John Hastings's Activities

CIBSE Heat Gain - Error

John Hastings — Fri, 07 Jan 2022 14:27:20 GMT

Good afternoon,

On my CIBSE heat gain calculations I'm getting an error against most of the rooms for the Sensible gain. When I dig into the calculation it's because the mean sol-air temperature is not being calculated correctly and returns a value of NaN as per the third image below. Do you have any ideas as to why this is? I have followed the video tutorials up until now but with my own model so I'm not sure what the issue could be.

Many thanks

Open Buildings - Energy Simulator - Common Partition Walls/Internal Floors/Ceilings

John Hastings — Thu, 06 Jan 2022 11:26:41 GMT

Good morning,

I hope this question finds you well.

I have a little red cross next to the internal floor and internal ceiling surfaces for my ground floor and first floor 'adjacent' rooms. What is the reason for this and will it prevent me performing calculations? (I haven't got round to performing calculations yet)

Clearly a ceiling to one room is an internal floor to the one above. Does the construction type of the ceiling have to be the same as the internal floor?

Lets say I define the internal floor construction for the first floor room as [outside] plaster/concrete/screed/ceramic tiles [inside] (this would account for the ceiling below as well in my case), the ceiling construction for the room below should be nothing as I've defined the entire floor/ceiling combo within the internal floor above? If I had the internal floor as [outside] concrete/screed/ceramic tiles [inside] and the ceiling construction below as just plaster, does the software combine the U values of the internal floor and ceiling?

With partition walls it makes sense as the partition wall for each adjacent room is the exact same construction type and it is a 'common surface', by that logic, do I have to have the same construction type for the internal floor and ceiling for it to be shared correctly as a common surface? If they're defined the same is this what would make the red cross disappear?

Hopefully this makes sense, your help would be greatly appreciated.

Energy Building Simulator - Doors

John Hastings — Wed, 05 Jan 2022 08:52:39 GMT

Good afternoon,

If I have a door that is a steel bar door (Security door) so with significant air gaps and openings, how would I model that within the materials manager?

Effectively there is no thermal resistance created by the door being there so should be modelled as an opening within a partition wall, how do I model this?

Does Open Buildings Energy Simulator model inter room/zone air mixing/changes?

Your help would be greatly appreciated.

Standards for AutoCAD drawings for Floorplans, Define a room function

John Hastings — Mon, 03 Jan 2022 11:07:59 GMT

Good afternoon,

I'm trying to use my own AutoCAD floor plan in Energy Simulator and I have some questions.

Is there a document which has hints/tips for how to formulate an AutoCAD floor plan so it integrates well/correctly with OBD Energy Simulator? Such as making sure the bottom left of the floorplan is at the origin in AutoCad, making sure dimensions are in metres etc.

Also, when trying to 'define a room' it seems a continuous internal traced outline of the room is required to select, do these internal tracings of rooms need to overlap to indicated shared walls, or is it ok if there is a gap between them, how does the software know which thermal zones 'different rooms' are adjacent to each other?

Basically If I have rooms along a corridor for example, as per the second screenshot below (my own floor plan), do the traces of the room outlines need to overlap so that the software knows they are adjacent and share a wall? If there are shared walls between zones for example, surely the floorplan room perimeter traces need to overlap for the software to pick up on this rather than the software assuming each zone has its own independent wall.

Screenshot of the lobby floor plan example

Screenshot of my ground floor plan. The internal room traces do not overlap, does this mean the software will assume all zones have their own walls rather than shared walls?

Ask A Question I

Wed, 22 Dec 2021 05:26:57 GMT

Ask a question in a forum.

BIM QuickStart ES101: Modeling Learning Path

John Hastings — Wed, 22 Dec 2021 14:12:53 GMT

For the

BIM QuickStart ES101: Modeling

Course, is it possible to have .dwg templates used during the tutorial uploaded and accessible so that they can be used and opened by a trainee such as myself. This would help mimic the process better and add training value. Also, I really want to use the .dwg as an example for my draughtsmen and send it to him so he knows how he should be building/creating the CAD drawing.

Also a minor observation, videos 5 and 6 are not in chronological order.

Open Building Energy Simulator

John Hastings — Wed, 22 Dec 2021 10:40:04 GMT

Whilst adjusting defaults manager settings, it appears that the menu is cut off on the right hand side, I cannot put in preset heights for the walls, partitions etc. I am not sure how to resolve this. Please see the screenshot below.