How to Clean HVAC Coils Without Causing Corrosion or Voiding OEM Guidelines | John Pastorello Part 2
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AC SmartSeal, the professional's choice. All right, guys, are all coil cleaners made the same? No, they're not. And there's a reason why we got John Pastorello on the podcast for part two. He's going to talk about coil cleaning and aluminum fins and microchannel safe and all that kind of stuff and why water is corrosive to aluminum.

and why they put a special inhibitor in their coil cleaners. So when you're rinsing the coil cleaner off, that inhibitor prevents the water corrosion of the aluminum fins. Pretty interesting stuff. So this is part two with John Pastorello from Refrigeration Technologies.

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Your host and HVAC tech, Gary McCready, will take you on a deep dive into the industry discussing all things HVAC, from storytelling to technical discussion. Enjoy the show.

Can I make a statement and you tell me if this has any weight to it? The water only statement on the OEM's condenser coil is basically a blanket statement because they don't particularly trust that the technician is going to use the correct type of cleaner on it. So basically they're covering their ass by saying don't use any coil cleaner

Because somebody might come along and use something very acidic that starts eating away at a coil. Is that a fair statement? Oh, yeah. I think what they're really afraid of is that technicians out there are going to use brighteners. And that's certainly not the way to go. And they didn't really dive into the more passive cleaners like what we use that don't harm any services.

and we have corrosion and protection in our coil cleaners. So you have to rinse it with tap water after you're done cleaning the coil, but we have corrosion inhibitors in the coil cleaner that will keep the water, your rinse water, from causing further corrosion.

Yeah. So you brought up the fact, because that's where I was, I was going to ask you that in a few minutes because you brought up water being corrosive. Yes. To a coil. And I was going to ask you in a few minutes, how do we rinse coil cleaner off a coil if the water is corrosive? And you've just answered the question. We have inhibitors in some of the coil cleaners you use that prevent the corrosion from the water. Is that right? Is that what you're saying? Yes, because-

Interesting. Your coil is going to be aluminum, at least aluminum thin. Yeah. You don't find faucets made out of aluminum. Why? Because tap water will corrode it. Interesting.

Yeah. So you've got a bunch of different cloud cleaners. And I mean, the venom packs are great because they're concentrated and you can mix whatever you want into whatever concentration you need for that specific job. But what cleaners, is it all of your cleaners that have this inhibitor, corrosion inhibitor in it? Or is it only a few? Oh, definitely. I think we're the only ones that use a rinse aid. So just like the jet dry you'd use in your dishwasher, we use a rinse aid so that the

Detergent will sheet right off and not leave any hard water deposits behind. And then there's going to be some corrosion inhibitor to coat that aluminum and copper. So when they go to rinse with water, they're not going to have any corrosion effect after effect. Okay.

So even in, cause you do have a brightener as well. Like it's a, it's a high, sorry. It's like, it's, you would only use a brightener in cases where you have a really, really soiled plugged coil or something like that. Right. Yeah. We, we'd say only in extreme cases. I mean, there's a need for, if you're doing restaurants and all your rooftop units are condensers are just plugged with grease or

I see no need for ever using a brightener in a residential setting. Yeah. Basically just commercial settings. And it's really should only be used 10% of the time. Most coils are just dusty. Yeah.

And, you know, maybe some good buildup of soil. Yeah, natural airborne debris, stuff like that. Exactly, exactly. And, you know, it can be an industrial area where you have a lot of particulates, a lot of air quality issues, exhausts.

being sucked into uh the coil the reason i asked you about the bright the brightener is does the brightener have the uh the inhibitor as well to prevent corrosion from the water no because no no no that's why i asked because i thought because that's almost like a different animal on its own right oh yeah yeah i mean you can't remove aluminum because that's what brighteners and acids do acids and really often it cleaves by removing aluminum

And I mean, you possibly could go in afterward and use a corrosion protection in your rents. Okay. Yeah. That could be done too. So you're saying the way the brightener works is it actually removes a layer of the aluminum and that's why it gets so bright? Yeah. Yeah. Interesting. When I was growing up, and this goes way back, but we used to have to wash walls, right?

in our bathrooms and kitchens. It was kind of like, you know, every six months, we got to wash the walls. Well, when you wash the walls, all it did was remove a little layer of paint. Mm-hmm.

