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SEMESTER 1 - ENERPHIT SCHOOLS PROJECT SEMESTER 1 - ENERPHIT SCHOOLS PROJECT DANIEL COYLE MRIAI ARCHITECT DUBLIN SCHOOL OF ARCHITECTURE, DUBLIN INSTITUTE OF TECHNOLOGY, BOLTON STREET, DUBLIN 1 PG Diploma in Digital Analysis and Energy Retrofit DT774a DANIEL COYLE MRIAI ARCHITECT DUBLIN SCHOOL OF ARCHITECTURE, DUBLIN INSTITUTE OF TECHNOLOGY, BOLTON STREET, DUBLIN 1 PG Diploma in Digital Analysis and Energy Retrofit DT774a 10 300 150 100 100 100 22 120 250 40 75 20 100 20 20 25 497 Parex EWI / silicate render system or similar by approved subcontractor - Silicate 2 coat render finish on reinforcement mesh on base coat (all in accordance with supplier's detail specification) 40mm zinc flashing Parex EWI / silicate render system on 300mm EPS wall insulation 300 290 50 50 10 280 696 50 300 200 48 326 15 50 200 150 400 50 10 300 330 boys WC girls WC disabled WC boiler lobby HRV 1 corridor classroom 1 staff room / office classroom 2 classroom 3 classroom 4 HRV 2 staff wc staff wc lobby library Room Areas Schedule Room Name Boiler Boys WC Classroom 1 Classroom 2 Classroom 3 Classroom 4 Corridor Disabled WC Girls WC HRV 1 HVR 2 Library Staff / Office Staff WC Staff WC Measured Area (m2) 1.42 20.93 44.97 44.97 44.97 44.97 69.94 4.94 19.08 1.34 1.54 16.84 19.02 3.66 3.66 342.25 m 2 Treated Floor Area (m2) 1.42 20.93 44.97 44.97 44.97 44.97 41.97 4.94 19.08 0.80 0.93 16.84 19.02 3.66 3.66 313.13 m 2 330 North-East Elevation 1:100 North-West Elevation 1:100 South-East Elevation 1:100 South-West Elevation 1:100 Zinc standing seam parapet capping laid to 3º fall on 18mm WBP plywood Wild-flower planting / sedum in100mm soil layer, on root barrier / drainage membrane 20mm Asphalt roofing membrane, on 3 layers of 100m Foamglas flat roof insulation (joints to overlapping boards staggered), on Vapour Barrier / Airtight membrane laid on existing reinforced concrete flat roof 12.5mm gypsum plasterboard, with 3mm plaster skim coat, on 50x50mm timber battens (services zone), insulated with 50mm Thermafleece sheepswool insulation, on Intello Air-tight membrane, all joints taped and sealed 300mm Foamglass roof insulation Existing 70mm air cavity filled with Warmcell blown Cellulose cavity fill insulation Existing 25mm cement internal plaster finishes retained and repaired - all holes, cracks, shrinkage etc. filled and wall made good and redecorated Existing 100mm concrete block inner leaf Existing clear storey windows removed and opes infilled with new concrete blockwork Existing reinforced concrete sills to clear- storey windows removed 20mm Asphalt upstands at all edges of flat roof Zinc flashings to abutments 15mm continuous ventilation with Glidevale or similar insect guard new 150mm dia.. half-round zinc rainwater gutters and downpipes, fixed to rafters with zinc rafter brackets Existing slated / tiled pitched roof to classroom block retained / refurbished as required 12mm WBP plywood between rafters to maintain 50mm air gap for roof ventilation 140x38mm timber sprockets existing treated timber wall plate on DPC, on reinforced concrete band beam 350mm Cellulose / Mineral Fibre insulation batts (in 3 layers) between new ceiling joist and existing roof ties 300mm Foamglas T4+ roof insulation slabs (3 layers of 100mm laid with staggered joints), on airtight membrane / vapour barrier on existing concrete flat roof EnerPHit Schools Project - Low-Energy Retrofit Design Using PHPP Using the Passivhaus PHPP ("Passive House Planning Package") spreadsheet software as an iterative design tool, the Project explores the development of a comprehensive Design Strategy for the deep energy-retrofitting, upgrade and refurbishment of an existing single storey 1960s four-classroom Primary School Building, to achieve compliance with Passivhaus EnerPHit performance standards. The EnerPHit Retrofit Strategy focuses on building form and geometry optimised for Natural Daylighting and Passive Solar Gains, “super-low energy” Fabric Insulation levels, near elimination of Liner Thermal Bridging, Air-tightness to minimise heat loss through air infiltration, a high level of indoor air quality maintained by an efficient Mechanical Ventilation System with Heat Recovery, efficiencies in Domestic Hot Water production and distribution, and energy efficient Space Heating, Electrical Power and Lighting equipment with responsive controls. The proposed EnerPHit Retrofit solution is calculated to achieve a 95% reduction in Space Heating Annual Energy Demand, and an 85% reduction in Total Primary Energy Demand. The additional incorporation of on Photo-Voltaic panels and other on site renewables allows the potential to deliver a Nearly Zero Energy Building. Bird's Eye View from East LINEAR THERMAL BRIDGING External Wall / Ground Floor Slab Junction = + 0.067 W/(mK) 3D view of new roof truss & roof light opening DETAIL B (Window Sill) 1:5 DETAIL A (Ground Floor Slab / Foundation) 1:5 DETAIL F (Pitched Roof Eaves) 1:5 External Wall / Flat Roof Parapet Junction = - 0.033 W/mK PHPP - Linear Thermal Bridge Calculations: - External Insulation strategy with continuity of external insulation eliminates Linear Thermal Bridging for most junctions. - Thermal bridges, designed to have Maximum Value of + 0.01 W/mK (to avoid additional heat losses or condensation risks). - Foundation/Ground Floor Slab Junction - XPS Vertical & Horizontal Perimeter Insulation in Ground to minimise Thermal Bridging. - Foamglas roof insulation to allow thermal bridge free parapet construction to flat roof / external wall junction. AIRTIGHTNESS STRATEGY PASSIV WINDOWS & DOORS Lamilux CI System Passiv Rooflights: U g : 0.62 W/m 2 K G-Value: 0.6 Light transmittance: 0.71 Frame U f : 0.61 W/m 2 K Frame Width: 116mm Glazing Edge Thermal Bridge: 0.029 W/mK Installation Thermal Bridge: 0.100 W/mK EXISTING SCHOOL BUILDING Airtightness measures to achieve 1.0 ACH Exhaust air Intake air classroom PVs classroom classroom corridor student WCs Staff Room & Library disabled WC staff WC MVHR SYSTEM DETAIL A DETAIL B DETAIL D DETAIL E boiler Exhaust air Intake air PHPP EnerPHit Performance Criteria - Existing & Proposed Retrofit Solution The energy performance of the existing school building was examined and calculated using the PHPP spreadsheet software as well as a range of other analysis tools and methodologies such as Design Builder (Dynamic Simulation Software), U-Value calculation software (Build Desk-U), Linear Thermal Bridge Modelling (Therm), and Hygrothermal Moisture Assessments for Surface and Interstitial Condensation. This analysis demonstrates an unsustainably high energy usage for the existing school building with a calculated Space Heating Demand of over 531 kWh/ (m 2 a) , and a total Primary Energy Demand of 820 kWh/(m 2 a) - equating to an estimated total annual energy demand of over 257,480 kWh. The lack of thermal insulation and additional significant linear thermal bridging may also result in a substantial risk of surface and interstitial condensation, and potential mould growth. Daylight Analysis carried out on a typical classroom space also demonstrated poor daylighting and illumination levels, with Average Daylight Factor significantly below the current Dept. of Education and Science recommendations. Existing School Building - Energy Analysis using PHPP Criteria Existing Retrofit Specific Heat Demand max. 25 kWh/(m2a) 531 kWh/(m2a) Total Primary Energy Demand max. 132 kWh/(m2a) 820 kWh/(m2a) Overheating Frequency (>25ºC) max. 10% 0% Water Activity of Interior Surfaces max. 80% Criteria Existing Retrofit External Wall U-value max. 0.150 W/m 2 K Roof or top floor ceiling