Clarifications on Manual Heat Load Calculation

[PS]

Hello All,

I just want to be certain on a few things while doing heat load calculation. Please do advise.

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1. What is the significance of using "COOLING/HEATING DESIGN DAY and DESIGN MONTH conditions" over the "OCCURRENCE PERCENTAGE conditions" while selecting the outdoor weather data? Is the former meant to be used only if we design for extreme conditions? If so, for a typical commercial office space, is it sufficient to use the 1% values based on the occurrence(for cooling)?

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2. While computing CLTD, values are being read out for standard conditions and then they are corrected according to the location, outdoor, and indoor conditions. Here I just want to confirm which data should one use for outdoor conditions? Is it the EXTREME CONDITIONS or the OCCURRENCE PERCENTAGE conditions?

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3. While reading out values for Solar Heat Gain in W/m2, for which conditions do I need to read data? Should I use the DESIGN DAY and MONTH for doing this? I also find the values are printed for 21st day of all months. What is the significance of 21st day?

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4. In what situations do I need to use the "DESIGN DAY", "DESIGN MONTH", and "OCCURRENCE %" conditions for predicting outdoor weather conditions?

Kindly do help me in getting a better understanding on these points.

Thanks in advance.

 

[willard3]

You need to talk to a senior Engineer in your office and ask him these questions.

 

[trashcanman]

PS,

When asking about info in a book or document, how about also mentioning the NAME of the book/document?

On the other hand, congrats for at least having courage to do the hand calculations.

I suggest you obtain a copy of design books by Carrier, Trane or ASHRAE Handbook of fundamentals. They all explain how to do manual calculations.