Method and apparatus for calculating predicted mean thermal sensitivity

• US 5,436,852 A
• Filed: 09/22/1994
• Issued: 07/25/1995
• Est. Priority Date: 09/21/1990
• Status: Expired due to Fees

• Current Assignee: Yamatake-Honeywell Company Limited
• Original Assignee: Yamatake-Honeywell Company Limited
• Inventors: Kon, Akihiko
• Primary Examiner(s): Ramirez, Ellis B.
• Assistant Examiner(s): Stamber, Eric W.
• Application Number:
  US08/310,930
• Time in Patent Office: 306 Days
• Field of Search: 236/91 C, 236/91 D, 374/109
• US Class Current: 700/276
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: G01W 1/17 Catathermometers for measuring "cooling value" related either to weather conditions or to comfort of other human environment

Abstract

According to a method and apparatus for calculating predicted mean thermal sensitivity which is used to control an air conditioning or heating unit, an operative temperature T₀ is calculated on the basis of a radiant temperature Tr, an air temperature Ta, an air velocity Vair, coefficients b₁ and b₂, and a coefficient n according to the following equation: ##EQU1## Predicted mean thermal sensitivity PMV* is calculated on the basis of the operative temperature T0, the air temperature Ta, a relative humidity RH, a saturated water vapor pressure Pa*, a clothing thermal resistance Icl, a variable h₀ (h₀ =b₁ +b₂ ·Vairⁿ), and coefficients a₁ to a6 according to the following equation: ##EQU2##

Claims

1. A method of controlling an air conditioning and/or heating unit for regulating the degree of comfort in an environment in accordance with a predicted mean thermal sensitivity PMV* value, comprising the steps of:

measuring a radiant temperature Tr, an air temperature Ta, an air velocity Vair, a relative humidity RH and a saturated water vapor pressure Pa*;

calculating an operative temperature T₀ on the basis of the radiant temperature Tr, the air temperature Ta, the air velocity Vair, eigenvalue coefficients b₁ and b₂, and a coefficient n representing an index value of the air velocity Vair, according to the following equation;

##EQU27## where b₁ =3.9 (the radiant heat transfer coefficient for a human body (W/m² °

K.)),

b₂ =A (where hc=A×

Vair⁰.5 is the convection heat transfer coefficient for human body (W/m² °

K.)), and

the coefficient n ranges in value from 0.36 to 0.6;

calculating the predicted mean thermal sensitivity PMV* value on the basis of the operative temperature T₀, the air temperature Ta, the relative humidity RH, the saturated water vapor pressure Pa*, a clothing thermal resistance Icl, a variable h₀ (h₀ =b₁ +b₂ ·

Vairⁿ), and eigenvalue coefficients a₁ to a₆ according to the following equation;

##EQU28## where a₁ =a×

[10.28+49.52×

Met×

58.15-0.781×

Tsk-0.42 ×

(Met-1)×

58.15]

a₂ =a×

0.0814×

Met

a₃ =a×

(0.4067+0.1333×

Met)×

10^-2

a₄ =a×

fcl

a₅ =0.155×

fcl

a₆ =Tsk

a=0.303×

EXP (-0.036×

Met×

58.15)+0.028

Tsk=35.7-0.028×

Met×

58.15 (°

C.) ##EQU29## Met=Metabolism (met) fcl=Coefficient (N.D.)

Ta=Air temperature (°

C.)

Pa*=Saturated vapor pressure (mmHg);

generating an electrical control signal having a magnitude corresponding to the calculated predicted mean thermal sensitivity PMV* value;

supplying the electrical control signal to the air conditioning and/or heating unit; and

controlling at least the air temperature and air velocity of supply air output to the environment from the air conditioning and/or heating unit in accordance with the magnitude of the electrical control signal to regulate the degree of comfort in the environment.

