What is location?

How many supply runs? How many returns?

Ductwork material is generally quite cheap and usually the labor is on the low side of wages for HVAC. Really depends on location, marketplace competitiveness, and if dealer likes to use replacement ductwork system as a large profit center.

You want R8 insulation at a minimum. I would not use flex except for supply and return runs.

Ductwork is easily accessible and in attic?

Why do you feel new ductwork is needed?

Post back.

IMO

Start with having a load calculation done to determine your required capacity (tons). Very likely 3 tons is more than enough for that size home, and most of your issues are ductwork related. So I do not recommend going up in size simply based on your previous experiences with the old system -- oversizing would just create further issues.

This post was edited by ryanhughes on Sun, May 5, 13 at 13:25

I live in Bradenton Florida. 1 story house with catheral ceiling only in family room. Split bedroom plan - total of 3 bedrooms, 3 walk in closets and every room and closet has a air condition vent and a air return.

In 2005 FPL tested all our vents for possible air leakage. We had four vents as a problem and had furnace people come out to seal those leaks.

Supply runs - FPL based on that survey (I have a grid printout which I uploaded as a photo to this note) it looks like I would need 16 supply runs (assuming you mean number of connectors). I have a long metal duct work with flex tube connectors in attic that runs the width of the house. For the two back bedrooms it looks like one large duct and then flexi ducts attached at a box junction.

Most of the flex tubing can easily be replaced. Might have a bit of trouble getting the flex over the catheral ceiling to get to the two backs bedrooms. All vents and air returns are in the ceiling as we have our house on a cement slab.

When I clean my bathroom counter (small bathroom) the vent is fairly close to it and the very next day it feels like a coating has been laid over it. In the kitchen the vent is close to our two coffee makers and there is always specs of dust and white pieces on on the tops - every day. Wipe them clean and the tops are covered again the next day.

We run the air almost all year round in Florida and it was just this year that I noticed this happening. We also had a fruit rat infestation in the attic a few years ago and they could of chewed into some of the tubing too as it happened after we had the flex tubes sealed.

We use a high quality filter in the main air return vent inside the hosue too. My husband buys the one that stops pollen and dust as I have sinus problems.

Thank you for you assistance.

Ryan I will check on line to determine the load caluclation and then when I pick a firm I will have them recheck it too.l

upload

here is grid