Prise en compte de la climatisation et calcul d’un indice thermique du corps G. Pigeon et B. Bueno

27/01/20112 Rappels  TEB version “originale” :  représentation simple du bâtiment  Température intérieure n’est pas calculée en bilan d’énergie  Sorties pour le climat dans la rue :  Température de l’air, vent, humidité mais pas d’indication sur le ressenti thermique par les personnes sous l’effet du rayonnement/humidité etc..

27/01/ Introduction 2.Model description 3.Model inputs 4.Simulation-based model evaluation 5.Next steps Travail de Bruno Bueno : Amélioration de la représentation du bilan thermique du bâtiment Prise en compte de la climatisation

27/01/20114 Building energy demand calculations Heat balance method Separation between convective and radiative heat components. Multi-storey buildings are represented by an internal thermal mass. The model accounts for: Transmitted solar radiation through windows Thermal heat storage. Heat conduction through the enclosure: wall, roof, and windows. Infiltration/ventilation. Internal heat gains. Overview DOE 2010

27/01/20115 Overview HVAC energy consumption calculations Ideal HVAC system The system supplies the required energy to meet temperature and humidity setpoints. Real HVAC system The system capacity and efficiency depends on indoor and outdoor temperatures, as well as on situations of part-load performance. The model solves the psychrometrics transformations of the air passing through the system. It calculates the indoor air humidity, fan energy consumption, sensible and latent waste heat emissions. The model includes an “autosize” function. bsdsolutions.com HVAC – Heating, Ventilation, Air Conditioning

27/01/20116 Model physics Indoor surface energy balance Convective and radiative heat exchange based on heat transfer coefficients. Heat conduction based on finite differences (TEB routines). Steady-state conduction through windows. Calculation of view factors between indoor surfaces. DOE 2010 OUTDOOR INDOOR

27/01/20117 Indoor air energy balance The air sensible and latent heat balances are composed of: Convective heat fluxes from indoor building surfaces: wall, roof, floor, mass, and windows. Convective and latent fractions of internal heat gains. Infiltration/ventilation sensible and latent heat fluxes. Sensible and latent heat fluxes from the HVAC system Model physics pic2

27/01/20118 HVAC system Energy supplied by the system Ideal HVAC system For a given system supply flow rate, the model calculates the supplied air temperature and humidity to cover the building sensible and latent energy demand. Real HVAC system At each timestep, the model calculates the capacity of the system depending on indoor and outdoor air temperatures. The supply air temperature is calculated as in the ideal system, but with the capacity limitation. The supply air humidity is calculated applying the apparatus dew-point method to account for the dehumidification of the air passing through the cooling coil. environmaster.com

27/01/20119 HVAC system Energy consumed by the system It is calculated dividing the energy supplied by the system by an efficiency that depends on indoor and outdoor air temperatures, as well as on the part load ratio for a real cooling system. Waste heat emissions They are calculated as the sum of the supplied energy and the consumed energy for a cooling system, and as the difference between the consumed energy and the supplied energy for a heating system. home.howstuffworks.com

27/01/ The original TEB outdoor air energy/water balance is affected by: – Sensible ant latent waste heat fluxes released by the HVAC system inside the canyon or over the roof – The infiltration/ventilation – The reduction of the wall surface for glazing surfaces. Outdoor air energy/water balance pic2

27/01/ HVAC system Sensible and latent waste heat split In BEM, the user selects the type of condenser of the HVAC system: Air condensed Sensible waste heat. Water condensed Latent waste heat. Outdoor air temperature Outdoor air specific humidity Difference between an air-condensed and a water-condensed system. Monthly averaged diurnal cycle in summer (15/ /08). Case study corresponding to the experiment carried out in Toulouse between Feb and Feb (CAPITOUL).

27/01/ Model inputs. Building inputs Symbol Example Internal heat gain: QIN = 5.05 W m-2 Radiant fraction of internal heat gain: QIN_FRAD = 0.2 Latent fraction of internal heat gain: QIN_FLAT = 0.2 Window Solar Heat Gain Coefficient: SHGC = 0.78 Window U-factor: U_WIN = 0.2 W m-2 K-1 Facade glazing ratio: GR = 0.3 Floor height: FLOOR_HEIGHT = 3.0 m Infiltration air flow rate: INF = 0.7 ACH Ventilation air flow rate: V_VENT = 0.0 ACH Mass and floor layer thickness: D_FLOOR = 0.1 m Mass and floor layer conductivity: TC_FLOOR = 1.15 W m-1 K-1 Mass and floor layer capacity: HC_FLOOR = J m-3 K-1

