Auxiliary Radiator Fans

[DrivingMissLazy]

I have mentioned several times the auxiliary fans I used on my radiator for extra cooling and for cooling the radiator when running the genset which was plumbed thru the main engine radiator.
The following link goes to the Hayden page in their catalog that discusses them.
They are available in 10, 12, 14, and 16 inch diameter and they have one unit that has two 12 inch fans mounted on an adjustable bracket, designed for motorhomes.

These units are easy to mount as the mounting clips, which are plastic, slip thru the fins of the radiator. They also have an adjustable thermostat  (160-230 degrees) to turn them on and off. It also slips thru the fins of the radiator.

I found that two 16 inch units made a significant difference when the coach started heating up, and they were mandatory when using the genset with the coach parked and the main engine off.

This is the link:

http://haydenauto.com/pdf/2003-imperial-catalog.pdf
 

[H3Jim]

Richard,

Good info. I found a temperature control that I'd lke to order but that link appears to be several years old and more importantly does not provide a place / phone number to order from.  Do you have that info?

Thanks

Jim

[DrivingMissLazy]

This is Haydens home page.

http://www.haydenauto.com/

You might be able to find something there regarding pricing. I really could not find much. A google search for hayden auto brings up some stores that sell Hayden products.
Richard

Richard,

Good info. I found a temperature control that I'd lke to order but that link appears to be several years old and more importantly does not provide a place / phone number to order from.  Do you have that info?

Thanks

Jim

[NJT5047]

Try Summit Racing. They sell Hayden products.  May have temp control if it is used on automotive or high perf cars.  They can get it I'll bet.   Web address is: http://www.summitracing.com/
Cheers, JR

[David Anderson]

Richard,

Without starting the disparaging rants that Twodogs received  last year on BNO about replacing the engine driven fans with electric, I'm curious.  I went to the Hayden site and found the biggest fans they had #226216, 16"x16"  mounting platform, 1300 cfm.  I could clip 4 of these to the front of my radiator on my eagle 10 and use them to supplement the airflow through it when needed, ie. over those big mountains I climb in Colorado.   I don't expect to get 1300 X4 the cfms through my radiator, but I would get a lot more than I'm getting now, wouldn't I?  The fans could be controlled by t-stat or manually from the cockpit as needed.   My alternator can handle the cumulative 80 amp total.

My reason for considering this is that I had a long conversation with the design engineer at Atlas Radiator Mfg in
Corpus Christi Tx.  His company manufactured most of the radiators for Eagle
Mfg Co. in the mid 80's thus the radiator in my coach probably came from
them.

He told me they were sized to unload about 10k btu's of heat from the
DD6v92.  I failed to ask if that was per minute or per hour.  I assume per
minute and assume this is under a near full power loading.   Even with this
engineering he said the eagles still had some heating issues.

The 41" OEM radiator in my 10 has 8.33 sqft of surface area to scavenge its air flow.
The requirement for proper btu removal is 2000 cfm of air per minute,
roughly 24mph according to him.   These are optimum amounts.  The cfm begins
to fall if the fan is too close to the core, shroud problems, etc., and a number
of the other things.  His take on the larger 46" radiator that is available will not be any more effective
without a larger fan.  The 46" requires 2700cfm for optimum heat removal.  Anything less reduces the efficiency, thus the heat load of the engine overcomes the radiator's ability to remove the heat load.

He recommended 2 smaller hydraulic high speed fans which could really move
some air.   This may not be practical in this setting because of the framing
etc., not to mention the cost.  Probably why Eagle never did it that way.

Your last post really intrigued me.  All I need is a supplement to get over the high altitude pass without the nagging heat gain and my problem is fixed.  This idea may be workable.

What do you guys think?

David

[TomC]

ALWAYS keep the original engine run fan whether it be a direct or hydraulic drive.  A 30" fan can consume in the 35hp range.  How could you duplicate that with an electric fan?  If you don't believe me, stand against the grill of the radiator (suggest using ear plugs) and have someone else rev up the engine to governor limit.  You'll have a hard time pulling yourself away from the grill.  If the radiator is clean inside and out, the fan is properly positioned in the fan shroud and the intake radiator shroud is complete, you shouldn't have heating problems. The objectionable thing about the electric radiator fans is that they make a high pitch fan hum when running that can be disruptive to you and your neighbors.  I have two 14" radiator fans inside my bus using the original heating element and there is no mistake when they come on.  Good Luck, TomC

[kyle4501]

Yeah, what Tom said.

