Return Grille Size For 3 5 Ton

You determine a return grille pressure zone required 340 cfm of return.

Return grille size for 3 5 ton. You may round this number off to 300 cfm. The square root of 576 is 24. Always round up and we have a tonnage value of 2 5. Therefore your return air duct and grill size will be 24 by 24 inches.

The return air grid to reduce noise should be 5 to 8 times the size of the fan outlet. It s a 1600 cfm system with 200 cfm of outside air 200 1600 12 5 of outside air. Using those examples you would see their square inches are 280 400 and 400 respectively. For example a 5 ton unit.

Engineering toolbox resources tools and basic information for engineering and design of technical applications. In order to determine the size of the tonnage you have simply divide 980 by 400 cfm per ton. 400 fpm is the median air speed for this calculation. Calculate the square root of the total.

Doing this for this space will yield a tonnage of 2 45. The size of the return air grill depends on the size of the forced air fan. 340 cfm of return air x 87 5 298 cfm. Air return intakes sizes and capacities.

Some of the common sizes include 20 by 14 25 by 16 and 20 by 20. Size and capacity of air return intake. 4 ton unit x 144 square inches 576 squared. Note also the return air grille sizing formula at the top of the chart.

For the same 2 5 ton system with a filter grille the grille size would need to be what size asked rick we usually use a 20 x 20 for 2 5 ton said the tech 20 x 20 x 2 800 800 cfm well that s big enough for a 2 ton but a 20 x 25 may be a better choice. Size and orientation of return grilles and supply registers june 15 2020 bryan orr 2 comments proper sizing and orientation of grilles registers and diffusers may seem like such a simple thing but it s an area where confusion and mistakes are commonly made. Take 100 12 5 to find a multiplier of 87 5.