Frost Protection - Panasonic 140 Installation And Maintenance Manual

10.6. Frost protection

10.6.1. Water loop glycoling
CAUTION The use of a glycol-based solution is the only effective frost-protection means
The glycol-based water solution must be suffi ciently concentrated to ensure appropriate protection and prevent ice from
forming. Take precautions when using non inert MEG antifreeze solutions (Mono Ethylene Glycol) or MPG (Mono Propylene
Glycol). With this type of antifreeze solution, corrosion may occur in the presence of oxygen.
Contact glycol resellers to ensure that its characteristics are compatible with environmental directives applicable on site (this is
not under manufacturer responsibility).
Glycol concentration in the installation's hydraulic circuit must be entered in the controller upon start-up.
CAUTION This parameter setting changes the safety and alarm triggering threshold limits. An incorrect value may
cause malfunctions and potential destruction of the unit's heat exchanger.
AVERTISSEMENT
Glycoling the water loop worsens slightly the performances, in particular the pressure drops. The hereunder table gives
corrective factors with respect of type and concentration of the glycol. For instance, the 20% MEG glycoling will:
• Increase the pressure drop: with glycol = 1,160 x without glycol
• Increase the fl ow rate: with glycol = 1,050 x without glycol
• Decrease the capacity: with glycol = 0,985 x without glycol
Mono Ethylene Glycol concentration
Load loss
Correction factor Water fl ow
Thermodynamic power
Mono Propylene Glycol concentration
Load loss
Correction factor Water fl ow
Thermodynamic power
Draining the water circuit is not recommended for frost protection, for the following reasons:
• The water circuit will rust, which will shorten its lifetime.
• Water will remain at the bottom of the plate exchangers and freezing may cause damage.
Never fi ll the hydraulic circuit with pure glycol. Maximum glycol concentration is 45%. The water and glycol
mixture must be precisely prepared before fi lling the hydraulic circuit. If the mixture is too concentrated, the
CAUTION
hydraulic circuit components may be damaged and the ECOi-W unit may not perform normally. In this case,
unit warranty will be void.
For Heat pump models, if the outdoor temperature is likely to fall below +1°C, provide means to prevent the
CAUTION
condensates from freezing (e.g. heating cord).
10.6.2. Outer air protection
In case of negative temperatures, the water loop must be protected against icing when the unit is off. Concentration must
comply with the temperature level:
Minimum outer air temperature
MEG concentration
MPG concentration
It is strongly recommended to post, on the electric box of the unit, glycol type and concentration in
the hydraulic circuit.
°C
%
%
% 10
1,070
1,015
0,995
% 10
1,112
1,005
0,991
5 > T > 0 0 > T > -5
10 20
10 20
18
20 30
1,160 1,235
1,050 1,085
0,985 0,970
20 30
1,175 1,290
1,030 1,067
0,977 0,945
-5 > T > -10 -10 > T > -27
30
30
45
1,368
1,169
0,949
45
1,520
1,162
0,894
45
45