Return Air Duct Sizing Chart Greenbushfarm The table on the right (or below if you’re viewing on a phone) shows the return duct size for hvac unit from 1.5 tons to 5 tons. based on 400 cfm per ton, the corresponding airflow is also provided. the next column is the diameter (in inch) for round rigid duct. the last column is the number of round rigid duct you need. For a 1 ton unit you will require the following return air duct as a minimum : round duct size: 12 " diameter rectangular duct options: . 11"x10" 12"x9" 14"x8" 17"x7" 20"x6" 28"x5".
Return Air Duct Sizing Chart Greenbushfarm 19” in diameter, according to the return air duct size chart. sizing rectangular cold air return ducts. rectangular ducts can be various sizes for the same ac unit as long as the number of square inches is nearly the same. for example, the right size 3 ton ac cold air return duct ranges from 16”x15” to 26”x10” to 40”x7”. These ducts can facilitate at least 1,200 cfm airflow. for a 3.5 ton unit, we use 20 inch round returns ducts or 22×22, 26×10, and 34×8 rectangular returns ducts. these ducts can facilitate at least 1,400 cfm airflow. for a 4 ton unit, we use 20 inch round returns ducts or 24×12 and 30×10 rectangular returns ducts. The return grill size would be 24x30. the run would be approximately 10 15 feet. thanks! in many cases 18" will be large enough. but i can't see how its being installed in your home to know for sure. however, a 24x30 return grille is not large enough for a 4 ton unit. Table 4.1 supply air duct installation sizes (based on .08 inches of pressure drop per 100 ft.) round duct rectangular duct cfm dia. 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 Sizing Chart Greenbushfarm The return grill size would be 24x30. the run would be approximately 10 15 feet. thanks! in many cases 18" will be large enough. but i can't see how its being installed in your home to know for sure. however, a 24x30 return grille is not large enough for a 4 ton unit. Table 4.1 supply air duct installation sizes (based on .08 inches of pressure drop per 100 ft.) round duct rectangular duct cfm dia. 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. Now, multiply 3 x 400 cfm to get 1200. you would need a blower that can move 1200 cfm. pro tip: round up – if you’re more than halfway to the next larger size, round up to it. in our example, if you needed 33,500 btu, or 2.75 tons, round up to 3 tons and multiply by 400 cfm per ton for the same result – 1,200 cfm. Example of return air duct size calculator. consider a residential room requiring an airflow rate (q) of 300 cfm to maintain proper ventilation and air quality. assuming a desired air velocity (v) of 800 fpm, the duct size (a) can be calculated as follows: see also barrels to metric tons calculator. a = q v = 300 800 = 0.375 ft².
Flex Duct Sizing Chart Greenbushfarm Now, multiply 3 x 400 cfm to get 1200. you would need a blower that can move 1200 cfm. pro tip: round up – if you’re more than halfway to the next larger size, round up to it. in our example, if you needed 33,500 btu, or 2.75 tons, round up to 3 tons and multiply by 400 cfm per ton for the same result – 1,200 cfm. Example of return air duct size calculator. consider a residential room requiring an airflow rate (q) of 300 cfm to maintain proper ventilation and air quality. assuming a desired air velocity (v) of 800 fpm, the duct size (a) can be calculated as follows: see also barrels to metric tons calculator. a = q v = 300 800 = 0.375 ft².
Requirements For Hvac Return Air With A Duct Sizing Chart Zoobledigita
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