Loss Cooling Capacity?

[rinsoproud]

Hi all,

Do you have experienced using air duct attached on the condenser? Will it cause air-cond to be reduced cooling capacity?

I have been assigned to do calculation of cooling capacity loss from the air-cooled condenser with or without air duct as attached.

The system is indoor unit: Liebert PEX (Precision Air Conditioner), outdoor unit: air-cooled condenser

What factor that we need to do calculation e.g. CFM (in/out), temperature (in/out), etc.?

The air duct's dimension is 850 x 850 x 1000 mm.
We use this because customer needs to reduce noice from condenser.

Please advice.

[Tesla]

I have seen many ducted condensers - but not for noise reduction, to minimise hot air recirculation. For noise reduction I have seen larger slower fans installed. Each system is different and perhaps it wouldn't take a tech too long to remove the hood, measure then put it back on and measure, considering its size. A discharge duct will sometimes increase cooling capacity.

[Brian_UK]

As per Tesla, you may need to change the condenser to one that will handle the increase in resistance.

[Eeram]

Standard fans on aircooled condensers are designed to remove air from the condenser in the easiest form, without any restriction!

If you need sound attenuation, consult the necessary manufacturer. Increase in fan pressure, without increase in airflow will decrease condensing capabilities.

[DEVIL]

I agree with the post before me, but to answer your question of calculation you have to do the next calculation:
Get the air volume of the condenser (preferably from the manufacturer ) , calculate the pressure drop in the elbow, reduction, and duct length.
By taking the fans specifications (pressure drop curve) and calculate what is the actual air volume of the fan for the special conditions (or you can skip all the above and directly measure the air volume in your case).

And then from the condenser's specifications you should find what is the capacity in the specified conditions (air volume of the fan) and extract the difference