FREEZLIGHT −32 °C Ethylene Glycol Heat Transfer Fluid

FREEZLIGHT® −32 °C Ethylene Glycol Heat Transfer Fluid for Closed Heating and Cooling Systems

What Is FREEZLIGHT® −32 °C?

FREEZLIGHT® −32 °C is an aqueous ethylene glycol solution with a functional additive package, designed to transfer thermal energy and protect equipment against accidental freezing.
Ethylene glycol heat transfer fluids are widely used in closed heating systems, HVAC systems, heat pumps and industrial refrigeration equipment. FREEZLIGHT® −32 °C is intended specifically for sealed technical and industrial circuits.
The carboxylate additive package reduces the corrosive activity of the water-glycol solution, stabilizes its properties, helps limit deposits and controls foaming.

Specification Value

What Does −32 °C Mean

The value −32 °C indicates the crystallization onset temperature, not the instant complete freezing of the entire fluid volume.
With further cooling:

• crystals gradually begin to form in the liquid;
• viscosity increases;
• fluid mobility decreases;
• the load on the circulation pump increases;
• crystalline blockages may form in narrow channels.

This crystallization behaviour reduces the risk of a sudden volume increase and equipment rupture compared with water. However, the system may lose its ability to operate before any mechanical damage to the pipes occurs.
The temperature of the coldest system section must therefore remain above the crystallization onset temperature, with an appropriate engineering safety margin.

Applications of Ethylene Glycol Heat Transfer Fluid

• sealed single-circuit heating systems;
• industrial and warehouse buildings;
• closed air-conditioning systems;
• ventilation systems with liquid heat exchangers;
• chillers and fan-coil units;
• industrial refrigeration units;
• closed heat-pump circuits;
• heat-recovery systems;
• process heat exchangers;
• indoor and outdoor technical circuits;
• industrial equipment cooling systems.

Use must be permitted by the manufacturers of the boiler, pump, heat exchanger, refrigeration equipment and all other system components.
A heat transfer fluid intended for stationary engineering systems must not automatically be used as automotive antifreeze or engine coolant. Vehicles require products that meet the specifications of the relevant manufacturer and applicable automotive standards.

When Is Ethylene Glycol a Practical Choice

An ethylene glycol heat transfer fluid is an appropriate choice when:

• the system is fully sealed;
• the system has a single isolated circuit;
• contact with drinking or domestic water is excluded;
• the fluid is used at an industrial or technical facility;
• personnel are familiar with the applicable safety rules;
• leaks can be detected and repaired quickly;
• cost-effective filling of a large system is important;
• a reduced-toxicity heat transfer fluid is not required.

Ethylene glycol formulations are often used in large industrial circuits that require a substantial fluid volume and are designed to prevent contact with people, food products or drinking water.

Ethylene Glycol Toxicity: What Must Be Considered

Ethylene glycol is toxic. The main hazardous route of exposure is ingestion. Once swallowed, it is metabolized into toxic compounds that may cause severe poisoning and damage to the nervous system and kidneys.
It is not entirely correct to explain ethylene glycol restrictions only in terms of “hazardous vapours”. At normal temperatures, ethylene glycol has low volatility. The principal practical risk is contamination of the mouth, drinking water, domestic hot water or food products.

For this reason, ethylene glycol-based FREEZLIGHT® −32 °C is not recommended for:

• open heating systems;
• systems with an open expansion tank;
• combination boilers;
• circuits connected with drinking water or domestic hot water;
• food and pharmaceutical production facilities;
• systems where the heat transfer fluid may contaminate a product;
• facilities where a leak may remain undetected;
• locations accessible to children or animals.

Ethylene Glycol vs Propylene Glycol Heat Transfer Fluids

Both types of heat transfer fluid provide freeze protection and may contain additive packages serving similar corrosion-control functions. The principal difference is their toxicological profile and recommended area of use.

