BUILDING ENERGY PERFORMANCE MODELLING Designbuilder getting started

BUILDING ENERGY PERFORMANCE MODELLING Designbuilder – getting started Miroslav Urban Katedra technických zařízení budov Stavební fakulta, ČVUT v Praze

Designbuilder simulation software ƒ British simulation software ƒ for checking building energy, carbon, lighting and comfort performance ƒ Calculation with hourly, daily, monthly simulation step

ƒ Used Energy Plus calculation engine for dynamic simulation ƒ Main typical uses are: ƒ Calculating building energy consumption ƒ Thermal simulation of naturally ventilated buildings. ƒ Daylighting - models lighting control systems and calculates savings in electric lighting. ƒ Visualisation of site layouts and solar shading. ƒ Calculating heating and cooling equipment sizes. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation energy consumption ƒ Annual, daily, hourly calculation time step ƒ Heating load ƒ Cooling load

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Visualisation of solar shading ƒ Shading and daylight calculation

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Visualisation of solar shading

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Temperatures calculation ƒ Operative, mean radiant and air temperature

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder - overview ƒ Model Data Hierarchy – organised in a simle hierarchy

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder - input data, hierarchy ƒ Default data is inherited from the level above in the hierarchy, ƒ block data is inherited from building level, zone data is inherited from block data and surface data from zone data.

ƒ Activity, Lighting, HVAC, Equipment data is used at the zone level, i.e. all Activity, Lighting, HVAC, Equipment data at building and block level is default data. ƒ Construction and Openings data is used at the surface level, i.e. all construction and opening data at building, block and zone level is default data and only data at surface level is actually used to define the model. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder - results ƒ Energy simulation detailed results (Daily, mothly, hourly calculation step) ƒ At zone level: ƒ Environmental/Comfort Output – average from a zone (Air temperature, MR temperature, operative temperature, PMV) ƒ Fabric and ventilation (heat gains) ƒ Airflow (HVAC air distr. Systém, infiltration, natural ventilation) ƒ System heat flows (zone heating/cooling, AHU heating, heat recovery …)

ƒ At building level: ƒ Fuel breakdown (heat generation, total energy for chiller, electricity for pumps, fans,) ƒ Fuel totals (Total fuel consumption for building) Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – getting started ƒ Creating of the building model in DB ƒ Before creating model in DB collect input data for SW

ƒ Activity tab: Activities in the building (templates in the library). ƒ Construction tab: Construction parameters (type of constructions from the library). ƒ Openings tab: Openings parameters (type of constructions from the library). ƒ Lighting tab: Type of lighting system, lighting system surface amount ƒ HVAC tab: parametrs for Heating, cooling, ventilation, humidification systems Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – Activity tab ƒ Activity tad: Defines activities in the building (templates in the library) ƒ Occupancy ƒ density (people / m2), ƒ occupation schedule (day, hour), ƒ metabolic rate (calculation comfort) ƒ Heat gains (computers, lighting, other) ƒ Envinmental control ƒ HVAC – setpoint temperatures, schedules, minimum fresh air, etc.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – Construction tab ƒ Construction tab defines construction of building ƒ Generic templates ƒ Define own construction

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – Openings tab ƒ Defines openings for the building (zone) ƒ From glazing templates ƒ Own openings

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – Lighting tab ƒ You can load generic Lighting data

ƒ Simple calculation ƒ internal gains are calculated by dividing the W/m2/100 lux data in the template by the required illuminance level as set on the Activity tab ƒ Lighting energy (W/m2) = Lighting (W/m2/100 lux) x Design lux level (Activity tab) / 100

ƒ Complex calculation ƒ control the electric lights according to the availability of natural daylight. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Defines HVAC systems fot the building (zone) ƒ Simple or Compact HVAC system type ƒ DB can automatically calculate heating and cooling capacity in each zone based on the output from the Heating and Cooling design calculations.

ƒ Simple HVAC system type – only on the building level ƒ the heating/cooling system is modelled using basic loads calculation algorithms. x System type (convective or convective/radiant). x Supply air temperatures for simulation. x HVAC auxiliary data (below). Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Compact HVAC system type ƒ Its possible to define a system type at the zone level ƒ the heating/cooling systems are defined in DesignBuilder using Compact HVAC descriptions but modelled in detail in EnergyPlus.

ƒ HVAC model option is set to Compact, there are 5 HVAC system types: ƒ ƒ ƒ ƒ ƒ

Unitary single zone Fan Coil Units Unitary multizone VAV CAV

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Compact – HVAC types – Fancoil units

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Compact – HVAC types – Unitary single zone

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Compact – HVAC types – Unitary multizone

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

DesignBuilder – HVAC tab ƒ Compact – HVAC types – VAV (variable air volume + CAV (constant air vol.)

