Multi-Family Model: PRF-01 Dwelling Unit Output

I’ve got an issue with the CF1R-PRF-01 not outputting the expected number of dwelling units and I’m wondering if I’m modeling something incorrectly.

I’m modeling a 3 story mixed-use/multi-family building with a total of 6 dwelling units. The first floor has 2 dwelling units, and two retail spaces (not included in the model, modeled separately as nonresidential). Above the first floor are 4 two-story dwelling units that make up the second and third floor. This makes for a total of 6 dwelling units, 2 on the first floor and 4 on the upper floors.

The issue I’m running into is with the upper floor two-story units. The mechanical design of these units is such that the lower floor is served by 1 system / 1 zone, and the upper floor is served by a separate system / zone. When I model 1 system for the lower floor and another for the upper floor, it counts this as 2 dwelling units, even though it should be 1. So on the final report instead of ending up with 6 dwelling units (2 + 4), it is double counting the upper floor units so I’m ending up with 10 dwelling units (2 + (4 x 2)).

How can I model these upper floor units with separate zones, without it double counting the dwelling units?

Topic

[EproUser1500Participant]

If the two systems are completely different this is what I assume we should do. I’m not too sure how to combine the efficiencies

• Heating Capacities – Add them together
• Heating Efficiency – take the average of the two (maybe take a weighted average based on capacity?)
• Cooling Capacity – Add them together
• Cooling Efficiency – take the average of the two (maybe take a weighted average based on capacity?)
• CFM – add them together
• horsepower or fan watts – add them together

Can you verify if these assumptions are correct and if any aren’t provide corrections?

[EnergysoftKeymaster]

A dwelling unit cannot be split across more than one zone, so you will need to combine the zones and systems into one.

[Author]

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