Residential ventilation concepts based on the idea of displacement airflow distribution

A strategy for reducing energy demand Student: Aris Gkitzias (I.D:4180380) Mentors: Dr. Regina Bokel, Ir. John van der Vliet MSc graduation project Department of Building Technology, faculty of architecture

CONTENTS A. INTRODUCTION RESEARCH QUESTION B. BASIC THEORY C. THERMAL STRATIFICATION SIMULATION MODELS + DEVELOPMENT AND VALIDATION OF THE PROPOSED MODEL D. CASE STUDIES + DESCRIPTION THE VENTILATION SYSTEMS THAT ARE TESTED E. BASIC SIMULATION PARAMETERS OF THE SYSTEMS F. SIMULATION RESULTS G. COCLUSIONS Residential ventilation practices: a) Decentralized inlets - intelligent demand control b) Balanced ventilation - HRU (BVS-HR) 01/50

A. introduction PROBLEM STATEMENT: Building Practice Minimize Heat losses by making the buildings a) more air tight b) more insulated How do we approach residential ventilation in such a context of energy reduction? 02/50

A. introduction PROBLEM STATEMENT: Building Practice Minimize Heat losses by making the buildings a) more air tight b) more insulated Residential ventilation practices: a) Decentralized inlets - intelligent demand control b) Balanced ventilation - HRU (BVS-HR) 03/50

A. introduction Problem statement: Building Practice Minimize Heat losses by making the buils a) more air tight b) more insulated Residential ventilation practices: RESEARCH FIELD : Airflow distribution Mixed air distribution Partially mixed air distribution Displacement air distribution a) Decentralized inlets - intelligent demand control b) Balanced ventilation - HRU (BVS-HR) MV DV 05/50

A. introduction temperature and contaminant stratification supply Displacement temperature air range distribution 16 C - 21.5 C) discharge velocities, 0.20 to 0.35m/s a stratified ventilation system with higher supply temperatures for cooling than mixing system, providing better indoor quality RESEARCH QUESTION: if under the climatic conditions of the Netherlands, it is more energy efficient than a traditional mixing system, providing better thermal comfort during summer if it creates better indoor air quality in dwellings? if it is possible to integrate displacement ventilation in residential buildings without a lot of design limitations? 06/50

A. introduction Methodology Step 01 Step 02 Step 03 Step 04 Research question: energy consumption comparison IAQ comparison key design limitation for the dwellings General literature research for the understanding of the physics and the requirements of DV Review existing simulation methods Analyze papers that comply with the conditions that we have in a dwelling Develop and validate the model Derive in some conclusions and estimations about what happens in dwellings Simulation in specific study cases Use the IAQ conclusions in the design airflow requirements in the study case in practice through the case study Output: The development of the simulation model A critical comparison in terms of energy consumption and IAQ between MV and DV 07/50

B. basic theory AIRFLOW DISTRIBUTION METHODS - uniform temperature and contaminant concentration - supply temperature range 3 C - 32 C - discharge velocities >3 m/s - temperature and contaminant stratification - supply temperature range 16 C - 21.5 C) - discharge velocities, 0.20 to 0.35m/s a stratified ventilation system with higher supply temperatures for cooling than mixing system, providing better indoor quality Normally used as a flexible in the design system both for cooling and heating in different type of buildings Mixed air distribution Displacement air distribution MV DV 08/50

AIRFLOW DISTRIBUTION METHODS - uniform temperature and contaminant concentration - supply temperature range 3 C - 32 C - discharge velocities >3 m/s B. basic theory - temperature and contaminant stratification - supply temperature range 16 C - 21.5 C) - discharge velocities, 0.20 to 0.35m/s a stratified ventilation system with higher supply temperatures for cooling than mixing system, providing better indoor quality Normally used as a flexible in the design system both for cooling and heating in different type of buildings Mixed air distribution Displacement air distribution 09/50

B. basic theory IAQ - Ventilation effectiveness e e=1,2 17% cut of the design airflow, Qv Mixed air distribution Ventilation effectiveness In front of standing person In front of seated person DV Ventilation effectiveness for DV MV 1,2-1,6 0,88-0,96 1,3-1,9 0,90-0,97 ASHRAE standard 62.1 (2007) 1,2 NEN-EN 15242(2007) 1,0 2,0 Displacement air distribution ε CO2 concentration 10/50 Mean age of air

