Community Forums

UV Owners · 02-21-2020, 09:39 PM

Hello Everyone,

It's been a long time since my last post. Life and obligations. Grin
So let me introduce myself again, for those who have not seen my old threads.

My name is Tony. I'm a retired ASE and US Army mechanic.

After years of first trying things and then having Computational Fluid Dynamics preformed; my first thought has become reality.

I need to install a Hydraulic Cooling Fan system.

I'm in need of a fan setup that is small enough to fit in my rare style class A.

What size is the fan on your DP and can you please provide a picture?

Here is one of my old threads about this RV we call UV520..

Thank you a head of time.

Sincerely, Tony

UV Owners · 02-21-2020, 10:23 PM

This is some of what has been done over the years to try to resolve the overheating issue.

Computational Fluid Dynamic model...
This is what they use to do wind tunnel test in a much smaller scale.

So far to date (over the years of classes) they have tested:

1. Over the coach
2. Under the coach
3. Around the coach
4. The engine compartment
5. Different style spoilers to direct the air over and down the back
More test still to come and on going...

shootist · 02-21-2020, 10:33 PM

Lexus used them from the 90s on, they may be big enough, or you could double them up. Super quality and should be 1/10th the price of motorhome stuff from a pic u part.

guardrail53 · 02-21-2020, 11:17 PM

I would think that electric fans would be the way to go! I have the hyd. fan on my side radiator Monaco, that has been converted to two electric fans, works great, can't even hear them running, no cooling problems at all! It never gets over 200* even in the mountains out west!
The hyd. fan systems on most diesel pushers are very big, and I would think they are not going to work for you!
Electric fans can be set to push or pull the air, so on a rear radiator MH, you would want them to push the air out the back, from the motor compartment, thru the radiator and out the back!
Not as efficient as a side radiator, that pulls the cool air from the outside, thru the radiator into the motor compartment!
I have used electric fans over the years, and have had very good luck with them! Rail!

UV Owners · 02-22-2020, 08:10 AM

Quote:

Originally Posted by shootist

Lexus used them from the 90s on, they may be big enough, or you could double them up. Super quality and should be 1/10th the price of motorhome stuff from a pic u part.

Thanks, I've looked into them. I would prefer a system that is more reliable.
The Lexus, Ford and the other auto makers hydraulic fan track record is not too good and they all went back to electric fans.

NOW they can get away with it - due to the fact that their radiator sits up front and is pushed through the wind at highway speeds.
Thus the electric fan does NOT have to work all the time.

However, on my setup and testing; Once the engine gets to operating temps - my fan stay on ALL the time and can not keep up once I start driving.

UV Owners · 02-22-2020, 08:18 AM

Quote:

Originally Posted by guardrail53

I would think that electric fans would be the way to go! I have the hyd. fan on my side radiator Monaco, that has been converted to two electric fans, works great, can't even hear them running, no cooling problems at all! It never gets over 200* even in the mountains out west!
The hyd. fan systems on most diesel pushers are very big, and I would think they are not going to work for you!
Electric fans can be set to push or pull the air, so on a rear radiator MH, you would want them to push the air out the back, from the motor compartment, thru the radiator and out the back!
Not as efficient as a side radiator, that pulls the cool air from the outside, thru the radiator into the motor compartment!
I have used electric fans over the years, and have had very good luck with them! Rail!

I would like to know more about the kind of electric fan you are using; size, RPM and who makes it.
A picture would be nice too.

NOTE: Electric fans are NOT designed to operate all the time.
However, Hydraulic fans can operate on low and ramp up only when needed.

FYI - My first attempt was with a NEW Flex-a-lite radiator and their highest volume electric fan.
Research shows that fans work better pulling than pushing for this kind of application.
I even built a doghouse, so to speak, style cover to ONLY allow fresh cooler air to pass through the radiator.
NOTE: The 3,200 CFM electric fan could not move enough air to keep it cool.

My next attempt was with a 2 speed Ford Taurus electric fan.
I still believe a Hydraulic fan is what is going to work for my application.
But I'm open to seeing what you have.

UV Owners · 02-22-2020, 08:38 AM

It would be most helpful if some DP owners with hydraulic fans could help out.
It would take a very long time to find different makes and models to look at and gather that info on my own.

FYI - Before this, I even tried to find info on DP school buses.
Sadly they don't use them in this part of Ontario.
All the school buses here are front engine.
I found a mechanic out west who works on DP school buses who said he would help.
But shortly after we started talking, he tried to direct me elsewhere.

I can't finish restoring and/or start using this coach until the over heating issue is solved.
I want to get ALL the mechanical stuff worked out - before I start making it look pretty. Grin

After the last ten years of doing everything we can to get out of debt (Thanks to God) and now that I'm 60; I really want to get this resolved so we can start enjoying it.

