Air Conditioning - Hanging air duct?

I noticed in some houses that the duct tubeing is suspended in the air all over the house. Is this better? What are the benefits and how high should they be hung off the ground? Mine are all layed down. thx!

Lost here ,You mean up in the attic or where.
For the flex duct to just lay down thats ok like in an attic . or to habng it is ok . Its all more in that you dont want any kinks in the pipe to shut off some of the air. "Hope this help"

ED;)

yes ducts in the attic... the inspector who did my house said I should hang the flex duct... he said this is how it is done now. Looked at my buddies house and sure enough its all hung. Im just trying to figure out my electric bill...

260$ and I run my a/c 78 during the day and 76 at night. During hte cooler months my electric bill is under 100$. I just recenlty put in new attic fans becuase the old ones were out and replaced the coil that was leaking water into the catch pan. I have an 1,800 sqft house with a 4 ton unit that is not like the newer high effecient units. The coil that was put in was high effecient tho like mentioned in my other post. I guess see if this helped when I get next months bill.

I should hang the flex duct... he said this is how it is done now.

Why????? Like I said We just hang the flex pipe so that there is no kink in it to cut off the air is all. So if there is no kink why hang it. This has not a thing to do with the cooling cost. ask him to show you the code that calls for it

I have an 1,800 sqft house with a 4 ton unit that is not like the newer high effecient units.
You dont say where you are but thats a lot of AC for 1800sq ft even down in FL. But I dont know what your load is for AC. Does it turn on and off a lot or run a long time when on??? just the start and stop on an over size unit can run up the cost,
Attic vent you need 1 sq ft for every 150sq ft of attic 1/2 in and 1/2 out. Sq ft of attic X 0.07 == the CFM for attic vent fan.

ED

Keep the runs as short & straight as possible. Sometimes with the flex laying on the ceiling joists, the joists will cause compression of the flex. This problem is easily prevented by slipping plywood under the flex.

I live in Texas and it gets pretty hot here. I dont think the a/c short cycles or anything like that. I thought a 4 ton was about right in size. My parents have a 4.5 ton in a 2200 sqft house. I guess im wrong. The unit is a York if that makes any difference. It seems like it has to run a while to keep teh house kewl but here again its been kewl ever since ive done all the new stuff. Im waiting for a hot day to see what happens. Also im running two 1400 CFM attic fans.. not sure how much sqft the attic is but I have some tall ceilings.

4 tons for 1800'ft???? close the windows.;) i think you need a load calc done.

It has to run a while to cool the house down. I know I wouldnt want anythng smaller that had to work any harder to the cool the house. Its an older unit. The other day it took about 45min to drop the house temp for 78 to 76 and it wanst even that hot outside. Our temps get right up to the 100s over here so im sure that will be the real test probably in August. The a/c does not short cycle on and off.. it turns on and usually runs about 45 min and then is off for a couple of hours... Then again its been cooler out lately.

The other day it took about 45min to drop the house temp for 78 to 76 and it wanst even that hot outside.
Doyou turn the unit off and open the home up to outside air ??? That dont work for a AC unit.

ED;)