U-Value max. 0.120 W/m 2 K Windows U-Value (Installed) max. 0.85 Wh/m 2 K Linear Thermal Bridges max. +0.01 W/(m 2 K) Ventilation (MHVR) Efficiency ƞ HR eff 75% 1.735 W/m 2 K 1.279 W/m 2 K 2.56 Wh/m 2 K FABRIC UPGRADES Elemental Fabric U-Values calculated in accordance with ISO 6946 using PHPP spreadsheet: DAYLIGHTING OPTIMISED SITE & BUILDING GEOMETRY Site & Building Design Interventions: - Tree Shelter-belt planting to provide wind protection (PHPP: Wind protection coefficient e, reduced to 0.7 - i.e. "moderate protection"). - Window openings optimised for passive solar gain in Winter: Enlarged openings to classroom SE wall + (+14.1m 2 ), Existing NW facing Clear-storey windows blocked up: (-7.5m 2 ), New Fixed and opening Rooflights added to NW roof (+24m 2 ) - Single sash windows (reduced frame, increased glass area). - Nett increase in Window Area: 32.6m2 . - Increased Enclosed Volume V e (Roof-light shafts): 378m3 - Reduced ceiling height in classrooms (-300mm). - Increased External Envelope Area (Pitched Roof - 24.3m2 & Gable Walls – 5.25m2). - Shading Devices (Brise-Soleil & Entrance Canopies) to provide Summer Shading. Existing Retrofit Proposal EnerPHit PHPP Verification Sheet: PASSIVE COOLING STRATEGY - SUMMER 1 2 3 6 7 5 8 KEY TO SOUTH-WEST ELEVATION 1 - 300mm EWI with silicate render finish. 2 - New Zinc clad entrance canopies. 3 - Zinc capping to parapet walls. 4 - New Passive alu-clad timber windows. 5 - Brise Soleil to South-East Facade. 6 - New ramped disabled access. 4 1 2 3 4 5 6 KEY TO NORTH-WEST ELEVATION 1 - Existing tiled / slated pitched roof (refurbished). 2 - New Fakro Passiv Opening Rooflights (automated) 3 - New fixed triple glazed roof-lights. 4 - New Zinc gutters & rainwater pipes KEY TO STRUCTURAL DIAGRAM: 1 - New timber box beam / truss spanning 7.2m between intermediate internal walls - 125x75mm bottom & top members, vertical uprights and diagonal bracing with 18mm plywood facings (not shown). 2 - New 150x44mm timber struts at 18" intervals, double-nailed to existing rafters. 3 - 110x44mm Timber noggins / trimmer to existing ceiling ties. 4 - New truss / box-beam bolted to Concrete bearing pads cast on existing 215mm internal load-bearing block walls. 5 - 110x75mm timber trimmers around roof light openings. 6 - New Fakro Passiv opening roof light (automated opening mechanism). 7 - New Lamilux triple glazed Passiv fixed roof light. 8 - Existing cut timber trussed roof structure retained - 110x38mm rafters, collar ties, roof ties and struts at 18" (490mm) centres. (Roof Structural Alterations all to Engineer's detail design) 1 2 3 4 KEY TO SOUTH-EAST ELEVATION 1 - Existing refurbished tiled pitched roof. 2 - PV Panels mounted on roof (100m2 array). 3 - Brise-Soleil (1m overhang) to provide Summer Shading. 4 - Enlarged window opening to Classrooms 5 - New External Access doors from Classrooms 6 - New Zinc entrance canopies 7 - Passivhaus rated Timber entrance doors & sidelights 8 - Fanlights over access doors with secure louvres for night- time purge ventilation in Summer. 1 3 6 7 4 5 2 DHW & ELECTRICAL EFFICIENCIES corridor Summer Sun 12noon Winter Sun 12noon KEY TO DETAIL CROSS SECTION 1 - Existing cut timber roof trusses / rafters. 2 - New Box beam roof truss to support roof and allow for forming new roof light openings. 3 - PV panels mounted on existing slated / tiled roof (refurbished). 4 - New Zinc gutters & rainwater pipes. 5 - Existing reinforced concrete ring beam - projecting edge cut back with con saw. 6 - 254x254 UC 46 Steel Supporting beam to form new single window opening (All to Engineer's details). 7 - Powder coated aluminium Brise-Soleil fixed though to RSJ with thermally broken connection pad (Schock or similar). 8 - 300mm EPS external wall insulation with 10mm silicate render. 9 - New Internorm Passiv triple glazed windows with thermally-broken frames, tilt and turn operation to provide night-time ventilation. 10 - Solar control roller blinds internally. 11 - MVHR supply air ductwork (250mm dia.) 12 - MVHR return extract ductwork (250mm dia.) 13 - New Internal glazing between classroom and corridor with 8mm laminated acoustic glass. 14 - New roof lights (opening vents for cross ventilation). 15 - Automated solar control blinds to roof-lights. 16 - Existing clearstory windows blocked up. 17 - 350mm Cellulose Roof Insulation. 18 - New 200mm polished reinforced concrete floor slab with 300mm XPS floor insulation. 19 - Low temperature hot water radiator with TRV 20 - Low energy T5 fluorescent lighting with full dimming controls and occupancy/day-light sensors. 1 2 3 4 5 6 7 9 8 6 10 15 14 16 11 12 13 19 18 2 17 20 Airtightness (n50 ) max. 1.0 -1 10.57 -1 kWh/(m2a) KEY TO GROUND FLOOR PLAN 1 - Existing blockwork cavity walls with 70mm full fill blown cellulose cavity fill insulation. 2 - New 300mm EPS External Wall insulation and silicate render. 3 - New Internorm Passiv triple glazed windows with thermally- broken frames. 4 - 254x254 UC 46 Steel Supporting columns to form new single window openings (All to Engineer's details). 5 - Existing 215mm blockwork internal dividing walls. 6 -Existing internal blockwork cavity walls. 7 - Powder coated aluminium brise- soleil with 1 metre overhang above. 8 - New disabled access ramps to entrance doorways. 9 - Cast in situ concrete wall/bench seating. 10 - Access ramp to classrooms. 11 - MVHR supply air ductwork. 12 - MVHR return extract ductwork. 13 - New Internal windows between classroom and corridor with 8mm laminated acoustic glass. 14 - Line of New roof lights above. 15 - New 200mm concrete floor slab with 300mm XPS floor insulation. 16 - Low temperature hot water radiators with TRVs. 17 - Paul Maxi 801 HRV Unit serving LHS of building. 18 - Intake & Exhaust air ducts (insulated) to HRV Unit. 19 - 5-10kW modulating gas condensing boiler (91% CoP). 20 - 500L DHW tank with 100mm PU foam insulation. 21 - New Canopy / porches to entrances doors. 22 - New Disabled WC. 1 2 4 3 18 19 21 8 7 14 11 20 17 18 16 5 6 13 12 9 10 15 DAYLIGHTING: - Daylight Factors & illuminance (Lux) calculated using Design Builder v.3.0.4 (Radiance daylighting engine). - Glazing - assumed as triple glazing in both models (Light transmittance value of 0.69) - Recommended Daylight Factors for Teaching Spaces - min 2% (CIBSE Guide A), Recommended 4.5-5.5% (DoES Guidelines TG-02). Minimum 400 Lux. - Existing Classroom 3: Daylight Factor < 2% for over half the room area. Average Daylight Factor - 2.53% (existing clear storey windows too high to significantly contribute to daylighting at working plane) - Proposed Classrooms: 1. New roof lights to North-West slope of pitched roof with sloped ceiling / light-shaft, 2. Enlarged single window opening to South-East facade, 3. New internal glazing & glazed doors between classroom and corridor. - Calculated Average Daylight Factor - 5.75% - Proposed: 50% Reduction in Annual Electrical Lighting Energy Load (from Design Builder Simulation) Existing Classroom - Daylight / Illuminance Map Proposed Retrofit - Daylight / Illuminance Map Existing Classroom - 3D Section View Proposed Classroom - 3D Section View PASSIVE HEATING STRATEGY - WINTER 1 2 3 4 5 6 Summer Sun 12noon 1 3 5 2 4 Winter Sun 12noon 8 6 Domestic Hot Water & Distribution: - Reduced DHW Demand - 0.5 litres/hour per pupil (Dept. of Education & Science TGD 002) - equivalent to 4 litres/day per person (PHPP). Reduced Tap Openings/year - 3,500/year - Student Toilets grouped together in one wing - reduces length of distribution pipework and dead- legs(15m total primary flow & return pipework, 10m distribution pipework). - Staff Room & WCs with individual 3kW electric instantaneous