Method and apparatus for calculating thermal sensitivity

Abstract: According to a method and apparatus for calculating thermal sensitivity, a set temperature ϑ (th) is calculated on the basis of an air temperature Ta and a clothing thermal resistance Icℓ. Thermal energy information Hϑ (th) is supplied to heater capable of adjusting a sensor temperature Tcr so as to set the set temperature ϑ (th) to be equal to the sensor temperature Tcr. An equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , a difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , an air velocity Vair, a coefficient c₁ expressed in consideration of the clothing thermal resistance Icℓ, coefficients c₂ to c₆, and a coefficient n , according to the following equation, when the sensor temperature Tcr is higher than the set temperature ϑ (th) , Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr - c₆ x Hϑ (th)

Description: Background of the Invention The present invention relates to a method and an apparatus for calculating thermal sensitivity, e.g., an equivalent temperature (Teq), felt by a human body, and a method and an apparatus for calculating a PMV (Predicted Mean Vote) value as predicted mean thermal Sensitivity representing the degree of comfort in an indoor environment. The equivalent temperature Teq is used as an evaluation index of a thermal environment felt by a human body, i.e., thermal sensitivity. As a first method of obtaining this equivalent temperature Teq, a method is proposed, in which an equivalent temperature Teq* substantially equal to the equivalent temperature Teq of the human body is obtained by measuring a radiant temperature Tr, an air temperature Ta, and an air velocity Vair by using different sensors, and performing predetermined arithmetic processing of the measured values. This method requires complicated arithmetic processing, and the processing time is undesirably prolonged. Under the circumstances, as a second method of obtaining the equivalent temperature Teq, a method is proposed, in which a heater is incorporated in a module main body, and the amount of power to be supplied to the heater is controlled to always keep a temperature (sensor temperature) T cr of the module main body to be a constant value (e.g., 36.5°C). According to this method, the equivalent temperature Teq* can be calculated by measuring the amount of power to be supplied to the heater and performing predetermined arithmetic processing of the measured value. In a conventional method, as a formula for calculating predicted mean thermal sensitivity PMV representing the degree of comfort in an indoor environment, the PMV equation defined by ISO 7730, i.e., the following equation (1), has been employed: PMV = (0.303e -0.036M + 0.028) x [(M - W') - 3.05 x 10⁻³·{5733 - 6.99(M - W') - Pa} - 0.42{(M - W') - 58.15} - 1.7 x 10⁻⁵·M·(5867 - Pa) - 0.0014·M·(34 - Ta) - 3.96·10⁻⁸·fcℓ·{(Tcℓ + 273)⁴ - (Tr + 273)⁴} - fcℓ·hc·(Tcℓ - Ta)] for Tcℓ = Tsk - 0.155·Icℓ·[3.96 x 10⁻⁸·fcℓ·{(Tcℓ + 273)⁴ - (Tr + 273)⁴} + fcℓ·hc·(Tcℓ - Ta)] Tcℓ = clothing surface temperature Tsk = skin temperature Pa = RH·Pa* RH = humidity Pa* = saturated water vapor pressure M = activity amount W' = work amount Ta = air temperature Tr = radiant temperature Icℓ = clothing thermal resistance Vair = air velocity fcℓ = factor According to this method, the predicted mean thermal sensitivity PMV can be automatically calculated by measuring the respective parameters and substituting the measurements into equation (1). In practice, however, it is difficult to measure all tie parameters in a room of a building. Moreover, the above PMV equation itself is complicated. Under the circumstances, the present applicant has proposed a method of obtaining a predicted mean sensitivity PMV*, as a value coinciding with the predicted mean sensitivity PMV with high accuracy, by using the above-mentioned equivalent temperature Teq* and simple formulae. In the above-described second method of obtaining the equivalent temperature Teq, however, since an environment measuring section constituted by the module main body and the heater is much smaller than a human body, as it is apparent, the air current sensitivity of the measuring section is much larger than that of the human body. This difference in air current sensitivity indicates that the equivalent temperature Teq can be properly measured within a low air velocity region in which the air velocity Vair is about 0.1 m/s, whereas the deviation of the equivalent temperature Teq* from the equivalent temperature Teq is increased in an air velocity region in which the air velocity Vair is higher than 0.1 m/s, and accurate measurement cannot be performed. That is, even with a