Making Heat

Mardie

New member
Hello everyone. I am shopping for my first heated pressure washer and have found that most systems are stating around 140 degree rise for there specs when it comes to producing hot water. I must be missing something because that would give most units less than 190 degree at the tip and much less in colder climates. As a suggestion why do pressure washers not utilize a heat exchanger using the engine exhaust to preheat the water before the water enters the boiler? Although this may save a little on fuel, the point would be to better manage high temps. in all weather conditions.

Thanks for your response
 
The idea of pre warming water in your tank with your exauhst is pretty interesting. I never thought about varying temps of water sources especially where you are. In Florida it seems to stay pretty constant around 70 degrees give or take 10 degrees or so, especially between March and october.

I could see how a heat exchange system could benifit someone in Ontario
 
Many systems already pipe the exhaust from the engine into the coil. I know this is not as efficient as a proper heat exchanger like a carpet machine, but energy input is energy input. It doesn't matter if it's before or after pressurization.

The best way to increase the heat rise is to increase the energy input. Put in a larger fuel nozzle and re adjust the air flow to accommodate, and the heat rise will be improved.

The other way is to decrease the flow of water, by adjusting your regulator or decreasing the engine speed( pay attention to your generator if you choose to do this because it will need to still produce ~115 volts)



Sent from my iPhone using Pro Power Wash
 
It seems like most of the systems out there only give about 120 degree heat rise with the exception of paying more money for the better and more expensive burner system like the Largo machines have which are great machines.

It is harder to heat water going at more gallons per minute, that is why the heat rise is what it is. If you have no problem spending a lot more money, they will build you whatever you want them to, like a 1 million btu burner system but it will cost a lot more money, more than the hot water rig itself so it comes back to how much do you want to spend and how hot of water do you really want.

For most contractors out there, it seems like what is available will work good for them, that seems to be what is accepted because not too many people complaining too much, too often about the water temperature for hot water cleaning. Sure, we all would love to have 225 degree water coming out of the hose but we also want a hot water rig that is affordable, will not cost a fortune when it needs to be repaired, something that most contractors can work on, etc..... where the heat exchanger systems are a little more complex than regular hot water rigs.

Aaladin came out with a heat exchanger type system and Powerwashstore.com also has something like that, you can look at those systems for more of a heat rise.

What temperature water do you need to clean with?

What temperature of water do you want to have coming out of the nozzle?

For the right price it can happen, how much do you want to spend? Like they say, money talks.
 
Thanks for your insight. I am looking at getting a pump rated at 4000psi and 5gpm pump with a burner rated at 8 gpm. Would that be a dumb thing to do ? because I am thinking that should give me full heat (220+)at the rated 5 gpm pump. I just do not understand why burners are sold that require the pump volume to be turned down to get high heat for cleaning.
 
What are you going to be cleaning? I find that when going above 180 I go through O rings and hoses much faster. For things like fleetwashing there isn't a need to go above 140 or so.
 
Uh where did you get the idea for that high of heat to clean concrete.150 to 180 with the proper chemicals an dwell time is all you will ever need.
 
I hear what you are saying Mardie, I have been to a few carpet cleaning conventions, the last one was with Joe Polish a while back. I talked to many chemical sales reps and a couple chemists about temperature and cleaning ability and it seems in the carpet cleaning industry they all say the same thing, the hotter the water the better the chemicals clean and that kind of makes sense. I asked them for some literature so I could read about it but they did not have any and could not refer me to anything to further my reading on the topic.

In the pressure washing industry several people I have talked to say to keep the temps below 180, preferably 160 degrees because over that temp the surfactants break down and then become useless. I also asked these guys about literature so I can read more about the surfactants breaking down at certain temperatures but they also could not present any literature to further my reading.

So, it seems both industries have their information or theories or maybe it has been proven but nobody can come up with any kind of documentation to show who is correct. This is not a contest to see who is right, I would like to know for myself if the chemicals do break down at certain temperatures or if they don't so that i know and use that to help my business.

In the years since I have met some very intelligent guys that know a lot about chemicals and I never think to ask them about the temperature issue. I will see if I can get Andy Vickers to come here and talk some as he is one of the smartest guys I know in many aspects of pressure washing, chemicals especially but also equipment, engineering, flow, etc.....

This reminds me of a funny little man that swears that you need over 300 degrees to clean concrete properly and clean the oil stains. He brought his rig to a Las Vegas event and some of us went out to the Vegas DMV in the evening when it was 65 degrees outside and tried popping gum. He swore that over 250 degrees the gum just "vaporized" when surface cleaning and they hardly ever had to do any gum removal by gun. Well his rig did get to 315 degrees when it was 65 degrees outside so do the math on that heat rise, it was impressive.

