How far apart should duct hangers be?
But the underlying “common sense” behind those recommendations is pretty simple: have no more than two duct joints between supports. That explains the 8 to 10 feet apart recommendation when you are installing 4 and 5 foot joints of rectangular duct.
How far apart must flexible duct be supported?
four feet
Flexible duct shall be supported at manufacturer’s recommended intervals, but at no greater distance than four feet. Maximum permissible sag is 1/2 inch per foot of spacing between supports. A connection to rigid ducting or equipment shall be considered a support joint.
How much space do you need for HVAC ductwork?
As a rule of thumb, you’ll need 400 CFM of airflow per ton of air conditioning; it takes about 1 CFM of air to heat or cool 1 to 1.25 square feet of floor area.
How often does ductwork need to be supported?
every 6 feet
A support should be installed between a metal connection and a bend and the duct should be allowed to extend straight for at least one duct diameter before making the bend. Vertically installed ducts shall be supported every 6 feet at a minimum.
How often does spiral duct need to be supported?
Most rectangular ducts need to be supported at least every 8′-0”. For round and flat oval spiral ducts, that support spacing is 12′-0”. 7. You’re going to need more insulation – it’s going to take more square feet of insulation to cover the increased perimeter/surface area of rectangular duct.
How many CFM is a 4 inch duct?
Reviewing the chart, a 4” pipe will convey 395 CFM at 4500 FPM.
How many CFM does a 7 inch duct?
CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)
| Duct Size (Inches) | Flex Duct Airflow (CFM) |
|---|---|
| 6 inches | 75 CFM |
| 7 inches | 110 CFM |
| 8 inches | 160 CFM |
| 9 inches | 225 CFM |
How much does it cost to install HVAC ductwork?
The national average cost for installing ductwork is between $1,900 and $6,000, with most homeowners spending around $4,000 for the professional installation of 300 linear feet of replacement aluminum ducts, insulation, and 10 vents and 2 returns.
