Martin Griffith

Hi Claudia, a new version is available, hopefully with this fixed: https://ventsim.com/download/minor-releases/ Please let us know how you go.

Hi Anna, Yes you can do this. Just edit the airway with the fan, go to the Fan tab and enter in a Fixed Power. Note, that the pressure and flow will be calculated based on the default fan efficiency (usually 80%) and electrical motor efficiency (usually 95%). You can check or edit these setting in Setting | General | Airway Defaults. Any questions, let us know.

Hi Martin, these data can be difficult to find. Our best resource for this has been Fire and Combustion textbooks. I don't have the reference we used for these values on me right now but I will find it. We added Hydraulic Oil as a default fairly recently; you may have an older version, or you may just need to restore your Presets. Go to File | New to create a new model and see if Hydraulic Oil appears. Alternatively you can enter it in yourself:

Hi, If you choose to Apply diffusion, then Ventsim will model the phenomenon where gases diffuse downstream of the convecting gas. This will generally have the effect of smoothing out the variations of gas in the mine. It will also slow down the simulation. You will generally see the effect more in slow-moving gas concentrations.

Hi Martin, Currently, there is no way to do this. Probably the best you can do at the moment is set the simulation to run a certain amount of time so that it pauses at the tie you want. But of course, this might not practical if you want lots of screenshots. We will have more of a think about this.

Thanks Claudia, I think I know what the problem might be. I'll post again when the version is ready.

Hi Calen, thanks for raising this. We've fixed this for the next version of Ventsim, which should be available this week.

Hi Calen, we can do this. Note, that the tool returns a single fan curve for one blade angle. Therefore, the maximum motor power for the fan will not necessarily correspond to the power curve you have, it will correspond to the maximum power across all design blade angles for the fan. I will post here again when the new version is available.

Hi Claudia, Thanks for bringing this to our attention and apologies for the inconvenience caused. We've fixed the first issue you've reported; we are releasing a new version of the software today or tomorrow which will have this fix. I'll post here again when it is available. The second issue we haven't been able to reproduce. To clarify, airway profile changes are sometimes not saving with the model save? Is this for applying custom shape profiles? We will keep investigating this.

Hi Calen, Thanks for your question. Have you looked at the Stage dropdown on the Edit Box? With this tool, you can add or subtract airways to any stage. Is this the sort of thing you're after? This doesn't create a detached copy though. Another option you have is to go to the Tools menu of the Edit Box and use the Apply To Specific Stages tool. With this tool, any change you've made in the Edit Box can be applied to any stage. If you apply the change to a different stage, then this will create detached copies of the airways. Let us know how you go.

Just an update: We are still working on this. It looks like we will need to add a feature to be able to do what you want. We'll give you another update soon about what we do.

ventsim.support@howden.com

Merhaba, bu garip ve olmamalı. Mümkünse, lütfen bize modeli gönderir misiniz, neler olduğunu bulalım.

Hi Kevin, I think I understand now. You want the vertical sections to have the same alignment. When you have sections with different alignement, can you check, do they have the same width and height? If you swap the width and height does it fix it? Normally, when you draw a new airway it will inherit the properties of the airway you are starting from. So the only thing I can think of is that the airway is inheriting the width and height around the wrong way. Is this what is happeining? If not, perhaps you could send us the model, if possible, and I'll try to recreate what you are seeing.

Hi, Thanks for getting in contact. Can you please give us some more information: Are you using Ventsim DESIGN or Ventsim HVAC? What method are you using to draw the duct when this happens? Is it possible to get a screenshot of the problem?

Hi Nathan, thanks for your question. I'm not sure what we can do about this. The Exclude option is not really synonymous with the Delete option. Exclude means to exclude from the Air simulation and to zero the airflow, but the airway is still there. We may have to have a think about this. Can I ask how the airways were accidentally excluded? Did you have some airways selected that you didn't know about when you were editing some other airways?

Hi Roy, thanks for the feedback, we've just released version 5.4.3.3: https://ventsim.com/download/minor-releases/ This version has a new setting: Raise this to a higher setting and you will be able to use the slider on the Scale Manager to get big icons. Thanks for the feedback, let us know if there are any problems.

Hi Sebastian, In Ventsim, it is sometimes useful to work with the true density or the apparent density, the difference being that the apparent density is the weight of air per unit volume of dry air, excluding the moisture in the air. Air density is the weight of moist air per unit volume, usually in units of (kg of moist air)/m3 Apparent air density is the weight of dry air per unit volume, usually in units of (kg of dry air)/m3 The terms Mid Entry/ Exit, inlet and outlet refer to the position on the airway where the data is from. A datum at the inlet of the airway is denoted "Inlet", at the outlet of the airway, "Outlet", immediately before wherever the icon is on an airway, "Mid In", and immediately after wherever the icon is on an airway, "Mid Out". You can shift the data in the Ventsim viewer between these 4 positions using the buttons at the bottom left of the Ventsim window:

Hi Martin, The Fire Simulation in Ventsim is set up for modelling underground fires, which behave differently to fires on the surface. Because of this you can't model the surface fire in Ventsim. In terms of the underground environment, what you can model are the effects of the fire on the mine, which would be the intake of smoke and any effect on the underground environment from the loss of whatever is burning, or from an emergency response. For the intake of smoke, you can place a contaminant source on the intake and run a Contaminant Simulation. You can't model how much smoke would actually come in, as this depends on all sorts of conditions outside of the mine which Ventsim can't model. For example, the wind could be blowing such that no smoke at all enters the mine. But the Contaminant Simulation will indicate to you what parts of the mine will be contaminated by any smoke entering, as well as how long the smoke will take to reach each part of the mine. Any secondary effects of the fire - such as the fire somehow causing a fan to fail, or a regulator changing as part of the emergency response - can be added as part of a dynamic event as part of a MultiSim. Let us know if you want to program such events as part of Dynamic Contaminant Simulation.

Hi Roy, Currently, there is no way to change the maximum value of the Icon Size Slider. The Size Icons in the settings goes beyond this maximum, but this doesn't affect the slider. Is this something that you'd want, a configurable maximum to the Icon Size Slider?

Hi Roy, we have added Attributes | Parallel Airways to the properties in the new version of Ventsim : https://ventsim.com/download/minor-releases/

Hi Shane, We made some improvement here to this calculation: https://ventsim.com/download/minor-releases/ It now uses 75% of the available processors on the computer. Let us know how you go. Other than that, you could possibly try to simplify the surface topography a little, as it's probably more detailed than it needs to be for the Calculate VRT function.

You'll find the airway age already in Rock | Age.

Hi Stephanie, The tool is not foolproof; it requires clean up after. For complicated airways, with small offshoots, or closely parallel sections, as in your image above, you need to fix these manually yourself. Also, the tool does not calculate an airway width. The airway width used is the default airway width, which is set in Settings | General | Airway Defaults | Size Width. You need to adjust the width of the airways afterwards yourself. This is also the case for the Convert Centrelines tool. Let us know how you go.

Hi Roy, I'm having difficulty finding the problem here. Could you possibly send a couple of screenshots of what you mean? Thanks.