Extreme Temperatures

What do you guys do to keep your ssrs cool when ambient temps are 105+? Heck, 95+ is still damn hot. I've got a fan with a small louver pulling hot air through the fins and up and out and the heat sinks are still super hot. The heat sink is a big aluminum sink on the top of my enclosure.

The only way to know is to actually measure the temp to know if your in the danger zone of 70C(158F) or so...

I will measure next brew day. I also bought a new fan that does about 3x the volume of air from my last fan. The old fan is now in the keezer helping to circulate the air in there. It made that setup much better!

Here is what I bought this try and keeping the heatsink cooler: http://www.amazon.com/gp/product/B009OWRMZ6/?tag=skimlinks_replacement-20

I might add another one if this doesn't do the trick. Brewing in 100+ weather sucks on many levels. This is my first summer in the desert and I am over it. And it isn't summer yet... Damnit.

Look on the bright side - you don't have to try as hard to maintain mash temp

Maxiimum surface area and convection is your first line of defence. You can bolt a new heat sink on the existing heat sink to increase surface area. Use heat sink grease on the joint. Anyth9ing you can do to add surface ara and mass will make the situation better.

If you are looking for anything you can do to reduce heat build up.....

And.....

Your heatsink is not black....

Paint it black. People who are in the know on the subject, say a black heat sink convects more heat than a plain heat sink.

The next possible solution is research what people do to cool down their overclocked CPUs. They have the same problem.

iijakii said:

Look on the bright side - you don't have to try as hard to maintain mash temp

Click to expand...

This literally made me laugh out loud!

RufusBrewer said:

Maxiimum surface area and convection is your first line of defence. You can bolt a new heat sink on the existing heat sink to increase surface area. Use heat sink grease on the joint. Anyth9ing you can do to add surface ara and mass will make the situation better.

If you are looking for anything you can do to reduce heat build up.....

And.....

Your heatsink is not black....

Paint it black. People who are in the know on the subject, say a black heat sink convects more heat than a plain heat sink.

The next possible solution is research what people do to cool down their overclocked CPUs. They have the same problem.

Click to expand...

My heatsink is black. It is external to the enclosure and on the top. It is 6"x10"x1.25" and only has two relays on it. One relay for the HLT (5500w) and one relay for the BK(5500w). I used a quality heat sink grease to attach the relays in the first place. And given the temperatures at the extremities of the heat sink I am confident that the heatsink is pulling heat from the relays effectively. It just looks like I need a great ability to pull heat!

RufusBrewer said:

Your heatsink is not black....

Paint it black. People who are in the know on the subject, say a black heat sink convects more heat than a plain heat sink.

The next possible solution is research what people do to cool down their overclocked CPUs. They have the same problem.

Click to expand...

Not sure if serious about painting I've never heard that, black heatsinks are black because they are chemically anodized, not painted. I don't think anodized does that much if anything for heat transfer, it just looks cooler.

I've not had the will power to brew in the summer in the 8 years I've lived here. I can't give advice on the heat but I admire your brewing dedication!

Gets worse for me every year. I'm just not built for this crap! Miss the cold and snow and SEASONS and changing weather.

GotPushrods said:

I've not had the will power to brew in the summer in the 8 years I've lived here. I can't give advice on the heat but I admire your brewing dedication!

Gets worse for me every year. I'm just not built for this crap! Miss the cold and snow and SEASONS and changing weather.

Click to expand...

It is so sad. Just hot. I came from Flag and the cold part of the 4-corners (abajo, la sal, and la plata mtns) and this desert thing is lame. It is for short term I think. So I will adapt! I adapt by brewing 1/2 bbl of saison!!

If you ever make it down south here to the "red-headed step child" city hit me up. Always have a pint on tap for another brewer!

RufusBrewer said:

Maxiimum surface area and convection is your first line of defence. You can bolt a new heat sink on the existing heat sink to increase surface area. Use heat sink grease on the joint. Anyth9ing you can do to add surface ara and mass will make the situation better.

