P.O. Box 245
Syracuse, NY 13211
www.roth-america.com
888-266-7684
Flow Center and Loop
Application/Installation
Guide
P/N: 2300100909
Table of Contents:
Section 1: Model Nomenclature
Section 7: HDPE Pipe
Section 2: Installation - Pressurized
Flow Centers
Section 8: Flow Center Selection
Nomenclature description.................................... 2
General Installation................................................ 2
Optional Adapter Sets........................................... 3
Mounting Flow Center........................................... 3
Interior Piping.......................................................... 4
Electrical Requirements......................................... 4
Multiple Units........................................................... 5
Section 3: Flushing & Charging
Overview................................................................. 5
Flush Cart Design.................................................... 6
Step by Step Flushing & Charging........................ 6
Section 4: Installation Non-Pressurized Flow Centers
General Installation................................................ 9
Interior Piping/Flushing........................................... 9
Section 5: Closed Loop Design
Basics..................................................................... 11
Parallel vs. Series................................................... 11
Header Design...................................................... 12
Closed Loop Heat Exchanger Design Rules..... 13
Soil Moisture Properties........................................ 16
Section 6: Antifreeze Selection
Overview............................................................... 17
Antifreeze Charging............................................ 18
Pipe Specifications............................................... 20
Fusion Methods..................................................... 20
Pressure Drop Calculations................................. 21
Pump Curves........................................................ 21
Pressure Drop Tables............................................ 22
Guide Revision Table:
August, 2010
KT
All
First Published
Section 1: Model Nomenclature
MODEL NUMBER NOMENCLATURE:
Model Number Digit:
1
2
3 4
5
6
Model Number: A G FC 1 A
Part Type
A = Unit Accessory
Operation
G = Pressurized
B = Non-Pressurized
Accessory Type
FC = Flow Center
FM = Flow Module
Number of Pumps
Flow Center Type
Pressurized Flow Centers:
A = Composite/Brass valve, double O-Ring fittings, UP26-116 Pumps
D = Composite/Brass valve, double O-Ring fittings, UP26-99 Pumps
B = Brass valve, 1” FPT, UP26-99 Pumps
C = Brass valve, 1” FPT, UP26-116 Pumps
E = Brass valve, 1” FPT, UP26-99 Pumps
F = Double O-ring XL fittings, UPS60-150 Pumps
Non-Pressurized Flow Centers:
A = UP26-99 Pumps, 1” FPT swivel
B = UP26-116 Pumps, 1” FPT swivel
[Consult the price book for more detailed Nomenclature Flow Center Hose Kit Adapter combinations.]
Section 2: Flow Center Installation -Pressurized
Note: The flow centers are injected with
foam for condensation prevention
during low temperature operation and for
noise attenuation. Pump heads can be
field replaced.
Safety Considerations
WARNING: Before performing service or
maintenance operations on the flow center
pumps, turn off all power sources. Electrical
shock could cause personal injury or death.
Before applying power, make sure that all
covers and screws are in place. Failure to
do so could cause risk of electrical shock.
Typical Pressurized Flow Center Installation
The flow centers are insulated and contain
all flushing and circulation connections
for residential and light commercial earth
loops that require a flow rate of no more
than 20 gpm. 1-1/4” fusion x 1” double
o-ring fittings (AGA6PES) are furnished with
the double o-ring flow centers for HDPE
loop constructions. Various fittings are
available for the double o-ring flow centers
for different connections. See table 1 for
connection options. A typical installation
will require the use of a hose kit. Matching
hose kits come with double o-ring adapters
to transition to 1” hose connection.
Flow Center Initial Inspection
Please read the complete instructions
before starting installation. Carefully
follow instructions to ensure optimum and
safe operation. Leave the instructions
with the owner after installation. The flow
center and Grundfos UP series circulating
pumps should be installed according to all
applicable codes. Unpack the flow center
and any other component kits required and
inspect them for shipping damage before
Note: Threaded flow centers all have 1” FPT
installation. Shipping damage claims must
be filed promptly by the purchaser with the connections. Matching hose kits come with
the AGBA55 adapter needed to transition
freight company.
from 1” FPT to 1” hose.
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2
Flow Center & Loop Application Manual
August, 2010
Section 2: Flow Center Installation -Pressurized
Figure 1: Typical Flow Center Installation
Figure 2a: Pump Mounting
Access Ports
S:
op piping is HDPE
3408, 160 psi
pipe joints are made
heat fusion (socket)
stem is a pressurized
sed loop, 0-60 psi
cess to loop for
shing/purging and
essure testing is at
w center
Flow
Center
GSHP
Figure 2b: Control box location
Hose
Kit
To/From
Loop Field
Source Water IN
P/T Ports
Source Water OUT
Flow Center Mounting
The flow center can be mounted to the
wall or the side of the unit opposite the air
coil. If you are mounting the flow center to
the stud wall make sure you have isolated
the flow center from the studs and/or lag
bolts to prevent noise and/or vibration. If
you are mounting the flow center to the
side of the heat pump, be careful not to
puncture any internal parts of the unit when
inserting the screws into the cabinet. Keep
in mind that heat pump access will be
limited in this mounting position. Be sure
when mounting the flow center that there
is adequate access to both the flush ports
and 3-way valves for any service required.
The flow center must be located between
the heat pump and the earth loop and
should be located as close to the unit as
possible to limit the length of rubber hose
and associated pressure drop (hose kits
come with 10’ of rubber hose - limit one unit
per hose kit connection). Other factors for
flow center location is the ease of future
service. The flow center must be mounted
with the pump shaft(s) in the horizontal
position. The only adjustment is that the
circulator pump electrical boxes be on the
horizontal side of the power head in the
mounted position to help prevent moisture
from being held inside the junction box
(See figures 2a and 2b).
Table 1: Adapter Sets
Part No.
AGA5INS
AGA6INS
AGA5MPT
AGA6PES
AGAFP
AGBA55
AGBA56
GFMA65
AGA5FPT
AGS5INS
AGS5MPT
Description
Double O-ring x 1” Brass Barb (Pair)
Double O-ring x 1.25” Brass Barb (Pair)
Double O-ring x 1” Brass MPT (Pair)
Double O-ring x 1.25” PE Socket (Pair)
Double O-ring x Cam Lever elbow (male)(pair)
1” Brass MPT x 1” Brass Barb (ea)
1” Brass MPT x 1.25” Brass Barb (ea)
1” Brass MPT x 1.25” PE Socket (ea)
Double O-ring x 1” Brass FPT (pair)
Double O-ring x 1” Brass Barb w/PT tap (pair)
Double O-ring x 1” Brass MPT w/PT tap (pair)
Connection Use
Unit Side
Loop or Unit Side
Loop or Unit Side
Loop or Unit Side
Flush Port
Unit Side
Loop or Unit Side
Loop or Unit Side
Loop or Unit Side
Unit Side
Units Side
FC Type
O-Ring
O-Ring
O-Ring
O-Ring
O-Ring
FPT
FPT
FPT
O-Ring
O-Ring
O-Ring
Note: Hose clamps included with hose kits.
Flow Center & Loop Application Manual
August, 2010
3
Roth
Section 2: Flow Center Installation -Pressurized
Interior Piping
Figure 3: External Pump Wiring
ECM Board
(Optional -- ECM only)
Lockout Board
(all units)
NO NC
COM
Blower Relay
(Optional -PSC only)
NO NC
Combo Board
(Optional -- Combo units only)
COM
Accessory Connections
ODD, HW, A, YT,YU, HUM, R
T-Stat Connections
C, R, Y1, Y2, O, G, W, L
All interior piping must be sized for proper
flow rates and pressure loss. Insulation
should be used on all inside piping when
minimum loop temperatures are expected
to be less than 50°F. Use the table below
for insulation sizes with different pipe sizes.
All pipe insulation should be a closed cell
and have a minimum wall thickness of
3/8”. All piping insulation should be glued
and sealed to prevent condensation and
dripping. Interior piping may consist of the
following materials: HDPE, copper, brass,
or rubber hose (hose kit only). PVC is not
allowed on pressurized systems.
Hot Water Pump Relay
(Optional -- Combo only)
or Fan Interlock
(Optional -- PSC only)
Pump Circuit Breaker
(added late 2008)
Table 2: Pipe Insulation
Wire external loop pump(s)
to the pump terminal
block in the control box.
