seamus murphy's Activities

Model Builder / 3D Model View - Old Model still showing up

seamus murphy — Tue, 22 Jun 2021 15:42:14 GMT

Hi Shane

Hope you are keeping well?.

I am wondering if I might be able to call on your expertise again.

I am having issues with a model I have drawn up.

The original model was done about two years ago. The building has since changed layouts. I have uploaded the new dxf and traced in the room.

When I go to view the model in 3D viewer I can still see the old Model (Marked with and X in the snip.)

When I deselect a floor in my new model is also deselect thhe corresponding room in the old Model , its like they have been linked together. This is the same for the 2^nd floor.

The first floor seems to be ok.

What I am worried about is when I run a heat loss simulation will the doublicate rooms be getting mashed or read into the new model causing a faulty results reading.

When I go to the heat loss program I can see the old rooms from the old model.

Would you have come across this before , if so is there any trick to fix this or is it a case of re starting over??

Any help is greatly apreaciated.

Snip 1

Kind Regards

Seamus Murphy

From: Shane Regan [mailto:bounce-03FBF8A3-8D24-488A-B7A0-F4C098648C95@communities.bentley.com]
Sent: 14 August 2020 10:17
To: HevacompForum@communities.bentley.com
Subject: RE: [Hevacomp Forum] Running low level pipe work and changing it to high level on the same floor??

Update from Bentley Communities

Shane Regan

No problem at all Seamus, glad that helped.

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HIU SIZING / HIU COLD FEED SIZING / HIU SIMULATION HELP

seamus murphy — Fri, 21 Aug 2020 10:58:12 GMT

Good Morning Shane

I was hoping I might be able to avail of your expertise.

We are designing a large scale development 500+ apartments split in to Block A-H. The development will be comprised mainly of 1,2,3,4 bed apartments.

Each apartment will have their own individual Heat Interface Unit unit for the production / Generation of hot water services.

I have being sizing the water services piping network using Hevacomp Netsy. Piping out individual appliances such as Basins Baths WC ect is ok.

Where we are having some difficulty is in the modelling the numerous HIU cold feeds.

It appears there is 2 different ways of entering the cold feed to the HIU.

Insert a special appliance and Enter the sum of the HWS Loading Units being generated by the HIU

Insert a special appliance and Enter a continuous flow which is representative of the sum of the HWS Loading units

Either way is not a hundred percent correct and oversizes pipework in different parts of the network

When entering the HWS Lu the effect is to oversize the pipework nearest to the HIU. This appears to be caused by the way EN806 is structured so 10 Lu is seen as a single appliance with 10 Lu so the chart is read in such a way that 10 Lu is 1l/s (see chart below with line in red).

In reality the biggest single appliance connected the HIU is a bath so 10 Lu should be read against the single biggest appliance having 4 Lu which gives a figure of 0.52 l/s (see the chart below with line in blue) which is just over half of the other figure.

This effect is carried through to about 150 Lu which is when the branch lines on the below chart start to come together and totally disappears at 300 Lu which is when the branch lines coincide.

A typical apartment has approx. 25 Lu so this effect is very obvious on the pipework serving apartment groupings of 6 or less.

The main system booster works out correctly though and the main distribution pipe from the booster.

If we convert the HIU HWS Lu to a continuous flow pipework at the HIU is correct but the distribution and riser pipework is massively oversized as the continuous flows are being summed together without diversity being applied.

So if we take a 2 bed apartment with 10 Lu on HWS generation as being the equivalent of 0.52l/s and we have a grouping of 6 apartments each with a HIU we have 3.12l/s + 1l/s (the diversified CWS flow) = 4.12l/s

whereas if done through loading units we would have 150Lu (with biggest appliance at 4 for a bath) which is approx. 1.2l/s from the chart.

The end result is an oversized booster set and primary pipework.

We have reviewed the previous topics on the forum but none seem to directly address this issue.

The nearest one we found was this post on cold feed to Hot water Systems https://communities.bentley.com/products/building/performance/w/building_performance__wiki/27598/including-hot-water-system-feed-in-your-cold-water-system ,

But this seems to be based on a single point of hot water generation in a system e.g. a central large capacity calorifier and not lots of smaller hot water generators spread over the water service network e.g. HIUs, Electric instantaneous water heaters, or individual calorfiers in each apartment .

I am wondering if you ( Hevacomp) have come up with a solution / work around to correctly simulate HIU’s within a piping network and how is this best achieved.

Your help and attention to this matter is greatly appreciated.

If it would suit you , myself and Daniel are free today if you would like to organise a conference call , where we could discuss the issue in more detail.

Best Regards

Seamus Murphy

Junior Mechanical Engineer

Homan O'Brien • Consulting Engineers

89 Booterstown Avenue Blackrock, Co. Dublin, A94 P2C2, Ireland.

Tel: +353 (01) 2056300 Fax: +353 (01) 2056301

Email: seamus.muprhy@homanobrien.ie Web: www.homanobrien.ie

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Running low level pipe work and changing it to high level on the same floor??

seamus murphy — Fri, 14 Aug 2020 08:14:09 GMT

Is it possible to run low level pipe work and then have it rise up to high level (ceiling Void)???. For context , the pipe work is serving the building at low level and when it entres the building it rises up to high level within the ceiling void. Is the a way to do this or do you have to draw the full pipe network at one constant level, IE low level or at high level?????

When I draw the pipe work at low level and then change it to ceiling level when it entres the building , the pipe work looks like it is at an angle or slopping up instead of having a nice 90 degree upward transiton from ll to hl.

Any help on this matter is greatly appreciated.

Kind Regards

Seamus Murphy

HELP WITH LOAD CALCULATIONS DATA AND TRANSFERRING IT INTO TOTAL BUILDING DESIGN

seamus murphy — Fri, 23 Aug 2019 14:45:41 GMT

I have constructed my hevacomp model in the design database using the load calculation tab along with sizing all my mechanical pipe and duct systems using the pipe and duct sizer netsys tab.

I am wondering if it is possible to transfer all this data into the SYSTEM BUILDER "TOTAL BUILDING DESIGN " tab without having to re model and size all my work that I have already done.

any help on this matter is most welcomed

Regards

Seamus Murphy , BEng , BEng Ord

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Fri, 23 Aug 2019 01:02:46 GMT

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