heat load calculation

[dowdeswell]

Summer's here with a vengeance. Store which was cool last month is suddenly not cool...a ship load of merchandise arrived - clothing. How much is this a factor to contend with?

[bruiseandy]

not a factor to really worry about at all as the clothing cannot add a heat load to the building. It's probably hotter than a month ago, I'd look at that and maybe redo the calculation. you have at least 1cfm per cu ft and the tonnage to match that?

[hvac3901]

alot of details have been left to speculation. the only thing that the addition of clothing could cause would be the initial infiltration and "pull down" if you will, of the clothing. after that any fault of the ac system would be that of tonnage, operation outside of design, system failure, or obstructed air distribution from the warehouse stock. another factor could be increased work levels from the introduction of stock? you did'nt mention the system, installed?

contrary to some misconseptions, the ASHRAE design tables are only based on 90% operation i think? that would mean 90% of a year it will meet the load requirements. it seems to me here in california that that 90% gets exceeded pretty frequently. there is one building of mine i rarely do more than check unit operation on exterior zones when outside design. i'm not talking about one or two degrees, i mean design of 86db and 80wb, operating in 98db and 85wb, and thats with air-cooled condensers mind you which as you know makes it even worse.

if you are going to use a typical cfm requirement for troubleshooting i would look one up, one cfm is probably too low for a store, i doubt you would even get one air change with that in most stores.

[trimble]

Originally posted by hvac3901
alot of details have been left to speculation. the only thing that the addition of clothing could cause would be the initial infiltration and "pull down" if you will, of the clothing. after that any fault of the ac system would be that of tonnage, operation outside of design, system failure, or obstructed air distribution from the warehouse stock. another factor could be increased work levels from the introduction of stock? you did'nt mention the system, installed?

contrary to some misconseptions, the ASHRAE design tables are only based on 90% operation i think? that would mean 90% of a year it will meet the load requirements. it seems to me here in california that that 90% gets exceeded pretty frequently. there is one building of mine i rarely do more than check unit operation on exterior zones when outside design. i'm not talking about one or two degrees, i mean design of 86db and 80wb, operating in 98db and 85wb, and thats with air-cooled condensers mind you which as you know makes it even worse.

if you are going to use a typical cfm requirement for troubleshooting i would look one up, one cfm is probably too low for a store, i doubt you would even get one air change with that in most stores.

I believe that is 97.5% of the year it will meet the load requirements.