Recently I have become very interested in effective air cooling of PCs, and I was thinking of adding an extra fan to my OHP. I have learned through case of my computer that the most effective way to cool is to bring fresh air in with an intake fan and then use an exhaust fan to pull the hot air out. By adding a simple exhaust fan to my friend's PC (he already had an intake), his temperatures dropped by about 6*C.
I was just wondering if there would be any problems that anyone could see with me adding an intake fan onto my projector. The bulbs are 360w 82v ENX bulbs in an Elmo HP-L355 Deluxe OHP.
I have attatched a file to explain what I am trying to do. The view is a crude top view of what the projector looks like. The triangles are the bulbs. The Blue triangle is the one currently in use, the violet rectangle is the current exhaust fan and the red rectangle is the fan I would like to mount on the opposite side of the OHP. If enough air can be pushed by this fan I am hoping to create a sort of wind tunnel effect.
Another question I have for this is, will this possibly lengthen the bulb lifespan? Because Halogen lights get so hot, I wasn't sure if this might possibly help to tag on a few extra hours of life to each bulb.
Thanks
-mike
I was just wondering if there would be any problems that anyone could see with me adding an intake fan onto my projector. The bulbs are 360w 82v ENX bulbs in an Elmo HP-L355 Deluxe OHP.
I have attatched a file to explain what I am trying to do. The view is a crude top view of what the projector looks like. The triangles are the bulbs. The Blue triangle is the one currently in use, the violet rectangle is the current exhaust fan and the red rectangle is the fan I would like to mount on the opposite side of the OHP. If enough air can be pushed by this fan I am hoping to create a sort of wind tunnel effect.
Another question I have for this is, will this possibly lengthen the bulb lifespan? Because Halogen lights get so hot, I wasn't sure if this might possibly help to tag on a few extra hours of life to each bulb.
Thanks
-mike
Attachments
anyone?
I'm not so much concerned as the bulb being "too cool" (I'm not using peltiers here 😉) as I am with contaminents possibly getting to the bulb more easily. I know my computer fans get quite dusty after a while (they would when they're pushing near 200cfm in each direction 😀) but I am not sure what effect this will have on my OHP.
I'm not so much concerned as the bulb being "too cool" (I'm not using peltiers here 😉) as I am with contaminents possibly getting to the bulb more easily. I know my computer fans get quite dusty after a while (they would when they're pushing near 200cfm in each direction 😀) but I am not sure what effect this will have on my OHP.
I'll take a guess at this, Defmike 🙂 (Disclaimer: I have very little electronics knowledge) However, after working on machinery and equipment all my life, cooler is almost always better. I don't believe that you could make the interior of that OHP too cool. I would think that a pair of evenly matched fans, one to force intake and one to improve exhaust, would only help the situation. It could also be easier on the fans themselves. However, I wonder if the heat of the exhaust would be hard on the exhaust fan? Over the years at the fire department we have switched from trying to "exhaust" smoke and heat out of buildings to "pressurizing" the building on the intake side to force the heat and smoke out of the building. This puts your fan in the fresh, cool air and not working in the heated exhaust air. Perhaps if you are using two fans, it would be better for the longevity of the fans if you use both for intake, "pressurize" the OHP box and then choose a few different exhaust points that ensure an even air flow over the necessary components? This could let you channel your air flow over the critical heat producing or heat critical areas. As far as extending the life of the bulb, I would think that keeping the bulb within its intended operating heat range would get the maximum life out of the bulb. Just my thoughts...
thanks for the reply 🙂
I am somewhat of a cooling nut with my computer, and I have noticed that "sufficient" cooling isn't always just that. When companies send out processors with stock heatsinks and zero case airflow it just kills me to see it done. For probably $20 more or less they could put on a decent heatsink and at least two fans in the case to help keep the processor running cool and stable.
I think I'll order a few 92mm fans today (push 48cfm, it should be sufficient) and use one of them for my projector. My last venture was to add a duct to the outside of my exhaust to push the hot air away from me while I'm watching TV/movies 😀. Along with the fan I'm going to cut off the power cord of the OHP and solder in one of these to allow for easy transport 🙂. This will also make connecting the fan more easy because I won't have to solder in at the innards of the lamp workings, I'll just take it straight from the source.
Anyway wish me luck 🙂
I am somewhat of a cooling nut with my computer, and I have noticed that "sufficient" cooling isn't always just that. When companies send out processors with stock heatsinks and zero case airflow it just kills me to see it done. For probably $20 more or less they could put on a decent heatsink and at least two fans in the case to help keep the processor running cool and stable.
