In vehicle air conditioning systems, the R12 and R134a are the two most common types of refrigerant gases. All the cars that are made after 1994 come with the R134a cooling system. All the cars that are made before 1994 come with the R12 cooling system. Owing to this, vehicle owners of old models who have the R12 refrigerant system tend to use a conversion chart to convert to R134a.
The R12 to R134a conversion chart is for converting the air conditioning system of the vehicle according to the operating condition and refrigerant type. It enables adjusting the charge accordingly and it is also suitable for HVAC equipment.
R12 to R134a Charge Conversion Formula
The conversion of R12 to R134a refrigerant is according to a formula. Applying this formula will convert the value of the original R12 charge to the R134a charge.
You can begin the formula in pounds by multiplying the R12 charge value by .75. When the scales are in point story .25 or .5 increments, it is adjusted to the highest quality.
The other method will be by multiplying the R12 charger specification by 0.9 and subtracting 0.25 lbs. This helps to provide the correct R134a charge. Here is an example to calculate r12 to r134a capacity conversion.
R12 to R134a Conversion Calculator:
If the R12 charge value is 3 lbs.
It will be (R12 charge specification x 0.9) – 0.25 lbs.
= (3 x 0.9) – 0.25 lbs.
= 2.45 lbs.
The charge level of 3 pounds of R12 will be 2.45 lbs. of R134a.
R12 to R134a Conversion Chart:
Here’s a general conversion between R12 and R134a based on industry standards:
Important considerations:
- Oil type: R12 systems use mineral oil, while R134a systems use PAG (polyalkylene glycol) oil. These are incompatible.
- System components: Some system components might need to be replaced or modified for a successful conversion.
- Regulations: Check local regulations regarding the use and disposal of refrigerants.
R12 to R134a Refrigerant Charge Conversion in pounds (lbs)
| R12 Charge Specification | R134a Refrigerant Charge Level | R12 Charge Specification | R134a Refrigerant Charge Level |
| 1 lb. | 0.65 lbs. | 1.5 lbs. | 1.1 lbs. |
| 2 lbs. | 1.55 lbs. | 2.5 lbs. | 2 lbs. |
| 3 lbs. | 2.45 lbs. | 3.5 lbs. | 2.90 lbs. |
| 4 lbs. | 3.35 lbs. | 4.5 lbs. | 3.8 lbs. |
| 5 lbs. | 4.25 lbs. | 5.5 lbs. | 4.7 lbs. |
| 6 lbs. | 5.15 lbs. | 6.5 lbs. | 5.6 lbs. |
| 7 lbs. | 6.05 lbs. | 7.5 lbs. | 6.5 lbs. |
R12 to R134a Refrigerant Charge Conversion in Ounces (oz)
| R12 Charge Specification | R134a Refrigerant Charge Level | R12 Charge Specification | R134a Refrigerant Charge Level |
| 3 oz. | 2.3 oz. | 3.5 oz. | 2.6 oz. |
| 4 oz. | 3 oz. | 4.25 oz. | 3.2 oz. |
| 4.5 oz. | 3.4 oz. | 4.75 oz. | 3.6 oz. |
| 5 oz. | 3.8 oz. | 5.25 oz. | 3.9 oz. |
| 5.5 oz. | 4.1 oz. | 5.75 oz. | 4.3 oz. |
| 6 oz. | 4.5 oz. | 6.25 oz. | 4.7 oz. |
| 6.5 oz. | 4.9 oz. | 6.75 oz. | 5 oz. |
| 7 oz. | 5.3 oz. | 7.25 oz. | 5.4 oz. |
| 7.5 oz. | 5.6 oz. | 7.75 oz. | 5.8 oz. |
| 8 oz. | 6 oz. | 8.5 oz. | 6.4 oz. |
| 9 oz. | 6.8 oz. | 10 oz. | 7.5 oz. |
| 11 oz. | 8.3 oz. | 11.5 oz. | 8.6 oz. |
| 12 oz. | 9 oz. | 12.5 oz. | 9.4 oz. |
| 13 oz. | 9.8 oz. | 13.5 oz. | 10.1 oz. |
Conclusion
The R12 to R134a conversion chart serves great for old vehicle models. By applying the above formula, you will be able to have the accurate R134a charge. You can easily do it for both lbs and oz. Enter the appropriate R12 charge specification in the formula which will provide the correct R134a refrigerant charge level.
FAQS: R12 to R134a Capacity Conversion
1. Can I simply replace R12 with R134a in my system?
Ans: While it is possible to convert a R12 system to R134a, it is not a straightforward process. Several factors need to be considered, including system compatibility, oil type, and refrigerant charge.
2. Will my system perform the same after R12 to 134a conversion?
Ans: While R134a is a suitable replacement for R12, it may not provide exactly the same performance. Factors such as system design and operating conditions can influence the overall efficiency and cooling capacity.
3. Is R134a a more environmentally friendly refrigerant than R12?
Ans: Yes, R134a is considered a more environmentally friendly refrigerant than R12. It does not contribute to ozone depletion, but it is a greenhouse gas with a global warming potential (GWP). However, it is a significant improvement over R12.
4. Are newer refrigerants better for the environment than R134a?
Ans: Yes, there are newer refrigerants, such as HFOs (hydrofluoroolefins), that have a lower GWP than R134a. These refrigerants are being increasingly used as alternatives to R12 and R134a.