The gum at the DMV in Las Vegas was like it is here in South Texas when it has sat in the sun baking for years, it is almost petrified. Even with 315 degrees the gum did not come up any faster than Tony Shelton's Landa rig that was 6gpm and hit about 180 degrees if I remember correctly with them verifying this with a laser temp gun.

During the event in the daytime several guys got to try this impressive rig to clean and pop gum and many mentioned that the gum was not "vaporizing" at 250, 280, 300 or even 315 degrees and it was not coming up any faster than when using Tony's Landa rig at about 180 degrees.

So, there are many different opinions on heat, chemistry, gum and other things out there that unless you experience it for yourself, it is hard to know who is right and who is wrong.

I will try to get Andy to post his comments and see what he has to say about the hot water temps needed for cleaning.
 
I hear what you are saying Mardie, I have been to a few carpet cleaning conventions, the last one was with Joe Polish a while back. I talked to many chemical sales reps and a couple chemists about temperature and cleaning ability and it seems in the carpet cleaning industry they all say the same thing, the hotter the water the better the chemicals clean and that kind of makes sense. I asked them for some literature so I could read about it but they did not have any and could not refer me to anything to further my reading on the topic.

In the pressure washing industry several people I have talked to say to keep the temps below 180, preferably 160 degrees because over that temp the surfactants break down and then become useless. I also asked these guys about literature so I can read more about the surfactants breaking down at certain temperatures but they also could not present any literature to further my reading.

So, it seems both industries have their information or theories or maybe it has been proven but nobody can come up with any kind of documentation to show who is correct. This is not a contest to see who is right, I would like to know for myself if the chemicals do break down at certain temperatures or if they don't so that i know and use that to help my business.

In the years since I have met some very intelligent guys that know a lot about chemicals and I never think to ask them about the temperature issue. I will see if I can get Andy Vickers to come here and talk some as he is one of the smartest guys I know in many aspects of pressure washing, chemicals especially but also equipment, engineering, flow, etc.....

This reminds me of a funny little man that swears that you need over 300 degrees to clean concrete properly and clean the oil stains. He brought his rig to a Las Vegas event and some of us went out to the Vegas DMV in the evening when it was 65 degrees outside and tried popping gum. He swore that over 250 degrees the gum just "vaporized" when surface cleaning and they hardly ever had to do any gum removal by gun. Well his rig did get to 315 degrees when it was 65 degrees outside so do the math on that heat rise, it was impressive.

The gum at the DMV in Las Vegas was like it is here in South Texas when it has sat in the sun baking for years, it is almost petrified. Even with 315 degrees the gum did not come up any faster than Tony Shelton's Landa rig that was 6gpm and hit about 180 degrees if I remember correctly with them verifying this with a laser temp gun.

During the event in the daytime several guys got to try this impressive rig to clean and pop gum and many mentioned that the gum was not "vaporizing" at 250, 280, 300 or even 315 degrees and it was not coming up any faster than when using Tony's Landa rig at about 180 degrees.

So, there are many different opinions on heat, chemistry, gum and other things out there that unless you experience it for yourself, it is hard to know who is right and who is wrong.

I will try to get Andy to post his comments and see what he has to say about the hot water temps needed for cleaning.



Thanks for your insight. Funny thing is when I hear the chem guys say the hotter the better, the first thing that comes to my mind is, sooo what is actually going to be doing the cleaning, is it the chem ? or the super high heat ? lol
 
Short thing is just run what the experienced guy do.
If you want extra heat just put a hot box after the unit for the extra heat.

You start running into how much heat can move from the water to the surface before it transfers to the air around it. Gas is a faster transfer than to solid.
If that kind of helps.
Geek out if you want but use the standard equipment everyone else does for your first year.
 
Well I do not know if I geeked out but I did just order a system with 6.5gpm @ 4 psi with a hot box rated at 8 gpm. I was told that Canadian specs for creating hot water are higher than the states because our ground water is colder and I did order my system with American spec from the states.
 
What was the heat rise on the hot box you ordered? That info should be in with the specs when you ordered it, if not they should let you know when you ask them. If they don't know I would hold off or stop the order until someone tells you what the heat rise is so you know. Being up in Canada I would want a minimum of 120 or 140 or higher heat rise because of the colder ground water. You are paying so you are entitled to this information. If they play dumb or act stupid or just don't want to tell you the heat rise then I would cancel the order and go with someone who will tell you the specs and work with you, it is your money.
 
I bought my system from Jerry M. Sirroco. Jerry easily answered all my questions. Jerry is going to set my hot box up with adjustments so I can run low volumes and pressure for stuff like indoor tile and grout to temperature controlled hot water pressure washing and then up to 300wet steam. This is my first pressure wash system so I figured i should get all the adjustments because it will give me the opportunity to take on different kinds of work. I also got his 21 inch surface cleaner (I have a vacuum system) and his sand trap. Because I wanted full portability the hot box and pump will on there own separate carts. Should be ready for shipping on the 20th of march.
 
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