Information Collector Pipe; Connection To Outdoor Unit; Connection Of Several Brine Coils - Danfoss DHP-H Installation And Service Instructions Manual

8.2

Information collector pipe

⚠ Local rules and regulations related to type of collector must
be followed.
Borehole collector: Fully welded plastic pipe collector (PEM PN 6.3)
according to the applicable local and national regulations with fac-
tory manufactured return bend.
Ground collector: Fully welded plastic pipe collector (PEM PN 10)
according to the applicable local and national regulations.
In countries where frost damage occurs, the collector pipe beside
an outer wall (minimum 2 metres) must be insulated in such a way
that frost damage is prevented. This applies regardless of ground,
rock or lake heat.
Minimum shaft depth between the energy well and the building is
0.5 m. If burial to that depth is not possible the pipes must be pro-
tected against any external mechanical damage.
Figure 63: Shaft depth for, and insulation of, collector hoses.
8.3

Connection to outdoor unit

Connection for the brine circuit from the heat pump to the out-
door unit can be carried out using pipes or hoses. Depending on
what connection is selected and what diameter the connection
has, there is a maximum length that the connection may be. The
maximum lengths in the table below are based on ethylene glycol
(which is mixed to anti-freeze protection down to -32°C) at 0°C.
DHP-A, P ytg Calculated maximum coil length between the
-AL
Size kPa Cu22
Ø = 20.0
in
6
30 34
(2 x 17)
8
63 21
(2 x 10.5)
10
50 11 *
(2 x 5.5)
12
43 5 *
(2 x 2.5)
*) Not recommended because of high liquid speeds with risk of corro-
sion/noise problems.
8.4

Connection of several brine coils

When several brine coils are used for a heat pump installation,
regardless of what heat source is used, the length of the coils must
not exceed the values in the following tables. The coil lengths are
based on ethanol 30% at 0°C.
For hoses of type PEM DN 32, Øi = 28,0:
DHP-H, P ytg Calculated maximum coil length per coil,
-C, -L
Size kPa 1 coil
6 31 182
8
33 94
32
HP and outdoor unit, in metres
Cu28 PEM
Ø = 25.6 DN 25 DN 32
in
Ø = 21.0 Ø
in in
133 48
(2 x 66.5) (2 x 24) (2 x 86.5)
98 30
(2 x 49) (2 x 15) (2 x 75)
47 13 *
(2 x 23.5) (2 x 6.5) (2 x 39)
26 8 *
(2 x 13) (2 x 4) (2 x 22)
in metres
2 coils 3 coils 4 coils
2 x 443 3 x 620 4 x 775
2 x 220 3 x 471 4 x 660
DHP-H, P ytg
-C, -L
Size kPa
10 67
12 64
16 56
For hoses of type PEM DN 40, Øi = 35,2.
DHP-H, P ytg
-C, -L
Size kPa
6 31
8
33
10
67
12
64
16
56
*) When dimensioning size 12, a borehole depth that exceeds this rec-
ommendation for coil length is often required. In such cases two coils
should be used.
The different brine coils are distributed from a common collec-
tion well. All return lines are led back to the well and are equipped
with choke valves because the flow of each individual coil must be
adjusted.
Brine coil 1
PEM
Brine coil 2
= 28.0
173
Figure 64: The collection well for distributing to several brine coils.
Choke valves with flow indicators (available as accessories from the
150
Danfoss range) are used to adjust the brine flow so that it is the
same in all coils.
78
If choke valves with flow indicators are not available adjust the
valves until the temperature of all the coil return hoses is the same.
44
VMBMA602
Calculated maximum coil length per coil,
in metres
1 coil 2 coils 3 coils
129 2 x 419 3 x 670
91 2 x 376 3 x 640
37 2 x 165 3 x 329
Calculated maximum coil length per coil,
in metres
1 coil 2 coils 3 coils
517 2 x 775 3 x 1033
367 2 x 660 3 x 943
394 2 x 1340 3 x 1675
291* 2 x 1067 3 x 1280
119 2 x 560 3 x 933
Choke valves
Collection well
4 coils
4 x 1117
4 x 914
4 x 400
4 coils
4 x 1033
4 x 825
4 x 1675
4 x 1600
4 x 1120