[armins]

Hello all,
I'm new in CCM+. I want to model the temperature profile inside a building. I have an AC inlet and some outlets. I was just wondering how should I define physics of my model. One solid for walls and one multi component gas for internal air?
Thank you so much in advance.

[me3840]

I mean that sounds fine, but you need to give far more detail to get more complete help.

[armins]

Originally Posted by me3840

I mean that sounds fine, but you need to give far more detail to get more complete help.

Thanks for your kind response.
I have a house with 3 bedrooms, dining room, etc. I have an AC connected to to the house. I have around 30 outlets. So The cooled air from AC goes through all section of house and grab the heat and exit from outlet. So we can hold thermal comfort inside the building in summer season. I have a lot of windows and doors. Also I have an attic. So I have a lot of heat flux from the outside.
I want to find temperature profile in each room. To doing this instead of mesh external walls, windows and doors, I've used Surface wrapper to grab internal air and just mesh the inside air which goes through each room. However, I got wrong answers. I've thought maybe this way is not correct and I need to solve simluation from external walls, windows, etc. For doing this, so I have a solid region( For external bodies) and a multi component gas (for inside air). But I'm not sure about. It would be highly appreciated to let me know your kind comment.

[me3840]

Why would you need multi-component gas? What's the other gas (besides air)?

How do you know your answers were wrong? What were you measuring? How were they wrong?

What are the 30 outlets? Typically in a house with the AC on, the air inside the house is desired sealed.

I'm not sure if in this problem the solids are necessary, but if they are dealing with the walls is very complicated since they're not just simple solids. I suspect for a model this large you have to 'fudge' some sort of thermal conductivity to get the right answer to simplify the geometry. In that case you will never get the correct answer, your model is just being tuned.

Are you using solar radiation in this?

Some parts may be dominated by natural convection, you will need to ensure you set up your reference density correctly.

[armins]

Originally Posted by me3840

Why would you need multi-component gas? What's the other gas (besides air)?

How do you know your answers were wrong? What were you measuring? How were they wrong?

What are the 30 outlets? Typically in a house with the AC on, the air inside the house is desired sealed.

I'm not sure if in this problem the solids are necessary, but if they are dealing with the walls is very complicated since they're not just simple solids. I suspect for a model this large you have to 'fudge' some sort of thermal conductivity to get the right answer to simplify the geometry. In that case you will never get the correct answer, your model is just being tuned.

Are you using solar radiation in this?

Some parts may be dominated by natural convection, you will need to ensure you set up your reference density correctly.

Many thanks for your kind response. Actually I have an evaporative cooler. Typically,the mixture using in evaporative cooler is water vapor+ air . So we have to choose multi component gas to be able to enter the relative humidity . If we don't have outlets, then we the relative humidity will be increased which definitely bothers residents of the house. The goal is to track how the relative humidity will change in building since the mixture will get the heat and for sure humidity will be changed. However, I can see that the humidity remains constant in everywhere! This is one reason that I know the answer is not correct.
Second, I've used Carrier HAP software which is a strong software to calculate cooling load in the building. and The CCM+ results for heat flux is much less than Carrier HAP.
One problem that I've found is that since I've activate solar calculator , we should have different heat fluxes based on the direction of the walls, window,etc. Because the radiation is different in each direction. However, the fluxes is same in all direction!
I've even asked CCM+ support and even I have sent my sim. file but they don't have any response for me. The last response was : You can't track changes in humidity in CCM+ ! For sure it can't be true.

[me3840]

I still don't understand your boundary conditions. Why are there 30 outlets? What are they doing? The AC should remove humidity by condensing vapor in the air, but the air in the house is essentially sealed. If you are using simple inlets and outlets there is no mechanism in the model to remove humidity and it will stay the same, that makes sense.

Can you please post a diagram of your geometry and explain how exactly you're modeling the air conditioner, what all the boundary conditions are and what they are intended to model.

When you say 'heat flux', where is it being calculated?

It looks like you have a simple setup problem with the solar radiation model, I highly recommend you go through the tutorials to learn to use it.