Electric Fans

[Wallaby Dan]

Hi, I just had my radiator recored and when I was there, I saw a cowling with two fans and had adjustable thermostat. looked like stainless steel. The guy said the salesman will be back Monday and couldn't quote a price. Said that they had sold about 50 units for Ford's and Chevy's Mh.
Does anyone have one of these on this web site that can tell me if it was worth it and just how quiet it is compared to a clutch fan? Guy said it takes a 25 amp circuit and it has a sender wire for the A/C. I know that when the clutch fan kicks in we have to shout to hear each other..Maybe! When the clutch is kicked out it is quiet enough to hear the china rattling in the kitchen closet. Anyone?? Capt.

[Wallaby Dan]

Hi, I just had my radiator recored and when I was there, I saw a cowling with two fans and had adjustable thermostat. looked like stainless steel. The guy said the salesman will be back Monday and couldn't quote a price. Said that they had sold about 50 units for Ford's and Chevy's Mh.
Does anyone have one of these on this web site that can tell me if it was worth it and just how quiet it is compared to a clutch fan? Guy said it takes a 25 amp circuit and it has a sender wire for the A/C. I know that when the clutch fan kicks in we have to shout to hear each other..Maybe! When the clutch is kicked out it is quiet enough to hear the china rattling in the kitchen closet. Anyone?? Capt.

[alvinc]

I'm not convinced that electric fans are any quieter. My only experience is with the Workhorse W22 fans.

My model has a clutch operated fan on the engine and the then a two motor electric fan. The electric fans only come on during a long pull on a grade, and you know it when they come on.

So based on this I would think that an electric fan could be just as noisy or worse than a clutch fan. Certainly an electric could be controlled so that its speed is variable, which would cut down on the noise somewhat.

If you are concerned about the noise, get them to demo one. Either have them hook one up to a battery and turn it on, or find out when they are going to install one and make arrangements to hear them test it.

Also ask questions about how they install it. Does it sit in front of the radiator or does it replace the clutch fan? There are pro's to both types. Having both electric and clutch fans is a backup in case of failure, but will probably be noiser than what you have now. Replacing the clutch fan is probably quieter, but those fans better work, and likely will have to run continuously (maybe at a slower speed).

[Wallaby Dan]

These set up in place of the clutch fan.Two fans in a shroud. $300.00. Maybe this isn't a good idea if it isn't going to be quieter. Thats the main reason we were going to do it but? I think I will rethink this. Thanks Capt.

[BellaBo]

Another added benefit to the electric fans is that they don't draw any horsepower from the engine. I think that clutch fan causes some significant horsepower draw when you need it most going uphill.

[alvinc]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Streamerman:
Another added benefit to the electric fans is that they don't draw any horsepower from the engine. I think that clutch fan causes some significant horsepower draw when you need it most going uphill. </div></BLOCKQUOTE>Doesn't energy for the electric fan come from someplace?

In this case it is from the alternator. The engine speed tends to be higher when you are climbing a hill, so the alternator is spinning faster. The alternator will always have a higher voltage than the battery so any load will draw from the alternator first, until it exceeds the amperage capacity of the alternator at its current RPM.

Ergo (therefore), electric radiator fans operating while climbing a grade will be powered by the alternator, not the battery, and the fan load will be on the engine.

By design the battery is used only when the total load exceeds the capability of the alternator at the current RPM and pulls the voltage below the battery terminal voltage.

I guess you would put a switch in to turn off the fans when you climb a grade, but that defeats the purpose of the additional cooling.

[BellaBo]

Your point is well taken and I cannot argue the theory but I have two thoughts about this.
1. It would seem to take more energy to turn the big fan and clutch assembly trying to draw air through the radiators (water,oil and a.c.) than the two little electric motors.
2. I thought the alternator had a direct cable to the battery through a regulator to recharge the battery when needed. My thinking is that the battery acts like a ballast and when it gets low from supplying all the electrical current for the entire system, the alternator replaces the charge. If you ran without the battery in the circuit I could see a much heavier load on the alternator.

[max49]

If I'm wrong some one will surely correct me but I'll go out on a limb and say, it is not the electric fans that make all that roar, it is the clutch operated fan behind the radiator.
I don't know how you could replace that with electric fans.

[M&EM]

Here's a thought:
While traveling up the hill, a simple wiring change could allow shutting down the alternator. Thereby allowing more usable power to get to the rear wheels. Then turn the alternator back on when going down the other side to replenish energy removed from the battery-- and at the same time add a small amount of brake effect. Gravity will provide the replacement energy consumed by the electric fans.

Hmmmm

Any body got a motor we can replace a drive shaft section with?

