The age old question and probably the one I have gotten the most by customers, “Is it better to use hot water?” This question comes in a lot of forms, but this is the basic point, should I be using hot water? Earlier in my car wash career, I wasn’t quite sure how to answer this question. I’m sure I stumbled around it because I really didn’t know. At the time, I felt like most car wash owners did not use hot water, and quite honestly, I probably did not see a difference. It wasn’t until I had the chance to learn from some industry mentors, and really committed to finding out for myself, the true answer to the question I got so frequent.
Now that I look back this, it truly seems like an easy question to answer. It is like asking if waffles taste better with syrup, which is undoubtedly a big yes. What I came to find out is that today’s paints on vehicles are porous. They contract and expand with the ambient air temperature, as well as exposure to sun and moving parts on the vehicle, such as wheels and the engine. Now of course this happens on a microscopic level, but you would be quite amazed at how the fluctuation of the temperature can lock in dirt. Additionally, as the vehicles’ paint ages, this factor becomes worse and the vehicle becomes harder to clean.
Once I understood this concept, I could finally answer this question, and I would do so with another question, which would instantly make sense to all car wash owners. When asked if it is better to be using hot water in a car wash, I would simply reply “do you wash your hands with hot water or cold water?” Again easy to answer “hot,” of course, but it is not because it feels better but because it helps to open the pores in your skin and get the deeper dirt out, this is the same concept in washing a car.
Now that we understand that hot water is better, the problem is that hot water comes as a premium, so lets be realistic. Gas is expensive and can significantly increase your cost per car when heating water. So here is your #carwashhack based on my experience of when to use and not to use hot water.
Detergents- no matter what, no if and’s or butts about it, it should be heated. It not only should use very little water, but be an efficient application. To heat the detergents, makes the chemical more active and it is the single most effective application to heat.
Undercarriage – There is no real need to use hot water on this application, although I’m sure it will help with removing some of the dirt deposits. This is an area that is rarely judged, because it is an area in which is not seen.
High pressure rinse – This can be a big controversy, whether to use hot water here or not. The issue is, this is likely the biggest consumption of water you have in your car wash. The obvious answer is yes, if you want to have the best output on the most consistent basis. This application should be hot. Most car wash owners do not heat this application because of the sheer volume of water that needs to be heated and the capability to keep up with the high demand of hot water on a busy day.
Spot free rinse – This application should not be hot. Not only is it your most expensive water, it has absolutely no benefit to be heated. In fact, it may actually do worse in the drying process.
Every other application in the car wash – Whether it is a drying agent, wheel blaster, and even hot wax, it is all the same, hot water is preferred but not necessary.
There you have it, what do you think? Come join in our discussion on our free forums https://carwashadvisor.com/forums/topic/hot-or-cold-water/