# Venting: Portable A/C exhausting to chimney?



## hanfhead (Jun 24, 2009)

I have read all around that plenty of people exhaust 6" can fans to their chimneys, so my question is this.  Are people taking into effect the hot water tank using a draft to exhaust the fumes?  Would that not just pressurize the chimney and blow anywhere it can?

That being said, the amount of air put out by a portable ac is minimal, and it is hot so it should rise up and out.  If I tie into my chimney to blow the hot air up it, where in relation to my other exhausts should I put it?  My furnace is irrelevant because the exhaust on that is electronically shut in the summer and I won't need the ac more than 3 months a year.  The hot water tank is my only concern really, should I put it above or below that?  Any advice would be great, I am sitting here with mortar, chisel, and ducting.  I need to do something today (that kush is stinkin' with a can 66 carbon filter and essential oils and ozone generator) so I'm gonna burn :joint: a few  and hope I get some advice in the next hour maybe 

:ccc:

Thanks in advance!


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## dirtyolsouth (Jun 24, 2009)

Hello Hemp Head!

Ah, yes...  the bane of portable A/C...   where to exhaust?  It's a little tough trying to envision exactly what you have going on.  Are you referring to a fireplace chimney or some type of vent chimney for household exhaust from your furnace and water heater?  Can you post a few pics to help us chime in?

I don't think routing your A/C exhaust to your chimney would cause problems.  Everything going into that chimney is hot exhaust and as long as there are no obstructions it should have no choice but to go up and out...   Can you hook it up somewhat temporary for a test run and either it will exhaust as desired or if there's a problem with flow the heat off the a/c will hit the obstruction and back up into your room...  I guess the main concern would be anything that would let carbon monoxide from the water heater exhaust back up into your house and gas you..? yikes...  I'd suggest whatever you end up with that it's a good idea to get a carbon monoxide detector in your house for safety and peace of mind.

There are a few guys on here that have some experience working with HVAC professionally...  Hey Mindzeye!   Are you out there?  Try posting a few pic's and try to be a bit patient for guys to get a handle on your situation and help out.  Smoke another! 

And that must be a bunch of some super stank kush plants for the Can 66 to need help with the odors...  WOW...   I only have four plants in a closet but as long as my air is constantly being pulled through my 40 lb filter I don't smell a thing with my closet door closed.  Do you cycle the air through your 66 and exhaust it back into the room or is routed into the chimney?  

Peace!


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## hanfhead (Jun 24, 2009)

I asked on some hvac forum and all I got was "why would you want to do that?"  So I figured someone here would know.   Here are some pics.  My furnace would be in between the two pictures. I would be running the ac exhaust past my cold air return and into the spot where I put a red arrow hopefully ( it has already been broken out and patched before)  I have a 5" 90 degree elbow and have it attached to the piece that the ac hose snaps onto.

My problem now is that my intake and exhaust are sharing the window behind that insulation board so it brings heat back inside.  And my neighbor asked my wife if she thought it smelled like skunk for the past week. OOPS

Yes, I am battling it with this kush.  (past month spent 300 on a/c - 200 on can filter - and 200 on can fan) But it is well worth it.


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## dirtyolsouth (Jun 24, 2009)

So...

You're exhausting air out of your window...  What's your ventilation chain?  Let me get this straight...  Is an inline ventilation fan pulling air from the window, through air cooled lights and then exhausting it out the same window?  Or are you just pulling hot air from the room and exhausting it?  Is the can filter on it's own with a can fan and cycling air constantly and exhausting the filter's output within your room or are you pulling your air through the filter and then exhausting it out the window?  Would there be a way to do all your exhaust through the chimney...  Like a 6" or 8" -  'Y' adaptor going into your chimney with your room's exhaust and A/C exhaust feeding the 'Y' adaptor?  You could use a reducer adaptor feeding one of the 'Y' inputs for your a/c and get whatever sized ventilation duct you're using on your fan to gauge what size of 'Y' adaptor you'd use.  This would route all the air above the neighbor's nose so they don't call animal control to look for Peppi LePew.  If the air was scrubbed of odors I'd exhaust everything out of the window if you can feed your intake from somewhere else but maybe that isn't an option?

I don't see a problem with tying into the chimney but then again I'm in the same boat with you as far as my HVAC experience goes...   But I've setup a number of rooms and exhausted air and learned plenty over the years...  I ran a portable A/C in a couple locations and my only thought is they don't have much 'push' on the exhaust and the elbow will slow things down a bit...   I'm sure you're trying to keep the run as short as you can.  If you're extending the a/c exhaust longer than the exhaust hose that came with the unit maybe consider an inline 'kicker' fan.  It would help pull the hot air off the unit and through the 5" duct to your chimney.  

so many questions...   

hmmmmmmmm.............


