Midea MCCDH30A-TA3SL, Technical & Service Manual

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Air-cooled modular chiller unit
Performance adjustment factors
The antifreeze must be required according to anyone condition as following:
1. The outlet water temperature is below 5
℃
;
2. The ambient temperature is below 0
℃
;
3. Don‟t start up the unit for a long time.
4. The power supply was cut off and needn‟t change the water in system.
Ethylene and Propylene Glycol Factors
A glycol solution is required when the unit with condition as mentioned. The use of glycol will reduce the
performance of the unit depending on concentration.
Ethylene Glycol
Quality of glycol
（
%
）
modification coefficient
Freezing
point
℃
Cooling capacity
modification
Power
modification
Water
resistance
Water flow
modification
0 1.000 1.000
1.000 1.000
0
10 0.984 0.998 1.118 1.019 -4.000
20 0.973 0.995 1.268 1.051 -9.000
30 0.965 0.992 1.482 1.092 -16.000
40 0.960 0.989 1.791 1.145 -23.000
Propylene Glycol
Quality of glycol
（
%
）
Modification coefficient
Freezing
point
℃
Cooling capacity
modification
Power
modification
Water
resistance
Water flow
modification
0
1.000 1.000 1.000 1.000
0
10 0.976 0.996 1.071 1.000 -3.000
20 0.961 0.992 1.189 1.016 -7.000
30 0.948 0.988 1.380 1.034 -13.000
40 0.938 0.984 1.728 1.078 -22.000
Units operating with glycol solutions are not included in the ARI Certification Program.
Altitude correction factors
Performance tables are based at sea level. Elevations other than sea level affect the performance of the unit.
The decreased air density will reduce condenser capacity and reduce the unit‟s performance. For
performance at elevations other than sea level refer to Table 3. Maximum allowable altitude is 1800meters.
Evaporator temperature drop factors
Performance tables are based on a 5
o
C temperature drop through the evaporator. Adjustment factors for
applications with temperature ranges from 3
℃
to 6
℃
in follow table. Temperature drops outside this range
can affect the control system‟s capability to maintain acceptable control and are not recommended.
Fouling factor
Fouling refers to the accumulation of unwanted material on solid surfaces, most often in an aquatic
environment. The fouling material can consist of either living organisms (biofouling) or a non-living
substance (inorganic or organic). Fouling is usually distinguished from other surface-growth phenomena in
that it occurs on a surface of a component, system or plant performing a defined and useful function, and
that the fouling process impedes or interferes with this function.
Other terms used in the literature to describe fouling include: deposit formation, encrustation, crudding,
deposition, scaling, scale formation, slagging, and sludge formation. The last six terms have a more narrow
meaning than fouling within the scope of the fouling science and technology, and they also have meanings
outside of this scope; therefore, they should be used with caution.
Fouling phenomena are common and diverse, ranging from fouling of ship hulls, natural surfaces in the
marine environment (marine fouling), fouling of heat-transfer components through ingredients contained in
the cooling water or gases, and even the development of plaque or calculus on teeth, or deposits on solar
panels on Mars, among other examples.