C. simulation models METHODS OF SIMULATING THE THERMAL STRATIFICATION IN DV J. Lau & Q. Chen - 2006 model developed by Carrilho da Graca a 3-node simplified energy conservation nodal - plume theory and the research that P.F. Linden has done on displacement ventilation E. L. Olsen & Q. Chen - 2002 Semi-empirical models embedded in Energy Plus T f estimated from the model developed by (Mundt, 1990) implemented in the building thermal analysis software tool EnergyPlus T f estimated from a model developed by (Chen, et al., 1999) ASHRAE Research Project - RP-949 : 11/50

C. simulation models PROPOSED 3-AIRNODE MODEL IN TRNSYS-TRNFLOW Link the height of the 2 nd airnode with the Stratification height in order to simulate the main temperature and contaminant layers that are created in a room with displacement airflow distribution Airflow coupling between the three airnodes uses the mass flow in order to have: Q in =Q coupling-1 = Q coupling-2 =Q out Internal gains distribute all the internal gains between proportionally 2 nd and 3 rd airnode, except of the gains from the lights that are assigned only in the 3 rd airnode 12/50

VALIDATION OF THE THERMAL STRATIFICATION IN THE PROPOSED MODEL C. simulation models case 01 experiment in chamber case 02 - experiment in chamber case 03 CFD simulation case 04 - experiment in chamber Test conditions Bjorn/Nielsen- Case 01 Chen/Yuan-Case 02 Huang/Chen- Case 03 Lee-Chen -Case 04 T s C 20 17 13,3 19 T surounding C 20-22? 0-10? T window C - 27-28?? A window m 2-4,32 2x 2,6 7,2 A floor m 2 48 18,7 32 20,16 Room height (H) m 4,7 2,4 2,5 2,43 Q v m 3 /h 160 179,7 22,5 293,4 ACH h -1 0,7 4 0,36 6 Q people + equip W 2x75 (2x75) +282 2x75 (2x75) +200 Q light W 240 204 200 581,4 Rc walls (K m2)/w 3 4 3,8 5,45 Rc roof (K m2)/w 5 5 5 5,45 U- value window (W/ (K m2) - 1,4 1,27 1,3 g-value window - 0,58 0,59 0,298 13/50

C. simulation models VALIDATION OF THE THERMAL STRATIFICATION IN THE PROPOSED MODEL case 01 experiment in chamber case 02 - experiment in chamber case 03 CFD simulation case 04 - experiment in chamber Two different methods of vertical airflow coupling. 15/50 For the selection of the final simulation model the main target was to use a model that will not underestimate the calculation of the heating demand for DV.

DWELLING TYPES Case study TYPE - 02 D. case studies Typical floor plan of a gallery housing complex Section and configuration of a central exhaust design of a gallery housing complex Floor plan 16/50

DWELLING TYPES Case study TYPE - 01 Case study TYPE - 02 D. case studies Floor plan Wall and window properties tot. thickness [mm] u-value [W/m 2 K] g- value External walls 290 0,33 - Internal walls 100 2,50 - Roof 460 0,20 - Floor 200 3,63 - Window (TYPE-01) 4-16-4 2,83 0,75 Window (TYPE-02) 4-16-4 1,27 0,6 Floor plan 17/50

VENTILATION CONCEPTS - ALL SYSTEMS D. case studies DV MV MENNS Integration of the ductwork design and the ventilation components in dwelling TYPE-02 18/50

VENTILATION CONCEPTS - ALL SYSTEMS D. case studies The ductwork exhaust design is similar in all the systems 19/50 DV mechanical balanced ventilation with heat recovery and displacement air flow distribution MV mechanical balanced ventilation with the same heat recovery unit like in DV, but with a mixing air flow distribution MENNS Decentralized self-regulating inlets which are controlled by a central unit This central unit adjusts the speed of the exhaust fan and subsequently the amount of air passing through the inlets.

