I had seen those and Land Rover also has them. Not sure what it would take to find a way to adapt it to my small case mounts but it is worth looking into.
Add heat-sink cooling fins to alternator?
- Thread starter Hayden Watson
- Start date
Running the engine a bit cooler can lead to increase in deposits in the combustion chamber and mixing elbow. That said, I know that a large percentage of marine diesels run with 160º T-stats. I did for years and changed it out for a 180º in an effort to resolve a water heating problem in my domestic water heat exchanger.
The engine compartment will run about 180º if I do not run the blower due to the 1" mass weighted foam sound insulation on all four sides and top. With the blower running and the battery full so that the alternator is not running, the alt case temperature is about 135 º - 140º so I assume that is about the space temp with fan. I have attached a drawing showing the run of the blower fan. the suction side is 15' - 20' and the outlet side is about 3'. The C30 has a very forward engine location so the hose run is more than on other boats of similar size.
I will check into that. I was planning to remove the alternator this winter and rebuild the bearings an brushes. I might look into remoting the diods as well. There is only about 4" clearance to the side sound insulation, and I might be able to route them to outside of there to put them in a "cool room".
Maybe I will look into mounting the case fan to the outside of the insulation wall and then put an elbow on the inside to turn the air in-line with the alternator. Something like this would be easy to do and I can get power from the fuel lift pump which is only on when the key is on. Red hose is hot exhaust and blue hose is cool intake.
It would likely be easier to keep my cool if I had not done such a good job with my insulation but not ready to go back to above the threshold of pain. 
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I am with Tedd and Ralph on this issue. Outside air directly to Alternator would be far better than attaching heat sinks to the alternator or the diodes. There is just not enough differential with the Engine heat in the confines of your diesel space box to lower the temp on the alternator enough to gain much if any increased performance. Blowing in 90º air on a hot day and providing a system to suck out the heat of the diesel would be least expensive and provide possible improvement to output a few more amps from the alternator to your batteries.
Even with the additional amps your battery recovery will be limited by the over all capacity of the alternator. Sometimes one might as well bite the bullet. Just how much more does the alternator owe you? I think you went into the space age with your LiFePo4 battery system… Why is it relevant to use a Ford model T alternator? I suspect you keep running the old alternator trying to power the new batteries it will eventually rebel and quit. Just hope it is a peaceful death and not one that goes out in anger.
Even with the additional amps your battery recovery will be limited by the over all capacity of the alternator. Sometimes one might as well bite the bullet. Just how much more does the alternator owe you? I think you went into the space age with your LiFePo4 battery system… Why is it relevant to use a Ford model T alternator? I suspect you keep running the old alternator trying to power the new batteries it will eventually rebel and quit. Just hope it is a peaceful death and not one that goes out in anger.
I think the fan location is a major obstacle to the volume of air moved.
Here is a quicky overview of mine :
This gives the maximum volume at the minimum available temperature.
To the first point, the idea of heat sink is to suppliment the fresh air intake blower and duct taken directly to the alternator in instead of it. It would be sending "below deck" air which in our cold water is pretty chill even on the hottest days. That should supply cooling air directly to the alternator at 50º to 70º.
To the second point, my Ample friend owes me nothing. It is I who owe a debt to him. For 25-years, Ample (Amp for short) has been faithful to me in providing for my ever increasing need for power. through thick and thin, good batteries and ones long past their "best by" dates, he has kept the lights on the the path found.
Now to the fighting words.
I refuse to equal Amp to a model-T. He was never a model-T. While it is true that he started life as an old-school GM Delco 10DN so never a Ford! If he had been a Ford, it would not be a model-T, it would be a '32 Duce Coupe with a flathead V8. He has been stroked and bored and will blow the doors off any other 10DN on my block.Amp is a classic and deserves better than to be sent to the junk yard because his radiator isn't big enough. A classic Hot Rod never deserves or desires a peaceful death in the recycle bin. He would prefer to go out in a blaze of glory... Like James Dean.
Just say'n.
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Currently, the make-up air for the exhaust fan is provided by the 1" gap at the bottom of the sound-foam on all four sides of the enclosure. It pulls air from the below-waterline hull similar to yours. The C30 also has a cowl vent on the starboard side combing near the transom that matches the one on port that the blower connects to. This cowl vent has a hose that runs down under the quarter berth.
