Air conditioning duct material
 

What determines whether insulated or non insulated ducting gets used for A/C?

Re: Air conditioning duct material
 

COST

Re: Air conditioning duct material
 

I am thinking cost. I believe it is so the cool air stays cool till it reaches its exit point. Why let cool air escape or warm air enter the ducting?,especially in hiden voids or compartments.

Re: Air conditioning duct material
 

Not worried whether I spend $11 or $17 for duct for a 25' peice. The insulated I think has no draw back, other than running it because of the larger size, which I am trying to work around. The A/C unit and 1/2 of the duct will be in the cabin, but do to the unit placement, I have to run the supply duct through the cabin wall and into a void between that wall and the cockpit liner, which is open to the side storage compartments and the bilge in the back of the side compartments. So not quite the same as running duct work thru the engine compartment directly.

Re: Air conditioning duct material
 

Damn I type slow.

Thanks

Re: Air conditioning duct material
 

I ran duct through a forward cabin bulk head and only cut it big enough for the 4 inch material to pass through. I ran the insulation around both pieces on either side and everywhere else it was convienent to use.....the last 1-1.5 feet weren't insulated either due to space constraints.

Re: Air conditioning duct material
 

US1, Insulated duct should always !!!!!!!! be run in non -conditioned areas. If not you have the potential to form condensate on the outside of the duct because of the temperature difference.
Dave

Re: Air conditioning duct material
 

Bingo........!!!

Re: Air conditioning duct material
 

PMT, Are you in the business ?

Re: Air conditioning duct material
 

Yessir...

Re: Air conditioning duct material
 

Yeah, if you are running duct thru an area where you don't worry about mildew then run whatever you wish (pvc, flex hose, etc). On long runs, though, you'll bleed duct temp to the surrounding compartment so take that into account..

On compartments where mildew can be a problem, you have to run insulated.

Also be aware, that if you "use a compartment" for a duct (by pressurizing a closet, etc) that you will get condensation in that compartment as well.

Re: Air conditioning duct material
 

Thanks for the replies!
I ended getting the insulated duct just for a peice of mind. Only 1 spot where it is too thick is where it goes inside of the power panel. I may either remove the insulation or thin it down just for that spot. The rest is no problem.
Here's my setup, if you see something wrong, speak up. :p

The A/C unit is mounted inside the counter in the location where the drop in cooler was, just to the left of the sink. The supply hose travels under the sink and up thru the AC/DC power panel to a TEE inside the plexy panel at top feeding a 4" round register right above the shorepower panel on the 45* angle, then across the top inside of the plexy panel above the mirror, into the side cockpit storage void (where the insulated duct is needed) then down and to a 2nd 4" vent near the door. The cabinet will get a large vent cut in for the return supply air.

1 consern I ran across.
The outer duct covering is of a 'metalic' covering. Looks like aluminum foil. It doesn't read continuity using a meter. The duct will be a tight fit inside the power panel and there is the live wires for the shorepower panel. I don't 'think' there will be a shorting problem if the duct touches the wiring since it shows no continuity, but not sure. Thoughts?

Thanks

Re: Air conditioning duct material
 

If your concerned about shorting,go to a local HVAC supply house or home depot. You should be able to get insulated flex duct where the outer skin is plastic, however all the flex i've ever used has a wire inside to keep it round.
Dave

Re: Air conditioning duct material
 

Ditto on the plastic hose...also, see if you can get a replacement door for that cabinet. You could mount/create a return in the door and have the option of putting the original door back on someday.

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Yep, thought about that wire today. That may be a little to chancy going the proposed route. May have to go back to plan B and exit the supply to the left side by the entry door, then up and over to the other vent, eliminating the need to run the duct thru the power panel.

Also thought of making a door/vent to keep from cuting a large hole in the cabinet and saving my original door.

Thanks again

Re: Air conditioning duct material
 

If you plan to run on shorepower and run the AC at night while you sleep, you'll want to address compressor noise with it inside that cabinet. Also make sure you sit the unit on some rubber damper feet. (and believe it or not, mount the circ pump on rubber mounts too).

Also, in the cabinet where the unit is mounted, glue outdoor carpet on all of the hard surfaces in the cabinet to kill the noise, and make 2 sound killers by gluing 2 pieces of carpet back to back and hanging one of them so that the air has to go around it to the evaporator, and also put another about an inch behind your intake slots. I did this on both units in the SeaRay and I can't tell when the compressors turn on in the dead of night, except for the relay click.