Answer Happy

Task 1.2 1. Write down the energy balance of a room in a general form and in a case when there is no heating system on and no ventilation is required and available solar energy is enough to maintain the indoor temperature at the stable level (of 20°C). 2. Determine the solar irradiance level if ambient temperature is equal to 5°C and the heat losses are only through a window. The window is characterized by the heat transfer coefficient of a UL = 1,2 W/m²K and the transmittance factor of (T) = 0,8 room absorptivity (a) is 0,9. Comment results. Taking into account the same room and knowing that temperature at 1900, after the sunset, is equal to Tw(t=1900)=20°C. 3. Calculate the room temperature Tw next day at 8 o'clock in the morning if ambient temperature is constant (T₁= const= 5°C) all the time, and thermal state of a building (in the morning) is a result of initial thermal conditions at Tw(t = 1900) = 20°C and thermal capacity of a room. The window constitutes the main south facade of 2,5 m x 6 m. There are two internal walls made of concrete: p= 2200 kg/m³, c = 0,8 kJ/kgK and each is 3 m height, 6 m length and 0.2 m thick. 4. Calculate thermal capacity of walls C [J/K] and time constant of a room. 5. Comment results.