I think I'll order a few 92mm fans today (push 48cfm, it should be sufficient) and use one of them for my projector. My last venture was to add a duct to the outside of my exhaust to push the hot air away from me while I'm watching TV/movies 😀. Along with the fan I'm going to cut off the power cord of the OHP and solder in one of these to allow for easy transport 🙂. This will also make connecting the fan more easy because I won't have to solder in at the innards of the lamp workings, I'll just take it straight from the source.
Anyway wish me luck 🙂
extra cooling
what about Peltier elements?
wouldn't that be a perfect solution?
i have tried it in a pc but had to give up cause the metal casing inside got concensed and i was affraid water was going to drip on vital components.
bu as i can see inside a OHP there is very little chance that that can happen....
what about Peltier elements?
wouldn't that be a perfect solution?
i have tried it in a pc but had to give up cause the metal casing inside got concensed and i was affraid water was going to drip on vital components.
bu as i can see inside a OHP there is very little chance that that can happen....
I think for extreme PC cooling peltiers are effective, but for cooling bulbs I don't think as much so. In order to effectively cool a PC with peltiers watercooling is a must, because while creating a cold side to the peltier element you are also creating MORE heat on the other side of the peltier that must be gotten rid of. Water is used because the heat transfer between the heatsink (usually aluminum, copper, or even silver) and water works better than between a heatsink and air. The water is then usually taken to a radiater where more surface area can be used to cool the water to a normal temperature.
With such small area actually being extremely cold, I can't see how effective a peltier would be with cooling a glass bulb. While the temperature of a certain spot (mainly CPUs and possible GPUs) with PC cooling is maintained, the ambient temperatures aren't affected at all.
Watercooling is the same idea. In order to efficiently cool the surface area actually TOUCHING the bulb would have to be of decent size for it to work well, otherwise the transfer of heat would go from bulb to air to copper to water...in which case you might as well air cool.
Just my 2 cents...
With such small area actually being extremely cold, I can't see how effective a peltier would be with cooling a glass bulb. While the temperature of a certain spot (mainly CPUs and possible GPUs) with PC cooling is maintained, the ambient temperatures aren't affected at all.
Watercooling is the same idea. In order to efficiently cool the surface area actually TOUCHING the bulb would have to be of decent size for it to work well, otherwise the transfer of heat would go from bulb to air to copper to water...in which case you might as well air cool.
Just my 2 cents...
cooling
Totally not for your particular application... but still interesting. I have seen in my travels on the net a water cooled bulb used for the hydroponics industry, as far as I remember it was a metal halide system....but quite large. As I said not for an OHP application.... just interesting.
Zardoz
Totally not for your particular application... but still interesting. I have seen in my travels on the net a water cooled bulb used for the hydroponics industry, as far as I remember it was a metal halide system....but quite large. As I said not for an OHP application.... just interesting.
Zardoz
As far as dust goes why not just put filters in front of the fans. This would help filter all the dust coming in as long as you cleaned the filters every once in a while. Peltier cooling to me sounds like a bad idea for an overhead bulb. You have really cold and damp peltier cooler while extremely hot and dry halogen bulb. It wouldn't take long before some thing bad happened like a short circuit or the bulb exploding from sudden tempature changes.
Peltiers and water cooling
Zardoc - interresting story about water cooled bulbs. I diid some google searches and found some companies that sell that (http://www.greenair.com/classic-series.htm). Now if somebody was cracy enough why couldn't this be used for our purposes? Wouldn't this remove the heat that hits the LCD?
defmike- how hot does peltiers get on the hot side? if you wanted to have a small closed watercooled system, (pc or what ever), could you use the cold side to cool a small water tank? Could the hot side be pointing to or even be part of the outside shell of the box? Could the peltier then radiate its heat to the room?
Exipnos
Zardoc - interresting story about water cooled bulbs. I diid some google searches and found some companies that sell that (http://www.greenair.com/classic-series.htm). Now if somebody was cracy enough why couldn't this be used for our purposes? Wouldn't this remove the heat that hits the LCD?
defmike- how hot does peltiers get on the hot side? if you wanted to have a small closed watercooled system, (pc or what ever), could you use the cold side to cool a small water tank? Could the hot side be pointing to or even be part of the outside shell of the box? Could the peltier then radiate its heat to the room?
Exipnos
Re: Peltiers and water cooling
Good question. I am by no means an expert on peltiers, but the temperature difference depends on the wattage of the peltier. There is a decent explanation of peltier coolers here. Basically they say that the difference between each side of the peltier usually ranges between 70 and 120 degrees F.
There are equations that must be taken into consideration when purchasing a peltier, however I don't know them. You must calculate the wattage of heat given off from your source in order to find the wattage of the peltier element you would be using to cool.
