Air conditioning airflow

[Third_techtrio]

hi any expert out there, i need your help.

One newly rehab air-con on the building i work in was not sufficiently cooling & after analyzing the problem,it seems that the problem got to do with the volume of air on new rehab a/c so i recommend to conduct a traverse.

I just want to what are the normal volume of air per capacity (tonne) of a/c. Hope someone can give any reference or manuals for this.by the way the capacity of unit is 20tonne.

edit: For tonne read Ton

[Toosh]

hi any expert out there, i need your help.

One newly rehab air-con on the building i work in was not sufficiently cooling & after analyzing the problem,it seems that the problem got to do with the volume of air on new rehab a/c so i recommend to conduct a traverse.

I just want to what are the normal volume of air per capacity (tonne) of a/c. Hope someone can give any reference or manuals for this.by the way the capacity of unit is 20tonne.

edit: For tonne read Ton

Hi Have a look at this it was found on GOOGLE you can find most of what you are looking for

http://wayneshirley.wordpress.com/2008/03/28/troubleshooting-heat-pump-systems-recognizing-low-airflow/

regards Norm

[nike123]

It is about 400 CFM per Ton of refrigeration

[Gary]

hi any expert out there, i need your help.

One newly rehab air-con on the building i work in was not sufficiently cooling & after analyzing the problem,it seems that the problem got to do with the volume of air on new rehab a/c so i recommend to conduct a traverse.

I just want to what are the normal volume of air per capacity (tonne) of a/c. Hope someone can give any reference or manuals for this.by the way the capacity of unit is 20tonne.

edit: For tonne read Ton

If you have no idea how much airflow the system should have, then how do you know it has an airflow problem?

[Third_techtrio]

I came up with the idea of an airflow problem when i observed the airflow of other unit (old unit with the same capacity) and the newly rehab unit, the new rehab unit seems to have a high air flow to the evaporator than the old one. I also tried to cover the inlet of one scroll,since the fan-coil unit have 2 scroll, to reduce the airflow and the result is I got a unit sufficiently operating.

[Third_techtrio]

By the way, Lots of thanks for the reply !

[Abby Normal]

the amount of air flowing depends on the sensible cooling load of the space.

400 cfm per ton is a good rule of thumb

you could have a higjly sensible load like a server room and the airflow is more like 600 CFM per ton.

You could have loads that are need a lot of moisture removed like an assembly occupancy, and perhaps the air flow is 300 CFM per ton.

You can have 100% outside air and the ariflow could be 100 to 200 CFM per ton depending on how humid the ambient air was