**3. Calculation method of performance factors by a simplified model of an actual opaque house, (Kanayama, K., et al., Oct., 2008)**

As shown in Fig.4, (τ・α)CS corresponds to an efficiency of collection of volumetric S. R. incident upon the composite surface.

That is, (τ・α)CS is always constant as 0.6 determined only by a radiation property of material, having no connection with S. R. intensity. In Fig.4, shows the efficiency, ηAC, of solar heat collection by a typical flat-type. However, ηAC is a function of IoND, changing in proportion to S. R. intensity.

Fig. 4. Transmission-absorption coefficient for volumetric solar heat collection and an efficiency of areal solar heat colection

#### **3.1 On the "South-North model"**

On the database shown in Table 1 (NEDO's Report, 1997), I(d)rf is S. R. incident on a roof surface, I(d)ws is S. R. incident on a south wall, I(d)ww/we is S. R. incidence on an east and a west walls, all of which are tilt S. R. incidence per unit surface and per one day (MJ/m2d) in each month respectively. Fig.5 shows a calculation model of an opaque house adopted in the conventional calculation method. The model of the opaque house (South-North model) is shaped a Quonset hut (floor area 5.0 m×5.0 m=25.0 m2, height 3.4 m), besides two insulated cylinders which are set vertically outside the house. Thus, all the surfaces of the house is covered by a composite surface consisting of triple transparent film and CF-sheet, so that the actual house looks opaque. As volumetric capacity of the opaque house, can contain stacked lumber of net 10 m3 in maximum to be loaded along south-north direction.

As shown in Fig.4, (τ・α)CS corresponds to an efficiency of collection of volumetric S. R.

That is, (τ・α)CS is always constant as 0.6 determined only by a radiation property of material, having no connection with S. R. intensity. In Fig.4, shows the efficiency, ηAC, of solar heat collection by a typical flat-type. However, ηAC is a function of IoND, changing in

Fig. 4. Transmission-absorption coefficient for volumetric solar heat collection and an

lumber of net 10 m3 in maximum to be loaded along south-north direction.

On the database shown in Table 1 (NEDO's Report, 1997), I(d)rf is S. R. incident on a roof surface, I(d)ws is S. R. incident on a south wall, I(d)ww/we is S. R. incidence on an east and a west walls, all of which are tilt S. R. incidence per unit surface and per one day (MJ/m2d) in each month respectively. Fig.5 shows a calculation model of an opaque house adopted in the conventional calculation method. The model of the opaque house (South-North model) is shaped a Quonset hut (floor area 5.0 m×5.0 m=25.0 m2, height 3.4 m), besides two insulated cylinders which are set vertically outside the house. Thus, all the surfaces of the house is covered by a composite surface consisting of triple transparent film and CF-sheet, so that the actual house looks opaque. As volumetric capacity of the opaque house, can contain stacked

**3. Calculation method of performance factors by a simplified model of an** 

**actual opaque house, (Kanayama, K., et al., Oct., 2008)** 

incident upon the composite surface.

efficiency of areal solar heat colection

**3.1 On the "South-North model"** 

proportion to S. R. intensity.

Fig. 5. A fully passive solar lumber drying house (South-North model)

Fig.6 shows an estimation, calculated by a conventional method, on the drying performance of the "South-North model" of the opaque house. During the season of spring to early summer, the volumetric solar heat collected QVC attained between 170~450 MJ/d. The rate of these numerals to S. R. incident on the floor is corresponds to an efficiency of volumetric solar heat collected ηVC, which are nearly to 120~200 %. ηVC is larger in winter and smaller in summer than yearly averaged value, thus its maximum value is 198 % in January and its yearly averaged value is 139 %.