If you are looking for anything you can do to reduce heat build up.....

And.....

Your heatsink is not black....

Paint it black. People who are in the know on the subject, say a black heat sink convects more heat than a plain heat sink.

The next possible solution is research what people do to cool down their overclocked CPUs. They have the same problem.

Click to expand...

To cool better you need more surface area (and enough cross section in the metal to conduct heat to the fins), and air flow over the surface area. You want the airflow parallel to the channels in the heatsink. The more air flow the better. If you can make a wind tunnel around your heatsink, that's the best situation. More mass doesn't allow you to dissipate more heat, it just takes a little longer for the heat sink to reach equilibrium temperature.

You definitely do not want to paint your heatsink. The paint is just a thin layer of insulation on the surface that interferes with the heat transfer from the heatsink to the air. Emissivity is important to radiation heat transfer, but with heatsinks you are depending on convective heat transfer, not radiation. Also, at the temps involved, the radiation is at long infrared wavelengths, so the emissivity does not correlate to perceived color in the visible spectrum (i.e. being black probably doesn't matter.)

I spent 36 years working in electronic packaging, and efficient heat transfer is one of the most important areas of electronic packaging. I am one of those "People who are in the know on the subject."

Brew on

FuzzeWuzze said:

Not sure if serious about painting I've never heard that, black heatsinks are black because they are chemically anodized, not painted.

Click to expand...

Correct. Never paint a heat sink. You're adding a layer of insulation. If you want it black, get it anodized.

105F ambient is ok given that the heat sink should be large enough and the SSR will be hotter than that. Just makes sure to size the heat sink properly and don't enclose it in anything like the control panel. Let it breath through convection.

Kal

FuzzeWuzze said:

Not sure if serious about painting I've never heard that, black heatsinks are black because they are chemically anodized, not painted. I don't think anodized does that much if anything for heat transfer, it just looks cooler.

Click to expand...

doug293cz said:

To cool better you need more surface area (and enough cross section in the metal to conduct heat to the fins), and air flow over the surface area. You want the airflow parallel to the channels in the heatsink. The more air flow the better. If you can make a wind tunnel around your heatsink, that's the best situation. More mass doesn't allow you to dissipate more heat, it just takes a little longer for the heat sink to reach equilibrium temperature.

You definitely do not want to paint your heatsink. The paint is just a thin layer of insulation on the surface that interferes with the heat transfer from the heatsink to the air. Emissivity is important to radiation heat transfer, but with heatsinks you are depending on convective heat transfer, not radiation. Also, at the temps involved, the radiation is at long infrared wavelengths, so the emissivity does not correlate to perceived color in the visible spectrum (i.e. being black probably doesn't matter.)

I spent 36 years working in electronic packaging, and efficient heat transfer is one of the most important areas of electronic packaging. I am one of those "People who are in the know on the subject."

Brew on

Click to expand...

kal said:

Correct. Never paint a heat sink. You're adding a layer of insulation. If you want it black, get it anodized.

105F ambient is ok given that the heat sink should be large enough and the SSR will be hotter than that. Just makes sure to size the heat sink properly and don't enclose it in anything like the control panel. Let it breath through convection.

Kal

Click to expand...

OK, let me chime in here.

First, my original comment was, if it is not black, paint it black. I assumed if it was not black, it was bare shiney aluminum.

Where did I get this crazy idea? My pe-brewing hobby audio electronics, a hobby that also needs to worry about heat management. On more than one occasion from different sources, sources that I trust, the conventional wisdom was bare aluminum heat sinks could be made more efficient by painting them black. Flat black was better than glossy black. Sorry, this is pre-internet, I cannot point you to link.

This is not automaically irrational idea when you consider that some manufactures will provide 2 specs for a given heat sink, one spec for anodized black, one spec plain finish. The anodized black is shown to be efficient at exchanging heat. can we agree black anodized is better than plain aluminum?

