Graphic representation of internal gains distribution
The initial investigation for the building included the design of an air delivery heating, cooling and mechanical ventillation system for the pretense of traditional building design and rental value prospects. With the potential for a passive facade system, is it possible to use mechanical ventillation for ventillation only and omit the heating and cooling component entirely...
Heat Balance and Environmental Control Passive and Actively Controlled Scenarios
AT3 Part 3a
Web Design Office Initial Duct Layout
Internal Gains Zoning Strategy Zone 3: North Envelope surface area 80m2 Volume 416m3
Zone 5: WC’s Volume 193m3 Zone 6: Kitchen Volume 41m3
Zone 2: West Envelope surface area 120m2 Volume 570m3 Zone 4: Internal Rooms Volume 240m3
Zone 7: Lobby and Stairwell Volume 1255m3 (conditioned independently)
Zone 1: South Envelope surface area 80m2 Volume 498m3
3d massing model demonstrating extent of shading (July, Noon)
-Floor Plan segmented into North, South and East -Internal rooms i.e. WC’s, meeting rooms, kitchen are not influenced by direct solar gains -Similar scenarios for heat balance based on orientation -Negative pressure in WC’s with MVHR extraction -Seperate zone for circulation at lower operative temperature than working space, with potential for feature heat source e.g. fire in reception lobby Heat Balance Calculations and Tout Qi + Qs ± Qc ± Qv ± Qmec = balance 1) Climate adaptive: Qi + Qs ± Qc ± Qv = 0
(-Qi) + (-Qs) + Qc + Qv = ± Qmec Cooling = negative (-) Heating = positive (+)
Floor Area (m2)
CFL can light lamp desktop and monitor laptop phone charger telephone power pack server photocopier laser printer kettle microwave Dishwasher Fridge Freezer Vending Machine People
wh gains Summer (each) 288 320 61.232 36.464 10.32 20.64 928.8 4004.16 219.3 140.18 172 615.76 103.2 412.8 258 112.24
wh gains Winter (each) 1440 1600 120.328 71.656 20.28 17412.408 1825.2 7868.64 430.95 275.47 338 1210.04 202.8 811200 507 223.56
No. gains 9 0 1 8 0 1 0 0 0 0 0 0 0 0 0 15
Total kwh equipment Total kwh floor open plan zone (floor area/3) South kwh/m2/day North kwh/m2/day West kwh/m2/day
Conference 1 53.4 kwh Summer 2592 0 61.232 291.712 0 20.64 0 0 0 0 0 0 0 0 0 1683.6
kwh Winter 12960 0 120.328 573.248 0 17412.408 0 0 0 0 0 0 0 0 0 3353.4
4649.184 87.06337079
34419.384 644.5577528
No. gains 7 0 1 15 0 1 0 0 0 0 0 0 0 0 0 8
Conference 2 32.4 kwh Summer 2016 0 61.232 546.96 0 20.64 0 0 0 0 0 0 0 0 0 897.92
kwh Winter 10080 0 120.328 1074.84 0 17412.408 0 0 0 0 0 0 0 0 0 1788.48
3542.752 109.3441975
30476.056 940.6190123
No. gains 2 0 1 0 0 1 1 0 0 0 0 0 0 0 0 0
Server 8.4 kwh Summer kwh Winter No. gains 576 2880 2 0 0 0 61.232 120.328 0 0 0 0 0 0 0 20.64 17412.408 0 928.8 1825.2 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 3 1586.672 22237.936 188.8895238 2647.37333
-Possible low thermal mass of facade and internal walls means hydronic systems would be much less efficient, and spaces are zoned accordingly so that air is instantly heated or colled only when necessary-radiators not left on unecessarily, time to heat up or cool down minimised for intermittent use.
