Exposed Round Duct
We are getting a geothermal system put in our house in Eastern PA. We have a large Solarium we wanted added to the system since it wasn't heated or airconditioned. We asked for exposed round duct in that room. Our contractor is concerned about all the direct sun exsposure that will hit the ducts. He feels they are going to sweat. I know sweating has more to do with humidity. Does anyone else feel that the ducts being exposed to so much sun will create sweating? Thanks
I attached a picture (hopefully). The duct is going mid level between the balcony and the doors to the first floor. It will be mounted to the brick wall.
Last edited by AMDAVN; 01-03-2011 at 11:13 AM.
Reason: added picture
I'm assuming you want this solarium to be the same temperature as the rest of the house? Also noticed large grill above small balcony. Is this a discharge from this same system? Your contractor will need to do an actual heat loss/gain computation (manual J) and see if the new system will be large enough. If he installs an exposed "pipe" and it is not adequate to actually condition the area, then there is a chance it may sweat. Based on your picture, this room could have a significant loss/gain total and may require an additiional GSHP system just to condition this area properly. Your contractor is right to be concerned. We have actually had "sun rooms" and solariums which took a system nearly as large as the main house by themselves. Most people don't or won't spend the extra money to do it properly. Usually it's a "just need a little more out there" type request, and when it does not work at all, it's the contractor's fault somehow. Make sure he runs the figures before getting any additional ductwork installed, and be prepared for a shock. It's hard to "count" this solarium as living space if it is not conditioned, but based on your picture this won't be cheap, or easily done.
Spiral duct, lined on the inside is available and should be able to offset sweating. Get a firm figure for the room load or you'll be sorry. Return path needs to be figured out too, or you may impose solarium loads on adjoining rooms.
You might be able to lessen the room heat concentrations with substantial return volumes in the solarium, but then again, you may upset the whole house comfort in the process. A couple thousand cfm of return/displacement can do more local work than a couple hundred cfm of supply. Can't tell over the internet what your options and opportunities are, so you need to rely on your contractor to do what's best.
Either way, the load needs to be accounted for in system capacity.
Window coverings/films will go a long way in reducing A/C loads too. Solve window problems with window solutions, then make up the gap with the equipment.
The existing grill is from the old system and will be removed. We are installing a unit just for this room and it going in a new mechanical closet below the second floor overhang seen in the picture.
Originally Posted by wahoo
Thanks for the info
They make insulated spiro duct.
Get that canvas duct that blows up full to a round shape when the system fan comes on. Neat stuff.
That stuff can make a loud noise when the system comes on.
Originally Posted by energy star
Check this link:
Remember, Air Conditioning begins with AIR.