Subtask 1 : Modelling and Common exercises

Whole building simulation tools : CLIM2000

Monika WOLOSZYN (Thermal Sciences Centre - Lyon - France) CETHIL

• Introduction• Software presentation• Existing models • Moisture models• Example application• Limits and possibilities

Annex 41: Whole Building Heat, Air and Moisture Response (MOIST-EN)

Zurich meeting : May 2004

Different aim – different tool

T2 T3

T4T1 T5

c - multizone

Tint

d - monozone

a– CFD b – zonal

T3

T4

T1

T2

T5

France(CETHIL)

+ Denmark

(DTU)

France(LEPTAB)

+

Brazil(PUCPR)

Clim2000 : modular simulation environment

Clim 2000EDF (Electricité de France)

• Pre-processor

• Model library

• Numerical solver

model assembly

Over 100 existing elementary models :

Energy – Airflow - Moisture

ESACAP :

Efficient variable time step, variable order methods

MODULES:

zone d’air 1

zone d’air 2

détail du plafond

extérieur

Clim2000 : modular simulation environment

• Heat : envelope (including windows), boundary layers, air zone, heat loads… (state variable : temperature)

• Detailed radiation : detailed infrared exchanges in a room (state variable : temperature)

• Airflow : air zone, air inlets and outlets, large openings with counter flow (elements of temperature-pressure network) (state variable : temperature and pressure)

• Moisture : moist air zone, moist air inlets and outlets, large openings, moisture loads and moisture buffer model (elements of temperature-pressure-moisture network) (state variable : temperature, pressure, relative humidity)

• Cooling : elements of HVAC systems

• Control

• Utilities : boundary conditions, simple mathematical operations

Clim2000 : model library

Clim2000 : model library – level of details

• balance equations : energy, dry air mass, vapour mass

• mainly 1 D or 0 D models (some reduced models for thermal bridges have been used)

• interactions between air, moisture and heat are represented at whole building scale

• complete and validated building energy modelling tool

• includes some moist air flow models

Clim2000 : model library – moist airflow models

Q = f (P)

Standard airflow models

Ai inlets and outlets Large openings

re-circulation)

P ? Ptotal = Pdry air + Pwater vapour

Qm ? Qm moist air = Qm dry air + Qm water vapour

Moisture introduction

bath : 95 % et 22°Chall : 60% 22°C

flow :about 200 m3/h

ex.

Clim2000 : model library – moisture in materials

Simplified modeling of moisture buffering capacity (Duforestel et Dalicieux, 1994)

? vap,int(t)

? vap, cœur

? vap,surf(t)

Interiorair

Buffer surface

Buffer heart

2 sets of 4 experimentally determined parameters

- representing room with high moisture buffering capacity(ex. bedroom)

- representing room with low moisture buffering capacity(ex. hall, bathroom …)

Moisture balance in buffer surface :

- mass flux between air and buffer surface

- mass flux between buffer surface and heart

MOISTURE Airbornetransport

AIRFLOW

Condensation Evaporation Moisture

sourcesHEAT

Moisture buffering in materials

AIRFLOW

HEAT MOISTURE

condensation, absorption

Enthalpy contribution

Densit

y densitytra

nsport

transport

Need of a

coupled model

Clim2000: model library: Heat, Airflow, Moisture Interactions

Clim2000 : application example : moisture controlled exhaust

kitchen 10 m²

bedroom 111 m²

bed. 211 m²

hall 8 m²

entrance 7 m²

bathroom 7 m²

bed. 3 10 m²

living room37 m²

bathroom

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

0:00 6:00 12:00 18:00 24:00

time [hours]

moi

stur

e re

leas

e [k

g/h

]

living room

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

0:00 6:00 12:00 18:00 24:00

time [hours]

moi

stur

e re

leas

e [k

g/h

]

kitchen

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

0:00 6:00 12:00 18:00 24:00

time [hours]

moi

stur

e re

leas

e [k

g/h

]

bathroom

kitchen

40 70 ?[%]

30100

10

30

exha

ust [

m3 /

h]

0%

20%

40%

60%

80%

100%

0:00 4:00 8:00 12:00 16:00 20:00 0:00

time [hours]

air

hu

mid

ity

[%]

-

0,5

1,0

1,5

2,0

2,5

mo

istu

re r

elea

se [

kg/h

]

moisture controlled exhaust

constant exhaustclosed doors

open doors

moisture release

Clim2000 : application example : humidity results

Moisture in kitchen air

Opening doors has more impact than ventilation control

1 500

2 000

2 500

3 000

3 500

4 000

4 500

1, 0:00 1, 12:00 2, 0:00 2, 12:00 3, 0:00 3, 12:00 4, 0:00

time [day, hour]

hea

tin

g lo

ad [

W]

-5

-2,5

0

2,5

5

7,5

10

tem

per

atu

re [

°C]

outside temperature

constant exhaustmoisture controlledopen doors

moisture controlledclosed doors

Clim2000 : application example : heating load results

Overall heating load

10 % gain by use of moisture controlled ventilation

Clim2000 : limits and possibilities

?

?

• good energy models

• existing moist airflow library

• heat / airflow / moisture interactions at building level

• easy introduction of new models

• ‘private’ code

• moisture in materials

• some convergence problems