View Full Version : Air flow and cooling capacity
jamo1989
02-12-2014, 09:22 AM
Does cooling capacity increase with increased air flow?
frank
12-01-2015, 08:20 PM
Short answer is no.
vijay_study
25-01-2015, 04:34 PM
Hi, room sensible heat = 1.08 x cfm x delta t.
So if all parameters are kept constant then increase in cfm will increase the cooling capacity.
The Viking
25-01-2015, 11:13 PM
Sorry Vijay,
If the energy input and efficiency is constant wouldn't the delta T change depending on airflow?
:cool:
vijay_study
26-01-2015, 01:15 PM
Hi,
Rsh = 1.08 x 1000 cfm x 10 delta t
Rsh = 10800Btu/he
Rsh = 1.08 x 2000cfm x 10 delta t
Rsh = 21600 But/hr.
So if we increase cfm, cooling capacity increases.
Vijay
The Viking
26-01-2015, 02:38 PM
OK,
But what if you only got a 10800Btu unit feeding the indoor coil?
Similary, what happens to the delta T if you got 21600 Btu unit feeding a 10800 Btu coil?
Surely the delta T can't be seen as a constant???
:cool:
chemi-cool
26-01-2015, 03:01 PM
Hi,
Rsh = 1.08 x 1000 cfm x 10 delta t
Rsh = 10800Btu/he
Rsh = 1.08 x 2000cfm x 10 delta t
Rsh = 21600 But/hr.
So if we increase cfm, cooling capacity increases.
Vijay
Not a chance. Dt changes and cooling capacity remains the same.
If you were right with your assumption, you could have cool a 10m by 10m cold room only by increasing air flow with a 1 btu unit output.
Please go back to the drawing board and try again.
The Viking
26-01-2015, 05:11 PM
Oh Chemi,
You never let me have any fun...
:D
vijay_study
26-01-2015, 05:18 PM
Hi, the question here is that, does the cooling capacity increase with an increase in airflow. My point here is that if I supply 1000cfm of air I can remove 10800 But/hr of heat if room temperature is 74degF and supply air temperature is 64degF.
Similarly if I increase the supply cfm to 2000cfm having supply air temperature of 64degF then I can remove 21600Btu/hr of heat if room temperature is 74deg F.
Vijay
r.bartlett
26-01-2015, 06:03 PM
Does a 18k btu rated split give the full 18k btu's of cooling on lo, med and hi or just hi?
chemi-cool
26-01-2015, 06:14 PM
Oh Chemi,
You never let me have any fun...
:D
Isn't fun depends on airflow?
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