DHW heaters for hand washing. - 500 litre glass-lined DHW cylinder with single coil calorifier and electric immersion, with 100mmm PU insulation layer (DxH:750x2100mm). Electrical Lighting & Equipment: - Energy efficient LED & T5 fluorescent light fittings, with linear automatic dimming, daylight and occupancy sensors. Additional reduced lighting load due to improved natural daylighting. - Auxiliary Energy - Specification of energy efficient Fans, pumps, computers and equipment. - PV: 100m2 roof mounted photovoltaic array to SE roof slope: 60 no. Sharp NU235E1 solar panels, generating 14 kWp (235W per panel), estimated 11256 kWh per annum, (50% of Primary Energy Demand) with feedback into Grid. 2 1 Energy Efficient Lighting + Controls 500L DHW tank 5-10kW Gas Boiler 90.1% Internorm HF200 Passiv Windows: U g : 0.62 W/m 2 K G-Value: 0.6 Light transmittance: 0.71 Frame U f : 0.73 W/m 2 K Frame Width: 114mm, Depth: 85mm Glazing Edge Thermal Bridge: 0.038 W/mK Installation Thermal Bridge: 0.040 W/mK Fakro FTTU08 Thermo Rooflights: U g : 0.3 W/m 2 K G-Value: 0.35 Light transmittance: 0.58 Frame U f : 1.10 W/m 2 K Window U w : 0.58 W/m 2 K Frame Width: 112mm Glazing Edge Thermal Bridge: 0.045 W/mK 3 4.640m 2.420m 2.417m 2.131m Daylight Map Colour Legend PHPP Windows Sheet: Heat Gains / Losses through windows (Net energy gains though Openings – 1760 kWh/a) DETAIL C (Window Head) 1:5 DETAIL D (Parapet/Flat Roof) 1:5 DETAIL C DETAIL F DETAIL E (Flat Roof & Wall Abutment) 1:5 Bird's Eye View from SE Bird's Eye View from South N Ground Floor Plan (Proposed) 1:100 300mm Kore silver Neopor EPS insulation boards, mechanically and adhesive fixed to plaster Parge coat substrate minimum 40mm EPS insulation overlap to all edges of window reveals 18mm WBP plywood sheathing upstand InterNorm or similar approved PassivHaus rated triple glazed windows 280mm Styrodur or similar Extruded Polystyrene insulation bonded and mechanically fixed to new plaster parge coat (air-tight layer), on rinsing walls / concrete footing DPC (existing) Existing reinforced concrete strip foundations (assumed) XPS horizontal perimeter insulation, 800mm width Airtight tape to edges of windows (pre- installed prior to fixing of windows), sealed to external parge coat / external render to provide airtightness exiting reinforced concrete lintels to window heads Warmcell cavity fill insulation Plaster parge coat (air-tight layer) continued down to top of existing foundations 100m perforated PVC drainage pipe, wrapped in geo-textile fabric and surrounded by washed stone / gravel paving, on 50mm sand/cement bedding on 150mm compacted Clause 804 hardcore 12mm ply window sill plywood cover strip / edging new 200mm polished reinforced concrete floor slab - 35N20 concrete, A142 mesh reinforcement with min 50mm cover (or to Engineer's specification), laid on 300mm XPS insulation, on Monarflex radon barrier, all joints lapped and taped, carried up 150mm above finished floor level and taped / stapled to existing walls behind skirting 50mm sand blinding on 150mm Clause 808 compacted hardcore base Edge of Concrete floor slab tapered as shown with triangular vertical insulation to all perimeters to minimise cold bridging at floor / wall junctions 8mm laminated safety glass to new internal windows between classrooms and corridor Ash or similar window frame with 10mm shadow gap rebate to edges ply cavity closer existing continuous reinforced cast in situ concrete lintels to internal cavity wall - provide additional column supports to new window openings as required in accordance with Structural Engineer's details exiting projection to edge of concrete flat roof cut off with con-saw, flush with external walls projection to existing reinforced concrete eaves band beam cut off with con-saw, flush with external walls Thermally broken timber/alluminium composite window frames, installed into outside face of existing window opes External Walls – Air-tight Plaster Parge coat on existing roughcast rendered walls, carried down to foundation level, to provide external airtight layer Floors - 200mm Solid concrete floor slab with Radon Barrier / DPM, sealed to walls. Air-tight sealing tape to junction between concrete floor and existing solid concrete footings Intello roof air-tight membrane, and external parge coat sealed to existing concrete band beam Pitched Roof – Intello membrane, with 50mm services zone / counter- battens below. Windows – Fitted externally with air-tight tape, sealed to render / plaster parge coat. Flat Roof - Air-tight membrane / vapour barrier above concrete deck, sealed to external plastered wall. Air-tight membrane / tape to opening and fixed rooflights 250mm Air Supply ductwork at 2.3m height - with supply air vents to corridor Fresh Air diffusers in corner of classrooms at Floor Level 300mm Intake & Exhaust Air Ducts to outside wall (insulated) 150-250mm Extract Duct from WCs Separate Low-temperature radiators to each classroom to provide space heating with individual thermostatic control valves (Space Heating decoupled from Ventilation System) MVHR Units in cupboard space to Lobby Areas 0.093 W/m 2 K (280mm XPS insulation) 0.098 W/m 2 K (300mm EPS insulation + 75mm Cellulose Blown Cavity Fill) 0.114 W/m 2 K (300mm Foamglas insulation) 0.088 W/m 2 K (350mm Cellulose insulation + 50mm Sheepswool) 0.107W/m 2 K (300mm XPS insulation) Calculated LTB-02 Calculated LTB-01 Plaster Parge coat (airtight layer) ss plaster stop Powder-coated aluminium window sill existing 25mm internal plaster 70mm full fill blown cellulose cavity fill insulation (Warmcell) existing reinforced concrete flat roof deck existing 3mm plaster skim and cork insulation boards to soffit MVHR Units - (2 no.) Paul Maxi 801DC Heat Recovery Efficiency - 90.01% PHPP. - 78.01% (-12% non-certified unit) Electric Efficiency – 0.38 Wh/m2 Length of supply duct – 0.85 m Length of exhaust duct – 0.85 m Insulation thickness – 100mm U-Value of Insulation – 0.025 W/m2K extract supply extract kWh/(m2a) kWh/(m2a) kWh/(m2a) kWh/(m2a) kWh/(m2a) kWh/(m2a) WINTER: 1. The retrofitted building is airtight with super insulated fabric and highly efficient triple glazed "Passiv" windows and doors. Thermal Mass is used to store heat and modulate heating loads. 2. Windows are optimised to take advantage of passive solar gains from the south-east facade (low angle winter sun). Internal blinds are used to control solar glare. 3. Classrooms are supplied with constant fresh air warmed via a heat exchanger by extract air (4), with CO 2 monitoring and control. 5. Heating is largely by passive gains from Users, electrical lighting & equipment, and solar gains. 6. Passive heat gains are supplemented by an efficient gas fired condensing boiler and low temperature radiators, easily controlled by users and with quick response to prevent temperature overshoot. SUMMER: 1. Solar gain is controlled by external Brise Soleil, internal solar blinds and the highly insulated building fabric. 2. The thermally massive construction (exposed concrete floors, concrete blockwork walls, & concrete roof slab) modulates cooling loads. 3. Lighting loads are controlled by daylight and motion detectors (good natural daylighting also minimises electrical lighting demand, and associated heat gains). 4. Summer ventilation is controlled by users opening the windows and insulated secure louvres to the external door fanlights. 5. High level automated opening roof lights provide cross ventilation / stack effect. These can also be used to provide night purge cooling supplemented if required by the Mechanical Ventilation system (6) operating in bypass mode. supply 0.87 kWh/(m2a)