FREEZLIGHT® −32 °C Based on Ethylene Glycol

Recommended for:
• industrial facilities;
• closed technical systems;
• refrigeration equipment;
• large sealed circuits;
• systems where contact with water and products is excluded;
• projects where a lower filling cost is important.

FREEZLIGHT® −32 °C Based on Propylene Glycol

Recommended for:
• residential buildings;
• systems with enhanced safety requirements;
• solar collectors;
• food-industry facilities;
• systems where accidental contact cannot be completely excluded;
• combination-boiler equipment, only where permitted by the boiler manufacturer.

Thermophysical Properties

An aqueous ethylene glycol heat transfer fluid has properties different from those of water. Compared with water, it has:

• higher viscosity;
• lower specific heat capacity;
• lower thermal conductivity;
• higher hydraulic resistance;
• different thermal expansion characteristics.

Replacing water with a glycol heat transfer fluid may therefore require verification of:

• circulation pump capacity;
• pipe diameters;
• heat-exchanger surface area;
• expansion vessel capacity;
• balancing valve settings;
• allowable system pressure.

It is incorrect to claim that an ethylene glycol heat transfer fluid has a higher heat capacity or thermal conductivity than water. Its main purpose is to provide freeze protection and corrosion control where the use of water would create a risk of accidental freezing.

Residual Water Changes the Crystallization Temperature

FREEZLIGHT® −32 °C is supplied ready for use and does not require further dilution.
After flushing or hydrostatic testing, water may remain:

• in low sections of pipework;
• in radiators;
• in heat exchangers;
• in manifolds;
• in pumps;
• in buffer tanks;
• in horizontal pipe runs;
• in sections without an effective drain point.

Residual water dilutes the heat transfer fluid and raises the actual crystallization onset temperature.
For example, if the total system volume is 1,000 litres and 100 litres of water remain after flushing, only approximately 900 litres of ready-to-use product can be added. The final heat transfer fluid concentration will therefore be reduced by about 10%.
After filling, ensure complete circulation, take a representative sample and check the concentration with a refractometer calibrated for aqueous ethylene glycol solutions.
Important: do not use the propylene glycol scale of a refractometer when testing an ethylene glycol heat transfer fluid. The two scales use different calibration.

Material Compatibility

FREEZLIGHT® −32 °C may be used in systems containing:

• carbon steel;
• stainless steel;
• cast iron;
• copper;
• brass;
• bronze;
• aluminium alloys;
• polypropylene;
• PEX;
• PE-RT;
• multilayer polymer-metal pipes.

Compatibility must not be assessed solely by the pipe material. The heat-exchanger material, pump design, gaskets, seals, expansion vessel diaphragm, sealants, solders and equipment manufacturer recommendations must also be considered.
The product should not be described as completely neutral to every type of rubber seal. Elastomers differ in composition, and their suitability for long-term contact with water-glycol solutions must be confirmed by the component manufacturer.

Follow this link and read what’s best to put in the heating system

System Preparation Before Filling

1. Confirm that the system is sealed and single-circuit.
2. Confirm that the equipment manufacturer permits ethylene glycol heat transfer fluids.
3. Remove the previous heat transfer fluid.
4. Flush the system to remove sludge, rust and deposits.
5. Drain as much flushing water as possible.
6. Test the system for leaks at operating or test pressure.
7. Check the condition and capacity of the circulation pump.
8. Check the expansion vessel capacity and pre-charge pressure.
9. Confirm that the safety group is operating correctly.
10. Remove air from every circuit during filling.

Water-glycol solutions may penetrate weak joints that did not leak when the system operated on water. All detected leaks must be repaired before the system is commissioned.

Before pouring antifreeze into the heating system we recommend flushing the system with a deposit remover Antirzhavin . Read more about flushing the system in the article “Recommendations for changing the heat transfer fluid and maintenance of the heating system”.

Can FREEZLIGHT® −32 °C Be Diluted

The product is supplied at its ready-to-use concentration and does not require dilution.
Adding water:
• raises the crystallization onset temperature;
• reduces the temperature safety margin;
• changes the additive concentration;
• may weaken corrosion protection;
• makes composition control more difficult.
If dilution is carried out on the basis of an engineering calculation, use demineralized water and verify the final concentration with an ethylene glycol refractometer.