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model ƒ Creating default data for a model ƒ Before building a medel is necessary to define templates and default data for a building ƒ Activity templates (for each different zone) ƒ Construction templates (for each construction) ƒ Openings templates (different glazing, glazing layout, frame..) ƒ HVAC templates (fancoil system, etc …)

ƒ Default data at ƒ Building level ƒ Zone level ƒ Surface level

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model – model data Default data is inherited from the level above in the hierarchy, so block data is inherited from Default wall building level, zone data is modification inherited from block data and Wall type 2 surface data from zone data. When you change a setting for a category this change is ‘inherited’ by all lower levels within the category. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Site

Building

Block

Wall type 2

Zone

Wall type 2

Surface

Opening for wall 2

Opening, wall

Building a model – default values Construction and window towall-ratios default values are inherited down to the surface level where the data is actually used in the calculations.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Site

For level below

Building

For level below

Block

For level below

Zone

Simulation data

Surface

Data from surface

Opening, wall

Building a model – hierarchy ƒ Model data hierarchy

Source: Harvard university Graduate school of Design Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Block types ƒ Building block – creating parts of building ƒ Component block – no building parts (ground, shading, adiabatic parts) ƒ Outline block – for creating building blocks

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Block types ƒ Building block – creating parts of building ƒ Component block – no building parts (ground, shading, adiabatic parts) ƒ Outline block – for creating building blocks

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Building block ƒ represents the outer shell of the model or part of the model ƒ A block may be divided internally into any number of zones by drawing partitions and where needed, voids or courtyards can also be incorporated

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Component block – 3 types ƒ 1-Standard - used for shading, reflection and visualisation ƒ balconies, pillars, shading obstructions (show in blue) ƒ 2-Ground - used for setting ground adjacency, shading, reflection and visualisation ƒ ground modelling, to modify the adjacency of the surfaces touching it to be 'adjacent to ground‚ (show in green) ƒ 3-Adiabatic - used for setting adiabatic adjacency, shading, reflection and visualisation ƒ Adiabatic surfaces do not transfer heat beyond their outer surface and are often used for modelling boundaries with other spaces (show in red) Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Component block ƒ Ground:

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

Adiabatic:

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Building a model - geometry ƒ Adding Blocks ƒ first go to the building level (if you are not already there) and click on the Add new block tool ƒ the dimensions of the block are those measured from the outside, the height of the block is the floor-floor height

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - geometry ƒ Zones ƒ Zone type in the activity tab: ƒ 1-Standard - occupied and heated or cooled. ƒ 2-Semi-exterior unconditioned - roofspaces, sunspaces, car parks etc ƒ 3-Cavity - the zone is a cavity such as the glazed cavity within a double facade or a Trombe wall ƒ 4-Plenum - the zone is a plenum (under the ceiling, technical double floor – for air flow distribution).

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model – editing templates ƒ Generic activity template ƒ You may check the parameters and edit the template ƒ ƒ ƒ ƒ

Generic template is locked Copy the temteplate Edit the template Save the teplate in to library

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - schedules ƒ Schedules ƒ Occupancy time, operation time for heating, cooling, mechanical ventilation, lighting …, temperature setpoints

ƒ You can define schedules in one of 2 ways: ƒ 7/12 Schedules - where each day of the week and each month of the year has a unique daily variation defined using profiles. ƒ Compact Schedules - more flexible definition using EnergyPlus Schedule: Compact text-based data format.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - schedules ƒ 7/12 Schedules ƒ Profile by overall picture of an operation schedule ƒ End use of defaults

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Building a model - schedules ƒ Compact schedule (energyplus schedule) Example 1 - Operation Schedule SCHEDULE:COMPACT, Office_CellOff_Light, Fraction, Through: 31 Dec, For: Weekdays SummerDesignDay, Until: 07:00, 0, Until: 19:00, 1, Until: 24:00, 0, For: Weekends, Until: 24:00, 0, For: Holidays WinterDesignDay AllOtherDays, Until: 24:00, 0;

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Example 2 - Temperature Setpoint Schedule SCHEDULE:COMPACT, Bedroom_Cool, Temperature, Through: 31 Dec, For: Weekdays SummerDesignDay, Until: 05:00, 0.5, Until: 09:00, 1, Until: 17:00, 0.5, Until: 24:00, 1, For: Weekends, Until: 05:00, 0.5, Until: 24:00, 1, For: Holidays WinterDesignDay AllOtherDays, Until: 24:00, 0;

Building a model - schedules ƒ Compact schedule (energyplus schedule) – edit schedule

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Simulation ƒ Calculation types: ƒ ƒ ƒ ƒ ƒ

