The Efw Sanitairy System: Installation Instructions; Stand-Alone Set-Up - Lochinvar EFW 85 Installation, Commissioning, User And Maintenance Instructions

9 THE EFW SANITAIRY SYSTEM: INSTALLATION INSTRUCTIONS

The EFW water heaters are designed for use with one or more hot water tanks, because the boiler needs a mini-
mum amount of water flow. To get an output temperature of 60°C, the temperature of the return should be
within the range 43.5 – 47.5 °C.
In designing the hot water system there are some points to consider:
- How many water heaters and how many tanks are needed to accommodate the desired domestic hot
water flow.
Water hardness: a high water hardness will lead to calcification of the heat exchanger, especially when
-
water temperatures are high. Calcification can be delayed by increasing the waterflow through the
boiler resulting in a smaller temperature difference between in- and output of the boiler:
•
If the water hardness is between 4 and 11 °dH (between 5 and 14 °Clark) the temperature dif-
ference between flow and return of the boiler should be 16.5 °C maximum
•
If the water hardness is between 11 and 14 °dH (between 14 and 17.5 °Clark) the temperature
difference between flow and return should be 12.5 °C maximum
•
If the water hardness is above 14 °dH (17.5 °Clark) a water softener should be used. Also above
11 °dH (14 °Clark) a water softener could be considered, because an installation at
12.5 °C temperature difference will need bigger pipes and pumps. After softening, the water
hardness should be minimum 4 °dH (5 °Clark)
Pipework has to be made of copper or stainless steel pipes, diameters according or bigger than pre-
-
scribed below. When using plastic pipes, make sure the inner diameter of the pipes is at least equal to
the corresponding copper size.
The applied pump must be a bronze or stainless steel pump and controlled only by the EFW water
-
heater control. If, for any reason, an external pump control is applied without written approval of Loch-
invar Ltd then the complete warranty on the EFW water heater and all delivered parts will become inva-
lid.

Stand-alone set-up

The basic form of a HW installation is one water heater with one tank.
Heater flow at ΔT = 16.5 °C (m
Pipework size at ΔT = 16.5 °C
Maximum pipe length (m)
Pump advice at ΔT = 16.5 °C
Table 1: Pipe sizes and pumps
1)
NB! An X in the pump table does not necessarily mean that the corresponding installation cannot be built. If
it can, it will need specific design effort and pump selection. Please consult Lochinvar technical support for
advice.
•
Adding bends or valves to the pipe system influences water resistance and maximum pipe length. In the table
below equivalent pipe lengths are given, which should be subtracted from the given maximum pipe length.
Equivalent pipe length
Copper pipe
90° bend
diameter D
R = 1  D
mmmm M
421.5 0.5
541.5 0.8
Table 2: Equivalent pipe lengths
Pump number Pump type
P1 Grundfos UPMXL GEO 25-125N 180
P2 Wilo Stratos Para Z 25/1-12
EFW 85
3
/h) 4.26
42 x 1.5
2 x 20
P1*
*(see table 3)
Equivalent pipe length
45° bend
R = 1  D
m
0.3
0.3
E93.1804.014
EFW 105 EFW 125
5.07 6.22
42 x 1.5 42 x 1.5
2 x 15 2 x 30
P1* P2*
Equivalent pipe length
valve
m
0.1
0.2
EFW 155
7.57
54 x 1.5
2 x 30
P2*
31