Marty

[NeilV]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Streamerman:
Your point is well taken and I cannot argue the theory but I have two thoughts about this.
1. It would seem to take more energy to turn the big fan and clutch assembly trying to draw air through the radiators (water,oil and a.c.) than the two little electric motors.
2. I thought the alternator had a direct cable to the battery through a regulator to recharge the battery when needed. My thinking is that the battery acts like a ballast and when it gets low from supplying all the electrical current for the entire system, the alternator replaces the charge. If you ran without the battery in the circuit I could see a much heavier load on the alternator. </div></BLOCKQUOTE>

The alternator usually connects straight through to the battery/battery isolator while the regulator controls the field wires that energize the alternator.

Now I am going to say something that my Dad would have, at least thats the way it used to be when I was involved with rebuilding alternators 30 years...

As for high output electric fans I have bought some and after having them installed for a few minutes removed them because of the noise.

It is not the fan clutch that makes the noise but the fan trying to move all that air. No mater what is powering the fan blades you will still have to deal with the sound of the air passing through the radiator and engine compartment.

Some electric fans are quieter simply because the don't move as much air as the stock engine fan others may seem quieter because the radiator is between you and them or the blades are better balanced than the stock engine fan.

On my coach, yes it is a Ford but noise is noise, putting sound insulation on the dog house elimiated much of the fan noise and heat comming in and was the best solution for me, it cost less too.

I would make sure that there was not a problem with the fan and clutch and replace it if it was defective and then insulate the dog house no matter what. Actually that is what I did, and it worked for me. Neither the fan nor clutch needed to be replaced.

[TOMF1936]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by max49:
If I'm wrong some one will surely correct me but I'll go out on a limb and say, it is not the electric fans that make all that roar, it is the clutch operated fan behind the radiator.
I don't know how you could replace that with electric fans. </div></BLOCKQUOTE>

Max 49 is correct, the noise does not come from the electric fans, it comes from the clutch fan. I wired 12 volts through a switch to my electric fans so I could manually turn them on before I hit a grade. They are so quiet you can barely hear them running.

Tom

[alvinc]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Streamerman:
2. I thought the alternator had a direct cable to the battery through a regulator to recharge the battery when needed. My thinking is that the battery acts like a ballast and when it gets low from supplying all the electrical current for the entire system, the alternator replaces the charge. If you ran without the battery in the circuit I could see a much heavier load on the alternator. </div></BLOCKQUOTE>Unfortunate this is the wrong analogy.

You are correct in that the battery and the altenator are directly connected with a heavy wire. The regulator makes it possible for the alternator to produce power, the diodes in the alternator change the alternating current to direct current. Otherwise they do not factor into the circuit.

But back to the battery and alternator, both are sources of voltage and power. The distribution of the power and which device supplies it is driven by the voltage.

Lets assume a charged battery and good alternator on a running engine.

If the voltage output by the alternator is higher than the battery voltage (with engine off) the battery will be charging and the power needs will be supplied by the alternator. No power will be coming from the battery.

If there are enough accessories turned on (lights, radio, brake lights, etc) and the car comes to a stop sign, the alternator may not be spinning fast enough to supply the power that is needed and the voltage will start to drop. If the voltage drops below the battery voltage, the battery will support the voltage and it will provide the additional power. Note that the load is shared between the battery and alternator. Once the alternator starts spinning faster, it will provide more power, the voltage will rise and the battery will not be providing the power. Indeed the battery will start charging as soon as the voltage rises above its terminal voltage.

In a properly designed system, the only time the battery should provide power is when the engine is off.

A good alternator (all the diodes working), and one that is properly sized, is important for healthy batteries. If the altenator is failing it will provide less power and will need the backup of the battery. If the alternator is undersized it will also require more from the battery.

[alvinc]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Streamerman:
1. It would seem to take more energy to turn the big fan and clutch assembly trying to draw air through the radiators (water,oil and a.c.) than the two little electric motors. </div></BLOCKQUOTE>A dual fan for a pickup varies between 12 and 20 amps (12V). These fans would supply between 2000 and 4500 CFM and are designed for 327 to 400 cu engines.

The interesting thing about energy is that you don't get it for free, so if the electric fans take 144 to 240 watts to turn, then it will take that much power to turn the alternator to make the electricity, plus some to pay for the conversion. In this case between 0.19 and 0.32 HP, plus some, to power the electric fan.

Does a engine mounted clutch fan use more HP than this? I don't know.

[E Z Livin]

I also hate the loud fans but also know they are doing their job and moving air.
I had the vents installed Christmas to stop the overheating wires.
I notice my fans are more active in the summer that the winter which makes sense.

Now my question is, do you think the vents will help keep the motor cooler and the fans will run less this summer?

If so, then if we could increase air flow to the dog box, the fans would not be such a nuisance.