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  • SEMESTER 1 - ENERPHIT SCHOOLS PROJECT

    SEMESTER 1 - ENERPHIT SCHOOLS PROJECT

    DANIEL COYLE MRIAI ARCHITECT DUBLIN SCHOOL OF ARCHITECTURE, DUBLIN INSTITUTE OF TECHNOLOGY, BOLTON STREET, DUBLIN 1 PG Diploma in Digital Analysis and Energy Retrofit DT774a

    DANIEL COYLE MRIAI ARCHITECT DUBLIN SCHOOL OF ARCHITECTURE, DUBLIN INSTITUTE OF TECHNOLOGY, BOLTON STREET, DUBLIN 1 PG Diploma in Digital Analysis and Energy Retrofit DT774a

    10 300

    150

    100

    100

    100

    2212

    0

    250

    4075

    20 100 20 20

    25

    497

    Parex EWI / silicate render system orsimilar by approved subcontractor -

    Silicate 2 coat render finish onreinforcement mesh on base coat (all in

    accordance with supplier's detailspecification)

    40mm zinc flashing

    Parex EWI / silicate render system on300mm EPS wall insulation

    300

    290

    5050

    10 280

    696

    5030

    020

    0

    330

    48

    326

    1550

    200

    150

    400

    50

    10 300 330

    boys WC girls WC

    disabled WC

    boiler

    lobby

    HRV 1

    corridor

    classroom 1

    staff room / office

    classroom 2 classroom 3 classroom 4

    HRV 2staff wc

    staff wclobby

    library

    Preliminary version for pilot phase - subject to alterations! _________________________________________________________________________________

    Quality-Approved Energy Retrofit with PH Components - Criteria for residential-use refurbished buildings, as of 17.08.2010 13 / 16

    4 Testing procedure

    An informal application for the certificate can be made to the selected certifier. The required documents must be filled in completely and submitted to the tester. The documents must be checked at least once. Depending on the procedure, further testing may also be arranged.

