1. OVERHEATING PROBLEM IN SINGLE FAMILY PASSIVE HOUSE
Jana Mlakar and Janez Štrancar

2. Introduction Living conditions comfort, efficiency, health Fanger 1972
Air temperature, relative humidity
ANSI/ASHREA :
Comfort zone: 20-26°C, % RH
Higher temperatures overheating:
Extensive solar radiation
High external temperatures
Internal energy sources

3. Aim Identify strategies to reduce overheating problem
To what extent the internal temperature could increase if residents would not cool house with opening of windows at night and would not shade the windows
Appropriateness of a pasive house strategy in hot summer climate

4. Description of test house
passive house in Limbuš, Slovenia – hot summer climate
wooden skeleton, cellulose insulation, U 0,1 W/m2 K
TFA 113 m2
the ridge is oriented in the direction east–west
triple glazed windows, two low emissive coatings, krypton, thermal transmittance: 0,8 W/(m2 K)
S: roof extension, E and W: Venetian blinds
tightness of the house at 50 Pa 1/h
heat recovery unit: 83 % efficiency, preheaters 100 W and 200 W, additional heater 280 W
floor heating system: max 29 °C, 1800 W
sensory control system is performed with the USB microcontroller

5. Acquisition system External temperature Internal temperature
Solar flux
Temperature in pipelines of the mechanical engeneering systems

6. Description of model

7. Simulation of internal temperature
Minute time scale

8. Fitting the response of the house in winter

9. Fitting the response of the house in summer
Simulation of internal temperature
Shading: E and W windows
Cooling of the house during the night:
When Text < Tint

10. Results Text temperature oscillations
Increased ventilation during hot periods and also first cold days
Simulations without shading or cooling

11. Conclusions Real passive house can resist excessively hot periods.
Shading and ventilation through opened windows can keep Tint within a comfort level.
Neglecting these strategies would result in serious overheating.

12. Thanks Janez Štrancar, Jožef Stefan Institute
Mirko Škvorc, Eko produkt d.o.o.
Other coworkers
European Social Fund for financial support