Qi + [A. η.SHGC.G] (Σ[A.U]+Σ[L.K]+[0.33.N.V]x24 )
Tin
2614.66 817283.99 198.080303 61915.4538
2220.196 27079.182 77.09013889 940.249375
N Air changes/hour
V Volume air in zone
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (8 hrs) Manufacturer SHGC Qi Internal Gains kwh/m2 (8 hrs) Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qi+Qs+Qc+Qv=
Tin
80 1 0.31 0.76 6277.340261 657.36 16 18.848 6296.188261 673.36 9.350404333 30.35040433 -5622.828261
N Air changes/hour
V Volume air in zone
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (8 hrs) Manufacturer SHGC Qi Internal Gains kwh/m2 (8 hrs) Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qmec Year Qmec kw/h kwh/month
16551.06706
N Air changes/hour
V Volume air in zone
Group 23 Thomas Wakeman, Clarissa Evans, Anna Ronayne Speculative Office Building, 1 Kingsway, Cardiff
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (8 hrs) Manufacturer SHGC Qi Internal Gains kwh/m2 (8 hrs) Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qi+Qs+Qc+Qv=
Tin
21 0.5 498 80 0.2 80 1 0.31 0.76 7438.743798 657.36 16 18.848 7457.591798 673.36 11.07519276 32.07519276 -6784.231798
N Air changes/hour
V Volume air in zone
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (8 hrs) Manufacturer SHGC Qi Internal Gains kwh/m2 (8 hrs) Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qmeckw/h kwh/month Qmec Year
19969.71457
N Air changes/hour
V Volume air in zone
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (24 hrs) Manufacturer SHGC Qi Internal Gains kwh Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qi+Qs±Qc±Qv=
Total kwh/month Annual Heaing Load Total kwh/year heating
Qi+Qs+Qc+Qv= Tin
21 0.5 416 80 0.2 80 1 0.31 0.76 6242 549.12 16 18.848 6260.848 565.12 11.07879388 32.07879388 -5695.728
N Air changes/hour
V Volume air in zone
A Surface area of wall #material 1# m2 Wall U value #material 1# kw/m2K A Surface area of frame #material 1# m2 Frame U value #material 1# kw/m2K A Glazing aperture area G Average Flux Density kw/m2 (24 hrs) Manufacturer SHGC Qi Internal Gains kwh Qv Qc Qstr [(A*U)+(0.33*N*V)]*24) = Tout
Qmec kw/h kwh/month Qmec Year
16765.65097
Qi+Qs±Qc±Qv=
53286.4326 639437.1911
Total kwh/month Annual Cooling Load Total kwh/year cooling
2220.196 27079.182 105.723619 1289.48486
80 1 0.70 0.76 452.6160989 657.36 16 42.7424 495.3584989 673.36 0.735651804 23.7356518 178.0015011
Based on typical office floor area = 1500m2 and benchmark of 113.25 kWh heating/m2, to heat to 20˚C. Increase from 20˚C to 22˚C requires extra 15.38% = 26,134.62kWh/ per year x 0.191KgCO2/kWh = 4991.71KgCO2 /year. Divide by 1.98m3/kg = 2521.07m3CO2/year. Average volume of a hot air balloon is 2500m3. www.carbontrust.co.uk/postercalculations Qmec Qmeckwh/month kw/h Year
523.9560316
23 0.5 498 120 0.2 120 1 0.755 0.76 426.0987802 657.36 24 68.856 494.9547802 681.36 0.726421833 23.72642183 186.4052198
(Qmec Qmec kwh/month kw/h Year
548.6927841
Qmeckw/h kwh/month Qmec Year
7111.885434
North façade
North façade
Tin
23 0.5 498 80 0.2
West façade
West façade
Tin
Qi+Qs+Qc+Qv=
3053.988 64535.646 127.2495 2688.98525