VENTILATION CONCEPTS - DISPLACEMENT VENTILATION D. case studies Design limitations The estimation of the adjacent zone in order to avoid draught and thermal discomfort The avoidance of shortcut phenomena The integration of the relatively big diffusers and the vertical ducts 20/50

VENTILATION CONCEPTS - DISPLACEMENT VENTILATION Design limitations D. case studies The integration of the relatively big diffusers and the vertical ducts Airflow grilles above the door to ensure the escape on the warm and contaminated air 21/50 Exhaust from the wet rooms Enough distance of the diffusers from the radiators to shortcut phenomena

VENTILATION CONCEPTS - DISPLACEMENT VENTILATION Design limitations D. case studies The integration of the relatively big diffusers and the vertical ducts Airflow grilles above the door to ensure the escape on the warm and contaminated air 22/50 Exhaust from the wet rooms Enough distance of the diffusers from the radiators to shortcut phenomena

VENTILATION CONCEPTS - DISPLACEMENT VENTILATION Design limitations Airflow grilles above the door to ensure the escape on the warm and contaminated air The integration of the relatively big diffusers and the vertical ducts D. case studies Exhaust from the wet rooms 23/50 Enough distance of the diffusers from the radiators to shortcut phenomena

AIRFLOW LINK NETWORK IN TRNSYS E. simulation parameters Similar structure for both study cases TYPE-01 & 02 Thermal and External airnodes MV DV DV Q in Supply air flow [m 3 /h] Q c Coupling airflow between airnodes of the same zone [m 3 /h] Q e Exhaust air flow [m 3 /h] Q o Airflow through large openings, gaps above or below the doors [m 3 /h] Q infilt Infiltration airflow [m 3 /h] 24/50

DUCTWORK DESIGN IN TRNFLOW E. simulation parameters Similar structure for both study cases TYPE-01 & 02 MV 25/50

DUCTWORK DESIGN IN TRNFLOW E. simulation parameters Similar structure for both study cases TYPE-01 & 02 DV 26/50

pressure loss [Pa] recovery efficiency [%] pressure loss [Pa] Residential ventilation concepts based on the idea of displacement airflow distribution DUCTWORK DESIGN IN TRNFLOW E. simulation parameters 450 400 350 300 250 200 150 100 50 0 fan curve 0 50 100 150 200 250 300 350 400 450 500 550 600 CFM14 (mode-1) CFMe (mode-4) K2E 190(c) K2E 190(a) airflow [m3/h] CFM14-T (mode-1) CFMe (mode-7) K2E 190(d) Fan curve & HRU 240 210 180 150 120 90 60 30 0 Heat exchanger pressure losses & efficiency 100.0 90.0 80.0 70.0 60.0 0 50 100 150 200 250 300 350 400 450 RVU-S3-225 RVU-S3-280 RVU-S3-325 RS160 (300) RS160 (400) RS160 (500) 27/50

MODELING OF HRU & HEATING COIL IN TRNSYS SIMULATION STUDIO E. simulation parameters Heat Recovery : (DV & MV) efficiency 85% Heating coil: DV : outlet set point temperature coil is 15 o C MV: outlet set point temperature coil is 8 o C MENSS: outlet set point temperature coil is 8 o C HRU Bypass: (DV & MV ) during winter the exhaust temperature from the unit (auxiliary node: AN_S09_HR1) should not be below 0 C High cut-out temperature exhaust from house (AN_S09_HR1) 24 C 28/50

DEMAND CONTROL SCENARIA WINTER - Demand controlled E. simulation parameters MV DV Demand control Max fan speed 100% Demand control based on the occupancy schedule Bedroom 01 Bedroom 02 Living room Kitchen Bathroom People People People People People 00:00-07:00 1 2 07:00-08:00 1 1 1 08:00-12:00 12:00-13:00 1 13:00-17:00 1 17:00-18:00 1 1 1 18:00-23:00 1 2 23:00-24:00 1 1 1 Max supply [m 3 /h] Max Exhaust [m 3 /h] Living Room 135 Kitchen 150 Bedroom 01 40 Bedroom 02 50 Bathroom 50 WC 25 Total 225 225 29/50

DEMAND CONTROL SCENARIA WINTER - Demand controlled E. simulation parameters MENNS MV MV DV Demand control Max fan speed 100% Demand control based on the occupancy schedule Bedroom 01 Bedroom 02 Living room Kitchen Bathroom People People People People People 00:00-07:00 1 2 07:00-08:00 1 1 1 08:00-12:00 12:00-13:00 1 13:00-17:00 1 17:00-18:00 1 1 1 18:00-23:00 1 2 23:00-24:00 1 1 1 Max supply [m 3 /h] Max Exhaust [m 3 /h] Living Room 135 Kitchen 150 Bedroom 01 40 Bedroom 02 50 Bathroom 50 WC 25 Total 225 225 30/50