Flat - matte black paint finish was presented as the poor man's anodizing. Not as good as anodizng, better than plain shiny aluminum,

So the question we have: Will a bare aluminum heatsink be improved by painting it black? Or . . . . . Does a coat of paint do more harm than good?

I have tried for the last few days to find some sort of objective, knowlegable reliable reference on the subject. Lots of PC overclocker threads, anecdotal evidence, nothing I would point to as "See I told you so!" And there is an equal amount of contrary evidence.

One thing I did find as a credible source was a paragraph or two from Aavid heatsink. If I read it correctly, the salient part is that with forced air cooling, color still helps but probably is not worth it. Which in audio, is not likely to come up because fans in home brew Hi-Fi fans are to be avoided like the plague. So this aspect was never discussed, from what I remember.

I would be interested in any documentation that contradicts what I have said. I am always happy to learn something. In fact I have an old amplifier project in my garage I am resurecting, it will need a heatsink. Any pertinent information would be welcome.

RufusBrewer said:

First, my original comment was, if it is not black, paint it black. I assumed if it was not black, it was bare shiney aluminum.

Click to expand...

I would imagine that painting should never be done as it adds an insulating layer. Anodizing is ok. Anodizing and painting are not the same thing.

Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. It's typically done for aesthetic reasons and to increase resistance to corrosion and wear.

Source: https://en.wikipedia.org/wiki/Anodizing

The conventional wisdom was bare aluminum heat sinks could be made more efficient by painting them black. Flat black was better than glossy black.

Click to expand...

Again, I, not sure I would paint it. That's not the same as anodizing.

Anodized aluminum does radiate heat better. With 1.0 being perfect (black body) emissivity anodized aluminum is 0.85 and unfinished is 0.05.

In natural convection on small heat sinks with open fins, and a high benefit from anodization by up to 45%.

Relatively large extrusions and those used at low temperature rise, as in many high power applications, will only gain up to 10% by the addition of an anodized surface.

Source: http://www.aavid.com/product-group/extrusions-na/anodize

More info:

http://www.qats.com/cms/2010/11/09/...ion-improves-thermal-performance-part-1-of-2/

can we agree black anodized is better than plain aluminum?

Click to expand...

I think so. Though in practice I don't think it's a huge difference for what we're using them for here.

Flat - matte black paint finish was presented as the poor man's anodizing. Not as good as anodizng, better than plain shiny aluminum

Click to expand...

That I'm not sure of, though I haven't searched around to find any studies on it (I'm sure they exist).

So the question we have: Will a bare aluminum heatsink be improved by painting it black? Or . . . . . Does a coat of paint do more harm than good?

Click to expand...

Definitely the question of the day. It would depend on many factors including fin distribution, thickness of the paint, type of paint, etc. It could very well be that a very thin layer could help while a thicker layer may hinder.

More comments welcome as RufusBrewer mentioned...

Kal

most newer cpu heatsinks are not black..... if manufactuers could make them more efficient by painting them black that means they could also make them smaller and save aluminum costs... As cheap as these companies are they would ALL be black if it meant a noticable improvement hence savings cost....

double post

augiedoggy said:

most newer cpu heatsinks are not black.....

Click to expand...

I would imagine that's because they are force air cooled usually and if you follow the Aavid link I posted above they mention:

"An anodized finish will only add 4 -8% to the overall cooling effect in forced air."

Anodizing is really expensive. I would imagine that the bean counters decided that a 4-8% increase just isn't worth the money. A reduction of 4-8% in materials isn't going to add up to much when you consider what anodizing costs (that said, I'm not sure if a 4-8% cooling increase means that reducing the mass by 4-8% would have the same result - I'm an electrical engineer, not mechanical. )

Usually when it's done for CPU heat sinks it's done for aesthetic reasons. It's not uncommon for high end video cards or cpu heat sinks to be anodized even though they also have fans on them as lots of high end PCs these days have clear windows, LED lights, and other bling.

