AC duct/vent system

[Dixie Life]

We are removing the old AC system an installing a new one. I'm not sure of the correct way to run the duct up the corner of the room. The plan is to make a square troff in the corner to get the air from the unit to a vent up next to the ceiling. My question is, can I place a adapter ring at the bottom of the troff to attach the duct, insulate the interior of the troff, then install my vent at the top next to the ceiling? Or, do I have to run the duct all the way to the vent? By running the duct all the way will mean the troff will have to be larger an somewhat of an eyesore.

Thanks for any advice.

 

[bilge53]

You can use the "trough" as a plenum. It will have frictional loss though but this will be minimal. Don't under size your new unit. I did a similar thing on a previous boat and it worked well.

 

[Dixie Life]

Thank you so much. That's what I needed to hear. Thanks.

 

[Dixie Life]

Darn spell check, "trough".

 

[bayview]

getting the cold air up top sounds like a great idea. I would paint the inside to smooth airflow and reduce surfaces for dust to adhere.

 

[bilge53]

I did paint mine as well as caulked any joints that were accessible just to minimize any leaks. I would also make sure I used an adjustable register on the top so you can fine tune the output.

 

[Shoalwaters]

When redoing my a/c systems I found that 4" PVC waste pipe made excellent ducting. Foil-coated bubble-wrap makes good easy insulation. I made a varnished mahogany trunking where part of the ducting was visible. My boat originally had the "slinky spring" type flexible ducting. Looked like it would restrict flow and that proved to be the case. Make sure the blades in your squirel-cage blowers are clean.

 

[Pgitug]

PVC pipe ducting is great and when using gentle 90 degree sweeps you really cut down on the reduction of air flow. The standard flexible duct work is convenient, but is the worst thing you can install with regards to air flow. And it's air flow that makes the unit function.

 

[FF]

Airflow both ways ,the return system.is as important as the delivery pipes.

 

[Gmarr]

I e been thinking about this- replacing the "soft sided" duct work in the backs of cabinets with pvc would allow one to cram more stuff in without fear of collapsing the duct! Amazing

 

[Shoalwaters]

I e been thinking about this- replacing the "soft sided" duct work in the backs of cabinets with pvc would allow one to cram more stuff in without fear of collapsing the duct! Amazing

Don't forget to insulate it well though, or the outside of the PVC will run with condensation and flood the cabinets.