DEMAND CONTROL SCENARIA WINTER - Demand controlled E. simulation parameters MENNS MV MV DV DV-17%cut Demand control based on the occupancy schedule Bedroom 01 Bedroom 02 Living room Kitchen Bathroom People People People People People 00:00-07:00 1 2 07:00-08:00 1 1 1 08:00-12:00 12:00-13:00 1 13:00-17:00 1 17:00-18:00 1 1 1 18:00-23:00 1 2 23:00-24:00 1 1 1 Max supply [m 3 /h] Max Exhaust [m 3 /h] Living Room 135 Kitchen 150 Bedroom 01 40 Bedroom 02 50 Bathroom 50 WC 25 Total 225 225 32/50

ENERGY CONSUMPTION-SIMULATION SCENARIO B WINTER - Demand controlled E. simulation parameters MENNS MV DV DV-17%cut Max fan x1 speed 100% Demand con. Max fan x2 speed 100% Demand con. Max fan x2 speed 100% Demand con. Max fan x2 speed 83% Demand con. SUMMER- Hybrid ventilation Max fan x1 speed 100% constant Max fan x2 speed 100% constant Max fan x2 speed 100% constant Max fan x2 speed 100% constant 33/50

ENERGY CONSUMPTION-SIMULATION SCENARIO A WINTER SUMMER Full Fan Speed E. simulation parameters MENNS MV DV DV-17%cut Max fan x1 speed 100% constant Max fan x2 speed 100% constant Max fan x2 speed 100% constant Max fan x2 speed 100% constant 34/50

WHOLE YEAR PRIMERY ENERGY CONSUMPTION F. results primary energy sens. heating [MJ] heat. coil [MJ] MENSS_ TYPE-01_ Max. exhaust fan speed all year MV_ TYPE-01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year -17% cut in ACH 13237 2772 2575 2350 8670 726 1085 894 fans [MJ] 682 2907 3167 1900 Total [MJ] 22589 6405 6827 5144 The BVS-HR systems are more energy efficient than MENNS under all cases. Under the same ACH DV is not significantly more energy efficient. primary energy sens. heating [MJ] heat. coil [MJ] MENSS_ TYPE-01_ demand controlled MV_ TYPE-01_ demand controlled - hybrid DV_TYPE- 01_ demand controlled - hybrid DV_TYPE- 01_ demand controlled -17% cut in ACH 4925 2200 2229 2093 3519 507 772 643 fans [MJ] 93 1962 1859 1189 Total [MJ] 8537 4669 4860 3924 35/50

WHOLE YEAR PRIMERY ENERGY CONSUMPTION F. results MENSS_TY DV DV_TYPE- TYPE-02_ MV_ MV_ DV_TYPE- 02_ 02_ fan primary exhaust Max. TYPE-02_ 02_ 02_ fan speed Max. fan energy fan exhaust speed fan Max. speed fan speed Max. fan 100% speed - all fan 100% speed all 100% speed all all 100% speed all all 17% year cut -17% yea all year year year year year cut all year in ACH sens. heating sens. 17144 3432 2867 2635 heating [MJ] 14105 3813 3186 2927 heat. [MJ] coil heat. 419 626 525 [MJ] coil 8746 775 1159 972 [MJ] fans [MJ] 559 1761 1709 1005 fans [MJ] 1036 3262 3165 1861 Total [MJ] 17703 5612 5202 4165 Total [MJ] 23887 7850 7509 5761 The BVS-HR systems are more energy efficient than MENNS under all cases. Under the same ACH DV is not significantly more energy efficient. primary energy sens. heating [MJ] heat. coil [MJ] MENSS_TY PE-02_ demand controlled MV_ TYPE-02_ demand controlled - hybrid DV_TYPE- 02_ demand controlled - hybrid DV_TYPE- 02_ demand controlled -17% cut in ACH 6647 3214 2876 2748 4047 567 849 728 fans [MJ] 169 1967 1898 1217 Total [MJ] 10864 5748 5623 4693 37/50