27/01/ Model inputs. HVAC inputs Symbol Example Fraction of waste heat released into the canyon: F_WASTE_CAN = 0.5 Cooling setpoint: TCOOL_TARGET = K Relative humidity setpoint: HR_TARGET = 0.5 Flag to autosize the HVAC system: AUTOSIZE =.F. Maximum outdoor air temperature for sizing calcs: T_SIZE_MAX = K Minimum outdoor air temperature for sizing calcs: T_SIZE_MIN = K Rated COP of the cooling system: COP_RAT = 2.5 Type of cooling coil: HCOOL_COIL = 'DXCOIL' Type of condenser: HCOOL_COND = 'AIR' Rated cooling system capacity: CAP_SYS_RAT = W m-2 Rated cooling system air flow rate: M_SYS_RAT = kg s-1 m-2 Cooling coil apparatus dew-point: T_ADP = K Heating setpoint: THEAT_TARGET = Type of heating coil HHEAT_COIL = 'IDEAL' Heating system capacity: CAP_SYS_HEAT = 100 W m-2 Efficiency of the heating system: EFF_HEAT = 0.9

27/01/ Simulation-based model evaluation Comparison between BEM and an equivalent building energy model defined in EnergyPlus. Case study corresponding to the experiment carried out in Toulouse between Feb and Feb (CAPITOUL). N Building Shading Adaptation of the building/shading morphology to the TEB parameters

27/01/ Statistical comparison BEM - EP Annual Root Mean Square Error VariableRMSE Indoor wall temperature0.33 K Floor surface temperature0.28 K Ceiling surface temperature0.74 K Mass surface temperature0.31 K Indoor air temperature0.23 K Solar heat transmission18.78 W/m2(bld) Building cooling energy demand8.26 W/m2(bld) Building heating energy demand4.41 W/m2(bld)

27/01/ Graphical comparison BEM - EP Monthly averaged diurnal cycle in summer(15/07- 15/08) Mass surface temperature Cooling energy demand

27/01/ Graphical comparison BEM - EP 12/1/10 17 Monthly averaged diurnal cycle in summer(15/07-15/08). Indoor air specific humidity Indoor air temperature System cooling energy consumption System supply air temperature

27/01/ Next steps Evaluate BEM-TEB with field data Capitoul Athènes Introduce a selection of passive and active building systems into BEM Solar protections, natural ventilation, heat recovery, economizer, VAV systems. Use the building data-base provided by CSTB. Create urban cover data-base with different model inputs for different urban configurations. Simulate the different urban covers for present and future climates.

Calcul d’un indice thermique : méthode retenue Bilan d'énergie à l'équilibre en suivant le modèle MEMI Diagnostic PET (physiological equivalent temperature)‏ Agrégation en fonction de scénarios de localisation et de période.

Résolution du modèle 3 équations indépendantes de bilan d’énergie : – Système corps : M – Q RES (Ta,qa) = F CoSk (T co,T Sk ) – Système vêtement : F ClSk (T Sk,T Cl ) = Rad(T Cl ) + Conv(T Cl ) – Système peau : F CoSk (T co,T Sk ) = F ClSk (T Sk,T Cl ) + E SW (T Sk ) 3 variables représentatives du corps : – T Co : température interne du corps – T Sk : température de la peau – T Cl : température des vêtements Calcul d’un indice thermique Physiological Equivalent Température : Température d'un environnement intérieur de référence qui conduirait au même état physiologique c’est à dire les mêmes valeurs des variables d'état du modèle Codage du modèle en cours

Données d’entrée pour le modèle Conditions « atmosphériques » ParamètreScénarios à choisir Temp. AirIntérieur / Extérieur Humidité spécifiqueIntérieur / Extérieur Vitesse du ventIntérieur / Extérieur Rayonnement solaireExtérieur : ombre / soleil Rayonnement infrarouge Intérieur : RdC/dernier étage Extérieur Pression atmos.- toutes les données sont disponibles en sorties de TEB les choix concernent la « localisation » des personnes

Données d’entrée pour le modèle Caractéristiques de la personne ParamètreScénarios à choisir Métabolisme (Activité) Marche / travail / debout / assis/ allongé Habillement isolation thermique couleur (réflexion solaire) les choix dépendent de la période (jour/nuit)

Choix des scénarios (pour les individus) Calcul de l'indice à chaque pas de temps de la simulation Intégration sur des périodes jour/nuit ; canicule entière  Choix d’enchaînement de localisation/activité d’un pas de temps à l’autre des périodes d’intégration

Conclusions et questions ? TEB maintenant doté d’un modèle énergétique du bâtiment incluant la climatisation, TEB a besoin d’entrée supplémentaire : vitrage, masse thermique interne, température de consigne, charge interne, taux de renouvellement d’air Calcul d’un indice thermique du corps humain en sortie des simulations Choix d’enchainements de localisation, activité, habillement à définir pour une intégration temporelle ? Synthèse des indices pour l’ensemble des scénarios ? Communication sur l’ensemble de la maille (quartier) ? De la ville ? Par catégories de scénarios d’activité ? Choix de seuils pour le confort / inconfort ?