Each system will require a different amount of glycol due to the varying amounts of circulated fluid as the loop changes in size, the amount of stored water and local weather conditions. The amount of glycol required will be based on a percentage of glycol versus water content in the loop. Each manufacturer will publish a supporting document for their product.
Example glycol performance chart:
| Outdoor Temperature |
Ethylene % of Glycol Required |
Propylene % of Glycol Required |
|
| C. | F. | ||
|
0 |
32 |
0% |
0% |
|
-5 |
20 |
18% |
18% |
|
-12 |
10 |
24% |
29% |
|
-18 |
0 |
32% |
36% |
|
-23 |
-10 |
39% |
42% |
|
-29 |
-20 |
44% |
47% |
|
-34 |
-30 |
48% |
52% |