Pressure Drop [Pa] Residential ventilation concepts based on the idea of displacement airflow distribution PRIMERY ENERGY CONSUMPTION -fans The influence of the ducts in the pressure drop is insignificant compared to the filter and the HRU. The fan energy consumption in TYPE-01 is higher for DV (under same airflow) due to the small length of the ducts, thus the extra vertical dusts of DV affect the total pressure drop more than the low drop diffusers. F. results Pressure drop_dv [Pa] Type :centifugal fan K2E 190(d) 100 50 0-50 -100-150 -200-250 0 1 2 3 4 5 6 7 Press. drop_dv (Gallery Apart.)_sup. stream [Pa] Press. drop_mv (Gallery Apart.)_sup. stream [Pa] primary energy MENSS_ TYPE-01_ Max. exhaust fan speed all year MV_ TYPE-01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year -17% cut in ACH fans [MJ] 682 2907 3167 1900 38/50

Pressure Drop [Pa] Residential ventilation concepts based on the idea of displacement airflow distribution PRIMERY ENERGY CONSUMPTION -fans The influence of the ducts in the pressure drop is insignificant compared to the filter and the HRU. The fan energy consumption in TYPE-02 is lower for DV (under same airflow) due to the bigger length of the ducts, thus low drop diffusers affect positively the total pressure drop more than the extra vertical dusts of DV F. results Pressure drop_dv [Pa] Type :centifugal fan K2E 190(d) 100 50 0-50 -100-150 -200-250 0 1 2 3 4 5 6 7 Press. drop_dv (Gallery Apart.)_sup. stream [Pa] Press. drop_mv (Gallery Apart.)_sup. stream [Pa] primary energy MENSS_TY PE-02_ Max. exhaust fan speed all year MV_ TYPE-02_ Max. fan speed all year DV_TYPE- 02_ Max. fan speed all year DV_TYPE- 02_ Max. fan speed all year -17% cut in ACH fans [MJ] 1036 3262 3165 1861 39/50

PRIMERY ENERGY CONSUMPTION -sensible heating F. results Small benefit (under same airflow) mainly due to higher recovered temperature from HRU. Without HRU the heating demand would be higher. significant benefit only under 17% cut of the design airflow (due to higher ventilation efficiency). sens. heating [MJ] Jan.- Feb. MV_TYPE- 1_ max fan speed _no HRU DV_TYPE- 1_max fan speed _no HRU MV_TYPE- 1_ max fan speed _ HRU DV_TYPE- 1_ max fan speed _ HRU 6496,87 6778,05 1475,27 1302,94 primary energy sens. heating [MJ] 40/50 MENSS_ TYPE-01_ Max. exhaust fan speed all year MV_ TYPE-01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year DV_TYPE- 01_ Max. fan speed all year -17% cut in ACH 13237 2772 2575 2350

DV - MV TYPE-01 (THERMAL STRATIFICATION AND HIGHER SUPPLY TEMPERATURE FROM HRU) F. results primary energy MV_ TYPE 01 _ fan speed 100% all year DV_ TYPE 01 _ fan speed 100% all year DV_ TYPE 01 _ fan speed 100% -17% cut all year 41/50 sens. heating [MJ] 2772 2575 2350

THERMAL COMFORT DURING SUMMER Use of operative temperatures DV is widely used as a passive cooling strategy, it is reasonable that lower temperatures are rendered in the occupied zone with DV.. F. results 43/50

THERMAL COMFORT DURING SUMMER F. results Hours above 25,5 C (percentage of the total occupation time) 29.34% 20.42% 22.65% 16.48% 2.85% 2.75% 6.36% 10.83% 9.21% L - 1,2 ACH K - 1 ACH B - 1 ACH L - 1,2 ACH K - 1 ACH B - 1 ACH L - 1,45 ACH K - 1,45 ACH B - 1,4 ACH HRU bypass at 24 o C Max fan x2 speed 100% constant DV MV 45/50 DV - fan K2E 190(d) Q v (tot)= 225 m 3 /h (HRU bypass 24 o C) MV- fan K2E190(d) Q v (tot)= 225 m 3 /h (HRU bypass 24 o C) MV- fan K3G190 Q v (tot)= 275 m 3 /h (HRU bypass 24 o C) Simulation time frame 1 st June 31 st August % h>25,5 o C % h>26,5 o C Living Room ACH=1,2 2,85% 0,00% Kitchen ACH=1 2,75% 0,00% Bedroom -01 ACH=1 6,36% 0,00% Living Room ACH=1,2 20,42% 2,09% Kitchen ACH=1 22,65% 0,66% Bedroom -01 ACH=1 29,34% 5,03% Living Room ACH=1,45 10,83% 0,47% Kitchen ACH=1,45 9,21% 0,00% Bedroom -01 ACH=1,4 16,48% 2,42%

