Duct design

1. HVAC
Topic of Notes :
MEP-Duct Design -Constant Velocity Method

2. 1st step First we have to select our Velocity for Hotel Bedroom

3. 2nd step Lets Consider our Machine capacity 5000 CFM and Duct is
 Section A =5000 CFM B =4000 CFM C =3000 CFM D=2000 E= 1000
,F=500 CFM All Branch
 We have 10 Diffuser And Every diffuser we have to supply 500 CFM

4. 1) INPUT: Open Duct sizer and select Condition 75° F and 50% RH Input flow rate 5000 CFM and
velocity 1000 FPM if we take 14” height
2) OUTPUT: We get the value of head loss .042 in WC and equivalent Round diameter 30.3”
and rectangular size 14”*62” inch .We can’t take this size for Aspect Ratio Greater then 4.
SECTION - A

5. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 5000 CFM
and velocity 1000 FPM if we take 16” height.
2) OUTPUT: We get the value of head loss .042 in WC and equivalent Round diameter 30”
and rectangular size 16”*52” inch .We can take this size because it’s less then 4.
SECTION - A

6. SECTION - A

7. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 4000 CFM
and velocity 1000 FPM if we take 16” height.
2) OUTPUT: We get the value of Head loss 0.049 in and equivalent Round Duct diameter 27.1” and
rectangular size 16”* 40 ”. We can take this size because it’s less then 4.
SECTION - B

8. SECTION - B

9. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 3000 CFM
and velocity 1000 FPM if we take 16” height.
2) OUTPUT: We get the value of Head loss 0.058 in and equivalent Round Duct diameter 23.5” and
rectangular size 16” * 30 ”. We can take this size because it’s less then 4.
SECTION - C

10. SECTION - C

11. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 3000 CFM
and velocity 1000 FPM if we take 16” height.
2) OUTPUT: We get the value of Head loss 0.058 in and equivalent Round Duct diameter 23.5” and
rectangular size 16” * 30 ”. We can take this size because it’s less then 4.
SECTION - C

12. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 2000 CFM
and velocity 1000 FPM if we take 16” height.
2) OUTPUT: We get the value of Head loss 0.074 in and equivalent Round Duct diameter 19.1” and
rectangular size 16” * 19 ”. We can take this size because it’s less then 4.
SECTION - D

13. SECTION - D

14. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 1000 CFM
and velocity 800 FPM if we take 19” Width.
2) OUTPUT: We get the value of Head loss 0.065 in and equivalent Round Duct diameter 15.1” and
rectangular size 10” * 19 ”. We can take this size because it’s less then 4.
SECTION - E

15. SECTION - E

16. 1) INPUT: Open Duct sizer and select Condition 75 ° F and 50% RH Input flow rate 1000 CFM
and velocity 1000 FPM if we take 8 ” height.
2) OUTPUT: We get the value of Head loss 0.1 in and equivalent Round Duct diameter 10.7” and
rectangular size 8” * 12 ”. We can take this size because it’s less then 4.
SECTION - F

17. SECTION - F

18. Put the all value from Excel sheet to Duct SLD and then started to drawing In Autocad