Re post # 20
On some airconditioning projects I worked on I found that condensers/radiators can act sometimes like that highspeed Delta fan with the downstream tuning vanes and increase/decrease flow through the condenser. PQ curve generally only puts you in the ballpark. OK for comparative devlopment to a point , then I confirmed/tweaked design by leasing Torrington Research's or EBM/pabst flow chambers for final evaluation on fans that my set up was not large enough for.
I never really get "to the bank" numbers until I test with a AMCA SET UP. Bootstapping airflow test set ups in my case usally ended being a hodgepodge. Too much wasted time trying to figure out whether the numbers were good or not.
Time is better spent putting together a reliable test set up rather than customizing each new test and then having to validate it. It takes me all of about 5 min to run a full PQ curve and less than a min. to take a system point like you would on a static radiator fan test. After all what is your engineering time worth? Mine is several hundred per hour