Partner 2 Manager Reception 18 12 70.8 kwh Summer kwh Winter No. gains kwh Summer kwh Winter No. gains kwh Summer 1440 7200 4 1152 5760 7 2016 320 1600 1 320 1600 10 3200 61.232 120.328 1 61.232 120.328 2 122.464 36.464 71.656 1 36.464 71.656 0 0 10.32 20.28 1 10.32 20.28 2 20.64 20.64 17412.408 1 20.64 17412.408 2 41.28 0 0 0 0 0 0 0 0 0 0 0 0 0 0 219.3 430.95 1 219.3 430.95 1 219.3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 112.24 223.56 1 112.24 223.56 4 448.96 2220.196 123.3442222
(right) South solar data showing peaks (See attached document for West and North data)
South façade
21 0.5 498 80 0.2
-Passive design should seek to allow users to open windows into double skin, allowing cross ventillation from the north and also mechanical override of exterior shading, allowing maximum user control on the low-tech scale
Kitchen Senior Partner Marketing Partner 1 13.2 28.8 24 21 kwh Summer kwh Winter No. gains kwh Summer kwh Winter No. gains kwh Summer kwh Winter No. gains kwh Summer kwh Winter No. gains 576 2880 5 1440 7200 4 1152 5760 5 1440 7200 5 0 0 1 320 1600 3 960 4800 1 320 1600 1 0 0 1 61.232 120.328 3 183.696 360.984 1 61.232 120.328 1 0 0 1 36.464 71.656 3 109.392 214.968 1 36.464 71.656 1 0 0 1 10.32 20.28 3 30.96 60.84 1 10.32 20.28 1 0 0 1 20.64 17412.408 3 61.92 52237.224 1 20.64 17412.408 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 219.3 430.95 1 219.3 430.95 1 219.3 430.95 1 140.18 275.47 0 0 0 0 0 0 0 0 0 0 172 338 0 0 0 0 0 0 0 0 0 0 615.76 1210.04 0 0 0 0 0 0 0 0 0 0 103.2 202.8 0 0 0 0 0 0 0 0 0 0 412.8 811200 0 0 0 0 0 0 0 0 0 0 258 507 0 0 0 0 0 0 0 0 0 0 336.72 670.68 1 112.24 223.56 3 336.72 670.68 1 112.24 223.56 1
Active HVAC Sizing South façade
-Zoning segregates circulation lobby space and stairs, as these areas do not need to be heated or cooled to the same extent as working spaces e.g. in winter, people enter buildings with multiple layers of clothes and are hit by a space heated to 22 degrees, this could be much lower or not heated at all, with a feature fire in the main lobby to give the sense of warmth, whilst only maintaining a comfortable entrance temperature. This would be coupled with a well designed vestible to minimise heat transfer with people entering and exiting
-High efficiency open loop ground source heat pump for active HVAC cooling/heating, employing nearby watercourse in place of a closed loop or borehole.
Qv = 0.33 x N x V x ∆T Qstr = A x η x G x SHGC
Zonal Internal gains distribution Room
-Possibility of double skin facade adapted for use with one actively/passively controlled building with self regulating shading on Exterior
-Perimeter supply diffusers for HVAC system, blowing curtain of warm or cool air over glazing, and returned from the center of the space, miminising cold spots and draught effects of conventional supply/return layouts. Zoned accordingly with full override controls accessible to users occupying each space
2) Actively controlled scenario:
Tout=Tin+
Alternative Concepts & Unconventionalities
23 0.5 416 80 0.2 80 1 0.7 0.76 342.1725857 1647.36 384 42.56 384.7325857 2031.36 0.189396555 23.18939655 2416.092586
8184.53425 98214.41099
Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-09 Jan-10 Jan-11 Jan-12 Jan-13 Jan-14 Jan-15 Jan-16 Jan-18 Jan-19 Jan-20 Jan-21 Jan-22 Jan-23 Jan-24 Jan-28