And I don't know, for some reason, but was it back then, too? There were spick and span and all this stuff for washing walls. People used it religiously. Yeah. And of course, they also use floor wax. You wanted to wax your floors in the kitchen and the and the bathrooms and to make them shiny.

Yeah. And, you know, you don't see those products around anymore. And it's kind of like the same analogy with coils. People want bright coils. People want shiny floors. But they don't realize what they're doing when they're washing their walls is they're removing paint. That's how they get it clean. Okay. So then let's move away from the brightener for a minute because, for instance, let's go to the microchannel safe cleaner that you have. Sure. Okay.

Okay, so there's obviously a pH level of that cleaner, but to my understanding, it's not on the acidic side of things, correct? No, no. People can confuse a relatively, you know, you think you have to use a cleaner in the range of 7 to 8, but you can go really as high as 11.

on your pH of a cleaner as long as there's corrosion inhibitors in there. So, you know, it's only when you get to the extreme pHs of 13, 14,

That you have to worry. Okay. Neutral cleaners really are not effective. They're not high performance cleaners. They're just very, very mild cleaners. They only remove a lot of surface. They don't remove soil that's embedded. Okay. Yeah.

All right. Now, I mean, I brought up the microchannel because that is seems to be the misconception amongst a lot of people online with all the comments is that you shouldn't be cleaning microchannel coils with any type of chemical whatsoever.

Yes. Now, yours is formulated specifically. Tell us how a microchannel coil cleaner is a little bit different from any other coil cleaner. What is different to say it's microchannel safe rather? Because are all your coil cleaners microchannel safe or do you do have specific one for microchannel cleaners? No, everything. Let's maybe talk about that. Everything we make is aluminum safe. Everything is aluminum safe. Yeah, except the bright one.

except the brightener. All right. So the pH scale you're saying for the aluminum safe stuff,

is seven to eight and it's got the corrosion inhibitor in it yeah actually we're more than nine to ten on the ph that doesn't matter okay the more effective corrosion inhibitors attach better and last longer at the higher phs so as we're applying cleaner we're also applying corrosion inhibitor and we want that corrosion inhibitor to bond to the metal

And that's only done by getting the pH up there around the 10 range. Okay. This is exactly why I wanted to talk to you, to get into the science of all this stuff. So moral of the story is water is corrosive. We can use a coil cleaner that is on the alkaline side, you said 8 to 10, with corrosion inhibitors. And that's why we can get away with cleaning water.

aluminum coils with chemical and not corrode it with the water after. So let's switch to evaporators because you have evaporator cleaners and how are they different from a condenser cleaner? Are they very similar or is there, what's the differences involved to say this one's for an evaporator and that one's for a condenser? They are very similar. Okay.

It's really indistinguishable because they're made from essentially the same detergents. People say, well, condenser gets a different soil than an evaporator, but that's not true. They're both sucking in the same air, the same air from the environment, whether it's outdoor or indoor. The outdoor air comes indoors. It's going to be the same. Maybe you're going to pick up more carpet fibers.

and that kind of stuff on your dog hairs. Yeah, pet dander and all that kind of stuff. But removing it is the same process. We went with our evaporator coil cleaner, we went with using detergent and built it with enzymes, and that was basically so we can get rid of the biofilms that may form in the indoor coil. Yeah, in the biofilms.

And the biofilms are basically coming from what? Like, what are they coming from? And why is the enzyme there? Any type of growth, any microbial growth you got going on in there. And I'm sure, you know, in your human areas, you know, it's just profuse, man. It's everywhere. If you live in the desert like Arizona, you don't have to worry about bugs growing on your coils, indoor coils. It's just too dry. They can't survive. I mean...

