Standard water heaters typically have integrated insulation with an R-value of between ____, while very efficient heaters may have R-values as high as 24.

A. 6 and 12
B. 8 and 16
C. 9 and 18
D. 12 and 20


Answer: B

Trades & Technology

You might also like to view...

How does an automatic expansion valve prevent liquid floodback in a system?

a. It is not capable of preventing floodback. b. Keeping the evaporator pressure low prevents floodback. c. Keeping the evaporator temperature low prevents floodback. d. Keeping the evaporator pressure high prevents floodback

Trades & Technology

On a CNC vertical spindle machining center, a Z axis offset is:

A) The distance from the tool tip to the work top surface in the X axis B) The distance from the tool tip to the work top surface in the Z axis C) The distance of the spindle to the Y axis D) The distance from the machine to the shop wall

Trades & Technology

The feedback attenuation of a voltage follower op-amp is:

A) < 1. B) = 1. C) Rf/Ri. D) > 1.

Trades & Technology

The commutative law of Boolean algebra states that A + B = A ? B

Indicate whether the statement is true or false

Trades & Technology