Add Lighting Loads

Lighting loads are the electrical power lighting systems consume within a building simulation. This includes both artificial lighting fixtures and any associated control systems, when applicable. Lighting loads are a critical aspect of energy simulations as they contribute to the overall energy consumption of a building and influence factors such as lighting energy use, peak electrical demand, and the overall thermal performance of the space.

Lighting Loads (W/m²) or (W)

To define Lighting Loads (W/m²) or (W), navigate to 'Spaces' and select the 'Default' Space. Then navigate to 'Lighting'. Next, use the Lighting slider to set the W/m² or W for the Space. 'Latent', 'Radiant' and 'Loss' Fractions can also be specified.

Heat Gains from Lighting Loads

The heat generated by electrical power lighting systems results in zone loads, with the electrical input transforming into heat. This heat is categorised into four fractions: Fraction Latent, Fraction Radiant, Fraction Lost, and a fourth fraction representing heat convected to the zone air. The convected fraction is calculated as 1.0 minus the sum of the Return Air Fraction, Fraction Radiant and Fraction Visible. It's crucial to avoid exceeding a total fraction value of 1.0, as an error message will be triggered otherwise.

Return Air Fraction

The Return Air Fraction is the fraction of heat from lights directed into the zone return air. Specify the Return Air Fraction as a decimal number between 0.0 and 1.0.

Radiant Fraction

The Radiant Fraction is the fraction of heat from lights that go into the zone as long-wave (thermal) radiation. Specify the Radiant Fraction as a decimal number between 0.0 and 1.0.

Visible Fraction

The Loss Fraction is the fraction of heat from lights that go into the zone as visible (short-wave) radiation. Specify the Loss Fraction as a decimal number between 0.0 and 1.0.