Jan Ave Feb Feb 14 Coldest Day March April May June July Aug-01 Aug-02 Aug-03 Aug-04 Aug-05 Aug-06 Aug-07 Aug-08 Aug-09 Aug-10 Aug-11 Aug-12 Aug-13 Aug-14 Aug-15 Aug-16 Aug-17 Aug-18 Aug 19 Hottest Day Aug-20 Aug-21 Aug-22 Aug-23 Aug-24 Aug-25 Aug-26 Aug-27 Aug-28 Aug-30 Aug-31 August Ave September October November December
27079.182 1504.399
1932.196 161.0163333
25639.182 2136.5985
6068.644 85.71531073
kwh Winter No. gains 10080 60 16000 50 240.656 50 0 40 40.56 40 34824.816 50 0 0 0 3 430.95 6 0 0 0 0 0 0 0 0 0 0 0 0 40 61616.982 870.2963559
Open Plan 138 kwh Summer kwh Winter 17280 86400 16000 80000 3061.6 6016.4 1458.56 2866.24 412.8 811.2 1032 870620.4 0 0 12012.48 23605.92 1315.8 2585.7 0 0 0 0 0 0 0 0 0 0 0 0 4489.6 8942.4 57062.84 413.4988406 137.8329469 452.6160989 342.1725857 426.0987802
1081848.26 7839.48014 2613.16005 6277.34026 6242.39467 7438.7438
SOLAR INCIDENT ABSORBED TRANSMITTED SHADE (W/m2) W (W/m2) W (W/m2) W ----------------------------------------66.00% 0.02 1599 5 366 14 1107 33.00% 0.02 1357 4 311 12 940 66.00% 0.02 1680 5 384 15 1164 66.00% 0.19 15428 44 3518 134 10688 70.00% 0.35 28096 80 6433 243 19464 72.00% 0.39 31330 90 7161 271 21705 66.00% 0.67 53654 153 12274 465 37170 66.00% 0.29 22984 66 5264 199 15923 61.00% 0.04 3045 9 696 26 2109 67.00% 450.00 36024 103 8245 312 24957 67.00% 745.00 59607 171 13644 516 41295 67.00% 1023.00 81829 234 18713 709 56689 67.00% 1026.00 82095 235 18774 711 56874 67.00% 1051.00 84086 240 19229 728 58253 67.00% 523.00 41845 119 9558 362 28989 80.00% 8.00 609 2 140 5 422 67.00% 1035.00 82821 237 18941 717 57377 64.00% 111.00 8867 25 2029 77 6143 67.00% 947.00 75743 216 17317 656 52473 80.00% 35.00 2822 8 641 24 1955 56.00% 60.00 482700% 14 1102 42 3344 33.00% 32.00 255600% 7 577 22 1771 33.00% 5.00 365 1 82 3 253 62.96% 306.65 31446.48 89.91 7191.26 272.30 21785.43 46.00% 479.00 38294 108 8665 332 26529 39.00% 521.00 4168300% 116 9242 361 28877 29.00% 488.00 39029 108 8674 338 27039 27.00% 889.00 71095 186 14914 616 49254 42.00% 805.00 64381 161 12920 558 44602 49.00% 537.00 42988 102 8160 372 29781 47.00% 703.00 56245 138 11033 487 38966 35.00% 149.00 11937 29 2320 103 8270 44.00% 322.00 25735 57 4589 223 17828 44.00% 1731.00 138496 349 27931 1199 95947 44.00% 1822.00 145745 365 29197 1262 100969 40.00% 862.00 68956 172 13765 597 47771 35.00% 1041.00 83264 214 17096 721 57684 35.00% 970.00 77621 198 15843 672 53775 29.00% 85.00 6822 17 1395 59 4726 30% 78.00 6260 17 1335 54 4337 29.00% 1454.00 116348 301 24074 1008 80604 27.00% 78.00 6265 16 1283 54 4340 21.00% 318.00 25417 69 5481 220 17608 27.00% 81.00 6496 17 1342 56 4501 27.00% 1208.00 96642 254 20313 837 66952 36.00% 842.00 67393 173 13804 584 46688 32.00% 1892.00 151357 383 30657 1311 104857 28.00% 1816.00 145293 376 30114 1258 100656 33.85% 1916.00 153293 390 31207 1327 106198 34.00% 1924.00 153888 391 31290 1333 106611 21.00% 318.00 25417 69 5481 220 17608 28.00% 1376.00 110065 281 22441 953 76251 28.00% 1943.00 155416 401 32115 1346 107669 23.00% 1187.00 94921 252 20153 822 65759 26.00% 463.00 37019 96 7680 321 25646 29.00% 96.00 7650 20 1564 66 5300 29.00% 1644.00 131502 348 27875 1139 91102 29.00% 553.00 44274 111 8868 383 30672 25.00% 988.00 79076 210 16825 685 54782 29.00% 229.00 18290 42 3356 158 12671 22.00% 143.00 11438 31 2478 99 7924 37.00% 900.00 71964 183 14652 623 49855 27.00% 861.00 68898 187 14933 597 47731 35.00% 602.00 48123 135 10792 417 33339 65.00% 247.00 19758 56 4505 171 13688 66.00% 135.00 10772 31 2466 93 7463
