Complete aircon system design, help with sizing coils (evap & cond)

[mannym]

Hi guys!
I've just registered in this site. I have a huge problem here trying to design an airconditioning system for a computer equipment container.

I worked out a plant capacity of 6.5kW, the ambient temperature being 40 deg C, room tempereature being 12 deg C with 75RH as see level.

I selected a danfoss/maneurop compressor MT028-4 (R22 refr)with cooling capacity of 7.3kW, Power = 2.55kW, To=7.2deg C (satureted suction), Tc=54.4deg C (saturated discharge).

According to my calculations, the THR at the condenser is: 6.5 + 2.55 = 9.05kW.

I have calculated the TD condenser to be: 54.4 - 40 = 14.4 K. I plan to use a fan/fans with 2m/s air velocity.

For the evaporator TD is: 12 - 7.2 = 4.8K. I plan to use a fan/fans with 2m/s air velocity.

Now i want to calculate the area of the evap & condensor coils including the depth (number of rows).

I was thinking that the this formula would help:
Q = U . A. dT.

Lets assume that both coils will be made from copper fins & tubes. I think the U factor can be looked up in the material specificifications. Change in temperature is already determined in TD. and Q is already calculated.
I can obviously find the Area by making A the subject of the formula, but, now how do i know how deep the coils should be?

I know that most coil manufacturers would have the software already to size all the components, but, i want to know how to work it out myself.

Please help guys.

[jana]

Calculate the total external surface area of fins & tubing required to handle the heat transfer. Size the coil & number of passes from this total area.

[Brian_UK]

12°C seems too cold for computer equipment, not a complaint, just interested.