Circulation spaces mysteriously included in Crit 3 check

[Wasted Energy]

A model that has had many iterations (to pass SBEM) has mysteriously started to included circulation spaces in the Criterion 3 check.
Some are failing (which of course shouldn't happen as they have transitory occupation).
The rooms included are all clearly within the correct thermal templates with the correct NCM activity types applied.
Not all rooms are being picked up this way - the effect seems random.
I can't see what is causing this or how to fix it.
Any ideas?

[btysoe]

If the circulation spaces have some form of cooling then the solar gain check applies.

[Wasted Energy]

Ah of course, now I see what is causing the problem.

These spaces do not have any installed heating or cooling systems. However, following the convention for indirectly conditioned spaces, they have been assigned the VRF system installed in the adjacent rooms. Hence the Criterion 3 trigger.

Now I'll have to think of a workaround.

Thanks btysoe for the pointer.

Wasted

[Complex Potential]

I tend to interpret that convention as only applying to unconditioned spaces drawing make up air from adjacent spaces like a toilet from a corridor. For your situation I would be changing the offending circulation spaces back to having no system applied.

[Wasted Energy]

I did originally have these spaces as having no system applied, and I agree that this is what should be done.

But when I did this the Ua-calc values shot up as did the heating and cooling demand and then whole project failed Critirea 1 and 2.

So now am thinking of creating a heating system that is an analogue of the heating only parameter of the adjacent VRF and applying this.

Or maybe I should try and find out why the Ua values are re-calculated if there is no heating applied to a space (which is defined as a 'heated or occupied' space), - because I don't think this should happen.

Not sure which way to go.

[Complex Potential]

The criterion 2 fail is happening because you've defined the space as unheated rather than just having no system applied. Keep the space defined as circulation but make sure the system applied is set to none (except for DHW which is always needed).

[Wasted Energy]

To confirm;

I've defined the spaces as 'heated or occupied' with heating defined as none. But this causes the Ua re-calc and the Crit 2 failure.

[Complex Potential]

That's a bit weird. It shouldn't be doing that when using the DSM. Are you using SBEM?

[Wasted Energy]

I'm using SBEM - but I don' think it should happen in either.