    Note: If possible, checking of the relevant documents should be carried out during the planning stage so that potential corrections or suggestions for improvement can be considered at an early stage.

    After the assessment the contractor will receive the results, with corrected calculation and suggestions for improvement, if applicable. Reviewal of the construction work is not the object of the certification. However, evidence of the building's airtightness, the adjustment protocol of the ventilation unit and the construction manager's declaration and at least one photograph must be provided. If the technical accuracy of the necessary evidence for the building is confirmed and the criteria given above are adhered to, the following certificate will be issued:

    Issuing only certifies the accuracy of the documents submitted, in accordance with the level of technological development of Passive House components. The assessment relates neither to the monitoring of the work, nor to the supervision of the user behaviour. The liability for the planning remains with the responsible technical planners, and the liability for the implementation lies with the appropriate construction management. The Passive House Institute logo may only be used in connection with certificates.

    Additional quality assurance of the construction work by the certifying body is particularly expedient when the construction management has no experience with the modernisation of existing buildings using Passive House components.

    We reserve the right to adapt criteria and calculation procedures to advancing technical development.

    Room Areas Schedule

    Room Name

    BoilerBoys WCClassroom 1Classroom 2Classroom 3Classroom 4CorridorDisabled WCGirls WCHRV 1HVR 2LibraryStaff / OfficeStaff WCStaff WC

    MeasuredArea (m2)

    1.4220.9344.9744.9744.9744.9769.94

    4.9419.08

    1.341.54

    16.8419.02

    3.663.66

    342.25 m2

    Treated FloorArea (m2)

    1.4220.9344.9744.9744.9744.9741.97

    4.9419.08

    0.800.93

    16.8419.02

    3.663.66

    313.13 m2

    330

    North-East Elevation 1:100

    North-West Elevation 1:100

    South-East Elevation 1:100

    South-West Elevation 1:100

    Zinc standing seam parapet cappinglaid to 3º fall on 18mm WBP plywood

    Wild-flower planting / sedum in100mm soillayer, on root barrier / drainage membrane

    20mm Asphalt roofing membrane, on 3layers of 100m Foamglas flat roof

    insulation (joints to overlapping boardsstaggered), on Vapour Barrier / Airtight

    membrane laid on existing reinforcedconcrete flat roof

    12.5mm gypsum plasterboard, with 3mmplaster skim coat, on 50x50mm timberbattens (services zone), insulated with50mm Thermafleece sheepswool insulation,on Intello Air-tight membrane, all jointstaped and sealed

    300mm Foamglass roof insulation

    Existing 70mm air cavity filled with Warmcellblown Cellulose cavity fill insulation

    Existing 25mm cement internal plasterfinishes retained and repaired - all holes,cracks, shrinkage etc. filled and wall madegood and redecorated

    Existing 100mm concrete block inner leaf

    Existing clear storey windows removed andopes infilled with new concrete blockwork

    Existing reinforced concrete sills to clear-storey windows removed

    20mm Asphalt upstands at all edges offlat roof

    Zinc flashings to abutments

    15mm continuous ventilation withGlidevale or similar insect guard

    new 150mm dia.. half-round zincrainwater gutters and downpipes,

    fixed to rafters with zinc rafterbrackets

    Existing slated / tiled pitched roof toclassroom block retained /

    refurbished as required

    12mm WBP plywood betweenrafters to maintain 50mm air gap for

    roof ventilation

    140x38mm timber sprockets

    existing treated timber wall plate on DPC,on reinforced concrete band beam

    350mm Cellulose / Mineral Fibre insulationbatts (in 3 layers) between new ceiling joistand existing roof ties

    300mm Foamglas T4+ roof insulationslabs (3 layers of 100mm laid with

    staggered joints), on airtightmembrane / vapour barrier on existing

    concrete flat roof

    EnerPHit Schools Project - Low-Energy Retrofit Design Using PHPPUsing the Passivhaus PHPP ("Passive House Planning Package") spreadsheet software as an iterative design tool, the Project explores the development of acomprehensive Design Strategy for the deep energy-retrofitting, upgrade and refurbishment of an existing single storey 1960s four-classroom Primary SchoolBuilding, to achieve compliance with Passivhaus EnerPHit performance standards.

    The EnerPHit Retrofit Strategy focuses on building form and geometry optimised for Natural Daylighting and Passive Solar Gains, “super-low energy” FabricInsulation levels, near elimination of Liner Thermal Bridging, Air-tightness to minimise heat loss through air infiltration, a high level of indoor air qualitymaintained by an efficient Mechanical Ventilation System with Heat Recovery, efficiencies in Domestic Hot Water production and distribution, and energyefficient Space Heating, Electrical Power and Lighting equipment with responsive controls.

    The proposed EnerPHit Retrofit solution is calculated to achieve a 95% reduction in Space Heating Annual Energy Demand, and an 85% reduction in TotalPrimary Energy Demand. The additional incorporation of on Photo-Voltaic panels and other on site renewables allows the potential to deliver a Nearly ZeroEnergy Building.

    Bird's Eye View from East

    LINEAR THERMAL BRIDGING

    External Wall / Ground Floor Slab Junction = + 0.067 W/(mK)

    3D view of new roof truss & roof light opening

    DETAIL B (Window Sill) 1:5

    DETAIL A (Ground Floor Slab / Foundation) 1:5

    DETAIL F (Pitched Roof Eaves) 1:5

    External Wall / Flat Roof Parapet Junction = - 0.033 W/mK

    PHPP - Linear Thermal Bridge Calculations:

    - External Insulation strategy with continuity of external insulation eliminatesLinear Thermal Bridging for most junctions.

    - Thermal bridges, designed to have Maximum Value of + 0.01 W/mK (toavoid additional heat losses or condensation risks).

    - Foundation/Ground Floor Slab Junction - XPS Vertical & HorizontalPerimeter Insulation in Ground to minimise Thermal Bridging.

    - Foamglas roof insulation to allow thermal bridge free parapet construction toflat roof / external wall junction.

