CALCULATING HEAT GAINS FROM AN ADJACENT SPACE W/ NO SEPERATION

[BIGTIMW]

HI,
I am attempting to claculate a cooling load for a new addation to an existing plant. The existing portion of the plant is maintained @ 81 degrees F in the cooling season. The new addation will be maintained @ 76 degrees F during the cooling season. There is no seperating wall between the new addation & the existing bulding. I have informed the owners that there will be a mixing of air at the end of the existing building and at the begining of the new Addation and that thoes areas will not control well.

Does anyone know how to or where I can find a calculation that will give the heat gain from the exisitng buiding ? Could I mutiply the inside still air U value by the square footage of the opening by the two spaces delta tee? Any help would be appreciated.

Thanks
Tim

 

[lilliput1]

Can't do. You should require partition/doors & pressurize the 76°F area relative to the 81°F. You may be able to use air curtain barrier but air curtain will not work if you require different relative humidity betwen the two spaces.

 

[wilg]

lilliput1 is correct, assuming a still air U-value
and multiplying it by the square footage
of the opening between new area and old area
and multiplying that by the delta-T
will be of little value, basically "still air"
doesn't exist in this case, your initial
message indicates that both areas will be
conditioned.
I have seen validated open area warehouses
with huge vertical airhandlers installed work
in this manner, but close temp and humidity control
is difficult, especially if you are dealing with
a high roof or ceiling.