Chapter 4, Problem 4.1P

Using Fig. 4-1, draw a conclusion about the comfort of a mixed group of men and women in typical seasonal clothing, with sedentary activity for the following cases:

a. Summer, operative temperature 77 F, wb 64 F

b. Winter, operative temperature. 77 F, wb 64 F

c. Summer, operative temperature 75 F, dp 50 F

d. Winter, operative temperature 73 F, dp 34 F

To determine

The comfort of mixed group of men and women in typical seasonal clothing.

Answer to Problem 4.1P

According to given condition, the group will feel comfortable.

Explanation of Solution

Given:

The operating temperature of summer is $77\text{F}$ .

The wet bulb temperature of summer is $64\text{F}$ .

Calculation:

From fig4-1,

According to ASHRAE standard, the acceptable range of operating temperature is $77\text{F}$ and wet bulb temperature is $64\text{F}$ on summer the mixed group of men and women will feel comfortable during this season because at this operating temperature the relative humidity reaches to $60\%$ .

To determine

The comfort of mixed group of men and women in typical seasonal clothing.

Answer to Problem 4.1P

According to given condition, the group will not feel comfortable.

Explanation of Solution

Given:

The operative temperature of winter is $77\text{F}$ .

The wet bulb temperature of winter is $64\text{F}$ .

Calculation:

From fig4-1,

According to ASHRAE standard, the acceptable range of operating temperature is $77\text{F}$ and wet bulb temperature is $64\text{F}$ on winter the mixed group of men and women will feel comfortable during this season because at this operating temperature the relative humidity reaches to $60\%$ due to this the temperature is maintained in this season.

To determine

The comfort of mixed group of men and women in typical seasonal clothing.

Answer to Problem 4.1P

According to given condition, the group will feel comfortable

Explanation of Solution

Given:

The operative temperature of summer is $75\text{F}$ .

The dew temperature of summer is $50\text{F}$ .

Calculation:

From fig4-1,

According to ASHRAE standard, the acceptable range of operating temperature is $75\text{F}$ and wet bulb temperature is $50\text{F}$ on summer the mixed group of men and women will feel comfortable during this season because at this operating temperature the relative humidity reaches to $40\%$ so that the temperature is maintained in this summer season.

To determine

The comfort of mixed group of men and women in typical seasonal clothing.

Answer to Problem 4.1P

According to given condition, the group will feel uncomfortable.

Explanation of Solution

Given:

The operative temperature of winter is $73\text{F}$ .

The dew temperature of winter is $34\text{F}$ .

Calculation:

From fig4-1,

According to ASHRAE standard, the acceptable range of operating temperature is $73\text{F}$ and wet bulb temperature is $34\text{F}$ on winter the mixed group of men and women will feel uncomfortable during this season because at this operating temperature the relative humidity decrease to $30\%$ due to this the temperature produce more heat in this winter season.