Cooling Load Calculation Procedure

()

Obtain Building Characteristics

  1. Construction materials.
  2. Construction material properties: U-values, R-values, shading coefficients, solar heat gain coefficients.
  3. Size.
  4. Color.
  5. Shape.
  6. Location.
  7. Orientation, N, S, E, W, NE, SE, SW, NW, etc.
  8. External/internal shading.
  9. Occupancy type and time of day.

Select Outdoor Design Weather Conditions

See http://hvac-eng.com/weather-design-conditions-for-selected-locations/
  1. Temperature.
  2. Wind direction and speed.
  3. Conditions in selecting outdoor design weather conditions:
  • Type of structure, heavy, medium, or light.
  • Is structure insulated? If the structure is heated or cooled, the structure must be insulated by code.
  • Is structure exposed to high winds?
  • Infiltration or ventilation load.
  • Amount of glass.
  • Time of building occupancy.
  • Type of building occupancy.
  • Length of reduced indoor temperature.
  • What is daily temperature range, minimum/maximum?
  • Are there significant variations from ASHRAE weather data?
  • What type of heating devices will be used?
  • Expected cost of fuel.

Select the indoor design temperature to be maintained in each space.

See http://hvac-eng.com/indoor-design-conditions/
  • Estimate temperatures in unconditioned spaces.
  • Select and/or compute U-values for walls, roof, windows, doors, partitions, etc.
  • Determine the area of walls, windows, floors, doors,  partitions, etc.
  • Compute the conduction heat gains for all walls, windows, floors, doors, partitions, skylights, etc.
  • Compute the solar heat gains for all walls, windows, floors, doors, partitions, skylights, etc.
  • Infiltration heat gains are generally ignored unless space temperature and humidity tolerance are critical.
  • Compute the ventilation heat gain required.
  • Compute the internal heat gains from lights, people, and equipment.
  • Compute the sum of all heat gains indicated in items G, H, I, J, and K earlier in this list.
  • Include morning cool-down for buildings with intermittent use and night setup.
  • Take into account excess HVAC system capacity permitted for morning cool-down.
  • Consider equipment and materials that will be brought into the building above the inside design temperature.
  • Cooling load calculations should be conducted using industry-accepted methods to determine the actual cooling load requirements.

How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Comments are closed.