Space heating

To analyse the performance of facades addressed to produce space heating, the top part of the tank in the facade is considered linked to a heat exchanger (a thermal radiator). Water from tank is pumped through the heat exchanger delivering heat to the annex room, and then it returns to the facade entering at bottom.

The following assumptions have been considered:

-Indoor room temperature is considered constant and equal to 20°C.

-Global heat transfer coefficient of heat exchanger has been considered constant UA = 100 W/°C. Return temperature to the facade is calculated according to:

QLOAD = UAIT — Tg) = mcp(OTL — Tinlet) (1)

where:

T = 0.5 (OTL + Tinlet) (2)

Tg is the indoor ambient temperature, OTL is the outlet water temperature from the facade, is the water flow rate [kg/s], QLOAD stands for the energy delivered from the heat ex­changer and Tinlet is the return temperature.

-The facade delivers heat from 17 to 24 hours each day of the heating months.