Worst-case scenario takes coldest and hottest months (Jan Winter, July Summer), based on worst case scenario, with other months producing much less demand for heating/cooling respectively. These values can be used as an initial estimate for heating and cooling sizing, with more detailed facade design changing U values, thermal bridging in frames and the areas of specific materials, the net load can be brought to near passive standards as much as possible
Heat Balance and Environmental Control Passive and Actively Controlled Scenarios
AT3 Part 3a
Active Scenario 1 (Thomas Wakeman)
Passive and Active Facade Strategies Heating and Cooling System Design: Open Loop water-source (Ground Source) Heating and Cooling with floor-specific air handler, ducted supply and extract and MVHR
Automatic sun tracking solar shading louvre systems available from Colt Tollfab by Colt International Pty limited Sun tracking, where the automatic louvres move perpendicular to the projected sun’s rays (vertical shadow angle –VSA). This is used when sunlight needs to be prevented from entering the space. Daylight optimisation, where a balance is struck between reducing heat energy and enhancing light energy. Mathematical algorithms enable the louvres to open to the right amount just to avoid having direct sunlight passing through the gap of two louvres next to each other. PV illuminating, where priority is minimising the amount of shading of the PV cells mounted on the louvres, whilst permitting as much daylight entry to the building as is permissible under this PV shading mode. (The efficiency of cells reduces drastically if they are shaded). Summer Situation: Stale air exits into south double skin facade, aided by the stack effect, reducing pull on fans and reducing operating costs, whilst drawing in fresh air from the north, which is naturally cooler, aiding to cool the building and reduce the air conditioning load. (All facades a glazing panel system with internal manual shading)
Water-source open loop
>Innovative geothermal heat pumps extract the naturally consistent energy from the ground or water body instead of using outside air like traditional heat pumps. Geothermal heat pumps provide both cooling and heating and are able to maintain the highest efficiency on even the coldest winter nights or the hottest summer days. Combined with a large volume thermal store it is possible to further optimise running costs by operating the heat pump using off-peak (economy 7) power during the night and using the stored heat body to divert to the heat exchanger to a certan extent during the day.
Winter Situation: Supply and exhaust ventillation ducts are reversed. Pre-warmed fresh air is pumped from the upper level of the south double skin facade, reducing the heating demand of the system, whilst expeling the stale air to the lower north level.
Active Scenario 2 (Anna Ronayne)
>Refrigerant can be diverted to each floor of the building with independent air handlers, arranged into North, South and West zones respectively. Each zone can be independently controlled thermostatically within the office space, with supply and extract ducts both designed at high level.
The Herringbone Houses, Alison Brooks Architects.
