Note
For water with antifreeze, such as ethylene glycol or propylene glycol, the supplier-specific values for the density ρ, the specific heat capacity c, and the kinematic viscosity ν are to be determined by way of concentration and medium temperature. These values must be observed when sizing valves to make certain that correct kvs values are obtained.
In the case of antifreeze concentrations with a kinematic viscosity of < 10 mm2/s, correction factors for the sizing of valves are not required. Refer to chapter "2.8.3 Impact of fluid properties on valve sizing", page 36.
Planning
The type of antifreeze (product and dosage) added to the system must be approved by the supplier for use in HVAC plants
If several additives are used (e.g. antifreeze and hardness stabilizers), the required combination must be approved by the same supplier
Install a strainer (dirt trap)
Installation and commissioning
The company making the installation is responsible for the correct antifreeze concentration and water quality in HVAC plants
Before filling a hydraulic HVAC circuit with a medium, the installer must observe the specifications of the supplier. If such specifications or regulations are not observed, severe damage to the plant can occur
When commissioning a plant, the company that made the installation is obliged to write a commissioning report including information about water quality, antifreeze concentration and filling (plant volume) and, if necessary, about water treatment and the additives used
Recommendation
Keep a plant record.
Maintenance and service
The installer should check hydraulic HVAC circuits at least once a year.
According to supplier specifications, the antifreeze concentration, the pH value, and the concentration of inhibitors must be checked once a year, for example.
Recommendation
The antifreeze concentration and water quality in open or closed HVAC plants must be checked at regular intervals. The plant record must always be kept up to date.