Alasan mengapa radiator coolant tidak bisa 100 persen tanpa air

Ternyata banyak yang berpikir bahwa radiator coolant itu bukan air. Dianggap bahwa coolant itu berbeda dengan air. Sehingga saat mekanik dari bengkel resmi menyarankan tambah cairan radiator dengan air, banyak yang jadi bertanya – tanya.

 

Ternyata coolant yang baik itu pasti ada airnya. Kita ambil contoh radiator coolant dari punya Honda:
Honda Genuine Coolant – Blue – 20 Litre

• Honda Genuine Radiator Coolant is made to meet Honda R&D specifications through the use of high purity Ethylene Glycol, highly durable additives and an accurate pre-mix of 50% demineralised water and 50% anti-freeze.

Disebutkan bahwa radiator coolant merek Honda 50% nya adalah air!

 

Apa alasannya? Karena air termasuk penghantar panas terbaik:
Things you should know about coolant

As far as carrying heat goes, water does a really good job. It’s actually one of the most effective coolants that could possibly be used. The specific heat capacity of ethylene glycol is only about 65% of water at the temperatures seen in a cooling system. That means that to cool the engine by one degree, you would need about 50% more of it than straight water. So even though you could use pure antifreeze as a coolant, or any other liquid for that matter, you would need a bigger radiator and more robust cooling system compared to one that used straight water.

From a cooling point of view, it seems ideal to have the system filled 100% with water. At that 65% mixture we’ve lost 20% of the cooling capacity of the system.

Website tersebutjuga memberikan beberapa diagram hubungan antara persentasi campuran air dengan antifreeze untuk suhu dan daya hantar panas.

 

Jadi intinya kalau cairan radiator menggunakan 100% tanpa air, maka sistem pendinginan hanya 50% efektif. Oleh karena itu campuran air tetap diperlukan. Walau diperlukan air mempunyai beberapa kelemahan. Diantaranya mudah membeku, mudah menguap, mudah menyebabkan karat dan bisa menimbulkan endapan yang dapat membuntu saluran pendinginan.

 

Radiator coolant itu memerlukan cairan yang bisa menghantarkan panas namun awet. Anti-freeze diberikan untuk mengurangi titik didih, mengurangi titik penguapan, mengurangi karat dan kerak. Berikut adalah saran rasio perbandingan antara air dan anti-freeze.
Radiator Fluid: What to Use & What to Avoid

If you live in more temperate climate areas such as states in the South or Southwest, you should mix a glycol antifreeze coolant with an equal amount of water. Most vehicle manufacturers recommend a 50/50 mix of glycol antifreeze and water when vehicles require adequate cooling but do not need much protection from the cold of a harsh winter. However, a 50/50 mix of antifreeze and water will offer adequate winter protection for a vehicle in all but the most extreme winter environments.

If you live in colder regions of the country, you should mix your glycol based antifreeze with water as well. However, you should use 70% glycol antifreeze and 30% water to provide additional weatherization protection for your vehicle. This will help prevent your engine block from freezing up in extremely cold temperatures.

Berdasarkan rekomendasi tersebut, kita hanya perlu menggunakan campuran 70% anti-freeze bila berada di temperature yang ekstrem. Jadi untuk kondisi seperti di Indonesia, yang lebih cocok adalah 50% air dan 50% anti-freeze.

Jadi, jangan heran bila disarankan untuk menambah radiator dengan air. Boleh ditambah dengan air aqua atau air suling lainnya. Tapi jangan ditambahi dengan air aki ya bro! Saya pernah eksperimen elektrolisis, dimana kondisi air sangat mempengaruhi proses. Saat pakai air aki (baik yang merah atau yang biru) proses elektrolisis sangat ganas, tanda bahwa air tidak netral. Menjaga pH dari cairan radiator sangat penting. berikut referensinya:
The Importance of Coolant pH Readings

Ph Value	Opinion
1	Extremely dangerous, Raw Acid. Replace coolant immediately.
2	Extremely dangerous, Strong Acid. Replace coolant immediately.
3	Extremely dangerous, Acidic. Replace coolant immediately.
4	Dangerous, Mild Acid. Replace coolant immediately.
5	Unacceptable, Mildly Acid. Replace coolant immediately.
6	Unacceptable, Mildly Acidic. Replace coolant ASAP
7	Questionable, Neutral. Probably not functioning. Replace coolant.
8	Acceptable.
9	Acceptable.
10	Acceptable, Alkaline. Some coolant inhibitor systems function very well at this pH eg. GMH specification HN2043 coolant.
11.	Unacceptable, Mildly Alkaline. Replace coolant.
12.	Dangerous, Highly Alkaline. Replace coolant immediately.
13.	Extremely dangerous, Highly Alkaline. Replace coolant immediately.
14.	Extremely dangerous, Caustic. Replace coolant immediately.

Harus diingat juga bahwa mencampur – campur tipe coolant sangat tidak disarankan. Lebih aman bila hanya menambah air daripada menambah coolant dari merek yang berbeda. Mungkin ada yang kasih saran diberi warna yang sama. Penulis tidak setuju karena jenis dan rasio dari coolant tidak ditentukan oleh warnanya. Penulis juga khawatir karena warna menunjukkan adanya partikel, malah bisa – bisa jadi sumber penyumbat aliran sistem / pompa pendingin.

Jangan pilih asal murah tapi mbendol biaya di kemudian hari bro!