Wxh wxh wxh wxh wxh wxh wxh wxh 80 8x4 90 8x4 100 6 6x6 7x5 9x4 125 7x6 8x5 10x4 150 8x6 9x5 11x4 175 7 7x7 9x6 11x5 13x4 200 8x8 8x7 9x6 12x5 15x4.
Duct size for 1000 cfm.
7 to 10 duct 700 to 900 cfm.
As systems increase in efficiency the tolerances of how we have always done it will no longer be adequate.
Air volume equivalent round air volume cfm 4 6 8 10 12 duct inches cfm 50 6 x 4 550 75 6 x 4 675 100 8 x 4 6 x.
But if the size of your duct matches your ventilation power your kitchen exhaust fan will do its job properly and quietly.
Design cfm 4 cfm 6 cfm 8 cfm 10 cfm 12 60 6x4 60 4x6 90 4x8 120 4x10 150 4x12 90 8x4 110 6x6 160 6x8 215 6x10 270 6x12 120 10x4 160 8x6 230 8x8 310 8x10 400 8x12 150 12x4 215 10x6 310 10x8 430 10x10 550 10x12 180 14x4 270 12x6 400 12x8 550 12x10 680 12x12 210 16x4 320 14x6 490 14x8 670 14x10 800 14x12 240 18x4 375 16x6 580 16x8 800 16x10 950 16x12 270 20x4 430 18x6 670 18x8 930 18x10 1100.
This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications.
For example for a natural draft furnace multiply 100 cmf by 100 to get 10 000.
Multiply that number by the amount of cubic feet of airflow per minute cfm your type of furnace produces.
Duct system sizes and airflow quick chart created date.
100 0 045 4 x 6.
Table 4 1 supply air duct installation sizes based on 08 inches of pressure drop per 100 ft round duct rectangular duct cfm dia.
Equipment sizing load blower cfm equipment sizing load btu hour 1 08 x td x acf.
A natural draft furnace produces 100 cmf an induced furnace produces 130 cfm and a condensing furnace produces 150 cmf.
Larger volumes or higher static pressures should be dealt with on an individual job basis.
6 to 8 duct 400 to 600 cfm.
646 3 28 0 16.
8 to 12 duct 900 to 1200 cfm 10 and up duct 1200 and higher 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.
1 000 14 14 x 10 18 x 8 12 x 12 1 200 14 16 x 10 24 x 8 14 x 12.