Thank you

guardrail53 · 02-22-2020, 08:51 AM

Go to Summit racing, they have all kinds of electric fans! If two electric fans can keep my 8.3 Cummins cool in the August temps out west, they will work for you! Google is your friend, lots out there, plenty of videos on YouTube also!
My MH is in Illinois, and I am in Thailand, so no pictures! Rail!

RVPioneer · 02-22-2020, 09:18 AM

I suggest asking this question on a Brand Specific Forum, Country Coach, Monaco, etc. These coaches were, in many cases, equipped with hydraulic cooling fans. Some owners of those coaches may be able to provide you with the information you need to convert your coach.

n2zon · 02-22-2020, 09:24 AM

I have no idea how your MH is packaged, or whether you'd consider the vents to be inappropriate for your restoration.

That said, have you considered a pair of NACA ducts, one per side, to get airflow through the compartment?

UV Owners · 02-22-2020, 09:37 AM

Quote:

Originally Posted by guardrail53

Go to Summit racing, they have all kinds of electric fans! If two electric fans can keep my 8.3 Cummins cool in the August temps out west, they will work for you! Google is your friend, lots out there, plenty of videos on YouTube also!
My MH is in Illinois, and I am in Thailand, so no pictures! Rail!

Thanks but NO thanks. I'm not going backwards... My setup is not the same as yours.
I spent the first five years down the path with ALL kinds of testing and throwing parts and ideas at it..
I've tried 2 different electric fans; the highest volume single speed NEW flex-a-lite available and one two speed Ford Taurus and they could not keep up with the demand.
I even built a doghouse and fresh air intake to ONLY allow cooler air to pass through the radiator.

Electric fans were never designed to be on full time.
Once this setup gets to operating temps - the fan needs to be on full time and still cannot keep up.

The CFD has shown that the way the air moves around this coach and what it does - it will not allow a weak electric fan to push enough air.
However, the RPMs of a Hydraulic fan can over come this.
Plus, I will not have to get a much larger ALT and rewire that part of the coach to handle the demand of such a big electric fan/draw.

Did you know:

A 375HP engine produces 954,163 BTUs and a 400HP engine produces 1,017,774 BTUs..

That's a lot of heat to deal with and more so trapped in the back of a very tight engine compartment and to have a radiator in the back too. Grin

This show just how tight my engine compartment is compared to a more open one of your DP.
Thus there is already much less air movement around the power-plant.

UV Owners · 02-22-2020, 09:50 AM

Quote:

Originally Posted by RVPioneer

I suggest asking this question on a Brand Specific Forum, Country Coach, Monaco, etc. These coaches were, in many cases, equipped with hydraulic cooling fans. Some owners of those coaches may be able to provide you with the information you need to convert your coach.

Thank you.

I might do that.
My thought was to reach as many DP with Hydraulic fans as possible, with only one thread and not have the same subject posted in many different forums.
I was also concerned about focusing only on one make and model and not benefiting from the variety of DP owners here..

Space restraints from different model designs can be most helpful.

FYI - It was during one of my many online searches, the other day, that I came across Monaco's Hydraulic fan setup.
I looked for more, but they not as helpful as the first that I found.
Then I recalled my post on IRV2 and it got me to thinking - why not. Grin

UV Owners · 02-22-2020, 10:01 AM

Quote:

Originally Posted by n2zon

I have no idea how your MH is packaged, or whether you'd consider the vents to be inappropriate for your restoration.

That said, have you considered a pair of NACA ducts, one per side, to get airflow through the compartment?

YES, Thank you.
I and others have thought about a lot of different ways to try to introduce air.
I'm still having some CFD being preformed with vents next, after they finish with the different styles of spoilers on top.
However, this ODD Ball configuration, has TWO walls to deal with; one outer and one inner and it has NO FRAME or CHASSIS at all!
So one has to be very careful what they remove.
Then you have the placement of rear suspension, tires, LP tank and whatnot to deal with.
I'm also trying my best to pay homage to the designer and builder of this coach and keep it looking as much as it did from when it was first hand built.

RVPioneer · 02-22-2020, 10:28 AM

Quote:

Originally Posted by UV Owners

Thank you.

I might do that.
My thought was to reach as many DP with Hydraulic fans as possible, with only one thread and not have the same subject posted in many different forums.
I was also concerned about focusing only on one make and model and not benefiting from the variety of DP owners here..

Space restraints from different model designs can be most helpful.

FYI - It was during one of my many online searches, the other day, that I came across Monaco's Hydraulic fan setup.
I looked for more, but they not as helpful as the first that I found.
Then I recalled my post on IRV2 and it got me to thinking - why not. Grin

Ours is equipped with a Sauer Danfoss TAM22-90/26.5 and an electronic fan controller. Earlier models used a wax valve to control fan speed. There is also a radiator to cool the hydraulic fluid. Side radiator stack includes radiators for engine, transmission and hydraulics. The system also provides boost for the hydraulic disc brakes. Yes, our Class A DP has hydraulic brakes.

I can’t imagine a DP that would have the limited space that you are faced with. Look forward to seeing your solution.