NABCEP NABCEP Solar Heating Installation Professional 2

Question 1

What is the Solar Fraction (SF) of a solar thermal system?

Accepted Answer

The percentage of the total heating load supplied by solar energy

Answer

Solar fraction represents the portion of a building's total water or space heating load that is met by the solar thermal system, with higher values indicating greater solar contribution.

Question 2

Which SRCC (Solar Rating and Certification Corporation) rating is used to compare solar water heating collectors?

Accepted Answer

OG-100 Collector Rating

Answer

SRCC OG-100 is the collector-level rating that measures thermal performance under standardized conditions, allowing consumers and installers to compare different collector models.

Question 3

In a drainback solar thermal system, what prevents freeze damage when the pump shuts off?

Accepted Answer

The water drains back into an indoor reservoir by gravity when the pump stops

Answer

Drainback systems are designed so that water flows only when the pump is running; when the pump stops, gravity returns all water to an indoor reservoir, leaving no water in the collectors to freeze.

Question 4

What is the recommended storage volume per unit collector area for a solar domestic water heating system?

Accepted Answer

1.5–2 gallons per square foot of collector

Answer

Industry guidelines recommend 1.5–2 gallons of storage per square foot of collector area to ensure adequate thermal mass without oversizing the tank to the point of poor solar fraction.

Question 5

What type of heat exchanger is most commonly used in pressurized closed-loop solar thermal systems to protect potable water?

Accepted Answer

Double-wall heat exchanger for separation of glycol from potable water

Answer

Many plumbing codes require a double-wall heat exchanger when toxic antifreeze (or any non-potable fluid) transfers heat to a potable water supply, preventing contamination in case of failure.

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 2