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

The angle of the collector relative to true south

Answer

The ratio of collector area to storage volume

Answer

The system's thermal efficiency at standard test conditions

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

OG-300 System Rating

Answer

ISO 9001 certification

Answer

ASHRAE 90.1 compliance

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

Antifreeze glycol in the fluid

Answer

An electric heat trace on all outdoor pipes

Answer

Foam insulation on collectors only

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

1 gallon per square foot of collector

Answer

5 gallons per square foot of collector

Answer

Storage volume has no relationship to collector area

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

Direct open-loop coil

Answer

Single-wall copper coil submerged in the tank

Answer

Plate heat exchanger with no double-wall requirement

Question 6

What sizing tool does SRCC and the solar industry use to estimate annual solar water heating system performance by location?

Accepted Answer

F-Chart method or Solar Rating and Certification Corporation OG-300 simulation

Answer

ASHRAE load calculator

Answer

Manual J residential load calculation

Answer

RETScreen energy analysis