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## hanfhead (Jun 24, 2009)

Well, I use one bathroom exhaust fan you can see in the picture to pull fresh air in.  I have another that expels air into my basement at the same time the intake is on.  The can is running on its own, suspended from the ceiling.  My hoods are not air cooled (yet).  I never had any smell problems after I got the carbon filter but the a/c is pulling stinky unfiltered air from plant level.  I really don't have any other options atm because if I put the a/c outside my room, I can not use the built in thermostat.  My room is close to the chimney stack, I shouldn't have to extend the exhaust hose longer than it came; maybe by a foot or so.  I don't think the a/c puts out enough volume to worry about not going up the chimney or pushing fumes back down, but the carbon monoxide detector is a good idea.  Thanks for your help.


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## dirtyolsouth (Jun 24, 2009)

Hey,

Another possible option...

I haven't used my portable in awhile but you just reminded of how we had to run our unit...  I know all it costs is $$$...   but I had to run my portable a/c in one location from just outside the grow room blowing in through the wall.  To control temps I hooked up my a/c power to the 'cooling' outlets on an atmospheric controller similar to the one below...  I had one around from dealing with CO2 injections years ago...  They also make a unit that is more simple with only a temp function for the outlet as in pic #2...  For what we had going just substitute the fan in pic #1 for an a/c unit ...  Pic #3 is another unit they make with a separate day and night temp setting...

The only curve ball using it this way is whether your A/C is a 'manual' model with knobs and analog (?) controls  or is everything electronically controlled...?  If you unplug the a/c when it's running and then plug it back in a few seconds later does it get stupid and stay off or does it kick right back on?  The manual units will just come back on but if it's electronic like my window a/c is now it won't come back on unless you hit the button...

The controller worked great with my manual model...  What's great is you get all the heat and the unit OUT of room.  I'd just set the A/C knobs however I'd like it to run and turned the unit's thermostat to always come on when it got power and boom...  Bob's your uncle!

If the unit is controlled electronically you may be able to fashion a way for just the front of the unit to come through your wall so the thermostat can function within the room and the back of the unit would exhaust some way out of the room next to your grow space...   If you have some type of temporary walls on your grow space this is easy but I doubt if you want to make an approx 16" x 24" hole in one of your sheetrock/2x4 walls for the a/c unit to poke into your room through...

Peace!


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## hanfhead (Jun 25, 2009)

OKAY, I went ahead and did it.  Success!! Here is a finished pic (the server is too busy at this time).  I was able to use a 5-7" hose clamp to secure the piece that came with the a/c to the 90 degree duct.  It even comes with a cap so I can take the hose off and put the cap on in the winter.  Well anyways, I just wanted to say that it is running now and the smell outside is gone! But almost most importantly, I held a lighter by my water heater flue and it still drafted the flame up the pipe.  For anyone wondering if it is safe to do, you can feel better about it now.  I wouldn't suggest a bigger cfm than a portable a/c exhaust without testing.  To be safe I hooked up my carbon monoxide detector in the basement and will post here if it ever goes off.  Thanks for the advice, DOS. I appreciate it.


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## dirtyolsouth (Jun 25, 2009)

NO worries...  Glad to help!  

Rock ON!:headbang2:


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## RCCIZMe (Jun 25, 2009)

I just wonder what the top of the of the house smells like


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## hanfhead (Jun 25, 2009)

RCCIZMe said:
			
		

> I just wonder what the top of the of the house smells like



Bubba and OG Kush :smoke1:




My house is a high 2 stories, that high up only the birds will know
I'm sure they're flyin':fly:


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## Oregon Bob (Jun 25, 2009)

This is interesting... haven't ever thought to tie into chimney b4... always just tore through the drywall into the attic.

Really an afterthought, but why not just close off the chimney opening in the room itself, especially if not in use?  Take a piece of 2" insulation board & seal around the edges best as possible.  Should there be any unintended back draft into the room, the makeshift door would likely keep most out.  Perhaps an added measure...?  Best & cool info.


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## hanfhead (Jun 27, 2009)

Oregon Bob said:
			
		

> This is interesting... haven't ever thought to tie into chimney b4... always just tore through the drywall into the attic.
> 
> Really an afterthought, but why not just close off the chimney opening in the room itself, especially if not in use?  Take a piece of 2" insulation board & seal around the edges best as possible.  Should there be any unintended back draft into the room, the makeshift door would likely keep most out.  Perhaps an added measure...?  Best & cool info.



I don't have a fireplace if that is what you mean by closing the opening.  The only place I was concerned it would escape was the water heater or furnace flues, but it does not. It works great and helps both by moving the heat away from my intake, and blowing any smell far above the house.


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