Tas seminar/demonstration on
Part L 2006 of the Building Regulations
Presented by Alan Jones
EDSL
February 2006
www.edsl.net
Part L2A 2006 (April)
What needs to be calculated, when and how?
There are two types of calculation required:
targeted CO2 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 CO2 emissions rate (TER) be generated?
CO2 emissions will be calculated for a notional building and systems.
This notional model will reflect Part L2 2002 standards and CIBSE TM32
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 28C 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 35W/m2 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 CO2 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 3D geometry model and analysis zones.
Export 3D 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, CO2 emissions and plant equipment sizing.
Use notional CO2 emissions to generate the target emissions for the design.
Process the results and model input data through the Part L2 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 L2 compliance
This is design undertaken by Foreman Roberts Partnership.
It is a new Bio-Chemistry building at the University of Oxford.
Creating the 3D geometry model
Import CAD floor plan as a template for drawing in walls etc
Creating the 3D geometry model
As the walls are drawn they are extruded to a defined floor to floor height
Creating the 3D geometry model
Windows are created and placed into the walls or roof
Creating the 3D geometry model
The model is divided into analysis zones
Creating the 3D geometry model
Internal and external shading is calculated
Creating the 3D geometry model
3D model exported for daylight simulation
Creating the 3D geometry model
3D model exported for daylight simulation
Internal lux levels in atrium
Creating the 3D geometry model
3D model exported for external daylight and sunlight studies
Creating the 3D geometry model
3D model exported as 3D DWG. gbXML to Autodesk Building Systems and Cymap
Creating the building model
Hourly climate data is selected for the region. There are 14 UK weather sets
External Temperature (deg.C)
35
30
25
Deg C
20
15
10
5
0
-5
-10
Annual hourly data
External Temperature (deg.C)
Creating the building model
Hourly climate data is selected for the region. There are 14 UK weather sets
Global and diffuse solar radiation
1000
900
800
W/m2 on the horizontal
700
600
500
400
300
200
100
0
Annual hourly data
Global Radiation (W/m2)
Diffuse Radiation (W/m2)
Creating the building model
Hourly climate data is selected for the region. There are 14 UK weather sets
Wind Rose MAY-SEPT
140
120
100
80
Total No. Hours
60
40
1
3
20
5
0
13
72
15
24
Wind Bearing (degrees)
120
11
168
216
9
264
312
360
7
0-20
20-40
40-60
60-80
80-100
100-120
120-140
Wind Speed (m/s)
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
40
35
30
25
20
15
10
Creating the building model
The difference between dynamic simulation and admittance
Simulated performance BRE office first floor south, summer 1994 weather
40
35
30
25
20
15
10
Creating the building model
The difference between dynamic simulation and admittance
40
Repeated hot day simulation with beam & diffuse shading (2)
35
30
25
20
15
10
Creating the building model
The difference between dynamic simulation and admittance
40
Repeated hot day simulation with beam shading only (3)
35
30
25
20
15
10
Creating the building model
The difference between dynamic simulation and admittance
Real weather simulation with beam & diffuse shading (1)
40
(3)
35
(2)
30
(1)
25
20
15
10
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
Lighting energy use with daylight saving
16
14
12
W/m2
10
8
6
4
2
0
Annual hourly data
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
Laboratory temperature and loads over a winter week
25
8000
7000
20
Temperature C
6000
5000
15
4000
10
3000
2000
5
1000
0
0
7 days
External Temperature (deg.C)
2 lab 1 Dry Bulb (deg.C)
2 lab 1 Heating Load (W)
2 lab 1 Cooling Load (W)
Post processing the results
A number of macros are available to produce frequently required data
Daily total demand for biochemistry building
6000.00
5000.00
4000.00
Demand (kWh) 3000.00
2000.00
1000.00
0.00
Heating
Cooling
Internal
Solar
Post processing the results
A number of macros are available to produce frequently required data
Peak demands for biochemistry building
700.00
600.00
Load (kW)
500.00
400.00
300.00
200.00
100.00
0.00
Heating Peaks on Day 46,
Hour 7
Cooling Peaks on Day
179, Hour 14
Humdify Peaks on Day
45, Hour 7
Dehumidify Peaks on Day Internal Peaks on Day 1, Solar Peaks on Day 139,
186, Hour 14
Hour 17
Hour 12
Post processing the results
A number of macros are available to produce frequently required data
Annual total demand for biochemistry building
2000000.00
1800000.00
1600000.00
1400000.00
1200000.00
Demand (kWh) 1000000.00
800000.00
600000.00
400000.00
200000.00
0.00
Heating
Cooling
Humdify
Dehumidify
Internal
Solar
Post processing the results
Basic room loads may be sized
Post processing the results
Frequency charts of internal temperatures may be generated
Cumulative Frequency of Resultant Temperature for Year
Lower level of atrium in biochemistry building
1200
1090
1085
1018
1000
Number of Hours
800
761
600
410
400
172
200
0
0
0
0
0
26
27
28
29
30
0
20
21
22
23
24
25
Temperature (C)
Calculating energy use and CO2 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 TM32.
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
Annual Energy Consumption for biochemistry
300
250
Consumption in kWh/m2
200
Lighting
Pumps
Fans
AHU Cooling
Room Cooling
Humidification
AHU Heating
Room Heating
150
100
50
0
Design
Notional
The system is simulated using the hourly room demands
Design CO2 emissions is shown against the notional standard
Annual CO2 Emissions for biochemistry
90
80
70
Emissisions in kgCO2/m2
60
TER
Lighting
Pumps
Fans
AHU Cooling
Room Cooling
Humidification
AHU Heating
Room Heating
50
40
30
20
10
0
Design
Notional
Target CO2 Emission Rate
The system is simulated using the hourly room demands
Peak demand for all systems are calculated
Peak Consumption for the biochemistry building
600
500
Consumption (kW)
400
300
200
100
0
Room Heating
Consumption
Peaks on Day 349,
Hour 7
AHU Heating
Consumption
Peaks on Day 45,
Hour 10
Humidification
Consumption
Peaks on Day 52,
Hour 16
Room Cooling
AHU Cooling
Fans Consumption
Pumps
Consumption
Consumption
Peaks on Day 135,
Consumption
Peaks on Day 181, Peaks on Day 195,
Hour 13
Peaks on Day 186,
Hour 15
Hour 9
Hour 11
Lighting
Consumption
Peaks on Day 1,
Hour 17
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