Gas Furnaces
This measurement is commonly abbreviated BTU.
What is a British Thermal Unit?
A nozzle's minimum operating pressure.
What is 100 PSI?
Most hydronic expansion tanks come pre-charged at this PSI.
What is 12 PSI?
During the defrost cycle, the heat pump switches to this mode.
What is cooling?
What are microfarads and volts?
The correct manifold pressure for a single stage, propane gas furnace.
What is 10 to 11 inches water column?
The maximum Ohms for flame signal on a burner.
What is 1,500 to 1,600 Ohms?
The weight of 1 gallon of water at 60 degrees Fahrenheit.
What is 8.33 pounds?
In heating mode, the outdoor coil functions as this.
What is an evaporator?
The amount of current a #10AWG wire can handle.
What is 30 amps?
The average BTU content per cubic foot of natural gas in our area.
What is 1,040 BTU/ft3?
The output voltage range of a solid state igniter.
What is 14,000 to 20,000 volts?
The height that water will be raised if 1 PSI of pressure is applied.
What is 2.31 feet?
What the large center pipe of a reversing valve is considered.
What is the true suction line?
The frequency at which electrical equipment in the USA is rated in.
What are 60 Hertz?
When checking polarity of a gas furnace transformer, this is the proper voltage between L1 and R on the control board.
What is approximately 96VAC?
When measuring resistance of a solid state ignition transformer, these should be the readings from post to post and from each post to ground.
What are 1,300 to 1,500 Ohms from post to post and half of that reading from each post to ground?
The number of BTU's a 3/4" copper pipe can carry.
What is 40,000 BTU's?
The type of liquid line filter drier used on a heat pump system.
What is a bi-flow?
This many BTU's is equal to 1 kilowatt.
What is 3,412 BTU's?
This formula is used to calculate CFM.
What is CFM = BTU output/(1.08*ΔT)?
The number of BTU's per gallon of #2 Fuel Oil.
What is 139,600 BTU's?
The pressure a system should be at if the highest point is 35 feet.
What is 18.15 PSI?
(35 feet/2.31 feet per PSI + 3 PSI)
Degrees above ambient temperature that the compressor discharge line temperature should be.
What is 100 to 110 degrees Fahrenheit?
The minimum wire size needed for a condensing unit with a rating of '21 Amp Minimum Circuit Ampacity, 50 Amp Maximum Over Current Protection'.
What is #10AWG?