THERMAL COMFORT DURING SUMMER F. results Hours above 25,5 C (percentage of the total occupation time) 12.20% 0.85% 0.76% 3.51% 5.98% 5.65% 0.00% 0.00% 0.00% HRU bypass all the summer time L - 1,2 ACH K - 1 ACH B - 1 ACH L - 1,2 ACH K - 1 ACH B - 1 ACH L - 2 ACH K - 2 ACH B - 1,8 ACH DV MENSS 46/50 DV - fan K2E 190(d) Q v (tot)= 225 m 3 /h (no HRU) MV - fan K2E190(d)(natural ventilation) MV Q v (tot)= 225 m 3 /h (no HRU) (natural ventilation) MV Qv= 366 m 3 /h (no HRU) Simulation time frame 1 st June 31 st August % h>25,5 o C % h>26,5 o C Living Room ACH=1,2 2,85% 0,00% Kitchen ACH=1 2,75% 0,00% Bedroom -01 ACH=1 6,36% 0,00% Living Room ACH=1,2 20,42% 2,09% Kitchen ACH=1 22,65% 0,66% Bedroom -01 ACH=1 29,34% 5,03% Living Room ACH=2 10,83% 0,47% Kitchen ACH=2 9,21% 0,00% Bedroom -01 ACH=1,8 16,48% 2,42%

G. conclusion Energy benefit of DV compared to traditional Mixing systems DV is not clearly more energy efficient in terms of the total energy consumption under the same airflow compared to MV. 24.66% 15.95% There is real energy benefit when DV works with 17% cut of the design airflow energy due to higher ventilation efficiency. In case 17% cut of the design airflow the better IAQ quality of DV is minimized -6.59% -4.09% Max. fan speed all year demand controlled- hybrid Max. fan speed all year -17% cut in ACH demand controlled -17% cut in ACH 23.28% 18,36% 4.35% 2.18% Max. fan speed all year demand controlled- hybrid Max. fan speed all year -17% cut in ACH demand controlled -17% cut in ACH 47/50

G. conclusion Energy benefit of DV compared to traditional Mixing systems DV is not clearly more energy efficient in terms of the total energy consumption under the same airflow compared to MV. Hours above 25,5 C (percentage of the total occupation time) 20.42% 22.65% 29.34% There is real energy benefit when DV works with 17% cut of the design airflow energy due to higher ventilation efficiency. 2.85% 2.75% 6.36% In case 17% cut of the design airflow the better IAQ quality of DV is minimized Thermal comfort during summer L - 1,2 ACH K - 1 ACH B - 1 ACH L - 1,2 ACH K - 1 ACH B - 1 ACH Hours above 25,5 C (percentage of the total occupation time) DV renders lowers temperature during the summer time compare to MV. However, MENSS with higher airflow supply is the same efficient as DV and requires also less energy as the supply fan do not have to work. 5.98% 5.65% 3.51% 0.85% 0.76% L - 1,2 ACH K - 1 ACH B - 1 ACH L - 2 ACH K - 2 ACH B - 1,8 ACH 12.20% 48/50

G. conclusion Indoor Air Quality DV systems have higher ventilation efficiency (1,2) - ASHRAE standard 62.1 (2007) The undisputable acceptance that DV under all boundary conditions has higher ventilation efficiency is quite risky. Limitations 24.66% 15.95% Restrictions maybe make the design of displacement ventilation less flexible However, they do not consist significant constraining factors, especially for new dwellings -6.59% -4.09% Max. fan speed all year demand controlled- hybrid Max. fan speed all year -17% cut in ACH demand controlled -17% cut in ACH Recommendations Since the energy benefit of DV is mainly a consequence of the higher ventilation efficiency. More research with thermal measurements and CFD simulation is required to verify the huger ventilation efficiency in dwellings. 23.28% 18,36% CFD and measurements are required for the further calibration of the propose model in TRNSYS-TRNFlow. 4.35% 2.18% Max. fan speed all year demand controlled- hybrid Max. fan speed all year -17% cut in ACH demand controlled -17% cut in ACH 49/50

THANK YOU! ARIS GKITZIAS 50/50