Example from SilenX (copper heatpipes, anodized aluminum fins):



Kal

kal said:

I would imagine that painting should never be done as it adds an insulating layer. Anodizing is ok. Anodizing and painting are not the same thing.

Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. It's typically done for aesthetic reasons and to increase resistance to corrosion and wear.

Source: https://en.wikipedia.org/wiki/Anodizing


Again, I, not sure I would paint it. That's not the same as anodizing.

Anodized aluminum does radiate heat better. With 1.0 being perfect (black body) emissivity anodized aluminum is 0.85 and unfinished is 0.05.

In natural convection on small heat sinks with open fins, and a high benefit from anodization by up to 45%.

Relatively large extrusions and those used at low temperature rise, as in many high power applications, will only gain up to 10% by the addition of an anodized surface.

Source: http://www.aavid.com/product-group/extrusions-na/anodize



More info:

http://www.qats.com/cms/2010/11/09/...ion-improves-thermal-performance-part-1-of-2/


I think so. Though in practice I don't think it's a huge difference for what we're using them for here.


That I'm not sure of, though I haven't searched around to find any studies on it (I'm sure they exist).


Definitely the question of the day. It would depend on many factors including fin distribution, thickness of the paint, type of paint, etc. It could very well be that a very thin layer could help while a thicker layer may hinder.

More comments welcome as RufusBrewer mentioned...

Kal

Click to expand...

Why do you insist on telling me anodizing and painting are not the same thing? I did not say they were the same. I said painting was the poor man's anodizing and better than a shiny surface.

augiedoggy said:

most newer cpu heatsinks are not black..... if manufactuers could make them more efficient by painting them black that means they could also make them smaller and save aluminum costs... As cheap as these companies are they would ALL be black if it meant a noticable improvement hence savings cost....

Click to expand...

Speculation on the economics of heatsink manufacturing. Who needs science or engineering? Taking what you say at face value, the conclusion I come to is that more aluminum is cheaper than anodizing to achieve a given level of cooling.

Wait a minute. How about something from a company that is in the business of making and selling heatsinks.

Natural Convection Overview

Natural convection is a mechanism of heat transportation in which the fluid motion is not generated by an external source. Instead the fluid motion is caused by buoyancy, the difference in fluid density between two locations, which is most commonly due to a temperature difference between those two locations. The fluid velocity is very low in natural convection which limits the ability of the heat sink to transfer energy to the environment. To improve the heat sink's ability, the surface area of the heat sink should be as large as permitted by the application. Radiation also plays a major role in the performance of the heat sink and so the heat sink should be treated, either anodized or painted. This surface treatment improves the surface emissivity, or its ability to radiate heat to other objects in the environment. When designing a heat sink for natural convection, the orientation should be vertical and the fins should be widely spaced, about ¼".

Click to expand...

http://www.wakefield-vette.com/products/natural-convection.aspx

Pretty much backs up everything I said, after I corrected myself about convection Vs forced air issue.

kal said:

I would imagine that's because they are force air cooled usually and if you follow the Aavid link I posted above they mention:

"An anodized finish will only add 4 -8% to the overall cooling effect in forced air."

Anodizing is really expensive. I would imagine that the bean counters decided that a 4-8% increase just isn't worth the money. A reduction of 4-8% in materials isn't going to add up to much when you consider what anodizing costs (that said, I'm not sure if a 4-8% cooling increase means that reducing the mass by 4-8% would have the same result - I'm an electrical engineer, not mechanical. )

Usually when it's done for CPU heat sinks it's done for aesthetic reasons. It's not uncommon for high end video cards or cpu heat sinks to be anodized even though they also have fans on them as lots of high end PCs these days have clear windows, LED lights, and other bling.

Example from SilenX (copper heatpipes, anodized aluminum fins):

Kal

Click to expand...

