Apache DSM for Part L2 (2013) not picking up shading

[wyliecoyote]

Any more thoughts on this gentlemen??

Regards

[Complex Potential]

Without being able to look directly at the model it is difficult to offer more advice. The good news is that your model is seeing and accounting for the shading. The bad news is that your BER and TER apparently remain the same which feels odd.

Maybe double check the BER/TER results between those models and make sure you are reading them correctly?

[wyliecoyote]

AS far i know, im reading them correctly, correct me if im wrong!

this is the model with the shading

[img][img]http://s2.postimg.org/xvuq5t41h/with_shading.jpg[/img][/img]


thsi is the model without the shading

[img][img]http://s23.postimg.org/d53ohb0p3/without_shadinbg.jpg[/img][/img]

Understandably you of course have to see the model and i appreciate you help

Regards

[Complex Potential]

Ok, so your BER does get slightly better with the shading included, but not by enough to impact the EPC asset rating.

To me, it looks as though it is working correctly.

CP

[wyliecoyote]

Thanks for your help.

Just seems a bit odd that such extensive shading has so little effect.

Anyway, ill keep digging and will update with any more findings.

regards

[Complex Potential]

The cooling load is reduced by about 15% by adding shading which is a decent chunk. But, as you say, the overall result is only reduced by 0.7%.

This would suggest that the cooling carbon emissions are only accounting for about 5% of the total regulated emissions for your building, which could easily be the case. You can check this in the carbon bit of the vista results for your actual building (look at the annual summations) by bringing up the "NCM" bits.

[wyliecoyote]

is this what you are talking about. If so, then these are the results for the shaded building

NCM cooling CE (kgCO2)

Date a_Model With Ceiling Voids.aps
Jan 01-31 26
Feb 01-28 19
Mar 01-31 99
Apr 01-30 311
May 01-31 3597
Jun 01-30 4247
Jul 01-31 6053
Aug 01-31 5696
Sep 01-30 2999
Oct 01-31 958
Nov 01-30 27
Dec 01-31 9
Summed total 24039

And these are for the non shaded building.
NCM cooling CE (kgCO2)

Date a_Model With Ceiling Voids.aps
Jan 01-31 27
Feb 01-28 22
Mar 01-31 169
Apr 01-30 544
May 01-31 4666
Jun 01-30 5460
Jul 01-31 7265
Aug 01-31 6761
Sep 01-30 3749
Oct 01-31 1270
Nov 01-30 34
Dec 01-31 9
Summed total 29975

Regards

[Complex Potential]

Those are the cooling components but the full result is made up of

NCM Heating CE
NCM Cooling CE
NCM Auxiliary CE
NCM Lighting CE
NCM DHW CE

The proportion of the cooling as compared with the combined total is the key thing here. I suspect the cooling is quite a small contributor hence the small effect the shading has overall.

[wyliecoyote]

NCM heating energy (MWh) NCM cooling energy (MWh) NCM auxiliary energy (MWh) NCM lighting energy (MWh) NCM DHW energy (MWh)

Date r_Model With Ceiling Voids.aps r_Model With Ceiling Voids.aps r_Model With Ceiling Voids.aps r_Model With Ceiling Voids.aps r_Model With Ceiling Voids.aps
Jan 01-31 57.4874 0.0234 2.5160 53.3799 40.3080
Feb 01-28 46.6129 0.0271 2.2867 48.4939 36.6427
Mar 01-31 19.2533 0.1004 2.5160 53.3793 40.3080
Apr 01-30 12.4117 0.3321 2.1836 46.6906 34.8279
May 01-31 1.3118 10.6423 2.4063 51.1589 38.4830
Jun 01-30 0.0562 14.6319 2.4030 50.9760 38.4779
Jul 01-31 0.0114 20.0044 2.5160 53.3219 40.3080
Aug 01-31 0.0084 18.6843 2.5160 53.3756 40.3080
Sep 01-30 0.1939 9.0830 2.2933 48.8594 36.6529
Oct 01-31 4.5467 1.9737 2.6257 55.5485 42.1330
Nov 01-30 25.9006 0.0375 2.5127 53.1969 40.3029
Dec 01-31 38.8565 0.0074 2.1869 46.8740 34.8330
Summed total 206.6508 75.5474 28.9624 615.2549 463.5856

So seems like thats the problem.

Its hard to see from the table above but the cooling energy is at 75MWh.

Heating at 206, aux at 28, lighting at 615 and DHW at 463

Could this be down to the g-value im using at 0.39?

[Complex Potential]

I don't think the g value is going to alter things that much considering that the cooling load is probably 60%+ internal gains and fresh air. Cooling is simply a small player in the UK when compared with things like heating and lighting. If you look at carbon rather than energy you'll probably see a slight increase in the cooling proportion (electric has a higher carbon factor compared with gas) but it's still quite small.

Based on those figures, you would be better off focusing on improving your lighting efficiency and, ironically, adding extra shading is probably making that worse (assuming you have dimming controls of course). Don't forget that lighting is on direct electric whereas cooling savings will have less impact due to the energy efficiency ratios of chillers/heat pumps.

As a secondary task, you might want to investigate if your DHW demand is realistic. If you have assigned spaces as changing rooms but they do not have showers, then consider reassigning them as something else because the changing room NCM templates assumes heavy shower usage throughout the day and pushes DHW demand through the roof.

CP