Cfm Flow Flexible Vent Vs Sheet Metal Ducting

I ve only been building since 1995 so i can t say for certain why we left the sheet metal guys behind but i suspect it was manly for cost reasons.

Cfm flow flexible vent vs sheet metal ducting.

Flexible ducts are fairly easy to install and will often cost less than the rigid ductwork. Never locate ducts at the end of the trunk line run. In this video i ll make a case for going back to rigid metal ducts for your trunk lines and keeping your flexable ducts to the last 10 or less of a. We have the original galvanized sheet metal ducts in our basement for the hvac.

While sheet metal ductwork tends to be a better long term choice flexible ductwork has the advantage of relatively low upfront cost and versatility. At 0 compression the maximum static pressure was 0 225 i w c. Use insulated duct or duct board in unheated spaces. Duct elbows square throat no.

Flexible duct work must be stretched tightly for maximum air flow. I don t know why but i have taken metal pipe apart to find a lot of crud which i don t think would live in flex duct. I am the owner of a home built in the 50 s. We can tell it s gotten worse than at 4 compression because the scale of static pressure has increased.

Always stagger take off ducts by 12 to maintain pressure. Sheet metal ducts are less likely to incur dangerous mold and growths because their surfaces are non porous and smooth. The performance of flex duct at 15 compression is significantly worse than sheet metal and also worse than flex at 4 compression. In order to maintain velocity reduce duct size.

Also i think spider webs are more likely to form in metal versus flex. So far we have gotten 4 estimates 2 companies say we need to tear out all the old ducts because they are. First let me start by saying i am not in the hvac business. It all depends on the unique needs of your home and your budget.

16 up to 11 40 el 12 to 15 55 el 16 to 21 75 el 22 to 27 100 el 28 to 33 125 el return air system no. Metal ductwork needs design measurement and installation by or with the help of an hvac professional. I am not hating on metal pipe but flex duct is more practical in many applications. I have seen many leaky metal ducts in crawl spaces as well.

It was suggested by a moisture control co to have the ducts looked at some needed to be repaired. Last take off run to be located 12 18 from end. Flex duct 05 on most metal duct calculator round metal pipe 06 on most metal duct calculators field duct sizing chart rectangular sheet metal duct 07 on most metal duct calculators.