Can It Be Mixed with Other Heat Transfer Fluids

We do not recommend mixing FREEZLIGHT® −32 °C with fluids of unknown composition.
Different products may contain incompatible corrosion inhibitors, buffer components, antifoam agents, dyes, stabilizers and sealing additives.
Mixing may cause cloudiness, sediment, pH changes, foaming and reduced corrosion protection. When changing from another heat transfer fluid, drain and flush the system as thoroughly as possible.

Application Restrictions

Ethylene glycol-based FREEZLIGHT® −32 °C is not recommended:
• for open heating systems;
• for systems with an open expansion tank;
• for combination boilers;
• for drinking-water or domestic-hot-water circuits;
• for food and pharmaceutical production facilities;
• for solar collectors; for these systems, we recommend FREEZLIGHT® −32 °C based on propylene glycol;
• for systems where contact with a product is possible;
• for electrode boilers unless approved by the equipment manufacturer;
• for systems with incompatible seals;
• for mixing with unidentified heat transfer fluids;
• as automotive antifreeze without the required approval.
For systems with enhanced safety requirements, we recommend FREEZLIGHT® −32 °C propylene glycol heat transfer fluid.

Operation and Service Life

During operation, monitor:
• system pressure;
• absence of leaks;
• circulation pump operation;
• crystallization onset temperature;
• heat transfer fluid appearance;
• presence of sediment;
• changes in colour or odour;
• the amount of added water.
The indicative service life is up to 5 years, provided the system is correctly prepared and operated.
Overheating, contamination, frequent water top-ups, excessive contact with air and mixing with other products shorten the service life of the heat transfer fluid.

Safety Precautions

When handling the product:
• wear protective gloves and safety goggles;
• prevent ingestion of the liquid;
• do not store the product in beverage bottles or food containers;
• do not reuse empty packaging for water or food;
• clean up spills immediately;
• keep children and animals away from the storage area;
• wash hands thoroughly after handling.
If swallowed, seek medical attention immediately. Do not wait for symptoms to appear, because severe ethylene glycol poisoning may have no obvious signs during its early stage.

Follow the link and choose your antifreeze for heating based on:

propylene glycol

glicerin

ethylene glycol

Storage

Store the product:
• in its tightly closed original packaging;
• in a covered indoor area;
• separately from food products;
• away from drinking water;
• protected from direct sunlight;
• in a location inaccessible to children and animals.

Do not transfer the product into unlabelled containers.

Frequently Asked Questions

What does −32 °C mean?

It is the crystallization onset temperature. With further cooling, the fluid gradually thickens and circulation may stop.

Can it be used in a private home?

Technically, it can be used in a completely sealed single-circuit system. However, for residential buildings Novohim recommends a propylene glycol heat transfer fluid, particularly where a leak or contact with domestic hot water cannot be completely excluded.

Can it be used in a combination boiler?

It is not recommended. If the heat exchanger fails, ethylene glycol may enter the domestic hot-water circuit.

Is it suitable for an industrial cooling system?

Yes, provided the system is sealed, the materials are compatible and the equipment manufacturer permits ethylene glycol heat transfer fluids.

Can it be used in a heat pump?

Yes, in a closed technical circuit, provided all equipment manufacturer requirements are met.

Does the product need to be diluted?

No. FREEZLIGHT® −32 °C is supplied ready for use.

Can water be added?

Adding water changes the concentration and raises the crystallization onset temperature. After adding water, test the fluid using a refractometer calibrated for ethylene glycol.

How does it differ from FREEZLIGHT® −32 °C based on propylene glycol?

The ethylene glycol product is intended primarily for closed technical and industrial systems. The propylene glycol version has lower toxicity and is recommended for residential, food-industry and other facilities with enhanced safety requirements.

Follow this link and read more about what kind of antifreeze to choose for heating