Low energy/CO2 building consultants

In-depth understanding of 'sustainability' building regulation and planning requirements

Commercial Part L2a/EPC, daylighting, adaptive comfort and 'real-life' predicted energy usage specialists

Please get in touch for an introductory discussion

 

The Basics - model building

Frequently clients may look to outsource this potentially time-consuming process due to in-house resource limitations

DesignCO2 has a wealth of model creation experience and can efficiently generate varying levels of model geometry complexities

A typical outsourced package of works would include:

  1. Receive and 'clean' architectural plan/elevation/section drawings (dwg format) and convert (to dxf format) for modelling purposes
  2. Generate accurate building geometry inclusive of internal volumes (construction thicknesses), external solar shading and relevant nearby/adjacent buildings
  3. Ensure all individual rooms/spaces are separately zoned and named as per architectural layouts and naming conventions
  4. Ensure all room 'typologies' are grouped and appropriate templates applied (i.e. offices, WC's, classrooms, circulation, storage etc.)
  5. Determine and apply fabric constructions (material build-ups) and ensure performances (U-values, thermal bridging, G-values and light transmittances) match specifications
  6. Parcel the model (.cab) and return to client for further in-house analysis

What is an Energy Model?

  • A 3D computer representation of a real building or design stage project
  • Models are created to enable simulations that quantify the impact of design 'optioneering' upon anticipated operational building energy/CO2/comfort performance
  • Typically an iterative process with varying levels of complexity available depending upon the applicable design stag

 

Energy models are developed for a range of simulation purpose, including:

  • Steady-state plant sizing - determination of peak plant (boilers/chillers/radiators/FCU etc.) loads based on industry standard CIBSE/ASHRAE calculation methodologies
  • Dynamic plant sizing - multiple time-step annual dynamic thermal calculations used to more accurately predict required plant capacities and associated response times (incl. LZC technologies)
  • Building Regulations Part L Compliance - Criteria 1, 2 & 3 assessments
  • Energy Performance Certification (EPC)
  • Internal daylighting performance assessment - incl. working plane daylight factors/lux levels and more complex climate based daylight analysis (CBDA)
  • Occupant thermal comfort assessments - incl. traditional overheating and more complex adaptive comfort calculations (CIBSE TM52 compliant)
  • Building certification credit compliance (i.e. BREEAM, LEED etc.)
  • 'Real life' energy consumption/CO2 emission predictions

 

Geometric models are constructed from plan, elevation and section drawings (i.e. AutoCAD DWGs) using tried and tested industry leading software (www.iesve.com). 

Correct building location/context, orientation and climatic data is applied

Geometric models are subsequently populated with performance information to allow building simulations to be completed

Building fabric performance details are assigned:

  • Construction build-ups - including extent of thermal mass exposures
  • Thermal transmittance (insulation) levels defined (U-values W/m2.K)
  • Glazing light transmittance and solar performances (G-values %)
  • Anticipated air permeability/infiltration rates

Space types are named, grouped (by usage type) and have realistic operational characteristics applied, including:

  • Occupancy, lighting and small power gains and profiles
  • Heating/cooling room temperature set-points
  • Ventilation rates and temperatures
  • HVAC and LZC technology performance information

 

Plant sizing and performance calculations

The next logical step once the model geometry relates to plant sizing and subsequent performance response times:

The two methodologies adopted are:

  1. Steady-state peak heating/cooling load calculations - adopting the UK industry standard CIBSE Guide A methodologies or if desired the equivalent ASHRAE routines
  2. Dynamic plant 

Building Regulations Part L2a/EPC calculations - model geometry can be provided by the client or developed by DesignCO2. Fabric/HVAC/lighting/LZC performance information can be provided or realistic recommendations applied

 

  • DesignCO2 has extensive experience developing models for most building types and climates
  • Building Regulations and Planning requirements are key drivers for the development of robust energy models