Let's all remember, the previous disparaging rant about elec fans degraded when someone insisted they would work without the engine driven fan and argued against the laws of physics.

David, I believe you are on the right track. Like Richard & Tom have said, these elec fans can help when used to supplement the engine fan as increased air flow usually helps.

Pressure drop & mass of air moved determines required HP. Be carefull when looking at the cfm #'s for the elec fans. If you don't know the pressure drop for the 'rated cfm', you don't know much about the usefullness of the fan. We use fans at work on some equipment & the cfm moved by one of our fans is 6400cfm @ 0"sp, 4410cfm @ 1-1/4"sp (2.0HP required) . (1"sp = 1 inch of water)  While 1-1/2"sp doesn't seem like much, it cost ~50% of this fan's capacity. I have not been able to get the fan curves (cfm vs pressure drop) for these automotive fans. I suspect the manufacturer is afraid we will realize they don't move as much air as they want us to think.

[DrivingMissLazy]

First, let me state that the fans I used were to supplement the main radiator fans, not to replace them as Two Dogs suggested.

I initially installed two 16 inch fans, thermostatically controlled, to permit running the diesel genset which was plumbed into the main coolant system of the coach. Thermostat was rated to come on at 190 degrees and open at 175 degrees. Otherwise the genset would shut down after several minutes of operation. The fans did cycle on and off, so I know they were providing some supplemental cooling. They also cycled on and off when driving thru places like Texas when I was pushing the coach at 80+ mph and the outside temperature was in the three digits. They also came on anytime I started climbing some good grades.

Based on the problems that David is having, I would install four 16 inch fans. I would install two adjustable thermostats, one set at 190 degrees and one set at 200 degrees. Each thermostat would control two fans thru a cube type control relay(s). Also, I would install two dash indicator lights, one yellow for the 190 degree fans and one red for the 200 degree fans.

Based on my actual experience with tens of thousands of miles traveled thru-out all parts of the country I believe this would solve the majority of your overheating problems. The misters will take care of the rest.
Richard

Richard,

Without starting the disparaging rants that Twodogs received  last year on BNO about replacing the engine driven fans with electric, I'm curious.  I went to the Hayden site and found the biggest fans they had #226216, 16"x16"  mounting platform, 1300 cfm.  I could clip 4 of these to the front of my radiator on my eagle 10 and use them to supplement the airflow through it when needed, ie. over those big mountains I climb in Colorado.   I don't expect to get 1300 X4 the cfms through my radiator, but I would get a lot more than I'm getting now, wouldn't I?  The fans could be controlled by t-stat or manually from the cockpit as needed.   My alternator can handle the cumulative 80 amp total.

My reason for considering this is that I had a long conversation with the design engineer at Atlas Radiator Mfg in
Corpus Christi Tx.  His company manufactured most of the radiators for Eagle
Mfg Co. in the mid 80's thus the radiator in my coach probably came from
them.

He told me they were sized to unload about 10k btu's of heat from the
DD6v92.  I failed to ask if that was per minute or per hour.  I assume per
minute and assume this is under a near full power loading.   Even with this
engineering he said the eagles still had some heating issues.

The 41" OEM radiator in my 10 has 8.33 sqft of surface area to scavenge its air flow.
The requirement for proper btu removal is 2000 cfm of air per minute,
roughly 24mph according to him.   These are optimum amounts.  The cfm begins
to fall if the fan is too close to the core, shroud problems, etc., and a number
of the other things.  His take on the larger 46" radiator that is available will not be any more effective
without a larger fan.  The 46" requires 2700cfm for optimum heat removal.  Anything less reduces the efficiency, thus the heat load of the engine overcomes the radiator's ability to remove the heat load.

He recommended 2 smaller hydraulic high speed fans which could really move
some air.   This may not be practical in this setting because of the framing
etc., not to mention the cost.  Probably why Eagle never did it that way.

Your last post really intrigued me.  All I need is a supplement to get over the high altitude pass without the nagging heat gain and my problem is fixed.  This idea may be workable.

What do you guys think?

David

[boogiethecat]

Hmmm....

