# Ventilation duct simulation results

#1

Hello,

I am trying to design my own ventilation ducting and simulate the results using SimScale. My goal is to install a system which would cost at most 2000€ so I will get standard ducts and fitings from airguru.ro and perhaps a Vents VUE 250 ERV. So far I feel I am making progress but I need some feedback from you guys to see if I’m on the right track.

Basically, here it’s a duct connected to an ERV capable of 250 m^3/h (150 cfm) and which sends air to 4 outputs.
I estimate that air requirements on each output are 50 m^3/h (30 cfm) but I have no ideea how to actually verify if those requirements are met.

The link to my project is this:
https://www.simscale.com/projects/bogdanr/ventilation/
and the OnShape model can be accessed here.

I have two slightly different simulations. In a second version I decreased the size of two of the ducts. Is that any better/worse or it doesn’t matter?

Can you please advice how to interpret the results? Does my design make any sense?
Do you have any suggestions for optimizing this?

#2

Greetings @bogdanr,

There’s an easy way to verify if those requirements are being met: by setting appropriate result controls. In this case it sounds like you’re looking for area integrals:

You can select the patches of interest and the software will give you the resulting flow rate in m³/s.

Based on this, you should be able to tweak the geometry and achieve the flow rates you’re looking for

And just in case… keep in mind that air flowing through a pipe can generate quite a lot of noise at high velocities.

/Ric

#3

Hello @Ricardopg,

Thanks for the tips. I tried to do that but either I didn’t select the right thing or my design is completely hopeless.

From what I understand, this chart tells me that the flow rate is ~12m^3/h (0.0035*3600) ?! My understanding by looking at velocities and multiplying it with the area of the output is the flow rate should be at least double. Also, I am putting in 160m^3/h (1m/s through 12cm pipe) and I am getting out less than a quarter of that. What am I missing here?

#4

Hummm… flow rate wouldn’t be 160 m³/h in this case.

Q (m³/h) = U * A * 3600 = 1 * pi * 0,12²/4 * 3600 = 40~ m³/h
These 40 m³/h will be divided between the outlets.