Balance point temperature

The 2013 ASHRAE Handbook – Fundamentals, Chapter F18 provides more rigorous methodologies to calculate the heating loads in a nonresidential buildings.

This method only works if large quantities of data on the building energy use are available, preferably on a daily resolution.

Best-fit second-order polynomials of the form y=ax2+bx+c are then applied to the plots, which show various levels of curvature across the range of the data depending on the accuracy of the balance point temperature.

Large office spaces, schools and auditoriums are typical examples of internal load dominated buildings where the balance point temperature is around 10 °C (50 °F).

Outdoor conditions strongly affect these buildings due to a lack of internal heat gains.

[5] Balance point temperature is frequently used in modeling as a base by which to calculate the energy demand of buildings due to various stressors.

[6][7] This is achieved by calculating HDD or CDD based on the balance point, and extending these results to estimate energy use.

Internal and external heat gains and losses in a building.
Internal and external heat gains and losses in a building.
An example of determining a building's balance point temperature using the energy signature method.