NABCEP NABCEP Solar Heating Installation Professional

Question 1

What is the primary difference between a solar thermal collector and a photovoltaic (PV) module?

Accepted Answer

Solar thermal collectors convert sunlight into heat, while PV modules convert sunlight into electricity

Answer

Solar thermal collectors capture solar radiation and transfer that energy as heat to a fluid, whereas PV modules use the photovoltaic effect to generate direct current electricity.

Question 2

Which type of solar thermal collector is most efficient in cold climates with high heat demand?

Accepted Answer

Evacuated tube collector

Answer

Evacuated tube collectors use vacuum insulation to minimize heat loss, making them highly efficient in cold climates where flat-plate collectors lose significant heat to the environment.

Question 3

What is the function of a differential controller in an active solar thermal system?

Accepted Answer

It turns the circulator pump on when the collector is hotter than the storage tank and off when it is not

Answer

The differential controller compares temperatures at the collector and storage tank and activates the pump when the collector temperature exceeds the tank by a set threshold, preventing reverse circulation.

Question 4

Which heat transfer fluid is commonly used in closed-loop solar thermal systems to prevent freezing?

Accepted Answer

Propylene glycol-water mixture

Answer

Propylene glycol mixed with water is the standard non-toxic antifreeze heat transfer fluid for closed-loop solar thermal systems, providing freeze protection without plumbing contamination risk.

Question 5

What is the purpose of a pressure relief valve in a solar thermal system?

Accepted Answer

To release excess pressure and prevent damage to collectors or storage tanks from thermal expansion

Answer

Thermal expansion during stagnation (when the pump is off but collectors are hot) can create very high pressures, and the relief valve opens to prevent system damage or rupture.

NABCEP - North American Board of Certified Energy Practitioners Practice Test

NABCEP - North American Board of Certified Energy Practitioners Practice Test

NABCEP NABCEP Solar Heating Installation Professional