Issue overview

The calculation of the cycling ratio CR, here, always returns 1.0 because miniPLR_mod = this->minPLR, here. In this paper, CR is only calculated if the PLR is below the minimum modulation fraction (for the unit tested it is 0.25). For this unit the minimum cycle time is 45 min so it's minimum PLR is 0.75 * 0.25 ~= 0.2. So unless I am missing something, I think that perhaps we need a new input (perhaps something like Minimum Unloading Ratio to be consistent with the chiller objects) to calculate CR. Its value would have to be < 1 but > the minimum PLR and CR would be calculated if PLR_min <= PLR =< Minimum Unloading Ratio. The paper shows that CR = PLR / PLR_min but I think that it's actually CR = PLR / Minimum Unloading Ratio so for the unit tested in the paper we would have CR = PLR / 0.25.

Operating System (Multiple choices)

Windows

Operating System Version

11

Version of EnergyPlus

25.1

Unmethours link or helpdesk ticket number

N/A

Defect file

No response