Electric Heater Connections
C, W1, W2, W3
Piping Material
1" IPS Hose
1" IPS PE
1-1/4" IPS PE
2" IPS PD
Pump
Connection
Insul Description
1-3/8" ID - 3/8" Wall
1-1/4" ID - 3/8" Wall
1-5/8" ID - 3/8" Wall
2-1/8" ID - 3/8" Wall
Transformer
Contactor
Flow Center Electrical Wiring
Grounding block
Power wiring to the flow center must
conform to all applicable codes. Figure
4: Pump Sharing Module
Figure 1: Figure
Board Layout
3 illustrates the wiring required at the
unit control box. Flow centers are only
240VAC
240VAC
to Pump(s)
available in 230V single phase voltage.
Power Source
Pumps are fused through a pair of circuit
240V IN 240V OUT
breakers in the unit control box.
Multiple Units on One Flow Center
When two units are connected to one loop
pumping system, pump control is achieved
24VAC
connection
by using APSMA loop pump sharing
to unit #1
(compressor contactor coil)
module. Using this module allows either
unit to energize the flow center. Connect
the units and flow center as shown in
Figure 2: Board Schematic
Figures 4 and 5. The APSMA module must
be located in a NEMA enclosure or inside
DC
Bridge
the unit control box. Figure 6 shows unit
+
24VAC input
connections to a common loop with one
from unit #1
flow center per unit.
Roth
4
24VAC input
from unit #2
Relay
Relay
24VAC
connection
to unit #2
24VAC 24VAC
(compressor contactor coil)
LED
Diode
RY1
RY1
240VAC input
RY2
+
Diode
RY2
240VAC to pump(s)
Flow Center
& Loop Application Manual
August, 2010
Section 2: Flow Center Installation -Pressurized
Two Units with to
One
FlowFlow
Center
Figure 5: Two Units Connected
One
Center
To Ground Loop
pmuPPump
taeH
Heat
Flow
wolF
rCenter
ellortnoC
pmuPPump
taeH
Heat
Field-supplied
full-port ball valve
for balancing
T
WL
EWT
T
WL
EWT
T
WE
LWT
T
WE
LWT
Each heat
Multiple Units
onpump
Common Loop Field
must include P/T
Parallel
ports toPumping
verify flow ratesArrangement
Figure 6: Common Loop with One Flow Center per Unit
To Ground Loop
Flow
Center
Each heat pump
must include P/T
ports to verify flow rates
Heat Pump
Flow
Center
Flow
Center
Heat Pump
Heat Pump
EWT
T
WL
EWT
EWT
TLWT
WE
LWT
LWT
Field-supplied
check valve to
prevent short-cycling
Field-supplied
full-port ball valve
for balancing
Section 3: Flushing & Charging
failure could result. The flush ports located
on the flow center are access to the piping
system for the flush cart. See figure 7 for
connection details.
Overview
Once piping is completed between the
unit, flow center, and the earth loop, final
The 3-way valves on the flow center include
Two Units
Flow Center
purging and charging of the system
is with Onedirection
indicators on the valves which
needed. A flush cart (at least a minimum of determine the flow path (see figure 8). A
1.5 hp pump motor or larger) is needed to
3/8” socket drive is
required to operate
To Ground Loop
achieve adequate flow velocity (2 fps in all the 3-way valves. The valves will turn in
piping) in the loop to purge air and debris
either direction, 360 degrees. Make sure
Flow
wolF
from the loop piping (unless the headerrCenter
e
l
l
o
r
t
n
o
C
duringHeat
that the valves are in the
pmuPPump
taeH
pthis
muPPump
taprocess
eH
Heat
manifold is located inside and has isolation
same position so that air does not become
valves). All air and debris must be removed trapped in the system.
from the system before operation or pump
Field-supplied
Flow Center full-port
& Loop
ball valveApplication Manual
for balancing
August, 2010
T
WL
EWT
5
Roth
T
WL
EWT
Section 3: Flushing & Charging
Figure 7: Flush Cart Connections
Figure 8: Flow Center 3-Way Valves
Loop
Loop
Flush Port
Unit
Flush Port
Unit
Unit
Flush Cart Design
The Roth flush cart has been designed to
effectively and efficiently flush the earth
loop and to facilitate injecting and mixing
of the antifreeze. The single most important
element in flow center reliability is the ability
to remove all the air and debris from the
loop and to provide the proper working
pressure.
Unit
2. Connect water supply to hose
connection on return line of flush cart.
3. Turn both 3-way valves on flow center to
flush ports and loop position.
4. Turn on water supply (make sure water is
of proper quality).
5. As the reservoir fills up, turn the pump on
and off, sucking the water level down.
Do not allow the water level to drop
below intake fitting to the pump.
6. Once the water level remains above the
water outlet in the reservoir leave the
pump running continuously.
7. Once the water level stays above the “T”
in the reservoir, turn off the water supply
(this also allows observation of
air bubbles).
8. Run the pump for a minimum of 2 hours for
proper flushing and purging (depending
on system size it may take longer).
9. “Dead head” the pump every so often
and watch the water level in the reservoir.
Once all the air is removed there should
not be more than a 1” to 2” drop in water
level in the reservoir. If there is more than
a 2” drop, air is still trapped in the system.
This is the only way to tell if air is still
trapped in the system.
Features of the flush cart:
•Cylinder: HDPE, SDR15.5, 10” dia. (10 Gallons)
•Pump: Myers High Head QP15, 1.5hp, 115V
•Hose connections:
Cam Lock quick connects - 1-1/2” hoses
•Hand Truck: 600lb rating with pneumatic tires
•Wiring: Liquid Tight metal on/off switch
•Tubing: SDR11 HDPE
•Connections:
2 - 3/4” connections for antifreeze
and discharge
•Drain: one on the pump and the tank
Step 1: Flushing the Earth Loop
1. Connect flush cart hoses to flow
center flush ports using proper
adapters #AGAFP.
Roth
Loop
Flush Port
Flush Port
Loop
6
Flow Center & Loop Application Manual
August, 2010
Section 3: Flushing & Charging
Figure 10: Flush Cart Pump Curve
Figure 9: Roth Flush Cart
Meyers QP-15
1-1/2 HP Self-Priming
Centrifugal Pump
120
110
Total Head in Feet
100
90
25’
80
70
20’
60
15’
50
40
30
20
10
0
SUCTION LIFT
10
20
30
40
50
60
CAPACITY - U.S. GPM
70
80
90
on to keep the water level in the reservoir
above the return tee.
4. This should only take 5 to 10 minutes to
purge the unit.
5. Once this is done, the entire system
is now full of water, and the flush cart
pump may be turned off.
Step 3: Adding Antifreeze by Displacement
10. To dead head the pump, shut off the
return side ball valve on the flush cart.
This will provide a surge in pressure to
the system piping, helping to get the air
bubbles moving. Do not reverse flow
during flushing.
1. If the antifreeze was not added when the
loop was being filled, it will be necessary
to follow the next few steps.
2. Turn both 3-way “Ts” back to the original
position for flushing the loop only.
3. Close the return side ball valve on the
flush cart.
4. Connect hose to the return side
discharge line and run it to a drain.
Open the ball valve on discharge line on
flush cart.
5. Turn pump on until water level is sucked
down just above the water outlet in the
reservoir, and turn pump off. Be sure not
to suck air back into the system.
6. Fill the reservoir back up with
the antifreeze.
7. Repeat steps 5 and 6 until all the
antifreeze is in the system and reservoir.
8. Turn the discharge line ball valve off at
the flush cart. Turn the return line ball
valve back to the on position.
Water Quality: Even on a closed loop
system water quality is an issue. The system
needs to be filled with clean water. If the
water on site has high iron content, high
hardness, or the PH is out of balance,
premature pump failure may result.
Depending upon water quality, it may
need to be brought in from off site.
Step 2: Flushing the Unit
1. Turn off the pump on the flush cart.
2. Turn both 3-way valves to the unit and
flush port position.
3. Turn the pump back on. It may be
necessary to turn the water supply back
Flow Center & Loop Application Manual
August, 2010
7
Roth
Section 3: Flushing & Charging
9. It may be necessary to add some water
into the reservoir to keep the water level
above the return tee so that the solution
does not foam.
