Tas seminar demonstration on Part L 2006 of the

Tas seminar/demonstration on Part L 2006 of the Building Regulations Presented by Alan Jones EDSL February 2006 www. edsl. net

Part L 2 A 2006 (April) What needs to be calculated, when and how? There are two types of calculation required: targeted CO 2 emissions avoidance of summer overheating in naturally ventilated spaces These calculations need to be done when: design specifications are submitted to building control the building has been completed

How will the target CO 2 emissions rate (TER) be generated? CO 2 emissions will be calculated for a notional building and systems. This notional model will reflect Part L 2 2002 standards and CIBSE TM 32 TER is defined by reducing the notional emission by an improvement factor and LZC benchmark. For air conditioned or mechanically vented buildings the reduction is 28%. For naturally vented buildings the reduction is 23. 5% Use either accredited simulation software or SBEM for this calculation

How will the avoidance of summer overheating be demonstrated? Comfort criteria for avoidance of summer overheating are specified for various types of naturally ventilated buildings. Usually expressed as acceptable number of hours which threshold temperatures may be exceeded. Offices not to exceed 28 C for more than 20 hours per year for example. Accredited simulation software may be used for this calculation or average heat gains should not exceed 35 W/m 2 over a design day. SBEM or Admittance procedure not applicable.

What will the compliance checking software do? This is the procedure by which the building design is checked against all the criteria for compliance. A report is generated for submission to Building Control. The CO 2 emissions must meet the TER and minimum standards for U values, air tightness, occupation schedules and system efficiencies checked. High system efficiencies would be flagged for inspection by the BCO. Use either accredited simulation software or SBEM for this check Supporting documentation would be submitted on avoidance of summer overheating. Also O&M manuals and log book etc for completed building.

The stages of model building and analysis Create 3 D geometry model and analysis zones. Export 3 D model for daylight simulation. Add building construction details, occupation schedules, control set points and climate data to create a building model. This model is copied to create a notional equivalent. Simulate thermal performance of building hourly over a year to generate room loads and internal temperatures and humidity. Add plant type and controls detail with air supply specification to create a systems model. This model has a notional equivalent created to run with the notional building, Simulate the systems performance hourly over a year to generate energy use, CO 2 emissions and plant equipment sizing. Use notional CO 2 emissions to generate the target emissions for the design. Process the results and model input data through the Part L 2 compliance checking software to prepare a report for Building Control. If there are naturally ventilated spaces generate temperature frequencies to demonstrate avoidance of summer overheating.

An example project evaluated for Part L 2 compliance This is design undertaken by Foreman Roberts Partnership. It is a new Bio-Chemistry building at the University of Oxford.

Creating the 3 D geometry model Import CAD floor plan as a template for drawing in walls etc

Creating the 3 D geometry model As the walls are drawn they are extruded to a defined floor to floor height

Creating the 3 D geometry model Windows are created and placed into the walls or roof

Creating the 3 D geometry model The model is divided into analysis zones

Creating the 3 D geometry model Internal and external shading is calculated

Creating the 3 D geometry model 3 D model exported for daylight simulation

Creating the 3 D geometry model 3 D model exported for daylight simulation Internal lux levels in atrium

Creating the 3 D geometry model 3 D model exported for external daylight and sunlight studies

Creating the 3 D geometry model 3 D model exported as 3 D DWG. gb. XML to Autodesk Building Systems and Cymap

Creating the building model Hourly climate data is selected for the region. There are 14 UK weather sets

Creating the building model Hourly climate data is selected for the region. There are 14 UK weather sets

Creating the building model Hourly climate data is selected for the region. There are 14 UK weather sets

Creating the building model The difference between dynamic simulation and admittance

Creating the building model The difference between dynamic simulation and admittance Monitored performance BRE office first floor south, summer 1997

Creating the building model The difference between dynamic simulation and admittance Simulated performance BRE office first floor south, summer 1994 weather

Creating the building model The difference between dynamic simulation and admittance Repeated hot day simulation with beam & diffuse shading (2)

Creating the building model The difference between dynamic simulation and admittance Repeated hot day simulation with beam shading only (3)

Creating the building model The difference between dynamic simulation and admittance Real weather simulation with beam & diffuse shading (1) (3) (2) (1) Admittance method with no diffuse shade calculation

Creating the building model Construction and glazing details are selected from databases

Creating the building model Construction and glazing details are selected from databases

Creating the building model A calendar is used to identify days when different activities occur

Creating the building model Occupation schedules and heat gains are specified for the different day types

Creating the building model Thermostat control settings may be specified for the different day types

Creating the building model The daylight simulation can be used to calculate lighting energy savings

Creating the building model For naturally ventilated spaces window or vent opening strategies may be applied

Running a simulation and viewing the results Any combination of spaces and performance data may be displayed

Running a simulation and viewing the results Data may be exported into Excel for report preparation

Post processing the results A number of macros are available to produce frequently required data

Post processing the results A number of macros are available to produce frequently required data

Post processing the results A number of macros are available to produce frequently required data

Post processing the results Basic room loads may be sized

Post processing the results Frequency charts of internal temperatures may be generated

Calculating energy use and CO 2 emissions A copy is made of the design building model to create the notional model The notional building model is a copy of the design model retaining the shape, zones and occupancy. All U-values are replaced with elementally compliant values and glazing ratios changed to be elementally compliant. This process is automated.

The notional system, that is used with the notional building, is specified in CIBSE TM 32. It is a standard good practice fan coil system with gas boiler and air cooled chiller. The allocation of this notional system is automated.

Plant details may be added to the building model General plant details

Plant details may be added to the building model Fresh air supply and terminal unit

Plant details may be added to the building model Building zones to be supplied by a particular system type are selected

Plant details may be added to the building model Plant room equipment specifications are added

The system is simulated using the hourly room demands Design energy consumption is shown against the notional standard

The system is simulated using the hourly room demands Design CO 2 emissions is shown against the notional standard

The system is simulated using the hourly room demands Peak demand for all systems are calculated

The system is simulated using the hourly room demands Individual plant components are sized

Accredited software needs to comply with relevant BS EN ISO standards

Accredited software needs to comply with relevant CIBSE TM 33 Tests