Introduction To Hydronic Radint Heatng Design :A

Question 1

How much 1/2” tubing can be on one loop?

Answer 1

300ft

Question 2

How much 3/4 tube can be on one loop?

Answer 2

500 ft

Question 3

To determine tubing size what 3 factors must be known?

Answer 3

Gallons per minute flow rate

Length of circuit

Designed temperature drop through the circuit

Question 4

What is the formula for GPM on a circuit?

Answer 4

Question 5

What is the formulae to find the required BTU’ a per square foot required in a zone?

Answer 5

Btus divided by square feet of zone

Question 6

In floor heating heats by

Answer 6

Convection and radiation

Question 7

What is this piping layout called and used for?

Answer 7

Single serpentine
One exterior wall

Question 8

What is this piping layout called and used for?

Answer 8

Double serpentine
2 exterior walls

Question 9

What is this piping layout called and used for?

Answer 9

Triple serpentine
3 exterior walls

Question 10

What is this piping pattern called and used for?

Answer 10

Counterflow
Heat loss is evenly distributed

Question 11

What are the 4 installation methods for in floor radiant heating?

Answer 11

Poured in a concrete slab

Poured in an underlay on a suspended wooden floor

The sandwich method

Suspended below a wooden floor between joists

Question 12

How close must fasteners be on rebar?

Answer 12

At least every 3’

Question 13

Where else on the rebar must you put fasteners?

Answer 13

Each side of the arch and in the center

Question 14

What is the maximum spacing between tubes embedded in a thermal mass?

Answer 14

Maximum 12”

Question 15

What are the testing my parameters for in floor heating?

Answer 15

The greater of 60 psi or 1.5 times the working pressure for one hour with no pressure loss.

Question 16

What do expansion joints in the concrete do?

Answer 16

Absorb horizontal movement cause by thermal expansion and contraction

Question 17

A normally open zone valves power to do what?

Answer 17

Keep the zone valve closed.

Question 18

A normally closed zone valve requires power to do what?

Answer 18

Requires power to open it.

Question 19

A normally open zone valve requires why kind of thermostat?

Answer 19

Normally open thermostat

Question 20

A normally closed zone valve requires what kind of thermostat?

Answer 20

Normally closed thermostat.

Question 21

Installing the wrong kind of thermostat on a zone valve will do what?

Answer 21

Cause the valve to operate in reverse and supply heat when not required or remove heat demand when heat is required .

Question 22

How long does an actuator type zone valve take to fully open?

Answer 22

3-5 minutes

Question 23

Where are zone valves installed?

Answer 23

Prior to the manifold serving more than one circuit or directly on a manifold serving individual circuits.

Question 24

Where is the thermostat for a zone valve installed?

Answer 24

The area with the greatest heat loss.

Question 25

What can replace a zone valve?

Answer 25

A pump.

Question 26

In a primary/secondary piping system what is the maximum distance between T’s?

Answer 26

4 pipe diameters to a maximum of 12”

Question 27

What is this?

Answer 27

3 way mixing valve.

Question 28

In what position is this 3 way mixing valve?

Answer 28

Fully open

Question 29

What position is this 3 way mixing valve in?

Answer 29

Fully closed

Question 30

In what position is this 3 way mixing valve?

Answer 30

Partially open (mixing)

Question 31

When installing tubing in a radiant floor heating system which area of the room should the start of the loop be?

Answer 31

The areas with the greatest heat loss.

Question 32

Is insulation required below a poured in concrete application?

Answer 32

Yes. Code requires it.

Question 33

When are supplemental heating units installed in radiant floor heating systems?

Answer 33

When the radiant floor does not keep up with the heat load.

Question 34

What two factors are required to calculate header size?

Answer 34

Gallons per minute and velocity .

Question 35

Is a bypass pump between the supply and return piping required on a low mass boiler that is flow sensitive?

Answer 35

Yes

Question 36

What is required when a conventional boiler is installed in a low temperature radiant floor heating application?

Answer 36

A mixing valve

Question 37

What is the function of a 3 or 4 way mixing valve ina hydronic heating system?

Answer 37

Mixes water from the heat source and the system return in order to temper system supply water.

Question 38

What must be installed with a three or four way mixing valve in order to protect the heat source and the radiant floor system?

Answer 38

A drive motor and controller .

Question 39

What should be installed to separate the boiler water and system water when glycol is added to the water in a radiant floor heating system?

Answer 39

A plate heat exchanger

Question 40

What is required when a variable speed injection pump is installed in a two temperature system ?

Answer 40

A controller for the pump.