Lighting fraction improvements

[shorowit]

The goal of this change is to allow specifying, e.g.,:

• Interior lighting is 50% LED, 25% CFL, 25% Incandescent
• Exterior lighting is 100% CFL
• Garage lighting is 100% LED

The changes are as follows:

• Adds FractionofUnitsInLocation element to LightingGroup. Description: "The fraction of lighting units in the specified Location, where all the fractions for the Location sum to 1. If a Location is not specified, fractions apply to the entire building."
• Adds "garage" as a Location enumeration choice.
• Allows the same enumeration choices for both LightingGroup/ThirdPartyCertifications and LightingFixture/ThirdPartyCertifications. Adds "ERI Tier I" and "ERI Tier II" as enumerations choices.
• Removes LightingFractions (superseded by this proposal).

Example:

      <Lighting>
        <LightingGroup>
          <SystemIdentifier id='Lighting_Interior_LED'/>
          <Location>interior</Location>
          <FractionofUnitsInLocation>0.5</FractionofUnitsInLocation>
          <LightingType>
            </LightEmittingDiode>
          </LightingType>
        </LightingGroup>
        <LightingGroup>
          <SystemIdentifier id='Lighting_Interior_CFL'/>
          <Location>interior</Location>
          <FractionofUnitsInLocation>0.25</FractionofUnitsInLocation>
          <LightingType>
            </CompactFluorescent>
          </LightingType>
        </LightingGroup>
        <LightingGroup>
          <SystemIdentifier id='Lighting_Interior_Incandescent'/>
          <Location>interior</Location>
          <FractionofUnitsInLocation>0.25</FractionofUnitsInLocation>
          <LightingType>
            </Incandescent>
          </LightingType>
        </LightingGroup>
        <LightingGroup>
          <SystemIdentifier id='Lighting_Exterior_CFL'/>
          <Location>exterior</Location>
          <FractionofUnitsInLocation>1.0</FractionofUnitsInLocation>
          <LightingType>
            </CompactFluorescent>
          </LightingType>
        </LightingGroup>
        <LightingGroup>
          <SystemIdentifier id='Lighting_Garage_LED'/>
          <Location>garage</Location>
          <FractionofUnitsInLocation>1.0</FractionofUnitsInLocation>
          <LightingType>
            </LightEmittingDiode>
          </LightingType>
        </LightingGroup>
      </Lighting>

[GamalielL]

The intended use of the new inputs is not as clear as the old inputs. For instance, you could reasonably interpret that the intent is to sum fractions to one within each location. I assume that the intent is to sum fractions to one across the entire building. In that case it seems it would be easier to use counts than to figure out fractions for each type and location combination.

[shorowit]

@GamalielL Thanks for looking this over and great point about the ambiguity of the fractions. In hindsight, you're right that it is confusing. The problem with requiring counts rather than fractions is that some software tools only collect fractions as inputs and I'd prefer not to force them to make assumptions during HPXML export (or force them to change their interface).

I also just realized that my proposed changes here are really no different than simply adding the fraction field to the LightingGroup element.

So now I'm thinking that I should revert my changes and simply add a FractionInLocation field to the LightingGroup element with a description that makes it clear that the fractions should sum to 1 for a given location. If the Location field is not specified, then presumably the fractions apply for the whole building. This would be a non-breaking change then. Ideally, we'd also mark the LightingFractions element as deprecated for v4, since it's superseded by this more flexible approach.

[GamalielL]

That definitely sounds better. I understand the need to have fraction as an alternative to counts. I had forgot that the LightingLocation list was was so simple. I agree that it could make sense to specify fractions separately for location on the level of those particular enumerations. It wouldn't make sense to do it room-by-room. ᐧ

…

On Fri, Feb 8, 2019 at 10:59 AM Scott Horowitz ***@***.***> wrote: @GamalielL <https://github.com/GamalielL> Thanks for looking this over and great point about the ambiguity of the fractions. In hindsight, you're right that it is confusing. The problem with requiring counts rather than fractions is that some software tools only collect fractions as inputs and I'd prefer not to force them to make assumptions during HPXML export (or force them to change their interface). I also just realized that my proposed changes here are really no different than simply adding the fraction field to the LightingGroup element. So now I'm thinking that I should revert my changes and simply add a FractionInLocation field to the LightingGroup element with a description that makes it clear that the fractions should sum to 1 for a given location if you are using fractions instead of counts. If the Location field is not specified, then presumably the fractions apply for the whole building. This would be a non-breaking change then. Ideally, we'd also mark the LightingFractions element as deprecated for v4, since it's superseded by this more flexible approach. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#165 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AJQHDJpYzibpFXP1NeKuDsNX8f1KaVSxks5vLZ7KgaJpZM4aqkbC> .

-- Gamaliel Lodge OptiMiser LLC www.optimiserenergy.com

[shorowit]

OK, I am much happier with this now. It's fewer changes and is no longer a breaking change. I updated the PR title/description to reflect the current state.

[lirainer]

@shorowit One small typo in the example: I think you should use <Location>garage</Location> for the last group.

[shorowit]

@lirainer Oops. Yes, that's definitely a typo. I'll fix it, thanks.

[shorowit]

Should we remove LightingFractions instead of just marking it as deprecated for a future version?