible. With the reduced air flow, the condensor will run hotter, and the amperage draw of the unit will go up. But, it sound worth the extra effort, for the comfort.

[Stormin Mormon]

I've met my share of people who hack something together, and think I should come fix it for cheap. Really amazing, sometimes.

[Zyp]

Ok Dan, I'll give it a try;

Let's say your space is 10ft x 5ft x 7ft = 350 cu. ft. And lets say you need to ventilate your space completely 9 times an hour, so that's 3,150 cubic feet each hour, which requires 52.5 cubic feet per minute to ventilate - . Let's look at most blowers and what they can move, generally speaking, at 1/10" static you would need about 7" dia, at 1/2" static about

3" - 4" which is where you're at. So, if your blower can produce 1/2" static pressure, you can move 50 cfm approximately. [That's assuming per 100' of resistance in duct. Which you have much less.... ]

If you want to dehumidify an area, you need to remove not only the humidity, but the heat generated through the heat of compression as well. So good luck - if I were you, I'd call a local, competent, licensed, insured, and trained professional.

[dantheman]

Thank you for the information. I found a DeLonghi Mini-Split Portable A/C unit that has this small umbilical between the outside and inside unit (1" x 2.5"). However, it looks like overkill--11,000BTU rating-- something that is made to cool a large living room, not a 350 cu. ft. cellar space.

It's only 4yrs old, i saw it working fine, and he only wants $200 for it.

But will it work? Or will it cool too fast to dehumidify?

Again, always appreciate the information provided by the competent, licensed, insured, and trained professional hvac enthusiasts here on this newsgroup :)

Dan

[dantheman]

I assume that the mini-split unit is balanced and that the 50 cfm exhaust bath fan is enough to circulate? Obviously, i don't know what Static Pressure is.