2. A method according to claim 1, further comprising the step of obtaining a measured operative temperature T₀ * through the use of an environment measuring unit, the measured operative temperature To* having an eigenvalue coefficient b₃ and being represented by the following equation:

##EQU30## wherein the operative temperature T₀ is then calculated by the following three equations;

space="preserve" listing-type="equation">T.sub.1 =T.sub.0 *×

(b.sub.1 ×

b.sub.3 ·

Vair.sup.n)

T₂ =T₁ +(b₂ -b₃)·

Vairⁿ ·

Ta

T₀ =T₂ /(b₁ +b₂ ·

Vairⁿ)

and wherein

b3=A(sens) (where Hc(sens)=A(sens)×

(Vairⁿ) is the convection heat transfer coefficient for a sensor body (W/m² °

K.)).

3. An apparatus for providing adaptable control of an air conditioning and/or heating unit to regulate the degree of comfort in an environment in accordance with a predicted mean thermal sensitivity PMV* value, the apparatus comprising:

at least one environment measuring sensor for measuring a radiant temperature Tr, an air temperature Ta, an air velocity Vair, a relative humidity RH and a saturated water vapor pressure Pa* of the environment, the sensor outputting analog signals corresponding to the respective measurements;

an analog to digital converter for receiving the analog signals output from the sensor and converting the analog signals to respective digital signals;

a first operative temperature calculating means for receiving the digital signals output from the analog to digital converter and for calculating a digital signal value corresponding to an operative temperature T₀ of the environment on the basis of the radiant temperature Tr, the air temperature Ta, the air velocity Vair, eigenvalue coefficients b₁ and b₂, and a coefficient n representing an index value of the air velocity Vair, according to the following equation;

##EQU31## where b₁ =3.9 (the radiant heat transfer coefficient for a human body (W/m² °

K.)),

b₂ =A (where hc=A×

Vair⁰.5 is the convection heat transfer coefficient for human body (W/m² °

K.)), and

the coefficient n ranges in value from 0.36 to 0.6;

a predicted mean thermal sensitivity calculating means for receiving the digital signals output from both the analog to digital converter and the first operative temperature calculating means and calculating a digital signal corresponding to a predicted mean thermal sensitivity PMV* value on the basis of the operative temperature T₀, the air temperature Ta, the relative humidity RH, the saturated water vapor pressure Pa*, a clothing thermal resistance Icl, a variable h₀ (h₀ =b₁ +b₂ ·

Vairⁿ), and eigenvalue coefficients a₁ to a₆ according to the following equation;

##EQU32## where a₁ =a×

[10.28+49.52×

Met×

58.15-0.781×

Tsk-0.42 ×

(Met-1)×

58.15]

a₂ =a×

0.0814×

Met

a₃ =a×

(0.4067+0.1333×

Met)×

10^-2

a₄ =a×

fcl

a₅ =0.155×

fcl

a₆ =Tsk

a=0.303×

EXP (-0.036×

Met×

58.15)+0.028

Tsk=35.7-0.028×

Met×

58.15 (°

C.) ##EQU33## Met=Metabolism (met) fcl=Coefficient (N.D.)

Ta=Air temperature (°

C.)

Pa*=Saturated vapor pressure (mmHg); and

a digital to analog converter for receiving the predicted mean thermal sensitivity PMV* digital signal value output from the predicted mean thermal sensitivity calculating means and converting the predicted mean thermal sensitivity PMV* digital signal value into a predicted mean thermal sensitivity PMV* analog signal value; and

the air conditioning and/or heating unit receiving the predicted mean thermal sensitivity PMV* analog signal value and controlling at least the air temperature and air velocity of supply air output to the environment from the air conditioning and/or heating unit in accordance with the magnitude of the electrical control signal to regulate the degree of comfort in the environment.

