ASHRAE ASHRAE Thermal Comfort and Heat Transfer 2

Question 1

In ASHRAE load calculations, what term describes heat that affects only the sensible load without changing room humidity?

Accepted Answer

Sensible heat gain

Answer

Sensible heat gain changes the dry-bulb temperature of the space air without adding moisture, directly contributing to the sensible cooling load.

Question 2

Which ASHRAE method is the current standard procedure for calculating residential and commercial cooling and heating loads?

Accepted Answer

Radiant Time Series (RTS) method

Answer

The Radiant Time Series (RTS) method is the current ASHRAE simplified hand-calculation procedure described in the Handbook – Fundamentals for cooling load calculations.

Question 3

What is the sol-air temperature concept used for in ASHRAE load calculations?

Accepted Answer

To combine solar radiation and outdoor air temperature into a single equivalent outdoor temperature for wall and roof conduction calculations

Answer

Sol-air temperature is an equivalent outdoor temperature that accounts for both the actual outdoor air temperature and the solar radiation absorbed by an exterior surface.

Question 4

According to ASHRAE fundamentals, convection heat transfer coefficient h depends primarily on which factor?

Accepted Answer

Fluid velocity and flow regime (laminar vs. turbulent)

Answer

The convective heat transfer coefficient h is strongly influenced by fluid velocity and whether flow is laminar or turbulent, as described by dimensionless Nusselt number correlations.

Question 5

What is the significance of the U-factor (overall heat transfer coefficient) for a fenestration assembly per ASHRAE?

Accepted Answer

It quantifies the total rate of heat transfer through the window assembly per unit area per degree temperature difference

Answer

The U-factor is the overall heat transfer coefficient (Btu/h·ft²·°F) that accounts for conduction, convection, and radiation through the entire fenestration assembly.

ASHRAE - American Society of Heating, Refrigeration and Air Conditioning Engineers Certification Practice Test

ASHRAE - American Society of Heating, Refrigeration and Air Conditioning Engineers Certification Practice Test

ASHRAE ASHRAE Thermal Comfort and Heat Transfer 2