slight increase in the air velocity Vair, the equivalent temperature Teq* becomes much smaller than the equivalent temperature Teq because of the high air current sensitivity. According to the second method described above, therefore, there is a critical drawback that accurate measurement cannot be performed when the air velocity Vair is high, in spite of the advantage that the radiant temperature Tr, the air temperature Ta, and the air velocity Vair can be integrally measured, i.e., the advantage that the arithmetic processing can be simplified. The difference between the equivalent temperature Teq and the equivalent temperature Teq* affects arithmetic processing of the predicted mean thermal sensitivity PMV*. If the air velocity Vair is high, the predicted mean thermal sensitivity PMV* cannot be accurately obtained. For example, EP-A-0 495 117, reflecting a state of the art according to Article 54 (3) EPC, describes a method and apparatus for calculating thermal sensitivity in which thermal energy is supplied to a heater so as to keep a temperature of a sensor provided for the heater at a predetermined set temperature. The thermal sensitivity is calculated on the basis of an air temperature, a clothing thermal resistance, the predetermined set temperature and the thermal energy. This document further describes a simplified formula for predicted mean thermal sensitivity so that complicated arithmetic operations are not required. Furthermore, EP-A-0 476 691, also reflecting a state of the art according to Article 54 (3) EPC, describes a method and apparatus for calculating thermal sensitivity in which the above-mentioned set temperature is calculated on the basis of an air temperature and a clothing thermal sensitivity. The calculated set temperature is used to calculate an equivalent temperature Teq*: Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) which will be discussed later. Summary of the Invention The present invention has been made to solve the above-mentioned problems, and has its object, of to provide a method and apparatus for calculating thermal sensitivity, in which a set temperature ϑ (th) is calculated on the basis of an air temperature Ta and a clothing thermal resistance Icℓ, thermal energy information Hϑ (th) is supplied to heating means capable of adjusting a sensor temperature Tcr so as to set the set temperature ϑ (th) to be equal to the sensor temperature Tcr, and an equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the thermal energy information Hϑ (th) , and coefficients b₁ to b₄, according to the following equation (a), when the sensor temperature Tcr is lower than the set temperature ϑ (th) , whereas the equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , a difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , an air velocity Vair, a coefficient c₁ expressed in consideration of the clothing thermal resistance Icℓ, coefficients c₂ to c₆, and a coefficient n , according to the following equation (b), when the sensor temperature Tcr is higher than the set temperature ϑ (th) , Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr - c₆ x Hϑ (th) According to a particular embodiment of the present invention, the predicted mean thermal sensitivity PMV* is calculated on the basis of the obtained equivalent temperature Teq*, a humidity RH, an activity amount M et , a skin temperature T sk ( T sk = 35.7 - 0.0275 x M et X 58.15 ), the air temperature Ta, an absolute water vapor pressure P(Ta) at the air temperature Ta, the clothing thermal resistance Icℓ, a thermal resistance effect Fcℓ ( Fcℓ = E₁/(E₂ + E₃ x Icℓ) ) based on coefficients E₁ to E₃, and coefficients D₁ to D₇, according to the following equation (c), PMV* = α x LOAD* where α = 0.303 x EXP(-0.036 X M et x 58.15) + 0.028 if M et < 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - Fcℓ x (T sk - Teq*) if M et ≧ 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - D₇ x (M et - 1) - Fcℓ x (T sk -Teq*) According to the present invention, therefore, the set temperature ϑ (th) is determined on the basis of the air temperature Ta and the clothing thermal resistance Icℓ, and the thermal energy information Hϑ (th) is supplied to the heating means to make the set temperature ϑ (th) coincide with the sensor temperature Tcr. That is, the sensor temperature Tcr is controlled to be equal to the set temperature ϑ (th) which is not constant and changes depending on environmental conditions. According to the the present invention, when the sensor temperature Tcr is higher than the set temperature ϑ (th) , i.e., the module main body is in a heated state in which the sensor temperature Tcr is higher than the set temperature ϑ (th) , the equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the difference ΔTcr, the air velocity Vair, the coefficients c₁ to c₆, and the coefficient n , and when the sensor temperature Tcr is lower than the set temperature ϑ (th) , i.e., the module main body is set in a cooled state in which the thermal energy information Hϑ (th) is required, the equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the thermal energy information Hϑ (th) , and the coefficients b₁ to b₄. Brief Description of the Drawings Figs. 1(A) and 1(B) are block diagrams, each showing the process of arithmetic operations performed by a calculating section in a thermal sensitivity calculating apparatus in Fig. 2; Fig. 1(C) is a block diagram showing the process of arithmetic operations performed by a calculating section in a predicted mean sensitivity calculating apparatus in Fig. 4; Fig. 2 is a block diagram showing the thermal sensitivity calculating apparatus according to an embodiment of the present invention; Figs. 3(A) to 3(D) are schematic longitudinal sectional views, each showing an arrangement of an environment measuring section; and Fig. 4 is a block diagram showing the predicted mean thermal sensitivity calculating apparatus according to another embodiment of the present invention. Description of the Preferred Embodiments The present invention will be described in detail below. Fig. 2 shows a thermal sensitivity calculating apparatus according to an embodiment of the present invention, which is associated with the first, second, fifth, and sixth aspects of the present invention. This thermal sensitivity calculating apparatus 1 comprises an input section 2, a calculating section 3, and a display/output section 4. The input section 2 receives not only a clothing thermal resistance Icℓ as a set value but also an air temperature Ta and a sensor temperature Tcr from an environment measuring section 5 as detection values. These set and detection values are then supplied from the input section 2 to the calculating section 3. The calculating section 3 then obtains a set temperature value ϑ (th) , heater power Hϑ (th) as thermal energy, and an equivalent temperature Teq*. More specifically, in the calculating section 3, as shown in Fig. 1A, the set temperature value ϑ (th) is calculated by the following equation (2) on the basis of the air temperature Ta and the clothing thermal resistance Icℓ by using a set temperature calculating section 3-1. Note that values a₁ and a₂ in equation (2) will be described later. ϑ(th) = a₁ + a₂ x Ta Subsequently, a heater controlling/calculating section 3-2 measures the heater power Hϑ (th) (W) while performing PID control or fuzzy control to set the set temperature ϑ (th) to be qual to the sensor temperature Tcr. The obtained heater power Hϑ (th) (W) is supplied to the environment measuring section 5 through the input section 2. The environment measuring section 5 will be further described below. As shown in, e.g., Fig. 3(A), the environment measuring section 5 comprises a spherical module main body 5-11, a heater 5-12 arranged in the module main body 5-11, and a temperature sensor 5-13 arranged on the module main body 5-11. The module main body 5-11 consists of a metal having high thermal conductivity, such as copper or aluminum. The outer surface of the module main body 5-11 is formed to have high emissivity so as to be sensitive to a radiant temperature Tr. Note that the module main body 5-11 of the environment measuring section 5 may have a hemispherical shape, a cylindrical shape, or an elliptical shape, as shown in Figs. 3(B), 3(C), and 3(D). The above-mentioned heater power Hϑ (th) is supplied to the heater 5-12 of the environment measuring section 5. The module main body 5-11 is then heated by the heater 5-12 and is controlled such that the sensor temperature Tcr detected by the temperature sensor 5-13 becomes equal to the set temperature ϑ (th) . Assume that the sensor temperature Tcr is lower than the set temperature ϑ (th) , i.e., the module main body 5-11 is in a cooled state in which the heater power Hϑ (th) needs to be supplied to the heater 5-12. In this case, in an equivalent temperature calculating section 3-3, an equivalent temperature Teq* is calculated by the following equation (3) on the basis of the air temperature Ta, the clothing thermal resistance Icℓ, the set temperature ϑ (th) , and the heater power Hϑ (th) . Note that b₁, b₂, b₃, and b₄ in equation (2) will be described later. Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) In contrast to this, assume that the sensor temperature Tcr is higher than the set temperature ϑ (th) , i.e., the heater power Hϑ (th) is zero and the module main body 5-11 is in a heated state in which the sensor temperature Tcr is higher than the set temperature ϑ (th) . In this case, an equivalent temperature calculating section 3-3' shown in Fig. 1(B) calculates the equivalent temperature Teq * on the basis of the air temperature Ta, the set temperature ϑ (th) , the sensor temperature Tcr, a difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , the air velocity Vair, a coefficient c₁ expressed in consideration of the clothing thermal resistance Icℓ, coefficients c₂ to c₅, and a coefficient n , according to the following equation (4). Note that the coefficients c₁ to c₅ of equation (4) will be described later. Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr The equivalent temperatures Teq* obtained by the equivalent temperature calculation sections 3-3 and 3-3' are supplied to the display/output section 4 to be displayed. As described above, according to the thermal sensitivity calculating apparatus 1 of this embodiment, the set temperature ϑ (th) is obtained on the basis of the clothing thermal resistance Icℓ and the air temperature Ta, and the heater power Hϑ (th) to be supplied to the heater 5-12 is controlled such that the sensor temperature Tcr coincides with the set temperature ϑ (th) . If the sensor temperature Tcr is lower than the set temperature ϑ (th) , the equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the clothing thermal resistance Icℓ, the set temperature ϑ (th) , and the heater power Hϑ (th) . If the sensor temperature Tcr is higher than the set temperature ϑ (th) , the equivalent temperature Teq * is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , the air velocity Vair, the coefficients c₁ to c₅, and the coefficient n . Therefore, even if the air velocity Vair is high, or the sensor temperature Tcr is higher than the set temperature ϑ (th) , the equivalent temperature Teq* coincides with the equivalent temperature Teq felt by a human body with high accuracy. This allows accurate measurement of an equivalent temperature. The mechanism which allows coincidence between the equivalent temperature Teq * and the equivalent temperature Teq with high accuracy will be additionally described below. The mechanism which allows the equivalent temperature Teq * , obtained by the equivalent temperature calculating section 3-3 to coincide with the equivalent temperature Teq with high accuracy will be described first. Assuming that heater power to be supplied to the environment measuring section 5 is represented by H, the heater power H is dispersed by environmental conditions (the air temperature Ta, the radiant temperature Tr, and the air velocity Vair). If the surface temperature of the module main body 5-11 is T (°C), then H = Hr x (T - Tr) + A x Vair n x (T - Ta) where Hr = (heat transmission coefficient by radiation) x (area) A x Vair n = (heat transmission coefficient by convection) x (area) Equation (5) can be rewritten into equation (6): The equivalent temperature Teq felt by a human body is defined by equation (7): It is apparent from the comparison between equations (6) and (7) that if T = 36.5 is set, and to both the left- and right-hand sides of equation (6) the following expression is added then, the resulting value is substantially equal to the equivalent temperature Teq. Therefore, equation (6) is rewritten as equation (8): On the left hand side of the equations, the difference between equations (8) and (7) resides in Since the environment measuring section 5 is small, its air velocity sensitivity inevitably becomes higher than that of a human body. That is, because of the surface effect of the environment measuring section 5, its air velocity sensitivity portion becomes larger than that of a human body to be Since this inequality sign remains throughout the arithmetic processing, the obtained equivalent temperature is much lower than the equivalent temperature Teq felt by a human body at a place where the air velocity Vair is high. Therefore, an accurate equivalent temperature cannot be obtained. In this embodiment, therefore, in order to make the air velocity sensitivity of the environment measuring section 5 coincide with that of a human body, equations (8) and (7) are reconsidered in terms of temperature differences (36.5 - Ta) as well as air velocity sensitivity coefficients. As a result, it is found that such coincidence can be achieved by controlling the heater power Hϑ (th) supplied to the environment measuring section 5 at a temperature of ϑ (th) °C instead of 36.5°C so as to establish the following equation: That is, Since n varies from 0.35 to 0.6 in the range of 0.1 to 1.0 m/s, Vair 0.5 ≒ Vair n can be established, and the set temperature ϑ (th) can