HPWH Improvements

[jmaguire1]

Supersedes #932 and #862

Here's the high level TODO list for HPWH modeling, in order of priority (from my perspective):

• Code cleanup: remove any unnecessary EMS programs, any other simplifications we can make?
• Review if default HP input power (0.5 kW) is still a good assumption
• Additional operating modes (e.g., high demand and electric).
• Regular load up commands (top off tank). In the schedules, maybe we use decimal value to indicate load up? IE 125.1 is a "Load Up" command to 125.
• Split systems (including CO2). This is getting worked on as part of a standards funded project, but it's likely that at the end of that project we might need to do a little more validation/testing and add new HPXML extension elements to properly wrap this up. Split HPWHs #1172
  • Reduce minimum ambient temperature for HPWH operation EnergyPlus#9758
• 120 V HPWH #1427
• Confined space impacts: Ben Larson did a ton of additional research on this, waiting to pick his brain on if we ought to change our approach to confined space modeling. This one will require an EMS program. RESNET is considering a proposal in this area. HPWH adjustment for confined space #2009
• HPWH ducting #2096
• Heat Pump Water Heater (HPWH) Interaction Factor #2090
• Combi applications: Will be used during ICF gas HPWH work, currently no E+ limitations we're aware of.
• Multifunction devices (single HP for water heating, space heating, and cooling): Not widely available yet, and we'd need a good amount of information about how exactly the system works before we can do much evaluation of whether E+ is up to it or not. Put on hold until either these gain more market adoption or more users request this.
• Talk to Josh Butzbaugh about HPWH installation location data.
• Add Unmet Hours output metric Add unmet water heater loads EMS program #1502

Also while I'm working on this it would be an ideal time to also address #1085.