Lighting

The Room Type Manager Lighting panel contains controls used to define lighting data for use in steady state calculations and energy simulations for rooms of the selected type.

Note: By default, a lighting component containing the data defined in this panel is added to the room hierarchy in the project tree dialog box for all subsequently created instances of the selected room type. The lighting data can be edited for individual rooms by using the corresponding lighting data controls found on the Properties For: Lighting dialog box or globally using the controls found on the Global Changes dialog box’s Lighting data panel.

Setting	Description
New (Lighting data)	Used to create new luminaires for rooms of the selected type. Each of these lighting sub-components’ characteristics can be defined independently. (New) lighting area — When the New icon is pressed, a new properties panel opens containing options for defining the new luminaire. Delete icon — Used to delete the room luminaire.
Name	Used to enter a name for the luminaire. Once entered, the name appears in the property separator bar. Minimize the bar when you are not manipulating the luminaire characteristics.
Design level calculation method	Contains controls used to select the Design level calculation method to be used for energy simulations. Lighting level — A simplified method to calculate the light level in a room. This method is a series of calculations that uses horizontal illuminance criteria to establish a uniform luminaire layout in a space. In its simplest form, the lighting level method is merely the total number of lumens available in a room divided by the area of the room. Illumination per area — This factor is used, along with the room area to determine the maximum lighting level as described in the Lighting level method. Illumination per person — This factor is used, along with the room’s number of occupants (people) to determine the maximum lighting level as described in the Lighting level method.
Lighting level	Sets the lighting level (Illuminance) for the lighting sub-component when Lighting level is selected as the Design level calculation method. Illuminance is the measure of perceived power that comes from light.
Watts per Floor Area	Sets the amount of illumination per area unit of floor space for the lighting sub-component when Illumination per area is selected as the Design level calculation method. Illuminance is the measure of perceived power that comes from light.
Watts per Person	Sets the amount of illumination per person for the lighting sub-component when Illumination per person is selected as the Design level calculation method. Illuminance is the measure of perceived power that comes from light.
Schedule	Used to select a default lighting schedule for the lighting component used in the selected room.
End usage category	Allows you to specify a user-defined end-use subcategory, for instance, "Lighting Conditioned", "Lighting Unconditioned", etc. for the lighting component used in the selected room. A new meter for reporting is created for each unique subcategory. Subcategories are also reported in the ABUPS table. If this field is omitted or blank, the lights will be assigned to the General end-use subcategory.
Exemption	Used to select an exemption from lighting power allowance requirements for the luminaire. Although, most lighting power is subject to the requirements of the ASHRAE 90.1 standard, some lighting for specialized commercial and display purposes, such as outdoor manufacturing, retail display windows, televised sports lighting, theatrical productions, and lighting integral to medical equipment, is exempt. Also exempt are certain lighting systems or portions of systems required for emergency use.
Allowance	Used to select an Allowance type that defines the luminaire as qualifying for an additional lighting power allowance. An increase in the lighting power allowance is permitted in cases where lighting is installed in addition to the general lighting for the room or is used as display lighting.
Area	Used to enter an area the luminaires which qualify for additional lighting power allowances are to illuminate. The Area field is disabled when the Allowance property is set to None.
Luminaire category	Contains controls used to define the lights or luminaires as belonging to a certain category. The available categories are: Recessed fluorescent luminaire without lens Recessed fluorescent luminaire with lens Downlight compact fluorescent luminaire Downlight incandescent luminaire Not-in-ceiling fluorescent luminaire Luminaires add to gains in three ways; Through visible light, through heat or thermal radiation and through convection. The location of the lights relative to the ceiling (recessed, downlights or suspended) affects lighting gains as well. Each luminaire category affects the relative amounts of lighting gain. For instance, the total electric input to typical incandescent lights is converted to 10% visible radiation, 80% thermal radiation, and 10% convective gain. In contrast, the electric input to typical fluorescent lights is converted to 20% visible radiation, 20% thermal radiation, and 60% convective gain.
Return air fraction	For ducted luminaires used in the selected room, defines the fraction of the heat from lights that is directly convected out of the room and into the zone return air (normally into a return plenum).
Fraction radiant	Defines the fraction of heat from the lighting component that goes into the room as long-wave (thermal) radiation for luminaires used in the selected room.
Fraction visible	Defines the fraction of heat from the lighting component that goes into the room as visible (short-wave) radiation for luminaires used in the selected room.
Fraction replaceable	Used to define the maximum fraction of the lighting power that may be turned off and replaced with natural daylighting for luminaires used in the selected room.
Return air fraction calculated from plenum temperature	When on, the Return air fraction is calculated for luminaires used in the selected room by assuming that it is due to conduction of some of the lighting component heat into the zone’s return air plenum and that the amount of the conduction depends on the plenum air temperature. This should only be used for luminaires that are recessed and non-vented. – When off, the specified Return air fraction is used.
Return air fraction function of plenum temperature coefficient 1 & 2	Used to set the two Return air fraction function of plenum temperature coefficients, and are enabled only when the Return air fraction calculated from plenum temperature option is checked. The return air fraction is calculated each time step using the following: `(Return Air Fraction)` _calculated `= C1 – C2 x T` _plenum – Where T_plenum is the previous-time-step value of the return plenum air temperature, and C1 and C2 are the values of the coefficients.