Heating design simulation Cooling design simulation Simulation using hourly weather data CFD Daylighting

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – heating design ƒ Calculation results are typically used to size heating components systems and their components. ƒ Constant (Steady-state) external temperature set to the winter design external temperature ƒ No solar gain. ƒ No internal gains (lighting, equipment, occupancy etc). ƒ Heated zones are heated constantly to achieve the heating temperature set point using a simple convective heating system. ƒ Includes consideration of heat conduction and convection between zones of different temperatures. ƒ Schedules are not used for Heating design calculations which are based on a steady state analysis which does not account for timing. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – heating design ƒ Setting the design temperature Go to the “edit” tab go to “Site” level > “Location” > “Winter Design Weather Data”. - set outside design temperature - a 99% design temperature is one that will be exceeded for 88 hours in a typical year - a 99.6% design temperature is one that will be exceeded for 35 hours in a typical year.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – heating design ƒ Sizing factor

ƒ The Heating Design margin is used to multiply calculated steady state heating loads in each zone to give a recommended heating plant size. ƒ Set „1,2“

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – heating design ƒ Results ƒ Average temperatures ƒ Heat losses Glazing Walls Openings Roofs Ext. Ventilation Mech. Ventilation ƒ Etc … ƒ ƒ ƒ ƒ ƒ ƒ

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – cooling design ƒ Cooling design calculations are carried out to determine the capacity of mechanical cooling equipment required to meet the hottest summer design weather conditions ƒ Periodic steady-state external temperatures calculated using maximum and minimum design summer weather conditions. ƒ No wind. ƒ Includes solar gains through windows and scheduled natural ventilation. ƒ includes internal gains from occupants, lighting and other equipment. ƒ Includes consideration of heat conduction and convection between zones of different temperatures. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – cooling design ƒ Setting cooling design temperature Go to the “edit” tab go to “Site” level > “Location” > “Summer Design Weather Data”. - set outside design temperature - a 99% design temperature is one that will be exceeded for 88 hours in a typical year - a 99.6% design temperature is one that will be exceeded for 35 hours in a typical year.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – cooling design ƒ Sizing factor

ƒ The Summer Design margin is used to multiply calculated steady state heating loads in each zone to give a recommended heating plant size. ƒ Set default „1,3“

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – cooling design ƒ Results – hourly for typical summer day ƒ Temperatues ƒ Operative ƒ Radiant ƒ air

ƒ Heat gains ƒ Cooling loads ƒ Design Cooling load summary for ƒ Building ƒ zone

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – cooling design ƒ Analyzing temperature profiles – without mechanical cooling radiant temperature (red) operative temperature (green) air temperature (blue) outside temperature (dark blue) The operative temperature is also above the comfort temperature of 24°C-27°C recommended by ASHRAE STD 55 and ISO 7730 at 50%RH when considering natural ventilation. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – simulation ƒ Simulating summer design week At the “Building Level” go to the “Simulations” to perform the “real weather data simulation”. When you first select “Subhourly” weather data for a Summer Design Week calculation, you will be prompted to download the hourly from DesignBuilder web site. Select “OK”. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – simulation ƒ Simulating summer design week Building level select “5-Subhourly” data display in Data > Interval

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – simulation ƒ Annual simulation - results Building level/zonel level select “1-Annual” data display in Data > Interval Note: Monthly simulation select “2-monthly” data display in Data > Interval

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Calculation – simulation ƒ Daily simulation - results Building level/zonel level select “3-Daily” data display in Data > Interval

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Results ƒ Customizing results At the “Building Level”, select Data “1-All” data display, then go to the “Detailed” tab in the “Display Options”.

Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Conclusion ƒ Preparing and running a simulation takes time. ƒ Before rushing into doing a simulation you should have a clear idea of how the simulations results can help you resolve a specific design question that you could not answer otherwise. ƒ Always consider that buildings are a complex integration of energy flows and systems comprising not only the whole of building form and fabric, but also plant and various other environmental control systems. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Literature, Questions ƒ DesignBuilder>>Help>>Content. ƒ www.designbuilder.co.uk/helpv3/

ƒ “Knowledgebase” section in DesignBuilder’s webpage which has answers to most common questions about DB. ƒ go to: www.designbuilder.co.uk>Support>Knowledgebase.

ƒ “DesignBuilder Forum” - users post all sorts of questions which are usually answered by DesignBuilder software developers. ƒ go to: www.designbuilder.co.uk>Support>DesignBuilder Forum. Miroslav Urban, katedra TZB, Fakulta stavební, ČVUT v Praze

11/2011

Miroslav Urban Katedra technických zařízení budov Stavební fakulta, ČVUT v Praze [email protected]