asked 2023-05-22 09:33:09 -0500

jpierce's avatar

updated 2023-05-22 10:54:08 -0500

Is it possible to add native support for a preconditioning (CERV)/air treatment unit(ATU)/ventilating heat pump(VHP) to BEopt (v3)? The systems I'm looking at are geared toward single-family construction, but I know similar things exist in multifamily, although I believe it is typically shared equipment in that case.

I've tried faking up entries in both v2.8 and v3beta, but the inputs constrain the efficiencies pretty tightly. In the case of v2.8 this seems to have knock-on effects for fan efficacy. The best I could get was 92.5% TRE, 96% SRE, 0.42 W/CFM. I bumped up the efficacy to avoid warnings, but also to try to account for the preconditioning system's energy, although it's not clear this is the ideal means of doing so and is also a best guess given how specifications for this equipment are supplied.

An example of such a device which is HVI listed is the PentaCare-V12, with an SRE of 116%

P.S. The default fan efficacy in v3 seems to be much higher than 2.8 (although both are lower than code), why is that?

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