Should I move my air ducts?

[phreaq]

I just found this site, and signed up, so bare with me as I am a noob. I am a mechanical designer, so this question is a little outta my field.

I have a groundfloor loft, that is rectangular in shape, maybe a 3:1 ratio. Windows run the whole way down one of the longer sides of the rectangle. I have a large round heating duct with 3 outlets running parallel with the windows, about 10' from the ground (the ceiling is about 12') on the opposite wall.

Ok, here's my problem. In the winter months, there is a LOT of condensation on the windows and front door (it's all glass too). In fact, there is so much condensation, that the door has been frozen shut on numerous occasions, with severe ice build up at the base of the door.

I currently have a de-humidifier running 24/7 and I do what I can to keep moisture down (no open water sources, etc).

I'm wondering if I should move the ducts to be on the same side as the windows.

Any comments?

thanx in advance

 

[DRWeig]

Hiya phreaq,

It's hard to beat some baseboard radiation beneath windows for preventing both condensation and drafts. As for your door, you'll have to come up with something that blows on it directly at almost all times, or else get a nice insulating interior door.

Just suggestions from somebody who used to scrape interior ice in the winter.

Let's see what the rest of the crew comes up with!

Oh, and let us know what you decide to do...

Old Dave

 

[cme]

Where is the moisture coming from? Cooking?

Just bringing in cold OSA and heating it up will dehumidify. I do that in my car on trips, put it on vent and then adjust the temp.

 

[phreaq]

Where is the moisture coming from?

good question, I'm not sure where ALL of it comes from. I have a few plants, and take daily showers, but not a lot of cooking. The floors, walls and ceilings are concrete, so I don't know if that lets moisture in or not.

As for an open window, they are all near the top of the windows, so most of the heat escapes, and when it's -15C out, it's very coooooooold.

 

[lilliput1]

Is the glass single glass or insulating? The inside temperature of the glass must be above the room dew point temperature to not get condensation.

 

[KenRad]

phreaq,

ANY net moisture addition to the indoor air will result in an indoor dewpoint that is above the outside air temperature. And when the outside air is really cold, indoor relative humidity is low, and water evaporates readily. Showers, open water sources (like a toilet), and even your breath will add to the moisture level in the space.

But you say you are running a de-humidifier 24/7. What type is it? If it's a refrigerated type, the coil temperature will not get low enough to remove any moisture on your coldest days. On poorly insulated surfaces, you can easily have a surface temperature below indoor dewpoint, and there will be condensation.

I think the only answer is to keep the glass surfaces warmer, either by replacing them with some better ones (preferrable), or directing warm air on them like DRWeig suggested. If you move the duct, you'll want to keep the fan on during the very cold days to keep the air moving across the glass (that is, you don't want the fan cycling with the heat).

Hope this all made sense.

---KenRad

 

[CuriouslyGeorge]

The front door is ALL glass? ...Must be some thick-butt kicking glass! (You've never been robbed?) Maybe you should just swap-out the door for a more conventional exterior, security door! - CuriouslyGeorge

 

[cme]

where is the main return located?

what type furnace is it?

 

[phreaq]

Hey guys!

Thanx for all the replies! Lots of good stuff here. Just to answer/recap a few things...

Yes, it is an all glass door, and luckily, no break ins yets

It seems like I need to replace the windows to better ones (double pane), and the door too. I'm hoping this will mean I don't need to move the ducts.

The furnace has no 'real' air return (it's a loft), and is not the best at 81%+ effenciency.

I posted two pics of inside and outside here;

http://66.49.141.42/outside.jpg

http://66.49.141.42/inside.jpg

once again, thanx for all the replies