Let's say that your main engine-driven fan is moving air thru the radiator at 10 miles per hour.  If you then stick a small electric on there as well that is only capable of moving air at 5 miles per hour, it may not help much- in fact it could turn into a generator or simply freewheel, and actually make things worse.
If, on the other hand, your little electric is capable of moving air as fast as the main fan, or faster, it will help airflow to increase somewhat.  There's a lot of leeway depending on how it's motor is designed... usually it will act like a kid helping a bunch of big men to push someting- every little bit helps....

A simple way to tell if anything's being gained would be to measure the current in the electric fan with the main engine fan not running, and then measure that current with the engine fan running at full tilt.  Some DC motors are built so that they go faster under a lesser load, and if your electric does this, there's a good chance that it will be able to help as Richard found.
So if you see, for example 10 amps with the engine off and 8 amps with the engine on, there's a good chance it's helping... if you see 10 amps engine off and 1 amp engine on, there's a good chance it's hindering...

[DrivingMissLazy]

Since they have to be installed to do a test, why not just take it out for a cruise?
Richard

Hmmm....

Let's say that your main engine-driven fan is moving air thru the radiator at 10 miles per hour.  If you then stick a small electric on there as well that is only capable of moving air at 5 miles per hour, it may not help much- in fact it could turn into a generator or simply freewheel, and actually make things worse.
If, on the other hand, your little electric is capable of moving air as fast as the main fan, or faster, it will help airflow to increase somewhat.  There's a lot of leeway depending on how it's motor is designed... usually it will act like a kid helping a bunch of big men to push someting- every little bit helps....

A simple way to tell if anything's being gained would be to measure the current in the electric fan with the main engine fan not running, and then measure that current with the engine fan running at full tilt.  Some DC motors are built so that they go faster under a lesser load, and if your electric does this, there's a good chance that it will be able to help as Richard found.
So if you see, for example 10 amps with the engine off and 8 amps with the engine on, there's a good chance it's helping... if you see 10 amps engine off and 1 amp engine on, there's a good chance it's hindering...

[ChuckMC8]

Speaking of whom, Two Dogs is back on the BNO board with a new handle, Bob greenwood
JIC anyone wants his take ( pun intended) on electric fans....

[David Anderson]

Richard and Tom,

I value your advice and experience greatly.  Tom, I've done everything I could possibly do to get this OEM radiator as efficient as possible based on advice from you guys and professional help from high priced radiator shops.  I cannot stay below 200 in any protracted climb in triple digit ambient temps above 2000' msl without misting.  It doesn't matter what speed, what gear, or what rpm the coach runs, I cannot do it.  If the temps are 85 or below I can run Colorado or the Nevada desert without the misters until the fuel runs dry.

According to Atlas radiator in Corpus Christi, this coach was designed to run the Houston freeway, flat and level, in up to 99 degree temps.  It performs as engineered.

With Richard's positive experience with this in DML, I sort of feel like I now have somewhat of a choice.  I can throw $500 at 4 easily installed pusher fans or about $3000 for a 46" radiator, fan, shroud and all the ancillary goodies that may be needed to get the beast in it.  

I guess if I do it and it fails, you may see 4 fans on Ebay in the future.  LOL

David

[DrivingMissLazy]

David, be sure and keep some before and after test data on the same run so that all can benefit from your experience.
Richard

Richard and Tom,

I value your advice and experience greatly.  Tom, I've done everything I could possibly do to get this OEM radiator as efficient as possible based on advice from you guys and professional help from high priced radiator shops.  I cannot stay below 200 in any protracted climb in triple digit ambient temps above 2000' msl without misting.  It doesn't matter what speed, what gear, or what rpm the coach runs, I cannot do it.  If the temps are 85 or below I can run Colorado or the Nevada desert without the misters until the fuel runs dry.

According to Atlas radiator in Corpus Christi, this coach was designed to run the Houston freeway, flat and level, in up to 99 degree temps.  It performs as engineered.

With Richard's positive experience with this in DML, I sort of feel like I now have somewhat of a choice.  I can throw $500 at 4 easily installed pusher fans or about $3000 for a 46" radiator, fan, shroud and all the ancillary goodies that may be needed to get the beast in it.  

I guess if I do it and it fails, you may see 4 fans on Ebay in the future.  LOL

David

[Burgermeister]

As I mentioned in another thread, before you go and spend more $$ on another radiator, why don't you check your system for resistance between the outlet from the thermostats and the inlet to the coolant pump?

Simple, closed circuit, mercury manometer setup, sufficient to measure 20" pressure differential will do it.