ApacheHVAC for a naturally ventilated building

[JosephG]

You can connect every room together to a common supply and exhaust and just not have any airflow going through the network.

I'm not quite clear on why you'd need to use Apache HVAC. You might be able to get aroung this problem through zone discretisation, and have each discrete zone be heated by a particular system. It really depends on what your simulation objective is.

[JosephG]

I'm going to assume you have several heating systems in several individual rooms of differing size. So if I'm understanding your application correctly, if you know the capacity of the heat output from each component, you don't need to care what the source of heating is, just sum them together, and for each room set the maximum heat output from the existing heating system regardless of its source.

You're correct in saying that rooms can't overlap. But what you can do is discretise a specific room, so that if you really have to have each system be independent of each other, and then put a hole between the room parts so that air can freely move between parts of the room. For this to work you'll need MacroFlo to run during your simulation which will slow things down a bit.

Personally, I wouldn't go down the route of Apache HVAC unless I absolutely have to; you get a better feel for your system, but it is quite time consuming to create (and debug; some of the controls do not work properly)