The blue rectangle that you are pointing to would be a 120mm case fan I plan to mount to the outside of the insulation with a 4" elbow ducting the air from the intake fan to the back of the alternator. It would get power from the same wire that runs the fuel lift pump which gets power when the engine key is turned on.
It probably would not be too difficult to move the blower fan down near the engine space and then make the long run aft a discharge line. It would make the fan louder inside but probably not enough to be heard over the diesel even though it would be outside of the insulated box. I don't think there is enough room to put it inside the box.
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Our exhaust fan is noisy but with the engine noise and the fact that everyone is in the cockpit when the fan runs, the only noise we do hear is the air blowing out of the exhaust vent.
Here's where I get a little lost. The 120mm case fan you refer to is a squirrel cage fan ?
The 4" elbow is used to duct air from "that" ? "That" refers to the previously mentioned case fan ? So this is now a positive air supply back to the alt ? I like it. Where does it get its air supply from ............. the same below water supply as your 1" gap I presume ?
All I can add is to make sure your supply blower into the engine compartment supplies less ft³/min. than the exhaust fan is capable of removing from the engine compartment. Due to turbulation of air within the engine compartment, the supply fan could probably use a manual speed controller such as this cheap piece of crap :
It's a just a DC/DC transformer which you may want to spend a little more money on to ensure it lasts for more than the first week
. It looks like it "might" go from 0 - 12V but no guarantees.Please let us know how it works out as you've got me thinking about adding a supply fan. Pretty easy set up with my engine compartment.
Often when we are motoring, Sue is down below either reading, cooking or sleeping which is why we installed the sound insulaton.
1. There would be two fans. The red hose has the squirrel cage fan with hot exhaust air. That fan is currently mounted at the back edge of the port cockpit locker where Catalina installed them, but I can look into moving it to nearer the engine.
2. The blue rectangle is a new fan that I plan to add which will be a 120mm computer case fan. It will be mounted to the outside of the sound foam over a 4" ø hole through the foam. A 4"ø duct elbow will be mounted to the inside to direct the air flow to the alternator. It will pull cool air from the below deck space between the liner and the hull which is cooled by the cold PNW seawater. You are correct, the 120mm case fan provides positive cool air flow directly to the back side of the alternator case where its air intake vents are located.
3. The air for the 120mm and the 1" gap under the sound-foam both come from the cool space between the hull and liner so it should be very cool. The gap is passive, and the case fan is active. That is a good thing because it is problematic to have a forced intake and exhaust for the same space in a controlled loop because it is easy to get an unbalanced air flow, but the passive intake will balance any short fall. In no circumstance should the case fan be able to create positive presser which would be bad because it could force fumes into the cabin. That should not happen because the squirrel cage has greater flow than the case fan and add to that the volume of air that the diesel sucks in, I should not have any problems with fumes in the cabin.
I do not think I will have any problems with too much positive air flow as indicated above. If I do need to throttle the fan I use PWM. I already have three of them on Papillon.All I can add is to make sure your supply blower into the engine compartment supplies less ft³/min. than the exhaust fan is capable of removing from the engine compartment. Due to turbulation of air within the engine compartment, the supply fan could probably use a manual speed controller such as this cheap piece of crap :
View attachment 219992
It's a just a DC/DC transformer which you may want to spend a little more money on to ensure it lasts for more than the first week
Please let us know how it works out as you've got me thinking about adding a supply fan. Pretty easy set up with my engine compartment.
On the Hydronic heat I have two of them. One controls the fan speed the main cabin heat fan coils. The other controls the speed on the head fan coil. The PWM controllers I use have only a 3A relay and the two fans for the main cabin are 120mm @ 3.75A and 80mm @ 2.8A. The head has a seperate 80mm @ 2.8A fan. All of these fans are PWM computer server fans with the standard 4-pin wiring. I hooked up the +&-12v directly to the power supply and only the PWM control goes through the controller and it works great. I can turn them up to 100% and they will blow the dust off the walls but howl like a banshee. I do that when I first come on the boat when it is cold to get the cabin to warm quickly. Once it is up to temperature, I slow the fans down to about 10 to 15 percent and they are almost silent. That way then run on less than an amp total for all three of them.
