Stratification; Circulating Pumps - Lochinvar ECOKNIGHT EKW116CE Installation, Commissioning, Maintenance And User Instructions

13.3.2
EXPANSION VESSEL SIZING
The following information is based on an inlet pressure of 3.5 bar and an expansion vessel efficiency of 0.45 using a standard 6 bar
unvented kit. If the system will have different parameters a more detailed calculation will need to be made.
V V = S V * e
0.45
Where:
V V = Vessel Volume
S V = System Volume
e = Coefficient of Expansion
Stored Temp.
C
e
Stored Temp.
C
e
13.3.3
COEFFICIENT OF EXPANSION OF WATER AT 3.8 BAR COLD FILL PRESSURE
DE-STRATIFICATION
If the hot water system does not include a constantly circulated building return, it is recommended that a de-stratification pump is
fitted, between the building flow connection and the drain connection of the storage vessel, to ensure an even temperature distribution
throughout the stored water. De-stratification pump kits are available as ancillary items; please contact Lochinvar Limited for details.

CIRCULATING PUMPS

In order to ensure the correct flow rates through the water heater, the unit requires a bronze glanded pump sized to overcome the
resistance of the heat exchanger and a primary pipework loop. Lochinvar will supply a suitable bronze glanded shunt pump with
each water heater as shown in Section 12.5.1. The primary loop should be no longer than 14 metres plus the following fittings:
6 x 90 Elbows
2 x Unions
2 x Full bore lever ball valves
2 x Tee fittings (cold feed & building return)
For longer distances or a greater number of fittings, the pump may have to be resized.
The specification of this type of pump ensures that the bronze body and associated parts in contact with water are suitable for potable
use. A "glanded" construction is required to ensure that any scale in the system does not build up within the pump and cause a
resistance that can lead to a loss of water flow. Glandless (canned rotor) pumps are not recommended due to the fact that in hard
water areas, scale can build up within the rotor and failure can occur, not only of the pump but also the heater itself. The warranty
will be void if a failure of the heat exchanger occurs due to a "glandless" pump being used.
Model Differential (K)
EKW116CE
EKW146CE
EKW176CE
EKW206CE
EKW236CE
13.5.1
FLOW RATES AND SHUNT PUMP SIZES
Lochinvar will supply a suitably sized pump with all EcoKnight™ water heaters based on the parameters shown above, for projects
outside these parameters the pump will have to be re-sized.
30 35
0.005 0.006
65 70
0.020 0.023
FLOW
(Litre/sec)
10.0 2.82
10.0 3.19
12.2 3.30
12.2 4.00
13.3 4.20
40 45
0.008 0.010
75 80
0.026 0.030
Total System Pressure
Loss (Meter- H
8.51
7.93
7.90
9.80
9.40
50 55
0.012 0.015
82 85
0.031 0.033
Shunt Pump supplied
0)
2
LM900140A
LM900140A
LM900140A
LM900149A
LM900149A
60
0.017
90
0.037
49