Tees split but do not reduce and an appropriate reducer must be added.
What size duct do i need for 1000 cfm.
For instance a 2 5 ton system approximately 400 cfm per ton would require 2 14 flexible return ducts or 1 very short flexible 18 duct to move the 1000 cfm required by the 2 5 ton system.
Dampers on take off duct runs allow for adjustments of air distribution.
Divide your number by 10.
For example 10 000 divided by 10 is 1 000 cmf.
The minimum recommended duct size is 6 for 0 400 cfm range hoods.
Minimum duct size of 4 recommended duct size of 6 401 600 cfm.
One six inch round duct is good for about 120 cfm a six inch duct carries about 150 cfm and eight inch carries about 200 cfm of cool air.
The 5 pipe carries 615 cfm at 4500 fpm see chart above.
So if you have a two ton system you need ductwork that will carry 800 cfm.
Minimum duct size of 7 recommended duct size of 8 10 901 1200 cfm.
A rule of thumb says ducts should carry 400 cubic feet per minute cfm of air for every one ton of cooling.
For more information on duct size click here.
Your home needs ducts that support this much airflow.
Referring back to the chart under the 4500 cfm column 1500 cfm is not listed but is close to the.
Minimum duct size of 6 recommended duct size of 8 601 900 cfm.
The minimum duct sizes and recommended duct sizes based on a hood fan s cfm rating are as follows.
Added together there is a total of 615 885 1500 cfm coming together.
Most technicians are skeptical about these numbers especially on the return air side of the system.
The 6 pipe needs 885 cfm at the same velocity of 4500 fpm.
Never locate ducts at the end of the trunk line run.
The smaller the duct size the less cfm you need and the larger the duct size the more cfm you need.
How do you figure what size branch you ll need.
Minimum duct size of 8 recommended duct size of 10 12.
Humidity 400 cfm ton shr above 85 17º td low humidity 450 cfm ton cfm total heat equation cfm btu hr 4 5 x h x acf sensible load 1 08 x td x acf friction rate used in duct calculators friction rate pressure drop is the available static pressure asp allocated to the duct work.
In order to maintain velocity reduce duct size.
Return air cfm must be equal or greater than supply air cfm.