shall we consider System effect for Packed units/AHUs while doing ESP calculations?

[drk_in]

Hi frnds,
Y'day while discussing with my manager, I got this doubt. in my opinion, "since mixing box or space for mixing will provided by the manufacturer in the unit design itself, for Air handling units we need not to consider the system effect" . But my manager asked me to consider the same while doing the ESP calculations. As per the literature I got and studied while my Masters degree, all are explained for Ventilation fans only, no ware mentioned that it has to consider for AHU's/PAC's.

Can anyone clarify /give your views about it?

[Goober]

Yep, sure can.....what was that again?

[frank]

The term ESP refers to the resistance of the External Static Pressure - not the resistance of the internal components of the AHU, that is, the external ducting, louvres, attenuators, grilles/diffusers etc.

The AHU manufacturer should be able to provide the pressure loss of the AHU itself, including the mixing section.

[drk_in]

hi frank, thank you for your response. I want to make clear about my doubt. while doing ESP for Fans, we will consider the system effect. But what the query here is, will it be consider while calculating AHU's & PAC's ESP calculations or not? My Manager told for US projects, they will consider it as like as FAN ESP calculations. As per my opinion we should not consider System effect for AHUs. Hope you will got my point. will apreciate your insights about it.