10. The system must be run for 3 to 4 hours
to mix the antifreeze and water in the
reservoir. The fluid will not mix inside
the loop.
11. Check the antifreeze level every
so often to insure that the proper
amount was added to the system (see
antifreeze charging section).
8. Connect the water supply back to the
discharge line hose connection, and
open the ball valve. Turn on the water
supply and leave it on for 20 to 30
minutes. This will stretch the pipe properly
to insure that the system will not have a
“flat” loop during cooling operation.
9. Once the loop is pressured
(recommended pressure on initial start
up is 50 to 70 psi), turn the water supply
off. Turn off the discharge line ball
valve, and disconnect the water supply.
Maximum pressure should never exceed
Step 4: Final Pressurization of System
100 psi under any circumstance!
10. Turn the 3-way valves on the flow center
1. Once all of the air and debris has been
back to the normal operation mode,
removed, and the antifreeze has been
which closes the flush port connections.
added and mixed, the system is ready for 11. Open the ball valves on the flush cart to
final pressurization.
relieve pressure on the hoses. Disconnect
2. Turn one of the 3-way valves so that it is
the hoses from the flow center.
open to all 3 ports, the unit, loop, and
Note: Pressurized flow centers and Grundfos
flush port. Turn the other valve so it is
UP series pumps need a minimum of 3psi on
only open to the loop and flush port
(pressure is also applied to the hose kit in the suction side of the pump to operate.
Maximum operating pressure is 100 psi.
this arrangement).
3. Turn the flush cart pump on and allow the
system to start circulating.
Loop static pressure will fluctuate with the
seasons. Pressures will be higher in the
4. With the pump running, turn the return
line ball valve to the off position on the
winter months than during the summer
months. In the cooling mode the heat
flush cart, “dead heading” the pump.
5. There should be a maximum of 1” to 2”
pump is rejecting heat, which relaxes
inches of drop in the water level in the
the pipe. This fluctuation is normal and
reservoir. This only takes about
needs to be considered when charging
and pressuring the system initially. Typical
3-5 seconds.
6. Next, turn the supply line ball valve to the operating pressures of an earth loop are 15
off position on the flush cart (isolates the
to 50 psi.
flow center from the flush cart).
7. Now that the system is isolated from the
reservoir the pump can be turned off.
Do not open the main flush cart ball
valves yet.
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8
Flow Center & Loop Application Manual
August, 2010
Section 4: Flow Center Installation - Non-Pressurized
options (see interior piping), including PVC.
The flow center can be mounted to the wall
with the included bracket or mounted on
the floor as long as it is properly supported.
Note - Burping pump(s): On flow center
initial start up, the pumps must be bled of
air. Start the system and remove the bleed
screw from the back side of the pump(s).
This allows any trapped air to bleed out. It
also floods the pump shaft, and keeps the
pump(s) cool. Failure to do this could result
in premature pump failure.
Flushing the Interior Piping (Non-Pressurized)
Do not use the flush cart to purge the
interior piping and flow center in a nonpressurized system. Once the loop has
been flushed the ball valves may be
opened above the flush ports. Take a
garden hose from the flush port connected
to the water out to the loop pipe, and
run the other end of the hose into the
top of the canister (see figure 12). Fill the
canister with water and turn the pumps on.
Continue to fill the canister until the water
level stays above the dip tube. Once filling
is complete, remove the hose and close
the flush port. Turn the system on. Any air
that may still be in the system will burp itself
out of the top of the canister. Leave the
top open for the first 1/2 hour of run time to
ensure that all of the air is bled out. Tighten
the cap on the flow center to complete the
flushing and filling procedure (hand tighten
only -- do not use a wrench). See figures 12
and 13 for interior and exterior flushing.
General installation guidelines
Standing column flow centers are designed
to operate with no static pressure on
the earth loop. The design is such that
the column of water in the flow center
is enough pressure to prime the pumps
for proper system operation and pump
reliability. The flow center does have a
cap/seal, so it is still a closed system, where
the fluid will not evaporate. If the earth
loop header is external, the loop system will
still need to be flushed with a purge cart as
described above (Step 1 and 3). The nonpressurized flow center needs to be isolated
from the flush cart during flushing because
the flow center is not designed to handle
pressure. Since this is a non-pressurized
system, the interior piping can incorporate
all the above-mentioned pipe material
Figure 11: Typical Non-Pressurized Installation
Flow Center & Loop Application Manual
August, 2010
9
Roth
Section 4: Flow Center Installation Non-Pressurized
Figure 12: Flushing Inside Piping
Connect to
Heat Pump
To/From
Loop Field
Figure 13: Flushing Outside Piping
Connect to
Heat Pump
To/From
Loop Field
Flush Cart
and Pump
Roth
10
Flow Center & Loop Application Manual
August, 2010
Section 5: Geothermal Closed Loop Design
Closed Loop Basics
the pipe lengths. Since the fusion process
has become available, parallel flow using
smaller pipe diameters for loops 2 tons
and larger have become standard for a
number of reasons:
Closed loop earth coupled systems are
commonly installed in one of three different
configurations: horizontal, vertical, and
pond/lake loop. Each configuration
provides the benefit of using the earth’s
moderate temperatures as a heat source/
sink. All closed loop systems must be
designed to maintain entering water
temperatures above 25°F in heating, and
below 110°F in cooling. Temperatures
outside this range will cause the heat pump
to function improperly and lockout.
Cost of the pipe: The larger diameter the
pipe, the higher the cost. The benefit of
larger pipe only increases performance
by 10-20%.
Pumping power: Parallel systems generally
have much lower pressure drop, which
results in smaller pumping stations for
reduced pump energy.
Select the installation configuration
which provides the most cost effective
method of installation after considering
all application constraints. Determining
the style of loop primarily depends on lot
size and soil conditions. Loop design takes
into account two basic factors. The first is
accurately engineering a system to function
properly with low pumping requirements
and adequate heat transfer to handle the
load of the structure/system. The second
is to design a loop with the lowest installed
cost while still maintaining a high level of
quality. In the end, the consumer will have
paid approximately the same amount of
money for heating, cooling, and hot water
no matter which loop configuration was
installed. This leaves the installed cost of the
loop as the main factor for determining the
system payback. Therefore, proper design
includes the most economical system
possible given the installation requirements.
Parallel vs. Series Configurations
Initially, loops were designed using series
style flow paths due to the lack of fusion
fittings and procedures to insure there
there were no leaks. This resulted in large
pipe diameters being used (1-1/4” to 2”)
to reduce pumping requirements due to
the increase of pressure drop because of
Flow Center & Loop Application Manual
August, 2010
Installation ease: Larger diameter pipes
are harder to work with, especially during
cold weather conditions.
Antifreeze: Because parallel systems utilize
smaller size pipe, the volume of the systems
are smaller, requiring less antifreeze
Unlimited capacity: Series systems are
limited due to pressure drop reasons,
whereas parallel systems are unlimited
in capacity.
Parallel System Requirements
Design: Special care in the design is
required to ensure that all of the air and
debris can be removed from the system.
Reducing reverse-return header: Required
for all parallel systems.
Pressure drop: Loop lengths must remain
within +/- 5% of one another for equal
pressure drop and balanced flow.
Fusion: Special training and equipment is
required to provide fusion fittings.
Purging: Large pump flush cart is needed
to get all of the air and debris out of
the system.
11
Roth
Section 5: Geothermal Closed Loop Design
Loop Circuiting
Loops should be designed with a
compromise between pressure drop and
good turbulence in the heat exchange
pipe for heat transfer. Therefore the
following rules should be observed when
designing a loop:
1. Use 3 gpm per 3/4” loop flow rate to
reach turbulent flow.
2. Use 3 gpm per ton of nominal
equipment installed.
3. Maintain one loop/circuit per ton of
nominal capacity with 3/4” pipe and onehalf loop/circuit per ton with 1-1/4” pipe.
This rule can be deviated by one circuit or
so for different loop configurations.
4. Maximum loop length for 3/4” PE is 800 ft.
due to pressure drop.