The Cambridge Public Library, Massachusetts, McGraw Hill Construction Double-skin facade has horizontal louvers and laminated-glass visors to mitigate direct solar penetration. (right) Natural cross ventillation from north to south will be aided by the stack effect of the double skin facade. Operable windows and mechanical louvres with manual override optimise the internal environment whilst allowing maximum flexibility for the office users. (North and West facades with much lower % glazing, possibly with timber or brick construction to minimise conductive heat losses
Passive Scenario 2 (Anna Ronayne)
>By blowing heated or cooled air over the perimeter glazing of the building, given a highly efficient glazing specification, this eliminates the common problem of stratification, as the air has a tendancy of negating the cold or warm surface of the glass, decending down, into the centre of the space and extracted from the return grills in the centre. >Combined with the air handler distribution ductwork, an MVHR system will provide fresh filtered air which can be either preheated or precooled by reversing the inlet and outlet ducts from the north or south facade, and can be incorporated into a double skin facade system.
St Anne’s Community Centre, DSDHA Architects
Passive Scenario 1 (Thomas Wakeman)
Precedent Building and a Close-up of a Solar Fin; AVAX S.A. Headquarters For my passive design I am interested in using solar shading on the south and west facades to reduce the cooling load in the summer months. The solar shading will not block out the natural light as I think this is a very important factor contributing to a pleasant internal environment. Instead, the solar shading will stop glare and direct sunlight. Because the building is an office, this is very desirable as there will be a lot of people working at computers where glare would cause a lot of problems.
>Stale are is removed additionally from spaces such as bathrooms and kitchens, creating a negative pressure in these spaces and preventing unwanted odours escaping back into the return ductwork to the air handler and being redistributed into the office space.
Perspective View Of The Solar Fins
I have am particularly interested in the AVAX S.A. Headquarters designed by A.N. Tombazis and Associates Engineers from the University of Athens. I will use this building as a precedent for my facade design.
For the actively controlled design, I would like to look at timber clad facades. I like the aesthetic timber clad facades creates and given the thermal control system will be active, I have more freedom to create an interesting aesthetically pleasing timber clad facade will fewer restrictions. I will not ignore the passive design however as it is a huge advantage if the loads on the active system are reduced. Therefore, I will utilise every way I can improve the conditions in the building that the HVAC system will have to control. For example, I will still look at having solar shading to reduce solar gains and glare from the sun but I will put less emphasis on it for this facade design. I would like to create an interesting timber clad facade to MVHR Unit help attract high end clients. I found several interesting precedents such as St Anne’s Community Centre by DSDHA Architects and The Herringbone Houses designed by Alison Brooks Architects.
Active Scenario 3 (Clarissa Evans)
I would like the solar shading to be created with solar fins. These are vertical glass fins which are rotated to block solar glare according to the sun’s position. The glass fins have a silk screen prink on them which means they are translucent. This allows the daylight to still come into the building. To help heat the building in winter, I am looking at creating high thermal mass within the facades. I will build the facades with a high proportion of concrete block so they have a high thermal mass I require. The concrete blocks absorb the heat from the building during the day and slowly emit it during the night to keep the temperature more constant so less heating is required in the morning. As our building is within a cold climate, in order to make it a passive design, I will need to make in as air tight as possible to keep the heat from escaping. However, ventilation is still required so I will look at having a hybrid system which uses some mechanical ventilation and some natural cross ventilation. I feel this is a good compromise to the problem. I will also look at using the stack effect ventilation with vents in the building’s roof.A Architects and The Herringbone Houses designed
by Alison Brooks Architects.
Precedent- Numer One Northbank Offices, Sheffield,
Group 23 Thomas Wakeman, Clarissa Evans, Anna Ronayne Speculative Office Building, 1 Kingsway, Cardiff
BDP ARCHITECTS
Solar Fins in the Closed Position I will design the fins so that they can be closed completely if there is too much direct sunlight on the facade. As the fins are made from glass with silk screen printed patterns on them, it will still be possible to see outside and to let a lot of natural light in.
Passive Scenario 3 (Clarissa Evans)
For my Actively Controlled Scenario I drew inspiration from the Number one Northbank offices in Sheffield, I wish to look at how glass can be used in a façade with prefabricated panelling to create a professional aesthetic to attract potential clients.