4. An apparatus according to claim 3, further comprising an environment measuring unit for obtaining a measured operative temperature T₀ * having an eigenvalue coefficient b₃, and being represented by the following equation:

##EQU34## wherein the operative temperature calculating means calculates the operative temperature T₀ by the following three equations;

space="preserve" listing-type="equation">T.sub.1 =T.sub.0 *×

(b.sub.1 ×

b.sub.3 ·

Vair.sup.n)

space="preserve" listing-type="equation">T.sub.2 =T.sub.1 +(b.sub.2 -b.sub.3)·

Vair.sup.n ·

Ta

space="preserve" listing-type="equation">T.sub.0 =T.sub.2 /(b.sub.1 +b.sub.2 ·

Vair.sup.n)

and wherein

b₃ =A(sens) (where Hc(sens)=A(sens)×

(Vairⁿ) is the convection heat transfer coefficient for a sensor body (W/m² °

K.)).

5. A method of controlling an air conditioning and/or heating unit for regulating the degree of comfort in an environment in accordance with a predicted mean thermal sensitivity PMV* value, comprising the steps of:

measuring a radiant temperature Tr, an air temperature Ta, an air velocity Vair, a relative humidity RH and a saturated water vapor pressure Pa*;

calculating an operative temperature T₀ on the basis of the radiant temperature Tr, the air temperature Ta, the air velocity Vair, eigenvalue coefficients b₁ and b₂, and a coefficient n representing an index value of the air velocity Vair, according to the following equation;

##EQU35## where b₁ =3.9 (the radiant heat transfer coefficient for a human body (W/m² °

K.)),

b₂ =A (where hc=A×

Vair⁰.5 is the convection heat transfer coefficient for human body (W/m² °

K.)), and

the coefficient n ranges in value from 0.36 to 0.6;

calculating the predicted mean thermal sensitivity PMV* value on the basis of the operative temperature T₀, the air temperature Ta, the relative humidity RH, the saturated water vapor pressure Pa*, a clothing thermal resistance Icl, a variable h₀ (h₀ =b₁ +b₂ ·

Vairⁿ), and eigenvalue coefficients a₁ to a₆ according to the following equation;

##EQU36## where a₁ =a×

[10.28+49.52×

Met×

58.15-0.781×

Tsk-0.42 ×

(Met-1)×

58.15]

a₂ =a×

0.0814×

Met

a₃ =a×

(0.4067+0.1333×

Met)×

10^-2

a₄ =a×

fcl

a₅ =0.155×

fcl

a₆ =Tsk

a=0.303×

EXP (-0.036×

Met×

58.15)+0.028

Tsk=35.7-0.028×

Met×

58.15 (°

C.) ##EQU37## Met=Metabolism (met) fcl=Coefficient (N.D.)

Ta=Air temperature (°

C.)

Pa*=Saturated vapor pressure (mmHg);

generating an electrical control signal having a magnitude corresponding to the calculated predicted mean thermal sensitivity PMV* value;

supplying the electrical control signal to a controller of the air conditioning and/or heating unit, the air conditioning and/or heating unit having at least a fan for providing supply air to the environment and a heating element for heating the supply air, with the controller being electrically coupled to the fan and heating element for regulating at least the air velocity and air temperature of the supply air output to the environment; and

controlling at least the fan and heating element of the air conditioning and/or heating unit by the controller in accordance with the magnitude of the electrical control signal to regulate the degree of comfort in the environment.

6. A method according to claim 5, further comprising the step of obtaining a measured operative temperature T₀ * through the use of an environment measuring unit, the measured operative temperature To* having an eigenvalue coefficient b₃ and being represented by the following equation:

##EQU38## wherein the operative temperature T₀ is then calculated by the following three equations;

space="preserve" listing-type="equation">T.sub.1 =T.sub.0 *×

(b.sub.1 ×

b.sub.3 ·

Vair.sup.n)

space="preserve" listing-type="equation">T.sub.2 =T.sub.1 +(b.sub.2 -b.sub.3)·

Vair.sup.n ·

Ta

space="preserve" listing-type="equation">T.sub.0 =T.sub.2 /(b.sub.1 +b.sub.2 ·

Vair.sup.n)

and wherein

b3=A (sens) (where Hc (sens)=A (sens)×

(Vairⁿ) is the convection heat transfer coefficient for a sensor body (W/m² °

K.)).

