將三種玻璃搭配集熱器，實驗六小時，紀錄集熱器溫升情形，實驗發現隨著時間越長，集熱器溫度越高效率就越低。由溫升曲線中得到最高溫度，利用最高溫度96％時之最佳熱效率區段，可有效提升集熱器之熱效率，使用單層強化玻璃之熱效率為15.6％、單層優白玻璃之熱效率為16.6％、雙層優白玻璃之熱效率為17.4％。 This research aims to evaluate collecting ability and efficiency of small metallic flat plate collector. Luminous transmittance of visible light penetrating through various types of cover glasses, such as single-layer, super clear single-layer, and super clear double-layer glasses were measured. Collectors with same conditions were used to measure overall reflectivity, the smaller reflectivity the more solar radiation penetrating through.
Single-layer, super clear single-layer, super clear double-layer glasses, and stainless shell as single element were experimented for heat-transfer characteristic. The result of the experiment simulating single-sided natural convection and heat insulation showed that the surfaces of glass and stainless shells had different h (heat convection coefficient) and ε (reflectivity) at each ℃ point during temperature raising, thus its heat convection and radiation calculated had higher accuracy than single average value.
In the 6-hour experiment of these three glasses combining collectors respectively, temperature raise of the collectors recorded displayed that efficiency of the collectors were lowering with time due to increasing of temperature. The best heat efficiency section, 96% of the highest temperature of the temperature raising curve, increased heat efficiency of the collectors to 15.6% on the single-layer glass, 16.6% on the super clear single-layer glass, and 17.4% on the super clear double-layer glass.