    AIRTIGHTNESS STRATEGY

    PASSIV WINDOWS & DOORS

    Lamilux CI System Passiv Rooflights:

    Ug: 0.62 W/m2KG-Value: 0.6Light transmittance: 0.71Frame Uf: 0.61 W/m2KFrame Width: 116mmGlazing Edge Thermal Bridge: 0.029 W/mKInstallation Thermal Bridge: 0.100 W/mK

    EXISTING SCHOOL BUILDING

    Airtightness measures to achieve 1.0 ACH

    Exhaust airIntake air

    classroom

    PVs

    classroom classroom

    corridor

    student WCs Staff Room & Library

    disabled WC staff WC

    MVHR SYSTEM

    DETAIL A

    DETAIL B

    DETAIL D

    DETAIL E

    boilerExhaust air

    Intake air

    PHPP EnerPHit Performance Criteria - Existing & Proposed Retrofit Solution

    The energy performance of the existing school building was examined and calculated using the PHPP spreadsheet software as well as a range of otheranalysis tools and methodologies such as Design Builder (Dynamic Simulation Software), U-Value calculation software (Build Desk-U), Linear ThermalBridge Modelling (Therm), and Hygrothermal Moisture Assessments for Surface and Interstitial Condensation.

    This analysis demonstrates an unsustainably high energy usage for the existing school building with a calculated Space Heating Demand of over 531 kWh/(m2a) , and a total Primary Energy Demand of 820 kWh/(m2a) - equating to an estimated total annual energy demand of over 257,480 kWh. The lack ofthermal insulation and additional significant linear thermal bridging may also result in a substantial risk of surface and interstitial condensation, and potentialmould growth.

    Daylight Analysis carried out on a typical classroom space also demonstrated poor daylighting and illumination levels, with Average Daylight Factorsignificantly below the current Dept. of Education and Science recommendations.

    Existing School Building - Energy Analysis using PHPP

    Criteria Existing RetrofitSpecific Heat Demand max. 25 kWh/(m2a)531 kWh/(m2a)

    Total Primary Energy Demand max. 132 kWh/(m2a)820 kWh/(m2a)

    Overheating Frequency (>25ºC) max. 10%0%

    Water Activity of Interior Surfaces max. 80%

    Criteria Existing RetrofitExternal Wall U-value max. 0.150 W/m2K

    Roof or top floor ceiling U-Value max. 0.120 W/m2K

    Windows U-Value (Installed) max. 0.85 Wh/m2K

    Linear Thermal Bridges max. +0.01 W/(m2K)

    Ventilation (MHVR) Efficiency ƞHR eff ≥ 75%

    1.735 W/m2K

    1.279 W/m2K

    2.56 Wh/m2K

    FABRIC UPGRADES

    Elemental Fabric U-Values calculated in accordance withISO 6946 using PHPP spreadsheet:

    DAYLIGHTING

    OPTIMISED SITE & BUILDING GEOMETRY

    Site & Building Design Interventions:

    - Tree Shelter-belt planting to provide wind protection (PHPP:Wind protection coefficient e, reduced to 0.7 - i.e. "moderateprotection").

    - Window openings optimised for passive solar gain in Winter:Enlarged openings to classroom SE wall + (+14.1m2),Existing NW facing Clear-storey windows blocked up:(-7.5m2), New Fixed and opening Rooflights added to NWroof (+24m2)

    - Single sash windows (reduced frame, increased glass area).

    - Nett increase in Window Area: 32.6m2 .

    - Increased Enclosed Volume Ve (Roof-light shafts): 378m3

    - Reduced ceiling height in classrooms (-300mm).

    - Increased External Envelope Area (Pitched Roof - 24.3m2 &Gable Walls – 5.25m2).

    - Shading Devices (Brise-Soleil & Entrance Canopies) toprovide Summer Shading.

    Existing Retrofit ProposalEnerPHit PHPP Verification Sheet:

    PASSIVE COOLING STRATEGY - SUMMER

    1

    2

    3

    6

    7

    5

    8

    KEY TO SOUTH-WEST ELEVATION

    1 - 300mm EWI with silicate render finish.2 - New Zinc clad entrance canopies.3 - Zinc capping to parapet walls.4 - New Passive alu-clad timber windows.5 - Brise Soleil to South-East Facade.6 - New ramped disabled access.

    4

    1

    2

    3

    4

    5

    6

    KEY TO NORTH-WEST ELEVATION

    1 - Existing tiled / slated pitched roof (refurbished).2 - New Fakro Passiv Opening Rooflights (automated)3 - New fixed triple glazed roof-lights.4 - New Zinc gutters & rainwater pipes

    KEY TO STRUCTURAL DIAGRAM:

    1 - New timber box beam / truss spanning 7.2m between intermediateinternal walls - 125x75mm bottom & top members, vertical uprights anddiagonal bracing with 18mm plywood facings (not shown).2 - New 150x44mm timber struts at 18" intervals, double-nailed to existingrafters.3 - 110x44mm Timber noggins / trimmer to existing ceiling ties.4 - New truss / box-beam bolted to Concrete bearing pads cast on existing215mm internal load-bearing block walls.5 - 110x75mm timber trimmers around roof light openings.6 - New Fakro Passiv opening roof light (automated opening mechanism).7 - New Lamilux triple glazed Passiv fixed roof light.8 - Existing cut timber trussed roof structure retained - 110x38mm rafters,collar ties, roof ties and struts at 18" (490mm) centres.

    (Roof Structural Alterations all to Engineer's detail design)

    1

    2

    3

    4

    KEY TO SOUTH-EAST ELEVATION

    1 - Existing refurbished tiled pitched roof.2 - PV Panels mounted on roof (100m2 array).3 - Brise-Soleil (1m overhang) to provide Summer Shading.4 - Enlarged window opening to Classrooms5 - New External Access doors from Classrooms6 - New Zinc entrance canopies7 - Passivhaus rated Timber entrance doors & sidelights8 - Fanlights over access doors with secure louvres for night-

    time purge ventilation in Summer.

