Need Help with how to run return and source line off package unit

[boostedsilvia]

It is a 2000 sqft double wide with low ceilings. no fancy windows. Nice Shaded lot. I need to figure out how to run my return and source line. Judging off "Rule of thumb" i need 2 14inch lines coming off the return plenum that goes back to my package unit. I am guessing I will route the 2 14 inch lines into a junction box, and from there run duct too my unit. is that correct?


Also another question. The take off collar for my unit is only 14 inches in diameter. Do i need to rig something bigger? The square holes on the unit are 14x16 for supply and 14x24 for return. Am i stuck running 14 inch duct to the unit? I dont think so even with 2 14 inch ducts coming off the return plenum and running together at a junction. It seems like to me the 2 14s should run to a junction and then an 18 inch duct or so should connect the unit to the junction. There is no way an 18 inch duct will fit my 14 inch collar so im all out of ideas.


every bit of help will be greatly appreciated.

thanks!

[boostedsilvia]

this is how i am planning my setup to be. i am afarid the 14 inch duct that connects the unit to the junction will not flow enough air. The take off for the return on the unit is only 14 inches in diameter so i dont know if i have much choices.

Sorry for the poor kindergarden project quality. I am using paint

http://i641.photobucket.com/albums/uu134/srkoukimonsta/returnsetup.png


I know that 3.5 tons put out 1400cfms and that 20x24 return grills are good for 1000. should i put 1 20x20 grill on each side of my return plenum. Look at the place on the picture that says Dead space. that is roughly 2.5 ft by 4 feet. I am thinking about making a plenum that is 4 feet long so i can put a return on each side of that dead space. Is that a good idea or not? i have blue lines where i am thinking of putting the grills. Each red dash is a register. the Bathrooms will get 6 inch duct and everywhere else will get 8 inch. Is that sufficient enough?

http://i641.photobucket.com/albums/uu134/srkoukimonsta/hvac.png

[vstech]

unfortunately, this is not a DIY site, we are not allowed to assist you with this type of a/c support.

[boostedsilvia]

hmm thats a bummer. this is a great site. All of the hvac guys around here are too crooked for me. Thats why i try to do as much myself.

Does anyone know of any good DIY forums for stuff like this?

[beenthere]

Does anyone know of any good DIY forums for stuff like this?

Questions like that, get threads closed.