English
For heatpump models, if the outdoor temperature is likely to fall below +1°C, provide a system to
prevent the condensates from freezing (e.g. heating cord).
Caution
THE USE OF A GLYCOL-BASED SOLUTION IS THE ONLY EFFECTIVE FROST-PROTECTION MEANS
Caution
Never ll the hydraulic circuit with pure glycol. Maximum glycol concentration is 45%. The water
and glycol mixture must be precisely prepared before lling the hydraulic circuit. If the mixture is
too much concentrated, the hydraulic could be damaged and the unit SysAqua should not perform
normally. In this case, unit guarantee will be cancelled.
Caution
The glycol percentage in the installation's hydraulic circuit must be entered in the regulation upon
start-up. This parameter setting changes the safety and alarm triggering threshold limits. An incorrect
value may cause malfunctions and a destruction of the unit's heat exchanger.
Caution
Avertissement
It is strongly recommended to post, on the electric box of the unit, glycol type and concentration in
the hydraulic circuit.
15SysAqua
10.6. FROST PROTECTION
If the SysAqua is exposed to ambient temperatures between 1°C and -18°C, protect the water circuit
against frost.
Draining the water circuit is not recommended for frost protection, for the following reasons:
² The water circuit will rust, which will shorten its lifetime.
² Water will remain at the bottom of the plate exchangers and freezing may cause damage.
The glycol-based water solution must be sufciently concentrated to ensure appropriate protection and
prevent ice from forming at the minimum outdoor temperatures planned for the installation. 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 directive
applicable on site (this is not under manufacturer responsibility).
The glycol-based solution slightly modies the installation's performance, particularly in terms of load loss:
Minimum outdoor temp. °C
5 > T > 0 0 > T > -5 -5 > T > -10 -10 > T > -30
Mono Ethylene Glycol concentration %
10 20 30 45
Correction
factor
load loss
1.070 1.160 1.235 1.368
water ow
1.015 1.050 1.085 1.169
thermodynamic power
0.995 0.985 0.970 0.949
Example for a solution with 20% Mono Ethylene Glycol:
² Increase the pressure drop : with glycol = 1.160 x without glycol
² Increase the owrate : with glycol = 1.050 x without glycol
² Decrease the capacity : with glycol = 0.985 x without glycol
Minimum outdoor temp. °C
5 > T > 0 0 > T > -5 -5 > T > -10 -10 > T > -27
Mono Propylene Glycol concentration %
10 20 30 45
Correction
factor
load loss
1.112 1.175 1.290 1.520
water ow
1.005 1.030 1.067 1.162
thermodynamic power
0.991 0.977 0.945 0.894