Baseline and Proposed Lighting Via PRM

[NebK22]

Hi All,

I'm having trouble setting up my baseline and proposed lighting using the PRM manager.
Prior to the adjustments, I've already had the baseline generated and the lighting load match in both proposed and baseline. I'd like to lower my proposed lighting to 0.5.
Here's what I'm doing...

1) Under Internal Heat Gains -> Lighting -> Change the Proposed LPD from 0.7 to 0.5 W/ft^2
2) Check my proposed internal lighting and it's set to 0.5, wonderful!
3) Check my baseline internal lighting and it's still at 0.7, woo!
4) Regenerate baseline model and the baseline drops from 0.7 to 0.5 to match proposed.

Afterwards, I get this:


Should I be skipping the regeneration step to keep my baseline lighting at 0.7?

Any help would be appreciated as always

[farahghanem]

eh... I've had numerous problems with the ashrae navigator in IES where it keeps reset or changing the inputs randomly. It shouldn't be doing that to your LPDs for sure.

There's two ways to fix this:

1. If you really want to regenerate the baseline, then after you do so, check if the LPDs (and any other inputs for that matter) has changed. If yes, then go to the ASHRAE 90.1 Compliance module (under applications tab) --> select the baseline from drop down menu in model area --> select all rooms --> open tabular room data ---> under room conditions, make sure the gain inputs are set to "from template".

2. Skip regeneration (you only really need it if you changed geometry or HVAC I believe).

Honestly, I'm starting to lean towards not using the navigator at all, and doing everything through the modules, it just seems too buggy...

Hope this helps.

[NebK22]

Farahghanem,

As always, thanks for the response!
I'll try both methods to fixing this. I was under the impression that I should always re-generate the baseline model in the navigator after any changes.

According to the ASHRAE 90.1 PRM User Guide:
"Generate the Baseline Model
This is a very important step in the navigator workflow as it essengially assigns all model data setup in previous navigator steps. If any changes are made to navigator steps after the generation of the baseline models, the baseline models must be re-generated in order to assign updated model data i.e. lighting, ventilation rates, etc...."

Although if I am just changing the proposed lighting values, it sounds like I don't have to regenerate the baseline model. However, I feel like the navigator really shouldn't be changing the baseline lighting value to the proposed lighting value.

Thanks Farahghanem!

[farahghanem]

no problem, glad I could help.

please share with us an update when you resolve this, I'm interested to see what happens for you