be given by In this embodiment, the set temperature ϑ (th) is obtained on the basis of the clothing thermal resistance Icℓ and the air temperature Ta, and the heater power Hϑ (th) to be supplied to the heater 5-12 is controlled to make the sensor temperature Tcr coincide with the set temperature ϑ (th) , thus obtaining the equivalent temperature Teq* by calculating the following formula on the basis of the air temperature Ta, the clothing thermal resistance Icℓ, the set temperature ϑ (th) , and the heater power Hϑ (th) : Therefore, even if the air velocity Vair in a normal building office is high, an equivalent temperature can be accurately measured. If, in equation (10), then, ϑ (th) = a₁ + a₂ x Ta . If, in equation (11), then, Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) The mechanism which allows the equivalent temperature Teq * obtained by the equivalent temperature calculating section 3-3' to coincide with the equivalent temperature Teq with high accuracy will be described next. In a heated state in which the heater power Hϑ (th) is zero and the sensor temperature Tcr is higher than the set temperature ϑ (th) , the module main body 5-11 is heated in some way. In this case, the formulae associated with the environment measuring section 5 are checked again. Since Hϑ (th) = 0, 0 = Hr x (Tcr - Tr) + A x Vair n x (Tcr - Ta) Since Tcr > ϑ (th) , Tcr = ϑ (th) + ΔTcr (ΔTcr ≧ 0) . Consequently, 0 = Hr x [(ϑ (th) + ΔTcr) - Tr)] + A x Vair n x [(ϑ(th) + ΔTcr) - Ta)] Then, 0 = Hr x (ϑ (th) - Tr) + A x Vair n x (ϑ (th) - Ta) +(Hr + A x Vair n ) x ΔTcr Equation (14) can be rewritten into Similar to the rewriting from equation (6) to equation (8), if to the left- and right-hand sides of equation (15) is added, then, The left-hand side of equation (16) is This exactly represents the equivalent temperature Teq. If, therefore, the set temperature ϑ (th) is obtained on the basis of the clothing thermal resistance Icℓ and the air temperature Ta, and the equivalent temperature Teq* is obtained on the basis of the air temperature Ta, the set temperature ϑ (th) , the difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , the air velocity Vair, and the clothing thermal resistance Icℓ, according to the following equation: then, the equivalent temperature Teq can be properly measured even if the sensor temperature Tcr is higher than the set temperature ϑ (th) . Note that if, in equation (17), then Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr Although the heated state has been described above, in which the heater power Hϑ (th) is zero and the sensor temperature T cr is higher than the set temperature ϑ (th) , equation (4) represents only one case in which the heater power Hϑ (th) is zero in the following equation (4'): Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr - c₆ x Hϑ (th) where c₆ = +0.45/Hr. Furthermore, in the above embodiment, the air velocity Vair is obtained by using an air velocity sensor. Assuming that the environment measuring section 5 is arranged indoors, even if the air velocity Vair is set to be an arbitrary value, e.g., 0.2 m/s in consideration of the fact that the indoor air velocity mostly ranges from 0.1 to 0.3 m/s, a large error is not produced in the equivalent temperature Teq. That is, the air velocity sensor need not always be used. This ensures the simplification of the apparatus and prevents an increase in cost. Assume that the air velocity Vair is increased. Even in this case, since thermal energy is taken away from the module main body 5-11, and the sensor temperature Tcr eventually becomes lower than the set temperature ϑ (th) to start a normal heating operation by means of the heater, the equivalent temperature Teq can be obtained by the scheme in a cooled state. Fig. 4 shows a predicted mean thermal sensitivity calculating apparatus according to another embodiment of the present invention, which is associated with the third, fourth, seventh, and eighth aspects of the present invention. This predicted mean thermal sensitivity calculating apparatus 6 comprises an input section 7, a calculating section 8, and a display/output section 9. The input section 7 receives an activity amount M et of a human body and a clothing thermal resistance Icℓ as set values, in addition to an air temperature Ta, a humidity RH, and an equivalent temperature Teq* as detection values. The equivalent temperature Teq * is supplied as an output from the calculating section 3 of the thermal sensitivity calculating apparatus 1 shown in Fig. 2. These set and detection values are supplied from the input section 7 to the calculating section 8. The calculating section 8 then calculates a predicted mean sensitivity