AERMEC ANK 030 Installation Manual Download Page 23

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11 SYSTEM WATER CONTENT

MINIMUM SYSTEM WATER CONTENT

For correct unit operation, there must be a suitable amount of water in the system. A sufficient quantity of water not only ensures machine stability, but also helps avoid a high
number of hourly compressor start-ups.
To calculate it, use the formula: Unit rated cooling capacity (ton) x table value (gal/ton) = Minimum system content (gal).

Size

030

045

050

Minimum system water content

Minimum water content for air conditioning

°,A,P

gal/ton

2.6

Note

: the water content referred to in the tables corresponds to the amount of water effectively useful for inertial purposes; this value does not necessarily coincide with the

entire system water content, and must be calculated on the basis of the system layout and operating modes.

A example is given below, but it does not cover a possible situation.

Example

: for a chiller/heat pump equipped with a primary and a secondary circuit, and in which the zone pumps of the secondary circuit could (even occasionally) be turned

off, only the water content of the primary circuit has value of useful water content for the counting purposes.
If you are in any doubt, please refer to the relevant technical documentation or contact the AERMEC Technical-Commercial Service.

NOTICE:

Under no circumstances does the unit have to be operated when water flow rate on the heat exchanger is below the minimum water flow rate or above the

maximum water flow rate, under penalty of the warranty expiration. Aermec cannot be held responsible for any malfunction of the units which are operated outside
the established limits of water flow rate and for their consequences

NOTICE:

Under no circumstances does the unit have to be operated in a system in which the content of the water circulating is below the MINIMUM SYSTEM WATER

CONTENT, under penalty of the warranty expiration. Aermec cannot be held responsible for any malfunction of the units which are operated in a system in which the
content of the water circulating is below the MINIMUM SYSTEM WATER CONTENT and for their consequences

ATTENTION It is recommended to design systems with high water content (minimum recommended values shown in tab), in order to limit:

—

Number of peaks made by the compressors

—

The reduction of water temperature during defrosting cycles in the winter period for heat pumps.

NOTICE:

in the case of several units connected in parallel, the designer must ensure that the configuration of the system and the management logic adopted do not

cause too frequent START/STOP cycles and / or sudden changes in the water flow rate of the groups in operation

MAXIMUM SYSTEM WATER CONTENT

Units with the hydronic kit mounted come standard with the expansion vessel set at 21.8 psi, the pressure relief valve and the water filter mounted.
The maximum system water content depends on the capacity of the expansion vessel and on the calibration of the pressure relief valve.

Size

030

045

050

Hydronic kit

Expansion vessel number

°,A,P

no.

Expansion vessel capacity

°,A,P

gal

1.3

Pressure relief valve

°,A,P

n°/psi

1/87.0

The table gives an example of the maximum water content calculated at the indicated operating conditions and only to protect the unit.
If the volume of water in the system is higher, add another expansion vessel of the correct size.

System water temperature max/min

°F

104/39.2

Hydraulic height

98.4

82.0

65.6

49.2

≤40.19

Expansion vessel pre-load

psi

46.4