Thank you for the rational explanation. That makes total sense.

RufusBrewer said:

Why do you insist on telling me anodizing and painting are not the same thing? I did not say they were the same. I said painting was the poor man's anodizing and better than a shiny surface.



Speculation on the economics of heatsink manufacturing. Who needs science or engineering? Taking what you say at face value, the conclusion I come to is that more aluminum is cheaper than anodizing to achieve a given level of cooling.

Wait a minute. How about something from a company that is in the business of making and selling heatsinks.



http://www.wakefield-vette.com/products/natural-convection.aspx

Pretty much backs up everything I said, after I corrected myself about convection Vs forced air issue.

Click to expand...

You are ignoring the the part about paint being an insulator.... Its like comparing water to ethanol because they look and pour the same.... it doesnt matter if its dull or shiny so much as the fact that they are completely different thinks and work differently.

I will say that I learned thanks to your comments that anodized metal (regardless of color?) conducts better than bare metal.... but I dont see your logic on paint whether dull or glossy doing the same...

for the OP, what is the amp load specs on your ssrs? I use the cheapo $2 bare aluminum ssr heatsinks from ebay and I have a dual ssr preforming double duty on one heatsink and the other heatsink just has a single ssr mounted to it, they are installed inside my panel and I have a single 60mm fan blowing air through them from the side and out the toip of my panel... no heat issues in over 2 years with this setup however I brew indoors and its not 95 degrees out (isnt that one of the key advantages of electric?) I also chose more suitably sized 4500w elements for the task of 10 gallon brews rather than the larger 5500w ones and dealing with the additional costs for wiring and waste like cooling ssrs that goes with it.. however small it may be...

I have read that a 40amp speced ssr will run cooler than a 25a speced one when faced with the same load (like 22 amps from a 5500w element) but I have never seen anyone show proof of this myself..

RufusBrewer said:

Why do you insist on telling me anodizing and painting are not the same thing? I did not say they were the same. I said painting was the poor man's anodizing and better than a shiny surface.

Click to expand...

I don't insist. I merely restate to ensure that everyone is on the same page, not necessarily for yourself. There are many others reading this too. Some of the past comments may cause someone to think that anodizing = painting (which is not true).

Kal

I'm using the teledyne dual SSRs rated for 50-amps and using 5500w elements from bobby. I brew in the garage. I live in the desert. I keep the door shut as long as possible in the morning because it keeps the cool night air. But eventually I have to open the door because it is cooler outside than inside. The air is stagnant and it sucks. It takes long enough to brew 1/2bbl batches with 5500w let alone 4500w elements.

augiedoggy said:

You are ignoring the the part about paint being an insulator.... Its like comparing water to ethanol because they look and pour the same.... it doesnt matter if its dull or shiny so much as the fact that they are completely different thinks and work differently.

Click to expand...

You are ignoring the part where Wakefield says paint the heatsink. It really is that plain and simple.

Because you do not understand how it works does not mean that it does not work. I do not understand how gravity works, but I know my feet stick to the ground.

Years ago, I read an explanation why the shiny Vs flat matte thing works. Honestly, I cannot explain it to you today. As I recall the short answer is shiny surfaces (for some reason) do not radiate heat as well as matte finish. My take away: a can of black matte Rustoleum.

augiedoggy said:

I will say that I learned thanks to your comments that anodized metal (regardless of color?) conducts better than bare metal.... but I dont see your logic on paint whether dull or glossy doing the same...

for the OP, what is the amp load specs on your ssrs? I use the cheapo $2 bare aluminum ssr heatsinks from ebay and I have a dual ssr preforming double duty on one heatsink and the other heatsink just has a single ssr mounted to it, they are installed inside my panel and I have a single 60mm fan blowing air through them from the side and out the toip of my panel... no heat issues in over 2 years with this setup however I brew indoors and its not 95 degrees out (isnt that one of the key advantages of electric?) I also chose more suitably sized 4500w elements for the task of 10 gallon brews rather than the larger 5500w ones and dealing with the additional costs for wiring and waste like cooling ssrs that goes with it.. however small it may be...

