Venting AC to attic?

I was wondering if any of you vent your portable AC or window box conversion AC unites to the attic to get rid of the hot air. I can't vent via a window and am wondering how to exhaust the hot side of the AC unit. My only other option would be a split unit but the cost is pretty huge and I'd also need to get a 220 circuit ran as most splits use that. My main concern is that the hot exhaust would condensate in the attic and cause mold. Perhaps tee off on the bathroom exhaust fan outlet?

You are correct to be concerned about moisture in the exhaust causing moisture damage and mold. Another thing to think about is during winter will the heat build up and cause snow to melt on spots of the roof, making people wonder what is up with that.
I guess it depends on the type of attic/roof space ventilation the house has. Some have passive vents, some have temp. controlled vent fans, and some have both. How big is the space to be vented into? How much venting are you thinking?Is the vented air filtered? If not, smell can move into areas of the house.
If you have snow/freezing winters, do you have any bathroom exhausts that sometimes drip water during the cold? If so, you already have a ventilation/moisture problem.

The roof is a asphalt shingled roof, all the hvac shit is in the attic but at the other end of the house. The house is 1800 sqft which is a small house. the room is a 10x12 or 12x12 and is right next to a bathroom which does have a fart fan exhaust. All vents are passive and I have four of those spinning fans on top outside that pull air in through the soffit vents. But I also live in a area that is high in heat in the summer 90-105F with RH at about 40-60 and with rain this shoots up but it can not rain for months on end. I have two carbon filters in the room now, both phresh filters 1x600cfm 1x 1050 cfm, but they are polishing the air as oppose to negative pressure. This seems to work well now but I'm going to need AC coming in the summer and I need to keep RH under control so the carbon filters perform at their best. I'm running 1x600 & 1x250 hps so it's not extreme but it does get hot. I was thinking of a portable or building a window AC unit box and exhausting the heat into the attic or maybe tap into the bathrooms fart fan exhaust. Exhausting into the attic would be super easy but again I pause with reservation of mold concerns. The attic only has the soffit vents all around the house and the fans on top outside but when the wind is not blowing those whirley birds on the roof don't spin. I was thinking about 6-9K BTU for the AC unit. Only other option would be a split. It does get cold and snow but this is unusual and it last of a few days before melting.

those whirly birds let the excess heat out of your attic. pump some heat up there and watch em spin! I don't think theres much moisture in the a/c exhaust, more like heat! that's the job of the a/c to displace heat while cooling the air that is retuned to the space. ive seen portables that have flex hose attached to the exhaust and stuck out a window. so why not just find one of those type run it up thru the attic and either hook it to one of the whirly birds or a designated 6 inch exhaust vent somewhere

Yep, I've been looking at the portables as it's the easiest and I don't have to hack a box together but from my research they seem to be very flaky and inefficient compared to the window units. Also, I thought about a dedicated exhaust but the thought of cutting a hole in my roof makes me cringe; so this is one of the reasons I considered taping into the fart fan exhaust with a tee if possible. The drop dead easiest is a portable and cutting a small hole in the closet ceiling to run up and dump the exhaust, I should be able to save the piece cut out and dry wall it back in when needed. I can't seem to find any good reviews on the portables that are consistent which sucks.

where does your exhaust for your bathroom go? go rite next to it with a new one! you don't have to go out the roof , hell vent it out of the soffit if you have to. ive never dealt with the portables as to recommend one.

diamonddav said:

where does your exhaust for your bathroom go? go rite next to it with a new one! you don't have to go out the roof , hell vent it out of the soffit if you have to. ive never dealt with the portables as to recommend one.

Click to expand...

It vents out the roof, but out a sofffit might work.