Auf Wissen bauen

7. Annual North American Passive House Conference, Denver, USASeptember 28, 2012 - Florian Antretter

WUFI PassiveA new comprehensive design and certification tool for the next generation of passive houses

Outline

State of the art

Limitations of previous assessments

WUFI Passive introduction

GUI

Output

Combination with hygrothermal simulation

Example case

Summary

Outlook

Thermal Conditions in Zones and Building Energy Use (Examples)

Balance based: PHPP

Dynamic: Energy Plus, TRNSYS, ESP-r, …

Used for

design of buildings with low energy use

assessment of the integral interaction of building, HVAC and use

expected indoor thermal conditions and energy use

but…

no hygrothermal interaction with the envelope

State of the art - building energy assessment

Hygrothermal Conditions on and in Building Components Steady-state (e.g. Glaser method) Dynamic (e.g. WUFI, Delphin, Moisture ANK)

Used for ensuring damage-free constructions computation of the coupled heat and moisture transfer in building

components with predefined boundary conditions expected temperature and moisture distribution in building components

and energy and mass fluxes on surfaces

but… no interaction with the room predefined inner boundary conditions

State of the art - hygrothermal component simulation

Where we are…

Building energy design

PHPP

Dynamic building simulation

Hygrothermal component analysis

WUFI Pro

BUT:

Parallel assessment, no combination

Limitations of previous Passive House assessment

General Static calculation (Only annual / monthly method) No realistic inclusion of thermal inertia

Analysis No real comfort analysis No damage analysis (e.g. mold growth)

Limited Validation Only verified for European climates No broad scale North American verification

Usability No user-friendly input No assistance for missing / incorrect Data

© nelsoncleancare.com

The ideal world…

Building energy design / certification:

Passive house design / certification (monthly or annual balances)

Dynamic building energy simulation

Comfort analysis on a room by room basis

e.g. ASHRAE 55

Building component analysis

Hygrothermal component simulation

Interaction with the room

All based on “one” building model!

Partners to create a new tool

Technical Committee

Beta testing Methodology

development

Technical support

Industry involvement

Main stream

Scientific support Software programming Methodology

implementation

Hygrothermal whole building simulation

Hygrothermal Envelope Simulation

Climate DataConstruction Data

Material Data

WholeBuilding

Simulation

Hygrothermal Performance

Indoor EnvironmentEnergy Use

Balances – from components to whole buildings

Precipitation

Radiation

window ventilation

inner loads

HVAC

Weather data

Air exchange

Inner loads

Set-points

HVAC

WUFI Background and family

WUFI = Wärme und Feuchte instationär - Transient Heat and Moisture - developed by IBP

allows realistic calculation of the transient hygrothermal behavior of multi-layer building components exposed to natural climate conditions

Why hygrothermic and not just thermic? moisture damages hygienic problems and health risks due to mould growth thermal and hygric behavior are closely interrelated: an

increased moisture content favors heat losses…the thermal situation affects moisture transport…

WUFI® Plus

Purpose assessment of indoor climate and energy demand simulation of interactions between building envelope and inner air

Focus room, whole building including components consideration of Heating / Ventilation / Cooling

Setup simple, lots of parameters creating building, definition of constructions,

surfaces, initial conditions and numeric settings derived indoor climate (internal loads, heating, shading…)

WUFI® Plus – Application Fields

Fields of Application heat demand / energy flow comfort assessment issues to ventilation behavior

© schmidt-hohwald.de

Combination for a new tool – WUFI Passive

Hygrothermal Envelope Simulation

Climate Data

WholeBuilding

Simulation

Hygrothermal Performance

Indoor EnvironmentHeating/Cooling

De-/Humidification

Balance Based

Assessment

Passive House Verification

Building Geometry

Construction Data

Material Data

Ventilation

Inner Loads

Set-Points

IntroductionWUFI Passive Layout

Layout divided into: Tree Structure Input Mask 3D Preview of Building Output Window

