Martin Griffith

Hi Fred, To do this you could fix a temperature at the inlet. Make a small airway at the top of the shaft, scroll down on the Heat tab of the Edit box, under fixed data, you can set the temperature there. It would be a good idea to place a text box there explaining what the fixed temperatures represent.

Buenos dias Esmeralda, Probablemente no hay ruta por el aire hasta o desde esta ventilador. Verificar que tienes dos conneciones al superficie en el modelo y que todos los conductos de la ruta del aire estan de hecho connectados. Si quieres, envianos su modelo o imagenes de la problema.

Hi Stephanie, I'm not sure what this could be. Are there a lot of reference graphics in the model? These can increase the file size considerably. If that's not it, could you please tell us which version of the software you are using (Help | About) and send us the model? You can either send it to me through the forum direct messaging or send it to ventsim.support@howden.com.

Hi Toma, You can use the Inherit tool. Open in Ventsim the model that you want to bring the fan into, then go to File | Inherit and select the file that has the fan that you want. This will open the Inherit window. Expand Presets and then Fans and you can pick which fans you want to bring in to your model.

Hi Manuel, Try selecting the airways with the measuring tool rather than the select tool before running the tool. Also, run the Air Simulation to make sure everything is connected. If it still doesn't work, please send me the model via message and we will work out what is happening.

Hi Mick, thanks for your question. The answer is no, Ventsim will not adjust the area of the tunnel for the ducting, you need to do this yourself. The most straight-forward way of doing this is to add to the Obstruct property of the airway, on the first tab of the Airway Edit Box. Doing this will reduce the cross sectional area of the airway used in the simulation.

Hi Manuel, this feature should be working. Can you let me know what version of the software you are using (Help | About) ? If you are on a version earlier than 5.4.6.4, then you may need to update to the latest version from our website.

Hi, if you have a reference graphic for the surface, you can select all your airways, go to Tools | Filter | Calculate VRT and this will estimate the VRT based on the distance to the surface graphic.

Thanks Fred for the suggestion. We will try to do that for the next version.

Hi Toma, The piston effect tool is a feature only available with a Premium license.

Hi Nathan, That Move Airways tool has a unit conversion problem. We will fix it. For now, I suggest you use the standard Ventsim Move Tool to do this. Thank you for bringing this to our attention.

Hi Jacques, you either have a firewall or lack admin rights to update the software. If you go to our website you can download and install the new version from there. https://ventsim.com/download/currentdownloads/

Hi, for some mines, for example shallow ones, compressibility is not a big factor, so they use incompressible air. But most deeper mines have Compressible Flow enabled. You can do this in the Settings menu of the main Ventsim form. After simulating you should see changes in air density around your model.

Hi Ryan, Open the Visibility Manager with the button with the blue cog and then click on Data Value. You may need to switch the On button back and forth first. This is not behaving exactly as intended, so we will take a look to improve it.

Hi Bao, One way of ventilating the heading is a long duct as you mention. Depending on the properties of the duct and the fan feeding it, there will be a maximum length and beyond this the duct will be unable to provide adequate airflow. When this is the case, a new vent rise can be mined from the lowest exhaust down to the developing decline. A regulator will be required on the exhaust airway for the level above. This will force airflow down the decline to the return air access intersecting the decline closer to the face. The fan can be hung just above the return air access to reduce the length of ducting required to reach the face. I've annotated your screenshot below, see the red:

On the Fire and Safety tab of the Edit form you can now also specify a Refuge Bay Name and it's operational status, to help you keep track of the refuge bay system in the mine. You can also use the Spreadsheet Tool to generate a report about the refuge bays

Hi Roy, Thanks for the suggestion, we have added bookmarks to the Ventsim manual for the next version out of the software, it should be out soon. regards, Martin

Hi, A good place to start is the manual, page 91. The shock loss is modelling the loss of pressure from changes in airflow direction and airway size. When the airflow has to go around a corner, an amount of energy is lost in reestablishing the flow in the new direction, as compared with if the airflow didn't change direction. The amount of pressure loss will increase the faster the flow is going, so for the purposes of your Ventsim model accuracy, you should focus your attention on intersections with the greatest velocities. A good idea is to change your property in Ventsim to velocity, go to the highest velocity part of the model and look for any big changes in direction or airway area. In the airway immediately downstream of the intersection place an auto-high shock loss and resimulaute. There is a property called Pressure | Loss Shock which will tell you how much pressure you are losing at the intersection; you can compare this to the amount of pressure that your fans are adding to get a feel of the importance of shock loss.

Hi Fred, Thanks for your question. Although you can see thermal properties for the duct, such as VRT in the airway Edit Box, these are not used. When you build a duct, Ventsim remembers it's a duct and does not add any geothermal heat from the duct. In the Duct Builder Box you will see the duct heat transfer preset option, with thermal conductivity etc. This is to model the heat transfer between the air inside the duct and the air outside the duct. If you have high temperature outside the duct, this can heat up the air inside the duct. This heat transfer does not happen by default; it can also increase the time it takes for your Heat Simulation to converge. But if this heat transfer is something of interest to you, then you can select a Duct Heat Transfer preset and Ventsim will model it. There is also a setting in the Heat Settings that lets you toggle this effect on and off for the whole model. There are also properties in the Heat category that will show you the amount of heat transfered, which will also appear in a path graph generated from the Measuring tool. There is more of an explanation here:

Hi Rich, you can go to File | Icons | Clear Icons to get rid of them.

Hi Rich, thanks for your message. Correct, it detects the diameters of the connecting pipes and applies a contraction or expansion as appropriate. If there is no change in diameter of the connected pipes then Pumpsim applies it either as an expansion or a contraction, but you shouldn't be using this junction type on a node that doesn't have a change in pipe diameter. Hope this helps.

Hi Gavin, it's hard to tell what is going wrong. Send us an email at ventsim.support at howden.com and we will work out what is going wrong. regards, Martin

Hi Dante, A few things to check. Make sure you you're connected to the internet and make sure you do not have any firewall blocking access to the license server. Also, check your license details. Make sure to copy and paste each field into the license manager rather than typing them in. If it still doesn't work, send us an email at support with your version number and license number and we will work out what is going wrong.

Hi, You can adjust the speed of a pump in the percentage field on the pump edit form. If this doesn't work for you, let us know, or send us your model at ventsim.support at howden.com.

Hi Fred, I'm not sure what would have gone wrong here. If you like, email us the .dxf file and we will work out what has gone wrong (ventsim.support at howden.com) Martin