Header Design
Headers for parallel loops should be
designed with two factors in mind. The
first is pressure drop, and the second is the
ability to flush the loop. Figure 15 shows the
typical layout for a close header (no more
than 5’ between tees) for up to 12 tons and
2” header main line. Notice the reduction
in pipe size as circuits drop off. This design
is used to keep the pressure drop down,
yet maintain 2 fps for flushing. The other
critical design in the header is the reverse
return connections. This ensures that there
is equal pressure drop through each 3/4”
circuit, which eliminates the need for
balancing valves. This system will be autobalancing (if all circuits are within +/- 5% in
length from one another). Figure 16 shows
the reverse return layout of the supply/
return header manifold.
Figure 15: Typical Reducing Header up to 12 Tons
2” x 2” x 3/4” T
2” x 1-1/4” x 3/4” T
1-1/4” x 3/4” x 3/4” T
3/4” x 3/4” x 3/4” T
3/4” x 3/4” x 3/4” T
Circuit 1
Circuit 4
Circuits 9 - 12
Circuit 3
Circuit 2
Return Line
Circuit 8
Circuits 5 - 7
(1-1/4” x 1-1/4” x 3/4” T’s)
Figure 16: Reverse-Return Header
Supply Line
2 foot wide trench
1-1/4” x 3/4” x 3/4” T
3/4” x 3/4” x 3/4” T
3/4” elbow
3/4” elbow
3/4” x 3/4” x 3/4” T
1-1/4” x 3/4” x 3/4” T
1-1/4” elbow
1-1/4” elbow
Circuit 3
Roth
Circuit 2
Circuit 1
Circuit 3
12
Circuit 2
Circuit 1
Flow Center & Loop Application Manual
August, 2010
Section 5: Geothermal Closed Loop Design
Closed Loop Heat Exchanger Design Rules
• Loop design is based upon various
conditions specific to each job site.
Design software based on IGSHPA
standards such as GeoAnalyst is
the best way to size loops. Factors
include building load heat gain/loss
calculations, equipment capacity,
equipment efficiency, soil conditions,
required loop temperature operating
design, pipe size, antifreeze selection,
weather conditions and lifestyle.
• Know your soil type. Check the site
before you decide. Many sources
can be found locally for information
regarding the site location conditions.
Example: builders, water well drillers, soil
conservation district offices, geological
maps on the internet.
• One flow path (circuit) per ton (12,000
BTU’S) of equipment (round up or down
1 circuit for ½ ton sized units…e.g. 3.5
ton unit uses either 3 or 4 circuits). GPM
flow rates should be 2.25 GPM minimum
to 3 GPM per circuit for good turbulence
and heat exchange to the earth.
• Parallel vs. series configurations? Jobs
2 ton or larger should use parallel water
flow circuits to keep GPM flow rates
high and pumping HP requirements low.
Series loops are limited to small tonnage
unit sizes (2 total tons or less).
• Divide total trench or bore length as
shown in GeoAnalyst software by total
tons of equipment being applied to the
loop. Example: 4 ton packaged unit
trench length = 616 feet or 4 trenches,
154 feet long each.
• Trench/bore hole area should be
located 15 feet minimum from the
building. If the trench is longer than
300 feet, be sure to calculate the total
piping pressure drop for proper pump/
pipe sizing.
Flow Center & Loop Application Manual
August, 2010
• Trench/bore spacing should be kept to
a 10 foot minimum distance between
each trench/bore hole area.
• Horizontal trenches need not be deeper
than 4-5 feet for most locations, but
should be approximately 1-2 feet
deeper than the lowest expected frost
line conditions. This will place the pipe in
a stable temperature zone.
• Horizontal loop circuits installed in
trenches should have enough space
at the end of the trench to safely
turn around and return towards the
beginning of the trench without kinks
in the tubing or using elbows to reduce
the number of fusion joints in the circuit.
Good designers try to purchase coil pipe
that can go “down and back” without
the use of fittings in the trench, except
for the final connections to the manifold
header.
• Horizontal trenches/vertical bore holes
should be tapered together at one end
of loop field or the center of a bore field
to utilize a small header pit for parallel
circuits.
• Supply/return manifolds should utilize
reverse return design for equal water
flow rates on each flow path or circuit.
Try to achieve 10 foot trench spacing
as soon as practical as you leave the
header pit area and begin the circuit
trenches or bore holes.
• Good manifold header design should
keep header tee spacing close
together, less than 2 feet between each
tee outlet, for easy air removal from
piping system.
• Typical header pit excavated area is
approximately 4.5 feet long x 4 feet
wide x 4.5 – 5 feet deep.
13
Roth
Section 5: Geothermal Closed Loop Design
• Never place supply and return piping
• Supply/return piping will typically be 1.25”
next to the building foundation; always
diameter PE from the header manifold
maintain 15 feet minimum spacing away
(outdoors) to the flow center (loop pump)
from any foundation to prevent frost
located in the building near the unit. All
damage to the building.
piping penetrating the building foundation
should be protected in conduit.
• Supply/return line trenching from header
pit to building should taper uphill toward
building, but maintain approximately
4 feet below finish grade at wall
penetration. Typical trench width is 1824” wide. Lay supply and return piping
in each corner at bottom of trench. This
will reduce the chance of ground water
following piping into the building.
• All piping inside the building should be
properly insulated with pipe insulation to
prevent condensation damage to the
building.
• Loop fluid should be antifreeze
protected to 15°F with an approved fluid
type, typically Methanol, Ethanol or
Propylene Glycol. Test with the proper
hydrometer.
• All piping should be fluid pressure tested
hydrostatically with approximately 100
psi for 10 minutes to assure leak free
fusion joints and connections before
back-filling the trench.
• All vertical bore holes should be
pressure grouted with an approved
bentonite grout material utilizing 20%
solids minimum for proper sealing and
heat transfer. This must be done from the
bottom up, not just a cap at the top.
• Do not use sand or gravel to backfill
loop pipe trenches/bores, as it will dry
out and impede good heat transfer
between the fluid in the pipe and the
earth. Normally the same soil should be
placed back into the trench. Common
sense should be used regarding large
rocks or sharp stones that could crush or
cut the piping. Do not place rocks near
the piping. Cover the loop piping with
2-3 feet of good soil first.
• It’s a good idea to include a foil tracer
tape or copper wire in supply/return
trenching, placing tracer approximately
2 feet above piping between header pit
and building wall penetration area for
easy locating of the supply/return and
manifold area.
Roth
• All piping and connections should be
composed of an approved geothermal
polyethylene PE3408 type pipe, utilizing
socket fusion or butt fusion and installed
by a qualified fusion technician.
Notes:
Safety First!
We strongly suggest that contractors
attend either a factory training school or
IGSHPA training school for Loop Design and
Installation before attempting loop design
and installations.
Always check BEFORE YOU DIG! Contact
your local underground utility locator
service and verify any utility that might be
located nearby.
Stay away from electrical power, septic
systems and well water lines.
Check with your local building/health
department regarding permits, codes and
laws that may apply to your location or
state/province regarding geothermal loop
systems.
14
Flow Center & Loop Application Manual
August, 2010
Section 5: Geothermal Closed Loop Design
Contact your distributor for additional
information on training locations and dates.
Good loop design and proper installation
are necessary for any system to operate
properly.
We offer and support several design
schools and tools to take the guesswork
out of residential loop system design. Ask
your local distributor about our GeoAnalyst
software tool that will provide you with
the science behind the design and the
confidence you need to actively design,
install and service geothermal equipment
and loop systems.
“Like anything else… It’s not that hard
when you have the proper training and the
tools.”
Flow Center & Loop Application Manual
August, 2010
15
Roth
Section 5: Geothermal Closed Loop Design
Soil Moisture Properties
CLAY
Cross View (DRY)
An important factor affecting heat transfer
between the earth and the loop is moisture
migration. When heat is extracted from
the earth, soil moisture migrates toward
the earth loop, improving heat transfer
between the loop and the surrounding soil.
In the cooling mode, heat rejection to the
soil can drive away moisture, degrading
heat transfer. In heating dominated
climates, this later negative effect has not
been observed in practice. However, in
cooling dominated climates, this special
condition must be considered in regard to
loop lengths due to longer run times in the
cooling mode.
