Condensate pipe size 1

[newmind]

I am looking for a pipe size table for ahu condensate to size the pipe connection including the branch and main pipe. Any?

 

[quark]

Use 0.5m/s velocity for pipe sizing. If the size seems to be ridiculously high, use logic. Branch connection will be (generally) equal size to that of condensate tray outlet.

 

[flyrfan]

Google the Manning Equation which is for open channel gravity flow. There is a table in the ASHRAE Fundamentals in Pipe Sizing for water flow (lb/hr) based on pipe pitch.

 

[RossABQ]

Int'l Mech Code 307.2 says you may not reduce from the size of the connection on the AHU.

 

[nails002]

2006 UPC Section 814.0 and Table 8-2 outline minimum condensate pipe sizes based on tons of refrigeration.

Up to 20 tons -> 3/4"
21-40 tons -> 1"
41-90 tons -> 1-1/4"
91-125 tons -> 1-1/2"
126-250 tons -> 2"
Over 250 tons -> Sizing as approved by AHJ

 

[imok2]

The diameter of the drain line pipe should be at least the same diameter as the connection provided on the evaporator’s drain pan.

The pitch of these drain lines is also an important part of the overall installation. It is generally recommended that the horizontal section of pipe have a pitch of at least 4 inches per linear foot. This will be adequate to drain the water away from the evaporator and prevent it from draining too slowly or standing in the line.

Drain lines should be run to an open drain and never be connected directly to a sewer system. This will prevent sewage from backing up into the evaporator in the event the sewage system backs up.