The Relation between the Plastic House Geometry and the Heating Load

Abstract

The purpose of this paper was to investigate the relation between the cross section, number of doors of plastic houses and the heating load. If the heat lost from the plastic house is expressed in term of the conductivity (e) and the radiation (r), the rate of heating quantity required is expressed approximately byq=e+r≅ Reff∅FSaF (1+γ)where, Reff is the effective radiation, γ is equal to e/r. This e/r raises linearly with the decreasing rate of heating quantity (q) from -1 at non-heating to nearly 0 at the usual heating range. Therefore, the heating load for the plastic house is mainly affected by the view factor (∅FS) .Giving an example of the plastic houses having semi-circular and pentagonal cross section with various distance of spacing between and number of doors, the mean value of the view factor of the whole house (∅FS) has been calculated to show graphically that the heating load decreases as the spacing becomes smaller and the number of doors becomes larger.