Microscopic View
Cross View (WET)
H2O
H2O
H2O
H2 O
H 2O
Consistency: “Hershey Bar”
SAND
Another important factor affecting heat
transfer between the earth and the loop
is soil moisture freezing. Freezing allows the
extraction of energy from the soil without
the normal drop in soil temperature in the
vicinity of the pipe. The net effect is that
the antifreeze solution returning to the
heat pump from the earth loop returns at a
higher temperature than if freezing had not
occurred.
Visible to Eye
SILT
Earth loops are sized after the house
design heating and cooling loads have
been calculated, and the heat pump size
has been selected. All heat pumps are
designed with high and low limits on the
energy source liquid which are acceptable.
Microscopic View
Microscopic View
Moisture Content for All Soils:
DRY = No Water
MOIST = Damp Feel
WET = Visible Water
Definition of Sizes:
SAND = Visible to Eye - 1/4”
COBBLE = 3” - 12”
Roth
GRAVEL = 1/4” - 3”
BOULDER = 12” and up
16
Flow Center & Loop Application Manual
August, 2010
Section 6: Antifreeze Selection & Charging
Antifreeze Overview
In areas where minimum entering loop
temperatures drop below 40°F, or where
piping will be routed through areas
subject to freezing, antifreeze is required.
Alcohols and glycols are commonly used
as antifreeze. However, local and state/
provincial codes supercede any instructions
in this document. The system needs
antifreeze to protect the coaxial heat
exchanger from freezing and rupturing.
Freeze protection should be maintained to
15°F below the lowest expected entering
loop temperature. For example, if 30°F
is the minimum expected entering loop
temperature, the leaving loop temperature
could be 22 to 25°F. Freeze protection
should be set at 15°F (30-15 = 15°F). To
determine antifreeze requirements,
calculate how much volume the system
holds. Then, calculate how much
antifreeze will be needed by determining
the percentage of antifreeze required for
proper freeze protection. See tables 3 and
4 for volumes and percentages. The freeze
protection should be checked during
installation using the proper hydrometer
to measure the specific gravity and freeze
protection level of the solution.
Antifreeze Characteristics
Selection of the antifreeze solution
for closed loop systems require the
consideration of many important factors,
which have long-term implications on the
performance and life of the equipment.
Each area of concern leads to a different
“best choice” of antifreeze. There is no
“perfect” antifreeze. Some of the factors
to consider are as follows (Brine = antifreeze
solution including water):
Safety: The toxicity and flammability of the
brine (especially in a pure form).
Cost: Prices vary widely.
Flow Center & Loop Application Manual
August, 2010
Thermal Performance: The heat transfer
and viscosity effect of the brine.
Corrosiveness: The brine must be
compatible with the system materials.
Stability: Will the brine require periodic
change out or maintenance?
Convenience: Is the antifreeze available
and easy to transport and install?
Codes: Will the brine meet local and state/
provincial codes?
The following are some general
observations about the types of brines
presently being used:
Methanol: Wood grain alcohol that is
considered toxic in pure form. It has good
heat transfer, low viscosity, is non-corrosive,
and is mid to low price. The biggest down
side is that it is flammable in concentrations
greater than 25%.
Ethanol: Grain alcohol, which by the ATF
(Alcohol, Tobaco, Firearms) department
of the U.S. government, is required to be
denatured and rendered unfit to drink.
It has good heat transfer, mid to high
price, is non-corrosive, non-toxic even in
its pure form, and has medium viscosity.
It also is flammable with concentrations
greater than 25%. Note that the brand
of ethanol is very important. Make sure it
has been formulated for the geothermal
industry. Some of the denaturants are not
compatible with HDPE pipe (for example,
solutions denatured with gasoline).
Propylene Glycol: Non-toxic, non-corrosive,
mid to high price, poor heat transfer, high
viscosity when cold, and can introduce
micro air bubbles when adding to the
system. It has also been known to form a
“slime-type” coating inside the pipe. Food
grade glycol is recommended because
some of the other types have certain
inhibitors that react poorly with geothermal
17
Roth
Section 6: Antifreeze Selection & Charging
systems. A 25% brine solution is a minimum
required by glycol manufacturers, so that
bacteria does not start to form.
Ethylene Glycol: Considered toxic and is
not recommended for use in earth
loop applications.
GS4 (Potassium acetate): Considered
highly corrosive (especially if air is present
in the system) and has a very low surface
tension, which causes leaks through
most mechanical fittings. This brine is
not recommended for use in earth loop
applications.
Caution: Use extreme care when opening,
pouring, and mixing flammable antifreeze
solutions. Remote flames or electrical sparks
can ignite undiluted antifreezes and vapors.
Use only in a well ventilated area. Do not
smoke when handling flammable solutions.
Failure to observe safety precautions may
result in fire, injury, or death. Never work
with 100% alcohol solutions.
Antifreeze Charging
Calculate the total amount of pipe in
the system and use table 3 to calculate
the amount of volume for each specific
section of the system. Add the entire
Notes:
volume together, and multiply that volume
1. Consult with your representative or
by the proper antifreeze percentage
distributor if you have any questions
needed (table 4) for the freeze protection
regarding antifreeze selection or use.
2. All antifreeze suppliers and manufacturers required in your area. Then, double check
calculations during installation with the
recommend the use of either de-ionized
proper hydrometer and specific gravity
or distilled water with their products.
chart (figure 14) to determine if the correct
amount of antifreeze was added.
Table 3: Antifreeze Percentages by Volume
Minimum Temperature for Freeze Protection
Type of Antifreeze 10F (-12.2C) 15F (-9.4C) 20F (-6.7C) 25F (-3.9C)
Procool (Ethanol)
25%
22%
17%
12%
Methanol
25%
21%
16%
10%
Propylene Glycol
38%
30%
22%
15%
All antifreeze solutions are shown in pure form – not premixed.
Roth
18
Flow Center & Loop Application Manual
August, 2010
Section 6: Antifreeze Selection & Charging
Table 4: Pipe Fluid Volume
Volume/100 ft.
U.S. Gal.
Type
Size
Copper
1" CTS
4.1
Copper
1.25" CTS
6.4
Copper
1.5" CTS
9.2
HDPE
.75 SDR11
3.0
HDPE
1" SDR11
4.7
HDPE
1.25" SDR11
7.5
HDPE
1.5" SDR11
9.8
HDPE
2" SDR11
15.4
Additional component volumes:
Unit coaxial heat exchanger = 1 Gallon
Flush Cart = 8-10 Gallons
10’ of 1” Rubber Hose = 0.4 Gallons
NOTE: Most manufacturers of
antifreeze solutions recommend
the use of de-ionized water. Tap
water may include chemicals
that could react with the antifreeze solution.
Figure 14: Antifreeze Specific Gravity
1.0500
1.0400
1.0300
Specific Gravity
1.0200
1.0100
1.0000
0.9900
0.9800
0.9700
0.9600
-5
0
5
10
15
20
25
30
32
Freeze Protection (deg F)
Procool
Methanol
Flow Center & Loop Application Manual
August, 2010
19
Propylene Glycol
Roth
Section 7: HDPE Pipe
High Density Polyethylene Pipe (HDPE)
All earth loop piping materials should
be limited to only polyethylene pipe
underground. Copper, brass, galvanized,
or steel pipe or fittings should not be used.
For fusion applications, the HDPE pipe must
meet IGSHPA (International Ground Source
Heat Pump Association) cell classification
requirements (see below). The water well
industry uses similar black HDPE 160 psi rated
pipe. However, this pipe does not allow for
fusion joints. Below are the specifications for
the proper geothermal HDPE pipe:
1. All pipe and heat fused materials shall
be made from high density, extra-high
molecular weight PE 3408 resin.
2. The cell classification shall be 345444C as
specified in ASTM D-3350.
3. Extruded pipe shall conform to the
requirements of ASTM D-3035.
4. Socket fittings shall conform to the
requirements of ASTM D-2683 and rated
for pressure equivalent to SDR-11 pipe.
5. Wall thickness of pipe shall be in
tolerance of the specifications of 160 psi
and SDR-11 for heat fused pipe & fittings.
