Mixed mode natural ventilated and air conditioned model Honeybee 1.4

[cerianipascual]

Hi @SaeranVasanthakumar, thank you very much for your suggestion, sorry for my delay.

I am having some problems with this solution. I set the natural ventilation as shown in Fig. 1. And the SetPoits are defined as Fig. 2. But something is wrong because HoneyBee is opening windows and using heating and cooling throughout the whole year. As the balance plot shows in Fig. 3, obviously something is going wrong because natural ventilation is greater in winter than in summer. In winter the room needs a big amount of heating energy but at the same time is using natural ventilation. Of course, this is not logical, since in winter we should not open the window and turn on the heating. And on the other hand, the balance shows that in summer use some heating, another illogical result.

Fig. 1.

Fig. 2.

Fig. 3.

I take a quick look at the results in excel. It is clear that something is wrong since is considering the window opened at the same time that is using heating as shown in Fig. 4.

Fig. 4.

I know that I could set a min_ou_temp to control the natural ventilation in the winter season, but the problem is that this temperature it is also used in summer, which is a problem because in our climate we have summer nights with low temperatures, good for night cooling. Can you imagine any solution?

Another thing I was thinking is, in my logic, I should set the min_in_temp_ and max_in_temp_ with a degree difference to avoid calculation problems. Because if I set both equals, heating and cooling setpoint and natural ventilation min and max, the program will use turn on both at the same time. What do you think about that? Do you think I should place one degree more than the heating setpoint and one degree less than the cooling setpoint, in the minimum and maximum ventilation temperature respectively?

At the same time to deal with the heating problem during the summer season (Nov, Dec, Jan, Feb, and Mar), I used the Seasonal Schedule proposed by @chris as shown in Fig. 5.

Fig. 5.

When setting the cooling schedule, it is found that the seasonal schedule does not work, while the heating schedule works,

Actually, I have an update and I figured out what is going on. There’s no bug in EnergyPlus or OpenStudio. It’s just that the summer design day schedule of the Seasonal Schedule is set using the _base_schedule. And, in your case, the base schedule is a 50C cooling setpoint: [image] So your cooling system is effectively sized to zero since there’s no cooling demand when the thermostat setpoint is at 50C. An easy way to address this is just by flipping the _base_schedule and the _season_sched…

Maybe it’s a bit difficult to follow my logic, but I appreciate any possible suggestion.

Thank you very much.

Pascual.