    1

    3

    6

    745

    2

    DHW & ELECTRICAL EFFICIENCIES

    corridor

    Summer Sun 12noon

    Winter Sun 12noon

    KEY TO DETAIL CROSS SECTION

    1 - Existing cut timber roof trusses / rafters.2 - New Box beam roof truss to support roof andallow for forming new roof light openings.3 - PV panels mounted on existing slated / tiledroof (refurbished).4 - New Zinc gutters & rainwater pipes.5 - Existing reinforced concrete ring beam -projecting edge cut back with con saw.6 - 254x254 UC 46 Steel Supporting beam toform new single window opening (All toEngineer's details).7 - Powder coated aluminium Brise-Soleil fixedthough to RSJ with thermally broken connectionpad (Schock or similar).8 - 300mm EPS external wall insulation with10mm silicate render.9 - New Internorm Passiv triple glazed windowswith thermally-broken frames, tilt and turnoperation to provide night-time ventilation.10 - Solar control roller blinds internally.11 - MVHR supply air ductwork (250mm dia.)12 - MVHR return extract ductwork (250mm dia.)13 - New Internal glazing between classroom andcorridor with 8mm laminated acoustic glass.14 - New roof lights (opening vents for crossventilation).15 - Automated solar control blinds to roof-lights.16 - Existing clearstory windows blocked up.17 - 350mm Cellulose Roof Insulation.18 - New 200mm polished reinforced concretefloor slab with 300mm XPS floor insulation.19 - Low temperature hot water radiator with TRV20 - Low energy T5 fluorescent lighting with fulldimming controls and occupancy/day-lightsensors.

    12

    3

    4

    5

    6

    7

    9

    8

    6

    10

    15

    14

    16

    11

    12

    13

    19

    18

    2

    17

    20

    Airtightness (n50 ) max. 1.0-110.57-1

    kWh/(m2a)

    KEY TO GROUND FLOOR PLAN

    1 - Existing blockwork cavity wallswith 70mm full fill blown cellulosecavity fill insulation.2 - New 300mm EPS External Wallinsulation and silicate render.3 - New Internorm Passiv tripleglazed windows with thermally-broken frames.4 - 254x254 UC 46 Steel Supportingcolumns to form new single windowopenings (All to Engineer's details).5 - Existing 215mm blockworkinternal dividing walls.6 -Existing internal blockwork cavitywalls.7 - Powder coated aluminium brise-soleil with 1 metre overhang above.8 - New disabled access ramps toentrance doorways.9 - Cast in situ concrete wall/benchseating.10 - Access ramp to classrooms.11 - MVHR supply air ductwork.12 - MVHR return extract ductwork.13 - New Internal windows betweenclassroom and corridor with 8mmlaminated acoustic glass.14 - Line of New roof lights above.15 - New 200mm concrete floor slabwith 300mm XPS floor insulation.16 - Low temperature hot waterradiators with TRVs.17 - Paul Maxi 801 HRV Unitserving LHS of building.18 - Intake & Exhaust air ducts(insulated) to HRV Unit.19 - 5-10kW modulating gascondensing boiler (91% CoP).20 - 500L DHW tank with 100mmPU foam insulation.21 - New Canopy / porches toentrances doors.22 - New Disabled WC.

    1

    2

    4

    3

    18

    19

    21

    8

    7

    14

    11

    20

    17

    18

    16

    5

    6

    13

    12

    9

    10

    15

    DAYLIGHTING:

    - Daylight Factors & illuminance (Lux) calculatedusing Design Builder v.3.0.4 (Radiancedaylighting engine).

    - Glazing - assumed as triple glazing in bothmodels (Light transmittance value of 0.69)

    - Recommended Daylight Factors for TeachingSpaces - min 2% (CIBSE Guide A),Recommended 4.5-5.5% (DoES GuidelinesTG-02). Minimum 400 Lux.

    - Existing Classroom 3: Daylight Factor < 2%for over half the room area. Average DaylightFactor - 2.53% (existing clear storey windowstoo high to significantly contribute todaylighting at working plane)

    - Proposed Classrooms: 1. New roof lights toNorth-West slope of pitched roof with slopedceiling / light-shaft, 2. Enlarged single windowopening to South-East facade, 3. New internalglazing & glazed doors between classroomand corridor.

    - Calculated Average Daylight Factor - 5.75%

    - Proposed: 50% Reduction in Annual ElectricalLighting Energy Load (from Design BuilderSimulation)

    Existing Classroom - Daylight / Illuminance Map

    Proposed Retrofit - Daylight / Illuminance Map

    Existing Classroom - 3D Section View

    Proposed Classroom - 3D Section View

    PASSIVE HEATING STRATEGY - WINTER

    1

    2

    3

    4

    5

    6

    Summer Sun 12noon

    1

    3 5

    24

    Winter Sun 12noon

    8

    6

    Domestic Hot Water & Distribution:

    - Reduced DHW Demand - 0.5 litres/hour per pupil(Dept. of Education & Science TGD 002) -equivalent to 4 litres/day per person (PHPP).Reduced Tap Openings/year - 3,500/year

    - Student Toilets grouped together in one wing -reduces length of distribution pipework and dead-legs(15m total primary flow & return pipework,10m distribution pipework).

    - Staff Room & WCs with individual 3kW electricinstantaneous DHW heaters for hand washing.

    - 500 litre glass-lined DHW cylinder with single coilcalorifier and electric immersion, with 100mmmPU insulation layer (DxH:750x2100mm).

    Electrical Lighting & Equipment:

    - Energy efficient LED & T5 fluorescent light fittings,with linear automatic dimming, daylight andoccupancy sensors. Additional reduced lightingload due to improved natural daylighting.

    - Auxiliary Energy - Specification of energy efficientFans, pumps, computers and equipment.

    - PV: 100m2 roof mounted photovoltaic array to SEroof slope: 60 no. Sharp NU235E1 solar panels,generating 14 kWp (235W per panel), estimated11256 kWh per annum, (50% of Primary EnergyDemand) with feedback into Grid.

    2

    1

    Energy Efficient Lighting + Controls500L DHW tank 5-10kW Gas Boiler

    90.1%

    Internorm HF200 Passiv Windows:

    Ug: 0.62 W/m2KG-Value: 0.6Light transmittance: 0.71Frame Uf: 0.73 W/m2KFrame Width: 114mm, Depth: 85mmGlazing Edge Thermal Bridge: 0.038 W/mKInstallation Thermal Bridge: 0.040 W/mK

    Fakro FTTU08 Thermo Rooflights:

    Ug: 0.3 W/m2KG-Value: 0.35Light transmittance: 0.58Frame Uf: 1.10 W/m2KWindow Uw: 0.58 W/m2KFrame Width: 112mmGlazing Edge Thermal Bridge: 0.045 W/mK

    3

    4.640m

    2.42

    0m

    2.41

    7m

    2.131m

    Daylight Map Colour Legend

    PHPP Windows Sheet: Heat Gains / Losses through windows (Net energy gains though Openings – 1760 kWh/a)