Pipe Fusion Methods
The three basic types of pipe joining
methods that are used for earth coupled
applications are socket, butt, and side
saddle fusion. In all processes the pipe
is melted together with the fitting to
form a joint that is even stronger than
the original pipe. Although when any of
the procedures are performed properly
the joint is stronger than the pipe wall,
the preferred method for 2” and smaller
diameter pipe is socket fusion because of
the following:
Roth
1. Allowable tolerance of mating the pipe
is much greater. According to general
fusion guidelines, a 3/4” SDR11 butt fusion
joint alignment can be off by no more
than 10% of the wall thickness (0.01 in.).
A hundredth of an inch accuracy while
fusing in a difficult position can be almost
impossible to attain in the field.
2. The socket fusion joint is 3 to 4 times the
cross sectional area of a butt fusion joint
in sizes under 2”, and therefore tends to
be more forgiving of operator skill level.
3. Joints are frequently required in difficult
trench conditions. The smaller the socket
fusion iron is, the more mobile the operator
will be, which will provide less incentive to
cut corners during the fusion procedure.
Once the pipe diameter gets over 2”,
socket fusion loses its advantages, and
butt fusion is typically the method of
choice. Butt fusion requires a different
fusion machine, which is larger and less
maneuverable. All technicians doing
fusion joints should be certified by the pipe
manufacturer as well as IGSHPA. Please see
the pipe manufacturers and IGSHPA tables
and specifications for all fusion procedures.
Note: Earth loop systems require a
hydrostatic test of 40-50 psi before
backfilling to test for leaks. Do not use an
air test for leaks on an earth loop system.
20
Flow Center & Loop Application Manual
August, 2010
Section 8: Flow Center Selection
Pressure drop calculations
When designing the earth loop and
selecting the proper flow center, a pressure
drop calculation must be done to calculate
how much pumping power is needed for
proper flow through the heat pump and
loops. In general, if basic loop design
rules are followed, systems of 3 tons or less
would require a one pump flow center, and
system from 3.5 to 6 tons would require a
two pump flow center. As a precautionary
measure a loop pressure drop calculation
should be performed for accurate flow
estimation. The pressure drop must include
the following components:
Once the pressure drop of the system has
been calculated at design flow rate, review
the flow center pump curve to select a
flow center that matches design criteria.
There are many options with flow centers
from one pump, two pump, three pump,
four pump, and size pumps from UP26-99F
to UP26-116F. The following pages include
pressure drop tables for the pipe and the
flow center pump curves.
Note: Roth has software available to assist
in calculating the pressure drop of an
earth coupled system along with flushing
requirements.
1. Heat pump at design flow rate
2. Hose kit (maximum 10’)
3. Supply and Return header piping
4. Circuit piping (only one if piped in parallel)
5. Antifreeze
Figure 17: Grundfos Pump Curves
100
Legend
3 - UP26-99
2 - UP26-116
2 - UP26-99
1 - UP26-116
1 - UP26-99
90
80
Ft. of Head
70
60
50
40
30
20
10
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Flow Rate (U.S. GPM)
Flow Center & Loop Application Manual
August, 2010
21
Roth
Section 8: Flow Center Selection
Table 5: Procool (Ethanol)
Antifreeze (30°F EWT): 22% by Volume Solution of Procool - freeze
Flow Rate
3/4" SDR11
1" SDR11
US GPM
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
1
0.37
0.55
1029
0.13
0.35
2
1.25
1.10
2058
0.43
0.70
3
2.54
1.66
3105
0.87
1.06
4
4.20
2.21
4134
1.44
1.41
5
6.21
2.76
5163
2.13
1.76
6
8.55
3.31
6191
2.94
2.11
7
11.19
3.87
7239
3.84
2.47
8
14.13
4.42
8268
4.85
2.82
9
17.37
4.97
9296
5.97
3.17
10
20.89
5.52
10325
7.17
3.52
11
24.67
6.08
11373
8.48
3.87
12
28.74
6.63
12401
9.87
4.23
13
11.35
4.58
14
12.93
4.93
15
14.59
5.28
16
16.32
5.64
17
18.15
5.99
18
20.07
6.34
19
22.06
6.69
20
24.13
7.04
21
26.28
7.40
22
28.51
7.75
23
30.81
8.10
24
25
26
28
30
32
34
36
38
40
42
44
46
48
50
protected to 15°F
RE
820
1640
2483
3303
4123
4943
5786
6606
7426
8245
9065
9909
10728
11548
12368
13211
14031
14851
15671
16491
17334
18154
18974
PD (ft)
0.04
0.13
0.27
0.44
0.66
0.90
1.18
1.49
1.84
2.21
2.61
3.04
3.50
3.98
4.49
5.03
5.59
6.18
6.79
7.43
8.10
8.78
9.49
10.22
10.98
11.76
13.39
15.11
16.92
18.81
20.79
22.85
25.00
27.23
29.54
1-1/4" SCH40
Vel (ft/s)
0.21
0.43
0.64
0.86
1.07
1.29
1.50
1.72
1.93
2.15
2.36
2.57
2.79
3.00
3.22
3.43
3.65
3.86
4.08
4.29
4.50
4.72
4.93
5.15
5.36
5.58
6.01
6.44
6.86
7.29
7.72
8.15
8.58
9.01
9.44
RE
630
1291
1921
2581
3212
3872
4502
5163
5793
6453
7084
7714
8374
9004
9665
10295
10955
11586
12246
12876
13507
14167
14797
15458
16088
16748
18039
19330
20590
21881
23171
24462
25753
27043
28334
PD (ft)
0.02
0.06
0.13
0.21
0.32
0.43
0.57
0.72
0.88
1.06
1.26
1.46
1.68
1.91
2.16
2.42
2.69
2.97
3.27
3.57
3.89
4.22
4.57
4.92
5.28
5.66
6.44
7.27
8.14
9.04
10.00
10.99
12.02
13.09
14.20
15.35
16.54
17.76
1-1/2" SCH40
Vel (ft/s)
0.16
0.32
0.47
0.63
0.79
0.95
1.10
1.26
1.42
1.58
1.73
1.89
2.05
2.21
2.36
2.52
2.68
2.84
2.99
3.15
3.31
3.47
3.62
3.78
3.94
4.10
4.41
4.73
5.04
5.36
5.67
5.99
6.30
6.62
6.93
7.25
7.57
7.88
RE
560
1121
1646
2206
2766
3327
3852
4412
4972
5533
6058
6618
7179
7739
8264
8824
9385
9945
10470
11030
11591
12151
12676
13237
13797
14357
15443
16563
17649
18769
19855
20975
22061
23181
24267
25388
26508
27594
PD (ft)
0.01
0.02