© Fraunhofer IBP: WUFI Passiv Layout

IntroductionWUFI Passive Layout

Tree structure: Climate Building divided into

zones Each zone consists of

components / inner conditions

HVAC system

© Fraunhofer IBP: WUFI Passiv Layout

IntroductionWUFI Passive Layout

Input mask: Input mask changes

depending on selected tree node

Divided in tabs

© Fraunhofer IBP: WUFI Passiv Layout

IntroductionWUFI Passive Layout

3D Preview of building: Construction of building

components Building wizard Google SketchUp

import possible

© Fraunhofer IBP: WUFI Passiv Layout

IntroductionWUFI Passive Layout

Output window: Interaction with user User can jump to

invalid/missing data by clicking on error message

Report of main requirements

© Fraunhofer IBP: WUFI Passiv Layout

Passive house input - Geometry

Building input

Component list

3-D building input

building wizard

manual input

Google Sketch-Up Plug-In

Passive house input – Google Sketch-Up Plug-In

Google Sketch-Up Model

WUFI Passive Model

Passive house input - Components

Inhomogeneous component model

Passive house input - Windows

Detailed window inputs Frame width / U-value /

Psi Glazing Psi Pane Conductivity

Passive house output – Status Bar

Status Bar

Most relevant output

Fulfillment of certification criteria

Parameter comparison

Passive house outputReport

Report

All relevant values for certification

Detailed information on all fluxes

Graphical representations of all values

Design and certification support

Features of the Passive House verification mode

Special features

Instant calculation and case comparison

Automatic area detection

3-D visualization

Google Sketch-Up import

SI/IP units switch

Input support

Input in decimal feet and feet and inch

Some additional calculators

Comprehensive databases

WUFI Passive – Combination with dynamic simulation

Unlock dynamic hygrothermal whole building simulation Dynamic simulation on the same building model!

Dynamic input – Schedules

Periods and day profiles for

Inner loads

Set-Points

Ventilation rates

HVAC equipment operation

Dynamic input – Components

More comprehensive component input

Thermal storage

Hygric properties

Sources in the assembly

Dynamic output – Report

Report

Full project documentation

Range and Mean of all relevant parameters

Heat gain/loos for all components in heating and cooling period

Dynamic output Inner climate

Inner Temperature

Heating / Cooling

Dynamic conditions indoor

Hourly values for inner temperature and RH

Easy assessment of improvement strategies

Assessment of effect of thermal and hygric inertia

Dynamic output – Comfort conditions

Comfort assessment (ASHRAE 55)

Predicted mean vote

Adaptive method

Overheating hours

Dynamic output – Heat flows

Heat / moisture flows

Hourly values for all heat and moisture flows

Monthly sums of heat and moisture flows

Assessment of impact of different measures

Dynamic output – Component performance

Hygrothermal component performance

Hourly values for layer temperatures, RH and water content

Easy moisture safety assessment

Dynamic output – Movie

Movie

Visualization of temperature and moisture distribution

Heat and moisture fluxes on surfaces

Identification of “problem spots” in the assembly

Dynamic output – Export

Export

Export of all output values

Hourly resolution for zone and component results

Excel and text export option

Features of the dynamic WUFI mode

Special features

Dynamic hygrothermal whole building simulation

Easy to use graphical user interface

Multi-zone model

3-D visualization

Google Sketch-Up import

SI/IP units switch

extensive data bases

comfort analysis

Hygrothermal component analysis

Sophisticated building performance assessment

Examples for additional modeling options

Shading strategies

Ventilation strategies

Use of thermal and hygric inertia

Different usage profiles

Insulated shutters

Envelope optimization

Outlook

General

Thermal bridge (2-D and 3-D steady-state and dynamic)

Passive house verification

Implementation of new features

Complete certification documentation

Dynamic simulation

More detailed HVAC and photovoltaic simulation Net-Zero and Plus

User support for data analysis

Enhanced dynamic window model

Summary

WUFI Passive as comprehensive design and certification tool

One software combining two building assessment methods

User-friendly interface

Easy switch between Passive House verification and dynamic simulation

Just one building model for both features

Extensive data bases

Result export

Combined analysis of energy, comfort and hygrothermal component performance based on one building model

WUFI Passive is constantly improving and implementing features to keep it on top of the state of the art!

Auf Wissen bauen

7. Annual North American Passive House Conference, Denver, USASeptember 28, 2012 - Florian Antretter

WUFI PassiveA new comprehensive design and certification tool for the next generation of passive houses

Thank you!