The third one I have is for the fridge. It originally had a 0.49A two wire case fan that was the loudest 12v thing on board. I now have a 0.5A PWM and I run it at about 40% which cuts down the Ah used by the fridge and makes the cooling cycle work much better because it used to operate in the "Super-cooled" region where the freon would not fully evaporate until an inch or two after the capillary tube. In the AB manual, it states that if the air temperature to the condenser is below 60º you should block off 1/2 of the face to reduce the air flow. I did it by slowing the fan and using less energy in the process.
Better boating through Engineering!
I do not use any of the rheostat speed controllers like the one
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All I can add is to make sure your supply blower into the engine compartment supplies less ft³/min. than the exhaust fan is capable of removing from the engine compartment. Due to turbulation of air within the engine compartment, the supply fan could probably use a manual speed controller such as this cheap piece of crap :
View attachment 219992
It's a just a DC/DC transformer which you may want to spend a little more money on to ensure it lasts for more than the first week
Please let us know how it works out as you've got me thinking about adding a supply fan. Pretty easy set up with my engine compartment.
[but given that I am the OP I guess I can get away with it/]This is the control panel for my heating system which has from top to bottom.
- Espar control panel which turns on the diesel heater.
- Thermostat for main cabin fan-coils. One is a 6,000btu with 120mm @ 3.75A PWM fan under the quarter berth and another is a 3000btu coil with 80mm @ 2.8A PWM fan below the V-berth.
- Thermostat for head fan-coil 3,000btu coil with 80mm @ 2.8A PWM fan with vent into the head compartment.
- PWM and power
- left - head speed control.
- Center - master power on for heater fans.
- Right - main cabin speed control.
With my “not so new anymore” Beta 35, I put a 120a Balmar on it and rotated it as far away from the engine as I could.
Now you have my undivided attention. My refrigerator has driven me nuts from the moment I turned it on 24 years ago. One section freezes to absolute zero (or less
) and another section is temperate at its coldest.I had considered a small, dry cell operated fan to mix up the air but too many problems like remembering to renew the batteries each year. After looking at your description, it finally dawns on me to install a small computer fan (aka. case fan as you say) run it from the boats 12V system, wired into the compressor power supply and finally modulated by a PWM controller. What could be easier? Maybe finding a way to get the wires into the box, now there's a challenge.
Do you have any idea of the size of fan to use ? Or is it important given the use of the PWM controller ? I see none of the fans in Amazon list an amperage draw as it's of no interest in most applications.
I want to minimize the heat introduced into the fridge via the fan (Ahrs) and then pull it back out of the fridge with the refrigerator (more Ahrs).
The only experience I've had with refrigeration is in an NH3 plant. Liquid supply was controlled an expansion valve. You refer to a small refrigeration system with a capilliary tube to control liquid supply. Never worked on one (other than uploading my beer into one) but was under the impression that capilliary tube systems aimed to have the evaporator about 1/2 full of liquid when operating.
Could you enlighten me as to what you mean by :
An inch or two after the capilliary tube would be in the liquid area, or not ?
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Take a look in "Miriam's Book of Words" for thread drift and you'd probably see a copy of this posting.
Makes me wonder what has been the most extreme example of thread drift in SBO to date. I seem to remember one discussion a while back that ranged from propane, to thermodynamics, to chicken soup, to John Cleese in just over 100 postings :
Propane pressure gauge
What I open the solenoid valve on my propane tank the pressure guage drops to zero. Any help on the causes?
forums.sailboatowners.com
I defy anyone to read that without falling asleep at this hour.
What could be easier?!? Given that it sounds like you have a spill-over system, why not add a digital thermostat to control the on/off in addition to the PWM speed so that you can only run the fan when you need to take heat out of the fridge? To get the wires inside the box, drill a hole and feed the wires through. Then plug the hole with your sealant of choice.
I sent you a PM
Those mechanical thermostates are pretty much junk. The only thing that they can measure is if the evaporator coil is is frozen or not but do nothing about the air temperature inside the box.
Those mechanical thermostates are pretty much junk. The only thing that they can measure is if the evaporator coil is is frozen or not but do nothing about the air temperature inside the box.