0.04
0.07
0.10
0.13
0.17
0.22
0.27
0.32
0.38
0.45
0.51
0.58
0.66
0.74
0.82
0.91
1.00
1.09
1.19
1.29
1.39
1.50
1.61
1.73
1.96
2.22
2.48
2.76
3.05
3.35
3.67
3.99
4.33
4.68
5.05
5.42
2" SCH40
Vel (ft/s)
0.10
0.19
0.29
0.38
0.48
0.57
0.67
0.76
0.86
0.96
1.05
1.15
1.24
1.34
1.43
1.53
1.63
1.72
1.82
1.91
2.01
2.10
2.20
2.29
2.39
2.49
2.68
2.87
3.06
3.25
3.44
3.63
3.82
4.02
4.21
4.40
4.59
4.78
RE
450
854
1304
1708
2158
2563
3012
3417
3866
4316
4720
5170
5575
6024
6429
6878
7328
7733
8182
8587
9036
9441
9891
10295
10745
11194
12048
12903
13757
14611
15465
16319
17174
18073
18927
19781
20635
21489
RE
687
1406
2093
2812
3499
4218
4905
5624
6311
7030
7717
8404
9123
9810
10529
11216
11935
12622
13341
14028
14715
15434
16121
16840
17527
18246
19652
21058
22432
23838
25244
26650
28056
29462
30868
PD (ft)
0.02
0.06
0.13
0.21
0.31
0.42
0.56
0.70
0.86
1.04
1.23
1.43
1.65
1.87
2.12
2.37
2.63
2.91
3.20
3.50
3.81
4.13
4.47
4.81
5.17
5.54
6.30
7.11
7.96
8.85
9.79
10.76
11.77
12.81
13.90
15.03
16.19
17.39
1-1/2" SCH40
Vel (ft/s)
0.16
0.32
0.47
0.63
0.79
0.95
1.10
1.26
1.42
1.58
1.73
1.89
2.05
2.21
2.36
2.52
2.68
2.84
2.99
3.15
3.31
3.47
3.62
3.78
3.94
4.10
4.41
4.73
5.04
5.36
5.67
5.99
6.30
6.62
6.93
7.25
7.57
7.88
RE
610
1221
1793
2403
3014
3624
4196
4807
5417
6028
6600
7210
7821
8431
9003
9614
10224
10834
11407
12017
12627
13238
13810
14420
15031
15641
16824
18044
19227
20448
21630
22851
24034
25255
26437
27658
28879
30061
PD (ft)
0.01
0.02
0.04
0.06
0.09
0.13
0.17
0.22
0.26
0.32
0.38
0.44
0.50
0.57
0.65
0.72
0.80
0.89
0.98
1.07
1.16
1.26
1.36
1.47
1.58
1.69
1.92
2.17
2.43
2.70
2.99
3.28
3.59
3.91
4.24
4.59
4.94
5.31
2" SCH40
Vel (ft/s)
0.10
0.19
0.29
0.38
0.48
0.57
0.67
0.76
0.86
0.96
1.05
1.15
1.24
1.34
1.43
1.53
1.63
1.72
1.82
1.91
2.01
2.10
2.20
2.29
2.39
2.49
2.68
2.87
3.06
3.25
3.44
3.63
3.82
4.02
4.21
4.40
4.59
4.78
RE
490
931
1420
1861
2351
2792
3281
3722
4212
4702
5143
5632
6073
6563
7004
7494
7983
8424
8914
9355
9844
10285
10775
11216
11706
12195
13126
14057
14987
15918
16848
17779
18709
19689
20620
21550
22481
23411
Table 6: Methanol
Antifreeze (30°F EWT): 21% by Volume Solution of Methanol - freeze protected to 15°F
3/4" SDR11
1" SDR11
1-1/4" SCH40
Flow Rate
US GPM
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
1
0.36
0.55
1121
0.13
0.35
893
0.04
0.21
2
1.22
1.10
2242
0.42
0.70
1786
0.13
0.43
3
2.49
1.66
3383
0.85
1.06
2705
0.26
0.64
4
4.11
2.21
4503
1.41
1.41
3598
0.43
0.86
5
6.08
2.76
5624
2.09
1.76
4491
0.64
1.07
6
8.37
3.31
6745
2.87
2.11
5385
0.88
1.29
7
10.95
3.87
7886
3.76
2.47
6303
1.16
1.50
8
13.83
4.42
9007
4.75
2.82
7197
1.46
1.72
9
17.00
4.97
10128
5.84
3.17
8090
1.80
1.93
10
20.45
5.52
11248
7.02
3.52
8983
2.16
2.15
11
24.15
6.08
12390
8.30
3.87
9876
2.56
2.36
12
28.13
6.63
13510
9.66
4.23
10795
2.98
2.57
13
11.11
4.58
11688
3.42
2.79
14
12.65
4.93
12581
3.90
3.00
15
14.28
5.28
13474
4.40
3.22
16
15.98
5.64
14393
4.92
3.43
17
17.77
5.99
15286
5.47
3.65
18
19.64
6.34
16179
6.05
3.86
19
21.59
6.69
17073
6.65
4.08
20
23.62
7.04
17966
7.27
4.29
21
25.72
7.40
18884
7.93
4.50
22
27.90
7.75
19778
8.60
4.72
23
30.16
8.10
20671
9.29
4.93
24
10.01
5.15
25
10.75
5.36
26
11.51
5.58
28
13.11
6.01
30
14.79
6.44
32
16.56
6.86
34
18.41
7.29
36
20.35
7.72
38
22.37
8.15
40
24.47
8.58
42
26.65
9.01
44
28.91
9.44
46
48
50
Roth
22
Flow Center & Loop Application Manual
August, 2010
Section 8: Flow Center Selection
Table 7: Propylene Glycol
Antifreeze (30°F EWT): 30% by Volume Solution of Propylene Glycol
Flow Rate
3/4" SDR11
1" SDR11
US GPM
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
1
0.43
0.55
584
0.15
0.35
2
1.44
1.10
1169
0.49
0.70
3
2.92
1.66
1764
1.00
1.06
4
4.84
2.21
2348
1.66
1.41
5
7.15
2.76
2933
2.46
1.76
6
9.84
3.31
3517
3.38
2.11
7
12.89
3.87
4112
4.42
2.47
8
16.28
4.42
4697
5.59
2.82
9
20.01
4.97
5281
6.87
3.17
10
24.06
5.52
5866
8.26
3.52
11
28.42
6.08
6461
9.76
3.87
12
11.37
4.23
13
13.08
4.58
14
14.89
4.93
15
16.80
5.28
16
18.80
5.64
17
20.91
5.99
18
23.11
6.34
19
25.41
6.69
20
27.80
7.04
21
30.27
7.40
22
23
24
25
26
28
30
32
34
36
38
40
42
44
46
48
50
- freeze protected to 15°F
1-1/4" SCH40
RE
PD (ft)
Vel (ft/s)
466
0.05
0.21
932
0.15
0.43
1411
0.31
0.64
1876
0.51
0.86
2342
0.76
1.07
2808
1.04
1.29
3287
1.36
1.50
3753
1.72
1.72
4218
2.12
1.93
4684
2.54
2.15
5150
3.01
2.36
5629
3.50
2.57
6095
4.03
2.79
6560
4.59
3.00
7026
5.17
3.22
7505
5.79
3.43
7971
6.44
3.65
8437
7.12
3.86
8903
7.82
4.08
9368
8.56
4.29
9847
9.33
4.50
10.11
4.72
10.94
4.93
11.78
5.15
12.65
5.36
13.55
5.58
15.42
6.01
17.40
6.44
19.49
6.86
21.67
7.29
23.95
7.72
26.32
8.15
28.80
8.58
RE
358
733
1091
1466
1824
2200
2558
2933
3291
3666
4024
4382
4757
5115
5490
5848
6224
6582
6957
7315
7673
8048
8406
8781
9139
9514
10248
10981
11697
12430
13163
13897
14630
PD (ft)
0.02
0.07
0.15
0.25
0.36
0.50
0.66
0.83
1.02
1.22
1.45
1.68
1.94
2.20
2.49
2.79
3.10
3.42
3.76
4.12
4.48
4.86
5.26
5.66
6.08
6.51
7.42
8.37
9.37
10.42
11.52
12.66
13.85
15.08
16.36
17.68
19.05
20.46
1-1/2" SCH40
Vel (ft/s)
0.16
0.32
0.47
0.63
0.79
0.95
1.10
1.26
1.42
1.58
1.73
1.89
2.05
2.21
2.36
2.52
2.68
2.84
2.99
3.15
3.31
3.47
3.62
3.78
3.94
4.10
4.41
4.73
5.04
5.36
5.67
5.99
6.30
6.62
6.93
7.25
7.57
7.88
PD (ft)
0.01
0.04
0.08
0.13
0.20
0.27
0.36
0.45
0.55
0.66
0.78
0.91
1.05
1.20
1.35
1.51
1.68
1.86
2.04
2.23
2.43
2.64
2.85
3.07
3.30
3.53
4.02
4.54
5.08
5.65
6.24
6.86
7.51
8.18
8.87
9.59
10.33
11.09
1-1/2" SCH40
Vel (ft/s)
RE
0.16
3681
0.32
7363
0.47
10814
0.63
14496
0.79
18177
0.95
21859
1.10
25310
1.26
28992
1.42
32673
1.58
36355
1.73
39806
1.89
43487
2.05
47169
2.21
50850
2.36
54302
2.52