    DETAIL C (Window Head) 1:5

    DETAIL D (Parapet/Flat Roof) 1:5

    DETAIL C

    DETAIL F

    DETAIL E (Flat Roof & Wall Abutment) 1:5

    Bird's Eye View from SE

    Bird's Eye View from South

    N

    Ground Floor Plan (Proposed) 1:100

    300mm Kore silver Neopor EPSinsulation boards, mechanically andadhesive fixed to plaster Parge coat

    substrate

    minimum 40mm EPS insulation overlapto all edges of window reveals

    18mm WBP plywood sheathingupstand

    InterNorm or similar approvedPassivHaus rated triple glazed windows

    280mm Styrodur or similar ExtrudedPolystyrene insulation bonded and

    mechanically fixed to new plaster pargecoat (air-tight layer), on rinsing walls /

    concrete footing

    DPC (existing)

    Existing reinforced concrete stripfoundations (assumed)

    XPS horizontal perimeter insulation,800mm width

    Airtight tape to edges of windows (pre-installed prior to fixing of windows),

    sealed to external parge coat / externalrender to provide airtightness

    exiting reinforced concrete lintels towindow heads

    Warmcell cavity fill insulation

    Plaster parge coat (air-tight layer)continued down to top of existing

    foundations

    100m perforated PVC drainage pipe,wrapped in geo-textile fabric and

    surrounded by washed stone / gravel

    paving, on 50mm sand/cementbedding on 150mm compacted Clause

    804 hardcore

    12mm ply window sill

    plywood cover strip / edging

    new 200mm polished reinforced concrete floorslab - 35N20 concrete, A142 meshreinforcement with min 50mm cover (or toEngineer's specification), laid on 300mm XPSinsulation, on Monarflex radon barrier, all jointslapped and taped, carried up 150mm abovefinished floor level and taped / stapled toexisting walls behind skirting

    50mm sand blinding on 150mm Clause 808compacted hardcore base

    Edge of Concrete floor slab tapered as shownwith triangular vertical insulation to allperimeters to minimise cold bridging at floor /wall junctions

    8mm laminated safety glass to newinternal windows betweenclassrooms and corridor

    Ash or similar window frame with 10mm shadow gaprebate to edges

    ply cavity closer

    existing continuous reinforced cast in situ concretelintels to internal cavity wall - provide additional column

    supports to new window openings as required inaccordance with Structural Engineer's details

    exiting projection to edge of concreteflat roof cut off with con-saw, flush with

    external walls

    projection to existing reinforcedconcrete eaves band beam cut off

    with con-saw, flush with externalwalls

    Thermally broken timber/alluminiumcomposite window frames, installed intooutside face of existing window opes

    External Walls – Air-tight PlasterParge coat on existing roughcast

    rendered walls, carried down tofoundation level, to provide

    external airtight layer

    Floors - 200mm Solid concretefloor slab with Radon Barrier /DPM, sealed to walls.

    Air-tight sealing tape to junctionbetween concrete floor andexisting solid concrete footings

    Intello roof air-tight membrane,and external parge coat sealedto existing concrete band beam

    Pitched Roof – Intellomembrane, with 50mmservices zone / counter-battens below.

    Windows – Fitted externally withair-tight tape, sealed to render /

    plaster parge coat.

    Flat Roof - Air-tight membrane /vapour barrier above concrete

    deck, sealed to externalplastered wall.

    Air-tight membrane / tape toopening and fixed rooflights

    250mm ∅ Air Supply ductworkat 2.3m height - with supply airvents to corridor

    Fresh Air diffusers in corner ofclassrooms at Floor Level

    300mm ∅ Intake & Exhaust AirDucts to outside wall (insulated)

    150-250mm ∅ Extract Duct fromWCs

    Separate Low-temperatureradiators to each classroom toprovide space heating withindividual thermostatic controlvalves (Space Heatingdecoupled from VentilationSystem)

    MVHR Units in cupboardspace to Lobby Areas

    0.093 W/m2K(280mm XPS insulation)

    0.098 W/m2K(300mm EPS insulation

    + 75mm CelluloseBlown Cavity Fill)

    0.114 W/m2K(300mm Foamglas

    insulation)

    0.088 W/m2K(350mm Celluloseinsulation + 50mmSheepswool)

    0.107W/m2K(300mm XPS insulation)

    Calculated LTB-02

    Calculated LTB-01

    Plaster Parge coat (airtight layer)

    ss plaster stop

    Powder-coated aluminium window sill

    existing 25mm internal plaster

    70mm full fill blown cellulose cavity fillinsulation (Warmcell)

    existing reinforced concrete flat roofdeck

    existing 3mm plaster skim and corkinsulation boards to soffit

    MVHR Units - (2 no.) Paul Maxi 801DC

    Heat Recovery Efficiency - 90.01%PHPP. - 78.01% (-12% non-certified unit)Electric Efficiency – 0.38 Wh/m2Length of supply duct – 0.85 mLength of exhaust duct – 0.85 mInsulation thickness – 100mmU-Value of Insulation – 0.025 W/m2K

    extract

    supply

    extract

    kWh/(m2a)

    kWh/(m2a)

    kWh/(m2a)

    kWh/(m2a)

    kWh/(m2a)

    kWh/(m2a)

    WINTER:

    1. The retrofitted building is airtight with superinsulated fabric and highly efficient tripleglazed "Passiv" windows and doors.Thermal Mass is used to store heat andmodulate heating loads.

    2. Windows are optimised to take advantage ofpassive solar gains from the south-eastfacade (low angle winter sun). Internalblinds are used to control solar glare.

    3. Classrooms are supplied with constant freshair warmed via a heat exchanger by extractair (4), with CO2 monitoring and control.

    5. Heating is largely by passive gains fromUsers, electrical lighting & equipment, andsolar gains.

    6. Passive heat gains are supplemented by anefficient gas fired condensing boiler and lowtemperature radiators, easily controlled byusers and with quick response to preventtemperature overshoot.

    SUMMER:

    1. Solar gain is controlled by external BriseSoleil, internal solar blinds and the highlyinsulated building fabric.

    2. The thermally massive construction(exposed concrete f loors, concreteblockwork walls, & concrete roof slab)modulates cooling loads.

    3. Lighting loads are controlled by daylight andmotion detectors (good natural daylightingalso minimises electrical lighting demand,and associated heat gains).

    4. Summer ventilation is controlled by usersopening the windows and insulated securelouvres to the external door fanlights.

    5. High level automated opening roof lightsprovide cross ventilation / stack effect.These can also be used to provide nightpurge cooling supplemented if required bythe Mechanical Ventilation system (6)operating in bypass mode.

    supply

    0.87

    kWh/(m2a)