Temperature Regime and Heat Transfer in an Unheated and Unventilated Glasshouse at the Nighttime

This paper describes results of numerical experiments concerning the temperature regime and the heat transfer in an unheated and unventilated glasshouse at the nighttime. By making use of reasonable assumptions, the heat balance of the glasshouse can be expressed by iBs=(iTs-iTw){ihr+ih(1+2φ)/1+R}, for ground surface λ/d(iTw-oTw)=(iTs-iTw){R⋅ihr+R⋅ih(1+2φ)/1+R}, for inner surface of glass λ/d(iTw-oTw)=oFw+oh(oTw-oTa), for outer surface of glass The temperatures (iTs, iTw, oTw) in the above heat balance equations are determined numerically by the shooting method on an electronic computer (TOSBAC 3400). The mean air temperature in the glasshouse (iTa) was determined from the following relation with reasonable accuracy: iTa=0.5(iTs+iTw). The results are summarized as follows: 1. The temperature profiles inside and outside the glasshouse at the nighttime are considerably affected by both the soil heat flux (iBs) and the effective long-wave radiation flux (Fo). The temperature profiles can be classified into the following two groups: iTs>iTw>oTw>oTa, for iBs>Fo iTs>iTw>oTw