57983
2.68
61665
2.84
65346
2.99
68798
3.15
72479
3.31
76161
3.47
79842
3.62
83293
3.78
86975
3.94
90656
4.10
94338
4.41
101471
4.73
108834
5.04
115967
5.36
123330
5.67
130462
5.99
137825
6.30
144958
6.62
152321
6.93
159454
7.25
166817
7.57
174180
7.88
181313
RE
318
637
935
1253
1572
1890
2188
2506
2825
3143
3441
3760
4078
4396
4695
5013
5331
5650
5948
6266
6585
6903
7201
7519
7838
8156
8773
9409
10026
10663
11279
11916
12532
13169
13786
14422
15059
15676
PD (ft)
0.01
0.02
0.05
0.08
0.11
0.15
0.20
0.25
0.31
0.37
0.44
0.51
0.59
0.67
0.76
0.85
0.94
1.04
1.15
1.26
1.37
1.48
1.60
1.73
1.86
1.99
2.26
2.55
2.86
3.18
3.51
3.86
4.23
4.60
4.99
5.40
5.81
6.24
2" SCH40
Vel (ft/s)
0.10
0.19
0.29
0.38
0.48
0.57
0.67
0.76
0.86
0.96
1.05
1.15
1.24
1.34
1.43
1.53
1.63
1.72
1.82
1.91
2.01
2.10
2.20
2.29
2.39
2.49
2.68
2.87
3.06
3.25
3.44
3.63
3.82
4.02
4.21
4.40
4.59
4.78
RE
255
485
741
970
1226
1456
1711
1941
2196
2452
2682
2937
3167
3422
3652
3908
4163
4393
4648
4878
5133
5363
5619
5849
6104
6359
6845
7330
7815
8300
8786
9271
9756
10267
10752
11237
11723
12208
PD (ft)
0.00
0.01
0.02
0.04
0.06
0.08
0.11
0.14
0.17
0.20
0.24
0.28
0.32
0.36
0.41
0.46
0.51
0.57
0.62
0.68
0.74
0.81
0.87
0.94
1.01
1.08
1.23
1.38
1.55
1.72
1.91
2.10
2.29
2.49
2.71
2.93
3.15
3.39
2" SCH40
Vel (ft/s)
0.10
0.19
0.29
0.38
0.48
0.57
0.67
0.76
0.86
0.96
1.05
1.15
1.24
1.34
1.43
1.53
1.63
1.72
1.82
1.91
2.01
2.10
2.20
2.29
2.39
2.49
2.68
2.87
3.06
3.25
3.44
3.63
3.82
4.02
4.21
4.40
4.59
4.78
RE
2954
5613
8567
11225
14179
16838
19792
22451
25405
28359
31017
33971
36630
39584
42243
45197
48151
50810
53764
56422
59376
62035
64989
67648
70602
73556
79168
84781
90394
96006
101619
107232
112844
118753
124365
129978
135591
141203
Table 8: Water
Water -- No
Flow Rate
US GPM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
28
30
32
34
36
38
40
42
44
46
48
50
Antifreeze (50°F EWT)
3/4" SDR11
PD (ft)
Vel (ft/s)
0.23
0.55
0.78
1.10
1.59
1.66
2.62
2.21
3.88
2.76
5.34
3.31
6.99
3.87
8.83
4.42
10.85
4.97
13.05
5.52
15.41
6.08
17.95
6.63
RE
6760
13520
20402
27162
33922
40682
47565
54325
61085
67844
74727
81487
PD (ft)
0.08
0.27
0.54
0.90
1.33
1.83
2.40
3.03
3.73
4.48
5.30
6.16
7.09
8.07
9.11
10.20
11.34
12.53
13.78
15.07
16.41
17.80
19.25
1" SDR11
Vel (ft/s)
0.35
0.70
1.06
1.41
1.76
2.11
2.47
2.82
3.17
3.52
3.87
4.23
4.58
4.93
5.28
5.64
5.99
6.34
6.69
7.04
7.40
7.75
8.10
RE
5387
10774
16315
21703
27090
32477
38018
43405
48792
54179
59567
65108
70495
75882
81269
86810
92197
97585
102972
108359
113900
119287
124674
PD (ft)
0.02
0.08
0.17
0.28
0.41
0.56
0.74
0.93
1.15
1.38
1.63
1.90
2.18
2.49
2.81
3.14
3.49
3.86
4.24
4.64
5.06
5.48
5.93
6.39
6.86
7.35
8.36
9.44
10.57
11.75
12.99
14.27
15.61
17.01
18.45
19.94
Flow Center & Loop Application Manual
August, 2010
1-1/4" SCH40
Vel (ft/s)
RE
0.21
4142
0.43
8481
0.64
12622
0.86
16961
1.07
21103
1.29
25442
1.50
29583
1.72
33922
1.93
38064
2.15
42403
2.36
46544
2.57
50686
2.79
55025
3.00
59167
3.22
63505
3.43
67647
3.65
71986
3.86
76128
4.08
80467
4.29
84608
4.50
88750
4.72
93089
4.93
97230
5.15
101569
5.36
105711
5.58
110050
6.01
118530
6.44
127011
6.86
135294
7.29
143775
7.72
152255
8.15
160736
8.58
169216
9.01
177697
9.44
186178
9.87
194658
23
Roth
Section 8: Flow Center Selection
Table 9: Hose Kit Pressure Drop
1" Rubber Hose Pressure Drop per 100ft of Pipe Table
Procool (Ethanol)*
Methanol*
Propylene Glycol*
Flow Rate
US GPM
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
RE
PD (ft)
Vel (ft/s)
RE
1
0.13
0.35
820
0.13
0.35
893
0.15
0.35
466
2
0.43
0.70
1640
0.42
0.70
1786
0.49
0.70
932
3
0.87
1.06
2483
0.85
1.06
2705
1.00
1.06
1411
4
1.44
1.41
3303
1.41
1.41
3598
1.66
1.41
1876
5
2.13
1.76
4123
2.09
1.76
4491
2.46
1.76
2342
6
2.94
2.11
4943
2.87
2.11
5385
3.38
2.11
2808
7
3.84
2.47
5786
3.76
2.47
6303
4.42
2.47
3287
8
4.85
2.82
6606
4.75
2.82
7197
5.59
2.82
3753
9
5.97
3.17
7426
5.84
3.17
8090
6.87
3.17
4218
10
7.17
3.52
8245
7.02
3.52
8983
8.26
3.52
4684
11
8.48
3.87
9065
8.30
3.87
9876
9.76
3.87
5150
12
9.87
4.23
9909
9.66
4.23
10795
11.37
4.23
5629
13
11.35
4.58
10728
11.11
4.58
11688
13.08
4.58
6095
14
12.93
4.93
11548
12.65
4.93
12581
14.89
4.93
6560
15
14.59
5.28
12368
14.28
5.28
13474
16.80
5.28
7026
16
16.32
5.64
13211
15.98
5.64
14393
18.80
5.64
7505
17
18.15
5.99
14031
17.77
5.99
15286
20.91
5.99
7971
18
20.07
6.34
14851
19.64
6.34
16179
23.11
6.34
8437
19
22.06
6.69
15671
21.59
6.69
17073
25.41
6.69
8903
20
24.13
7.04
16491
23.62
7.04
17966
27.80
7.04
9368
*NOTES:
1. Procool is at 22% by volume; Methanol is at 21% by volume; Propylene Glycol is at 30% by volume.
2. Percentage by volume, shown above is 15°F freeze protection.
3. All fluids with antifreeze are shown at 30°F; water is at 50°F.
Roth
24
PD (ft)
0.12
0.42
0.85
1.40
2.07
2.85
3.73
4.71
5.79
6.96
8.23
9.58
11.02
12.55
14.16
15.85
17.62
19.48
21.41
23.42
Water*
Vel (ft/s)
0.35
0.70
1.06
1.41
1.76
2.11
2.47
2.82
3.17
3.52
3.87
4.23
4.58
4.93
5.28
5.64
5.99
6.34
6.69
7.04
RE
923
1847
2796
3720
4643
5567
6516
7440
8363
9286
10210
11160
12083
13006
13930
14879
15803
16726
17650
18573
Flow Center & Loop Application Manual
August, 2010
P.O. Box 245
Syracuse, NY 13211
888-266-7684 US
800-969-7684 CAN
866-462-2914 FAX
www.roth-america.com
info@roth-usa.com
**
*
* AHRI certification is shown as the Roth brand under the Enertech Manufacturing certification reference number
**Roth Industries geothermal heat pumps are shown as a multiple listing of Enertech Manufacturing’s ETL certification
*** Roth geothermal heat pumps are listed as a brand under Enertech Manufacturing’s Energy Star ratings
***