PMV* according to the following equation (18): PMV* = α x LOAD* where α= 0.303 x EXP(-0.036 x M et x 58.15) + 0.028 LOAD* = PMVLOAD - Fcℓ x (T sk - Teq*) If M et < 1.0, then PMVLOAD = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) If M et ≧ 1.0, then PMVLOAD = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - D₇ x (M et - 1) where the values of the D₁ to D₇ are set, for example, as follows: D₁ = 10.2895, D₂ = 49.5152, D₃ = 0.7808, D₄ = 0.08142, D₅ = 0.004067, D₆ = 0.00133338, and D₇ = 24.423, T sk = skin temperature (T sk = 35.7 - 0.0275 x M et x 58.15 ), P(Ta) = absolute water vapor pressure at air temperature Ta [P(Ta) = EXP(18.6686 - 4030.183/(Ta + 235)] , and Fcℓ = clothing thermal resistance effect (Fcℓ = E₁/(E₂ + E₃ x Icℓ)) . For example, the values of E₁ to E₃ are set as follows: E₁ = 8.976, E₂ = 1, and E₃ = 1.466. In this embodiment, P(Ta) is based on the Antoine equation (saturated water vapor pressure). However, other equations may be used. Fig. 1(c) shows the process of arithmetic operations performed by the calculating section 8. More specifically, in an Fcℓ calculating section 8-1, a thermal resistance effect Fcℓ is calculated by using the clothing thermal resistance Icℓ. In an α·T sk calculating section 8-2, the value α and the skin temperature T sk are calculated by using the activity amount M et . In a PMVLOAD calculating section 8-3, PMVLOAD is calculated by using the skin temperature T sk , the activity amount M et , the air temperature Ta, the relative humidity RH, and the absolute water vapor pressure P(Ta). In a calculating section 8-4, Fcℓ x (T sk - Teq*) is calculated by using the thermal resistance effect Fcℓ, the skin temperature T sk , and the equivalent temperature Teq*. Finally, in a PMV * calculating section 8-5, LOAD* is obtained by subtracting Fcℓ x (T sk - Teq*) obtained by the calculating section 8-4 from PMVLOAD obtained by the calculating section 8-3, and the predicted mean thermal sensitivity PMV* is calculated by multiplying the value LOAD * by the value a obtained by the calculating section 8-2. Equation (18) is obtained by the present invention by trial and error to simplify the conventional PMV equation (equation (1)). Owing to the synergistic effect based on the fact that the equivalent temperature Teq* can be accurately obtained, the PMV* value obtained by this equation coincides with the PMV value obtained by the conventional PMV equation with considerably high accuracy. Table 1 shows the comparison between PMV and PMV* in the presence of air and in a summertime under the following conditions: M et = 1.2, Icℓ = 0.5, RH = 50%, Ta = Tr = 30°C , and Vair = 0.4 m/s. Table 2 shows the comparison between PMV and PMV* in the presence of air and in a wintertime under the following conditions: M et = 1.2, Icℓ = 1.0, RH = 50%, Ta = Tr = 18°C , and Vair = 0.4 m/s. It is apparent from these tables that PMV and PMV * coincide with each other with only a small error (about 0.1). In the above tables, "LOAD" indicates a collective portion in equation (1) expressed as PMV = (0.303e -0.036M + 0.028) x LOAD . In addition, in R + C = 3.96 x 10⁻⁸·fcℓ·{Tcℓ + 273)⁴ - (Tr + 273)⁴} + fcℓ·hc·(Tcℓ - Ta) , "R* + C*" indicates Fcℓ x (T sk - T eq *) . As is apparent from the above description, according to the present invention, the sensor temperature Tcr is controlled to be equal to the set temperature ϑ (th) which is not constant and changes depending on environmental conditions. According to the first and fifth aspects of the present invention, if the sensor temperature Tcr is higher than the set temperature ϑ (th) , the equivalent temperature Teq* is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the difference ΔTcr, the air velocity Vair, the coefficients c₁ to c₅, and the coefficient n . According to the second and sixth aspects of the present invention, if the sensor temperature Tcr is lower than the set temperature ϑ (th) , the equivalent temperature Teq * is calculated on the basis of the air temperature Ta, the set temperature ϑ (th) , the thermal energy Hϑ (th) , and the coefficients b₁ to b₄. Therefore, even if the air velocity Vair is high, or the sensor temperature Tcr is higher than the set temperature ϑ (th) , the calculated equivalent temperature Teq* coincides with the equivalent temperature Teq felt by a human body with high accuracy, thus allowing accurate measurement of the equivalent temperature Teq. In addition, according to the third, fourth, seventh, and eighth aspects of the present invention, since the equivalent temperature Teq* which coincides with the equivalent temperature Teq with high accuracy is used, the predicted mean thermal sensitivity PMV* can be accurately obtained.

