Freon R407C is a hydrofluorocarbon mixture that replaces the R22 refrigerant that depletes the ozone layer. The absence of chlorine in the compound makes it environmentally friendly. Improved formula Freon is used in domestic and semi-industrial air conditioners.
What is freon R407C
Hydrofluorocarbon (HFC) Freon R407C is a gas without color or odor. It is used in climatic equipment as a refrigerant. In air conditioners, the property of freon is to absorb heat during evaporation and to release it in the process of condensation (transition to a liquid state). Freon R407C is chemically and thermally stable, its toxic level is equal to or lower than the parameters of R22. This is the best replacement for freon, which destroys the ozone layer.
Gas does not burn, decomposes under the influence of high temperature, forming toxic products. The system is filled and refilled only in the liquid phase of the refrigerant. If equipment malfunctions, refrigerant leaks. Uneven evaporation of fractions leads to a change in the proportions of the mixture.
The new chemical composition does not provide the desired performance. With significant leakage, partial replenishment of the loss is not recommended. Disposal of residues and full refueling are required.
Composition of Freon R407C
The formula of the zeotropic mixture: R32 (23%) + R125 (25%) + R134a (52%). Each component is responsible for a specific property of the resulting connection:
- R32 (difluoromethane) - increase in productivity;
- R125 (pentafluoroethane) - fire prevention;
- R134a (tetrafluoroethane) - working pressure control.
The components of the formula are selected to provide characteristics that are as close as possible to the parameters of R22. Substances included in the zeotropic refrigerant do not form a homogeneous mixture. This is the main disadvantage of the product. When refueling, it is necessary to control the proportions of the composition.
Application
Freon R407C is close to R22 refrigerant in technical specifications. Replacing it with an outdated structure does not require significant modifications to the existing refrigeration system. When switching to a hydrofluorocarbon mixture, elastomers, safety valves, filter adsorbent elements, oil are replaced. Zeotropic mixture is characterized by a low heat transfer coefficient. This difference is not noticeable in installations with plate heat exchangers.
Most of the air conditioning devices that used the R22 can be converted to safe refrigerant. Exceptions are centrifugal compressor systems and flooded evaporators. Not recommended for refrigeration units with an evaporation temperature less than -10 ° C. With a decrease in temperature indicators, cooling capacity deteriorates.
Scope of application:
- domestic and commercial air conditioners;
- industrial refrigeration equipment;
- heat pumps;
- refrigerators;
- cars with cargo cooling function;
- refrigerated warehouses;
- ice rinks.
Refrigerant benefits
A promising substitute for freon R22 has a zero effect on the ozone layer. This is its main advantage, among other advantages:
- The main indicators (saturated vapor pressure and cooling capacity) are close to the characteristics of R22.
- Climate and refrigeration equipment manufacturers use refrigerant for their products.
- Freon R407c is safe, the A1 / A1 index means that the mixture of refrigerants does not burn in the initial state and when the concentration of fractions changes.
- In the event of a leak, it is easy to refill the system further.
Freon R407C: characteristics
The main factors that determine the properties of a refrigerant are its thermophysical and thermodynamic characteristics.
| Characteristics | Units | |
| Average molecular weight | 86,2 | |
| Saturated fluid density at 25 ° | kg / cu m | 1.1 |
| Boiling point (at 0.1 MPa) | ° C | -25,6 |
| Critical temperature | ° C | 86,2 |
| Critical pressure | kg / sq. cm | 48,3 |
| Air ignition limit | no | |
| Ozone Depletion Potential | 0,000 | |
| Saturated fluid vapor pressure at 25 ° | kPa | 1,29 |
| Global warming potential | 0,34 | |
| ASHRAE Security Group | A1 / A1 |
Permissible temperature drift is 6-7 ° K.
Oils for R407C
For each brand of freon, a special type of oil is selected. Filling with incompatible components will damage the compressor. Polyester oil is used as a lubricant for air conditioning systems with R407c refrigerant. Recommended manufacturers and series: Mobil EAL Arctic 32, 46, 100, Biltzer BSE 42, PLANETELF ACD 32, 46, 68, 100. When working with essential oil, its ability to absorb water is taken into account. During storage and during refueling, conditions are created that exclude contact with any moisture sources. The use of mineral oil is prohibited.