Fig. 6. Monthly and yearly estimated performance of the volumetric solar heat collected Qvc and the efficiency of volumetric solar heat collection ηvc

#### **3.2 On the "East-West model"**

Table 2 shows a database from AMeDAS (NEDO's Report, 1997) at the proving test site. Fig. 7 shows a calculation scheme for the test for the "East-West model" of the opaque house. Similarly from Table 2, on the "South-North model", multiplying the daily S. R. on each tilted surface, per unit area, per day, i.e. I(d)rf on the roof surface, I(d)fl on the floor surface, I(d)ws on the south wall, and I(d)we/ww on east and west walls, by each area; Arf of roof area, Afl of floor area, Aws of south wall, and Awe/ww of east and west walls respectively, and by summing up all of them, the volumetric S. R. incidence I(Q)vI can be determined. Then multiplying the product of each term by the coefficient of transmittance-absorptance 0.6, and by summing up all the terms, thus the volumetric solar heat collected Qvc can be determined. The results are shown in Fig. 8 with a data Table. According to the results of Fig 8, an efficiency of volumetric solar heat collection ηvc based on solar radiation incident on the floor area, 206 % is maximum in January, 117 % is minimum in June, and 141 % is average value for the year. These are the largest merit in the concept of volumetric solar heat collection.


Table 2. Solar Radiation (S. R.) Incidence at Experimental Site; Ashoro (4314.5'N, 14333.5'E) MJ/m2d (East-West model)

Fig. 7. A fully passive solar lumber drying house (East-West model)

Table 2 shows a database from AMeDAS (NEDO's Report, 1997) at the proving test site. Fig. 7 shows a calculation scheme for the test for the "East-West model" of the opaque house. Similarly from Table 2, on the "South-North model", multiplying the daily S. R. on each tilted surface, per unit area, per day, i.e. I(d)rf on the roof surface, I(d)fl on the floor surface, I(d)ws on the south wall, and I(d)we/ww on east and west walls, by each area; Arf of roof area, Afl of floor area, Aws of south wall, and Awe/ww of east and west walls respectively, and by summing up all of them, the volumetric S. R. incidence I(Q)vI can be determined. Then multiplying the product of each term by the coefficient of transmittance-absorptance 0.6, and by summing up all the terms, thus the volumetric solar heat collected Qvc can be determined. The results are shown in Fig. 8 with a data Table. According to the results of Fig 8, an efficiency of volumetric solar heat collection ηvc based on solar radiation incident on the floor area, 206 % is maximum in January, 117 % is minimum in June, and 141 % is average value for the year. These are the largest merit in the concept of volumetric solar heat

**4. Performance calculation and proving test of the opaque house** 

Fig. 7. A fully passive solar lumber drying house (East-West model)

Table 2. Solar Radiation (S. R.) Incidence at Experimental Site; Ashoro (4314.5'N, 14333.5'E)

=I(d)HT <sup>θ</sup> =0°a=0° 6.768 10.15 13.86 15.95 17.75 17.86 15.88 13.82 11.77 9.828 6.696 5.544 12.17 Roof S.;I(d)rf=I(d)10° <sup>θ</sup> =10°a=0° 8.665 12.17 15.61 16.96 18.32 17.92 16.23 14.40 12.72 11.33 8.300 7.202 13.34 13.46 15.84 14.18 10.33 8.928 8.316 7.956 7.992 8.928 11.23 10.91 11.16 10.76 South S. ; I (d)ws θ=90°a=0° East-West Ss.;I(d)we/ww <sup>θ</sup> =90°a=90° 11.59 17.57 18.58 18.72 20.458 19.94 17.64 15.41 14.04 12.89 9.360 8.748 15.41

Azimuth a Jan Feb Mar Apl May Jun Jly Aug Spt Oct Nov Dec Year

**3.2 On the "East-West model"** 

collection.

Surfaces

Roof S.; I(d)rf=I(d)fl

MJ/m2d (East-West model)

Anglesof Tiltθ &

Fig. 8. Monthly and yearly estimated performance of the volumetric solar heat collected Qvc and the efficiency of volumetric solar heat collection ηvc