Claims: A method of calculating thermal sensitivity, comprising the steps of: calculating a set temperature ϑ (th) on the basis of an air temperature Ta and a clothing thermal resistance Icℓ; supplying thermal energy information Hϑ (th) to heating means capable of adjusting a sensor temperature Tcr so as to set the set temperature ϑ (th) to be equal to the sensor temperature Tcr; and calculating an equivalent temperature Teq* on the basis of the air temperature Ta, the set temperature ϑ (th) , the thermal energy information Hϑ (th) , and coefficients b₁ to b₄, according to the following equation (a), when the sensor temperature Tcr is lower than the set temperature ϑ (th) , and calculating the equivalent temperature Teq* on the basis of the air temperature Ta, the set temperature ϑ (th) , a difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , an air velocity Vair, a coefficient c₁ expressed in consideration of the clothing thermal resistance Icℓ, coefficients c₂ to c₆, and a coefficient n , according to the following equation (b), when the sensor temperature Tcr is higher than the set temperature ϑ (th) , Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr - c₆ x Hϑ (th) The method according to claim 1, further comprising the step of: calculating predicted mean thermal sensitivity PMV* on the basis of the obtained equivalent temperature Teq*, a humidity RH, an activity amount M et , a skin temperature T sk ( T sk = 35.7 - 0.0275 x M et x 58.15 ), the air temperature Ta, an absolute water vapor pressure P(Ta) at the air temperature Ta, the clothing thermal resistance Icℓ, a thermal resistance effect Fcℓ ( Fcℓ = E₁/(E₂ + E₃ x Icℓ ) ) based on coefficients E₁ to E₃, and coefficients D₁ to D₇, according to the following equation (c), PMV* = α x LOAD* where α = 0.303 x EXP(-0.036 X M et x 58.15) + 0.028 if M et < 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - Fcℓ x (T sk - Teq*) if M et ≧ 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - D₇ x (M et - 1) - Fcℓ x (T sk -Teq*) A thermal sensitivity calculating apparatus, which is arranged with respect to an environment measuring section (5) having heating means (5-12) capable of adjusting a sensor temperature Tcr, comprising: set temperature calculating means (3-1) for calculating a set temperature ϑ (th) on the basis of an air temperature Ta and a clothing thermal resistance Icℓ; thermal energy supplying means (3-2) for supplying thermal energy information Hϑ (th) to said heating means (5-12) so as to set the set temperature ϑ (th) to be equal to the sensor temperature Tcr; and thermal sensitivity calculating means (3-3, 3-3') for calculating an equivalent temperature Teq* on the basis of the air temperature Ta, the set temperature ϑ (th) , the thermal energy information Hϑ (th) , and coefficients b₁ to b₄, according to the following equation (a), when the sensor temperature Tcr is lower than the set temperature ϑ (th) , and calculating the equivalent temperature Teq* on the basis of the air temperature Ta, the set temperature ϑ (th) , a difference ΔTcr between the sensor temperature Tcr and the set temperature ϑ (th) , an air velocity Vair, a coefficient c₁ expressed in consideration of the clothing thermal resistance Icℓ, coefficients c₂ to c₆, and a coefficient n , according to the following equation (b), when the sensor temperature Tcr is higher than the set temperature ϑ (th) , Teq* = b₁ + b₂ x ϑ (th) + b₃ x Ta - b₄ x Hϑ (th) Teq* = c₁ + c₂ x ϑ (th) + c₃ x Ta + c₄ x (1 + c₅ x Vair n ) x ΔTcr - c₆ x Hϑ (th) The apparatus according to claim 3, further comprising: predicted mean thermal sensitivity calculating means (8) for calculating predicted mean thermal sensitivity PMV* on the basis of the equivalent temperature Teq* obtained by said thermal sensitivity calculating apparatus (1), a humidity RH, an activity amount M et , a skin temperature T sk ( T sk = 35.7 - 0.0275 x M et x 58.15 ), the air temperature Ta, an absolute water vapor pressure P(Ta) at the air temperature Ta, the clothing thermal resistance Icℓ, a thermal resistance effect Fcℓ ( Fcℓ = E₁/(E₂ + E₃ x Icℓ) ) based on coefficients E₁ to E₃, and coefficients D₁ to D₇, according to the following equation (c), PMV* = α x LOAD* where α = 0.303 x EXP(-0.036 x M et x 58.15) + 0.028 if M et < 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - Fcℓ x (T sk - Teq*) if M et ≧ 1.0, then LOAD* = D₁ + D₂ x M et - D₃ x T sk + D₄ x M et x Ta + (D₅ + D₆ x M et ) x RH x P(Ta) - D₇ x (M et - 1) - Fcℓ x (T sk -Teq*)

Inventors: KON AKIHIKO C O FUJISAWA FACTO, KON, AKIHIKO, C/O FUJISAWA FACTORY
Applicants: YAMATAKE HONEYWELL CO LTD, YAMATAKE-HONEYWELL CO. LTD.
Application year: 1991
Main classification: G01W1
IPC codes: G01J5, F24F11, G01W1