Hydronic Heating System Calculations

Kelly, the mathematic plumber, explains how to calculate gallons per minute (GPM) in a hydronic heating system using the BTU load and temperature difference (Delta T). The video covers the importance of these calculations for sizing pumps, provides an example of a boiler system, and demonstrates the formula for GPM calculation. It also explores using different Delta T values for more common scenarios.

What is the primary purpose of calculating gallons per minute in a hydronic heating system?

• To determine the size of the building

• To size the pumps in the system

• To calculate the cost of heating

• To measure the efficiency of the boiler

What two factors are essential for calculating gallons per minute in a hydronic heating system?

• Boiler size and fuel type

• Room size and insulation quality

• Water pressure and pipe length

• BTU load and temperature drop

What does delta T represent in a hydronic heating system?

• The total heat output

• The temperature difference between supply and return

• The efficiency of the boiler

• The flow rate of water

In the example provided, what is the supply temperature of the boiler system?

• 100 degrees Fahrenheit

• 120 degrees Fahrenheit

• 150 degrees Fahrenheit

• 180 degrees Fahrenheit

What is the return temperature in the example used to calculate delta T?

• 80 degrees Fahrenheit

• 90 degrees Fahrenheit

• 110 degrees Fahrenheit

• 100 degrees Fahrenheit

What is the formula used to calculate gallons per minute in a hydronic heating system?

• Total BTUs times 8.33 divided by 60 times delta T

• Total BTUs times 60 divided by 8.33 times delta T

• Total BTUs divided by 60 times 8.33 times delta T

• Total BTUs divided by 8.33 times 60 times delta T

What does the number 8.33 represent in the GPM calculation formula?

• The weight of water in pounds for one US gallon

• The number of minutes in an hour

• The average temperature of the system

• The efficiency rating of the boiler

If the delta T is 20 degrees Fahrenheit, what is the approximate result of the multiplication in the denominator of the formula?

• 12,000

• 9,996

• 8,000

• 10,000

Using a delta T of 15 degrees Fahrenheit, what is the calculated gallons per minute for a 100,000 BTU load?

• 15 GPM

• 13 GPM

• 12 GPM

• 10 GPM

What is the rounded gallons per minute when using a delta T of 20 degrees Fahrenheit for a 100,000 BTU load?

• 12 GPM

• 8 GPM

• 14 GPM

• 10 GPM