So let's switch it to...

to degreasing because degreasing is something that is important to any kitchen equipment that I've come across in the past has had some level of grease. Now, I know your coil cleaner in a can, the red can of Viper coil cleaner, that's not a brightener, right? Let's just talk about that for a minute. Is it a brightener or is it not a brightener? Oh, no, it's not a brightener. It's aluminum safe. It's aluminum safe. Okay, perfect. Yeah, because I've used it a ton of times. I've actually...

You can tell me what you think about this. I've used that stuff on a kitchen evaporator. I've sprayed it on. I've let it.

obviously it's going to drip down and it makes, you're going to have a bit of a pooling of the coil cleaner as it starts to go from its foam into its sort of liquid form and drips. But I've never, ever, ever rinsed that stuff off with water. Never. And I've never come back and seen any sort of issues with it. So this, this is a bit of an experiment on my end, but I think in the instructions, it says rinsing is, is not needed or it's optional. There is something about that in there, is there not?

Supplyhouse.com is your shortcut for part shopping. They have thousands of HVAC parts from all the leading brands and the orders get shipped and delivered across the U S and the day or two tops. HVAC professionals can get free shipping, free returns and discounts on every other order through their trade master program, order parts and get them delivered right to your door at supplyhouse.com. Yes. You got to look at, yeah, we actually have to read, read the instructions. Oh,

Of course. The evaporator is going to be dependent on condensation for the rents.

A condenser, you need to rinse it. You need to, because I haven't been rinsing my condensers at all. Yes, we thought that was common sense. Everybody would think that you could, once you apply a foamy detergent on, you need to rinse that condenser. But the evaporator, it's going to self-rinse with the condensate. I agree. I agree there. Just from a standpoint of me not rinsing the condensers and not seeing issues with

years down the road, because when I worked for a contractor, it was my buildings and I just rotated through them on a yearly basis, making sure that the maintenance was done and all the repairs were finished. And I could see three, four years down the road, a coil that I've cleaned with your Viper coil cleaner, that there's no visual corrosion happening at least. Cause I've never, I've never rinsed them just because I'm

When you're in the middle of a warehouse and you've cleaned a coil, you really don't have access to water. Or I guess you could figure it out in some way or form, but I've just done it and left it just to see what happens. So give me your thoughts on leaving it on. Okay. First of all, leaving it on about half the cleaning job is done as you rinse with water.

because the detergents will break down and loosen the soil but then you need the wrist water that carry the soil away yeah no i i agree with that but because i haven't rinsed them am i going to get scolded from you on on that because i literally have not rinsed any of the condensers and it's i'm usually i'm talking about small condensers from small condensing units that are like

packed inside of a reach-in freezer or cooler or something like that yeah no it'll eventually it'll go through a process known as blister and lift okay because um the if you can think of uh it just just blistering of separating away from metal and fine flakes will just

dissipate. Okay. So there's no real danger to the actual coil or fins? No, but I'd say just for the sake of carrying that dirt away and off, rinse with water. Okay. Perfect. All right. I mean, as far as coil cleaners go, we've talked about pH levels and inhibitors and stuff like that. Is there anything else you think is important

for someone that's going to clean an evaporator or a condenser before or after using a chemical? Well, if you spend 10 minutes on cleaning a coil, it's probably not going to get as clean as if you spent 20 minutes on cleaning the coil. Okay. If you just go in there and just do a quick one application, don't let it sit in there and let the detergent do its work, you know, and rinse it off real quick. It's not going to come as clean as...

allowing the detergent to sit on that coil, what we call dwell time, to where detergent has a chance to work. It can break the bond between the surface and the soil, allow you to rinse it off. The longer you soak your pots and pans in soapy water, the cleaner they get and the easier it is to remove the spoils.

So we, we, we like to see a good dwell time of at least five minutes. Five minutes with the cleaner on it. Okay. Perfect. Cool. Well, John, this is, um, I've talked to you about coil cleaning before. I think I've talked to you about coil coating before, but every time I do, we learn something new and it's the pH levels. I didn't, I don't think I knew about the water being corrosive and I don't think I knew about the corrosive inhibitor that goes into the

the chemical. So that, that was very cool. So for that, I thank you very much for your time today, John. Okay.