duct size cfm chart

How to use duct chart. For instance a 100x200mm duct at 1 meter length has an area of 06 m 2.

Kea General Information Sizing Within Flex Duct Sizing Chart 24391 Duct Work Hvac Engineer Flex Duct

The cost of a duct is heavily dependent on the total area of the duct.

. Download Full PDF Package. Convert Rectangular duct to Round Equivalent. A short summary of this paper. Last take-off run to be located 12 - 18 from end.

AC DUCT SIZING TABLE Author. Follow the duct size chart to find the diameter of the round duct. Now comparing it to the chart I get a diameter of 16 inches. Charts listed below show what duct diameter to use given a CFM and Velocity.

Never locate ducts at the end of the trunk line run. Duct Sizing Charts Tables Carrier Air-Conditioning Manual1960- TABLE 6 - CIRCULAR EQUIVALENT DIAMETER EQUIVALENT AREA AND DUCT CLASS OF RECTANGULAR DUCTS FOR EQUAL FRICTION. Air Conditioning - Air Conditioning systems - heating cooling and dehumidification of. Flex duct has a higher pressure drop and as such may require the size shown on this guide be increased by 1 round size for up to 800 CFM and 2 round sizes above 800 CFM to insure proper airflow.

A round duct with a cross sectional area of 06m2 has a perimeter of 275m. Volumetric Air Flow Rate. 29 rows Duct Sizing Chart CFM This chart should not be used if you are designing a full duct. Youll see tables for both metal ducts and flex ducts on charts for circular ducts.

Duct is sized to the fan inlet and curb under-sizing or over-sizing duct will cause system. The velocity in the rectangular duct is. CFM SIZE CFM SIZE CFM SIZE CFM SIZE 50 4 DIA 900 3800 20X21 50 6X6 100 4X6 925 3900 75 10X6 150 950 4000 20X22 100 10X8 175 6X6 975 10X15 4100 125 12X8 200 6X8 1000 10X16 4200. FIELD DUCT SIZING CHART ROUND DUCT SIZE ESTIMATE Flexible Duct Round Metal Pipe Duct Size Design Airflow Duct Size Design Airflow 5 50 5 50 6 75 6 85 7 110 7 125 8 160 8 180 9 225 9 240 10 300 10.

In our example if you needed 33500 BTU or 275 tons round up to 3 tons and multiply by 400 CFM per ton for the same result 1200 CFM. If you dont have the actual rating use 400 CFM per ton. The values from the table below can be used for rough sizing of ducts in comfort industrial and high speed ventilation systems. If you calculate the duct size required for 200 CFM one of the most cost-optimized duct sizes is 100x200mm.

The volumetric flow rate of air that will be conveyed through the duct in an air conditioning system is determined by the coolingheat load and the desired supply air temperature. 22 Full PDFs related to this paper. 26 rows To use our duct size calculator simply enter the maximum CFM of your blower then click. The rectangular duct therefore requires more metal for its construction this adds more weight and costs to the design.

Since we are not conditioning cfms of air but rather pounds of it we need a. 11 rows Example of big metal round and rectangular ducts 3000 CFM airflow. Air change rates ducts and pressure drops charts and diagrams and more. Cfm at 70F it will also move 3000 cfm at 250F.

16 Up to 11 40 EL 12 to 15 55 EL 16 to 21 75 EL 22 to 27 100 EL 28 to 33 125 EL RETURN AIR SYSTEM No. If desired airflow exceeds the CFM rating increase to the next duct size 4. Cubic Feet Per Minute Unit Size in Tons x 400 total square foot of your home. Now multiply 3 x 400 CFM to get 1200.

Select the duct material from the drop-down list most duct sizing tools are typically based on galvanised steel ducting by default Enter the air flowrate in cubic feet per minute CFM Enter an internal duct size in inches this must be limited to a maximum aspect ratio of 51 for the results to be valid The resulting velocity. Inwg Duct TEL. CFM for each individual room Rooms Square Footage x Unit Size x 400 total square foot of your home. Friction rate Velocity Friction Rate.

Always stagger take-off ducts by 12 to maintain pressure. So identify the BTU needed for each room and divide it by 30 to get the required CFM for the respective room. 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. Listed CFM is based on typical field results and may vary install dampers 5.

Include fittings in the Duct TEL Enter either. You would need a blower that can move 1200 CFM. V 2000 cfm 10 inches 112 ftinches 12 inches 112 ftinches 2400 ftmin 122 ms The velocity in the the equivalent 12 inch circular duct according the table above is 2589 ftmin 132 ms. Select the duct size from the table that can carry that volume of air 3.

Flexible duct work must be stretched tightly for maximum air flow. DUCT ELBOWS SQUARE THROAT No. Flex duct 05 on most metal duct calculator Round metal pipe 06 on most metal duct calculators FIELD DUCT SIZING CHART Rectangular sheet metal duct 07 on most metal duct calculators Duct Size. 810 Cold air boot collar duct 45- 65 EL AIR FLOW DYNAMICS DUCT SIZING REFERENCE GUIDE SUPPLY OR RETURN DUCT SIZECAPACITY 09 to 10 pressure drop per 100 EL.

What matters is that you have sufficiently large cross-section size of the duct if you will that can handle that airflow. Duct Sizing Rules Of Thumb Rely On Friction Loss Rate. Title information for each block identifies the name of the fans the curb size and the duct transition part numbers needed to transition from the listed duct to the curb. Failure to do so.

Air Ducts - Friction Loss Diagram - A major friction loss diagram for air ducts - Imperial units ranging 10 - 100 000. Most HVAC units are designed to have a 400 CFM of airflow for every 12000 BTU or 1 ton of cooling capacity and 12000 BTU divided by 400 CFM is 30. Identify the volume of air that will be passing through the duct 2. If you consult the duct sizing chart here for flex and round ducts you can see that for 2000 CFM airflow you can choose a 20-inch metal round duct or either 3610-inch or 3012-inch rectangular duct.

In order to maintain velocity reduce duct size. Round up If youre more than halfway to the next larger size round up to it. A rectangular duct with an equal cross sectional area has a perimeter of 387m. Continuing with my 2-ton system example airflow 2 400 or 800 CFM.

Calculate the CFM for Each Room. Use insulated duct or duct board in unheated spaces. The chart is based on metal duct. The reason why the duct cost is lower is because the height of the duct is lower.

Round duct and rectangular duct comparison. The next important unit to know when determining duct sizing is the friction loss rate. To figure out exactly how. Convert Round duct to Rectangular Equivalent.