CRD Residential Energy Efficiency & Load Calculations 3

Question 1

A building has 2,400 sq ft of wall area with an overall U-factor of 0.065 BTU/hr·ft²·°F and a DTD of 65°F. What is the wall heat loss?

Accepted Answer

10,140 BTU/hr

Answer

Heat loss = U × Area × DTD = 0.065 × 2,400 × 65 = 10,140 BTU/hr.

Question 2

In Manual J calculations, the 'latent load' refers to:

Accepted Answer

Heat associated with moisture removal from the air

Answer

Latent load is the cooling energy required to condense and remove moisture from indoor air, distinct from sensible (temperature-related) heat.

Question 3

Which window property most directly affects the cooling load from solar radiation?

Accepted Answer

Solar Heat Gain Coefficient (SHGC)

Answer

SHGC measures the fraction of incident solar radiation admitted through a window, making it the primary factor for solar-driven cooling loads.

Question 4

For a geothermal heat pump with an EWT of 50°F in heating mode, which effect does a lower entering water temperature have on capacity?

Accepted Answer

Capacity decreases and power consumption increases

Answer

As EWT drops, the heat pump must work harder, reducing heating capacity and COP while increasing electrical consumption.

Question 5

Which of the following best describes 'degree-days' as used in energy consumption estimation?

Accepted Answer

Cumulative sum of daily mean temperature deviations from a base temperature (65°F)

Answer

Heating degree-days (HDD) sum the daily differences between 65°F and the average outdoor temperature, providing a seasonal measure of heating energy demand.

(CRD) Certified Residential Geothermal Designer Practice Test

(CRD) Certified Residential Geothermal Designer Practice Test

CRD Residential Energy Efficiency & Load Calculations 3