7. An apparatus for providing adaptable control of an air conditioning and/or heating unit to regulate the degree of comfort in an environment in accordance with a predicted mean thermal sensitivity PMV* value, the air conditioning and/or heating unit having at least a fan for providing supply air to the environment, a heating element for heating the supply air and a controller electrically coupled to the fan and heating element for regulating at least the air velocity and air temperature of supply air output to the environment, the apparatus comprising:

at least one environment measuring sensor for measuring a radiant temperature Tr, an air temperature Ta, an air velocity Vair, a relative humidity RH and a saturated water vapor pressure Pa* of the environment, the sensor outputting analog signals corresponding to the respective measurements;

an analog to digital converter for receiving the analog signals output from the sensor and converting the analog signals to respective digital signals;

a first operative temperature calculating means for receiving the digital signals output from the analog to digital converter and for calculating a digital signal value corresponding to an operative temperature T₀ of the environment on the basis of the radiant temperature Tr, the air temperature Ta, the air velocity Vair, eigenvalue coefficients b₁ and b₂, and a coefficient n representing an index value of the air velocity Vair, according to the following equation;

##EQU39## where b₁ =3.9 (the radiant heat transfer coefficient for a human body (W/m² °

K.)),

b₂ =A (where hc=A×

Vair⁰.5 is the convection heat transfer coefficient for human body (W/m² °

K.)), and

the coefficient n ranges in value from 0.36 to 0.6;

a predicted mean thermal sensitivity calculating means for receiving the digital signals output from both the analog to digital converter and the first operative temperature calculating means and calculating a digital signal corresponding to a predicted mean thermal sensitivity PMV* value on the basis of the operative temperature T₀, the air temperature Ta, the relative humidity RH, the saturated water vapor pressure Pa*, a clothing thermal resistance Icl, a variable h₀ (h₀ =b₁ +b₂ ·

Vairⁿ), and eigenvalue coefficients a₁ to a₆ according to the following equation;

##EQU40## where a₁ =a×

[10.28+49.52×

Met×

58.15-0.781×

Tsk-0.42 ×

(Met-1)×

58.15]

a₂ =a×

0.0814×

Met

a₃ =a×

(0.4067+0.1333×

Met)×

10^-2

a₄ =a×

fcl

a₅ =0.155×

fcl

a₆ =Tsk

a=0.303×

EXP (-0.036×

Met×

58.15)+0.028

Tsk=35.7-0.028×

Met×

58.15 (°

C.) ##EQU41## Met=Metabolism (met) fcl=Coefficient (N.D.)

Ta=Air temperature (°

C.)

Pa*=Saturated vapor pressure (mmHg); and

a digital to analog converter for receiving the predicted mean thermal sensitivity PMV* digital signal value output from the predicted mean thermal sensitivity calculating means and converting the predicted mean thermal sensitivity PMV* digital signal value into a predicted mean thermal sensitivity PMV* analog signal value; and

the controller of the air conditioning and/or heating unit receiving the predicted mean thermal sensitivity PMV* analog signal value and controlling at least the fan and the heating element of the air conditioning and/or heating unit in accordance with the magnitude of the predicted mean thermal sensitivity PMV* analog signal value.

8. An apparatus according to claim 7, further comprising an environment measuring unit for obtaining a measured operative temperature T₀ * having an eigenvalue coefficient b₃, and being represented by the following equation:

##EQU42## wherein the operative temperature calculating means calculates the operative temperature T₀ by the following three equations;

space="preserve" listing-type="equation">T.sub.1 =T.sub.0 *×

(b.sub.1 ×

b.sub.3 ·

Vair.sup.n)

space="preserve" listing-type="equation">T.sub.2 =T.sub.1 +(b.sub.2 -b.sub.3)·

Vair.sup.n ·

Ta

space="preserve" listing-type="equation">T.sub.0 =T.sub.2 /(b.sub.1 +b.sub.2 ·

Vair.sup.n)

and wherein

b₃ =A(sens) (where Hc(sens)=A(sens)×

(Vairⁿ) is the convection heat transfer coefficient for a sensor body (W/m² °

K.)).