I have read that a 40amp speced ssr will run cooler than a 25a speced one when faced with the same load (like 22 amps from a 5500w element) but I have never seen anyone show proof of this myself..

Click to expand...

The rest of this is a red herring for me. At least how it relates to the OP and my comments.

In the OP, the sandyeggoxj was worried that his SSR was getting too hot and asked for advice on how to make his situation better. I said, "If it is not black, paint it black." Wakefeild, who has been engineering and selling thermal products back me up.

Your lack of knowledge of how it works does not make it any less true.

kal said:

I don't insist. I merely restate to ensure that everyone is on the same page, not necessarily for yourself. There are many others reading this too. Some of the past comments may cause someone to think that anodizing = painting (which is not true).

Kal

Click to expand...

Sorry for the confusion.

RufusBrewer said:

You are ignoring the part where Wakefield says paint the heatsink. It really is that plain and simple.

Because you do not understand how it works does not mean that it does not work. I do not understand how gravity works, but I know my feet stick to the ground.

Years ago, I read an explanation why the shiny Vs flat matte thing works. Honestly, I cannot explain it to you today. As I recall the short answer is shiny surfaces (for some reason) do not radiate heat as well as matte finish. My take away: a can of black matte Rustoleum.



The rest of this is a red herring for me. At least how it relates to the OP and my comments.

In the OP, the sandyeggoxj was worried that his SSR was getting too hot and asked for advice on how to make his situation better. I said, "If it is not black, paint it black." Wakefeild, who has been engineering and selling thermal products back me up.

Your lack of knowledge of how it works does not make it any less true.

Click to expand...

http://www.overclockers.com/forums/...our-heatsink-black-Ideas-Experiences-comments

http://forum.overclock3d.net/showthread.php?t=46321

http://www.reddit.com/r/explainlike.../eli5_why_does_painting_something_flat_black/
black rustoleum is insulating more than its helping. Now all the pages I have read state that a thermal paint may help and anodizing will for sure. (a small degree) .. but regular paints will almost certainly hurt more than they help.. I'm sure that wakefield and rustoleum spray paint are not the same product...

augiedoggy said:

http://www.overclockers.com/forums/...our-heatsink-black-Ideas-Experiences-comments

http://forum.overclock3d.net/showthread.php?t=46321

http://www.reddit.com/r/explainlike.../eli5_why_does_painting_something_flat_black/
black rustoleum is insulating more than its helping. Now all the pages I have read state that a thermal paint may help and anodizing will for sure. (a small degree) .. but regular paints will almost certainly hurt more than they help.. I'm sure that wakefield and rustoleum spray paint are not the same product...

Click to expand...

As I said before, the internet is full of anecdotal evidence. I could find just as many posts that counter what you found. Instead, I went with a professional, in the business, company reputation on the record information.

Do you realize one of your own links confirms what I said earlier? But you pretty much dismissed because it made no sense to you.

It's actually much more important that the product have a matte or flat appearance than the color it is. The reason for that is that on a microscopic scale a matte surface is bumpy and a shiny surface is smooth, and the bumpy surface has a larger surface area than a flat one.

Click to expand...

http://www.reddit.com/r/explainlike.../eli5_why_does_painting_something_flat_black/

Go ahead and reply. I will not respond. You get the last word. If I respond, you get to call me a liar.

I put a bigger fan on it. All better. 98 in the garage today. I could hold my hand on the heatsink at all times. Big improvement. This bigger fan is 120x120 and is rated at 110cfm. I have it centered on the heatsink and pulling air through the fins and pushing that air up and away from the heatsink. This fan should be big enough. I think I'll be adding a thermostat so that when I brew when it is cooler I don't have to listen to it all the time.