Zoning exterior with interior room

[illuzionb18c1]

Say I had a split system serving 2 rooms, one being exterior and one being interior space. I understand you should not group these two together on the same zone bc they have different cooling loads. But why can you just not have more air flowing to the exterior room and have the damper in the interior room in more of a 'minimal' position to limits its airflow from overcooling the space?

 

[illuzionb18c1]

nevermind, i think i figured it out. correct me if im wrong.

assuming the exterior wall is west facing...the exterior room will reach peak load at say 5pm, while the interior peak is say 3pm. so if the Tstat is in the exterior room, at 5 pm the indoor unit will be on satisfying the exterior room, while the interior room is being overcooled b/c by 5 pm it is no longer at its peak load.

Im assuming one would have to continuosly adjust the interior damper in order for it to not be overcooled if they were on the same zone?

 

[btuhack]

go back to a jan 10 posting, it may apply to you. regarding exterior zones, try to solve/minimize window problems with window solutions(ext shading, film, drapes, etc) when possible. Also, keep the fan "on" to mix the differences and see where that gets you. return & stat locations matter too, so give it some thought. don't forget to manage the occupants expectations(most important), convey that improvements may be made but the system "is what it is" and will never be ideal.

 

[tys90]

The biggest issue is when the exterior needs heat and the interior needs cooling. The interior is likely to never need heating in most cases, especially if there is a floor above and not a roof.

 

[EnergyProfessional]

continuously adjusting damper = VAV system.

but careful, you can run into the problem needing reheat due to ventilation requirements. Maybe a dedicated ventilation helps.

 

[ChasBean1]

I think you were right in your first assumption. The interior zone might not have a peak at a certain time—all based on equipment and people loads. Interior is generally cooling only and exterior can vary based on sun load.. The zones should be separate. If you want to avoid heartache, separate all like zones (N, S, E, W, and interior vs. exterior).

 

[EnergyProfessional]

in winter you also will need heating in perimeter, but possibly cooling in core zone.