I really don't think peltiers would be very effective for cooling bulbs. There are a few problems I can see.
1- They create MORE heat on one side, it is harder to deal with
2- They can create humidity which is destructive to halogens
3- Changing hot glass into cold glass too quickly will crack or shatter it.
Water cooling, however, is something I can see being done more easily and effectively. If you have water at room temperature, it will NOT be too cold for the bulb to crack it. It will also absorb heat very efficiently in order to cool the bulb more to room temperature. The difference between peltiers and watercooling alone is this: Watercooling is meant to bring temperatures down to ambient temperatures, peltier cooing is meant to bring temperatures into sub-zero temperatures. For CPU cooling this may be OK (though some consider it overkill sometimes), but for cooling glass I don't see any benefits. You're not trying to freeze the bulb, you're trying to dissipate the heat off of it.
If a shroud of metal (preferably copper, though aluminum will work) that will fit around a bulb with water flowing inside of it could be created this would probably be the best method for bulb cooling. Keep in mind too, a thermal grease would need to be between the copper surface and the bulb surface in order to create a good thermal flow between the two. There are a few flaws in this design, however.
1- When cooling a CPU the heatsink must sit perfectly FLUSH with the die of the CPU. Any miscontact and temperatures rise like crazy.
2- Creating the metal shroud with such precision would NOT be an easy task, neither would be switching the bulbs out of it.
3- It would be expensive to make...you will need a pump, tank (to hold the water while it's still cooling), radiator, fans (to cool the radiator, they could be as quiet as needed) tubing, and the "heatsink" for the bulb. The pump, tubing, and radiator could be purchased or salvaged from cars etc, but the block (or "heatsink") must be created to custom fit the bulb you would be using.
Unless you could have water actually TOUCHING the glass...which I don't think would be possible without damaging the bulb....it would be a very difficult task. Actually, if there was a coating of some type that does not limit thermal flow but somehow waterproofed the bulb this would be the best solution because the thermal contact would be directly between the bulb and water...there would be no metal to pass through on the way. If this would still be too hot, it would be a good idea to use thermal paste to connect metal fins (to increase the surface area where heat can dissipate) to the surface of the bulb.
If you ask me, any of these methods would take a lot of time and a lot of thought. I think that air cooling would work fine for bulbs, but for the person that just *HAS* to have the projector be dead quiet, watercooling is the solution. (unless you want to submerse the back of your bulb in 3m non-conductive liquid...but that's something else ALL together 😀)
exipnos said:
Good question. I am by no means an expert on peltiers, but the temperature difference depends on the wattage of the peltier. There is a decent explanation of peltier coolers here. Basically they say that the difference between each side of the peltier usually ranges between 70 and 120 degrees F.
There are equations that must be taken into consideration when purchasing a peltier, however I don't know them. You must calculate the wattage of heat given off from your source in order to find the wattage of the peltier element you would be using to cool.
I really don't think peltiers would be very effective for cooling bulbs. There are a few problems I can see.
1- They create MORE heat on one side, it is harder to deal with
2- They can create humidity which is destructive to halogens
3- Changing hot glass into cold glass too quickly will crack or shatter it.
Water cooling, however, is something I can see being done more easily and effectively. If you have water at room temperature, it will NOT be too cold for the bulb to crack it. It will also absorb heat very efficiently in order to cool the bulb more to room temperature. The difference between peltiers and watercooling alone is this: Watercooling is meant to bring temperatures down to ambient temperatures, peltier cooing is meant to bring temperatures into sub-zero temperatures. For CPU cooling this may be OK (though some consider it overkill sometimes), but for cooling glass I don't see any benefits. You're not trying to freeze the bulb, you're trying to dissipate the heat off of it.
If a shroud of metal (preferably copper, though aluminum will work) that will fit around a bulb with water flowing inside of it could be created this would probably be the best method for bulb cooling. Keep in mind too, a thermal grease would need to be between the copper surface and the bulb surface in order to create a good thermal flow between the two. There are a few flaws in this design, however.
1- When cooling a CPU the heatsink must sit perfectly FLUSH with the die of the CPU. Any miscontact and temperatures rise like crazy.
2- Creating the metal shroud with such precision would NOT be an easy task, neither would be switching the bulbs out of it.
3- It would be expensive to make...you will need a pump, tank (to hold the water while it's still cooling), radiator, fans (to cool the radiator, they could be as quiet as needed) tubing, and the "heatsink" for the bulb. The pump, tubing, and radiator could be purchased or salvaged from cars etc, but the block (or "heatsink") must be created to custom fit the bulb you would be using.
Unless you could have water actually TOUCHING the glass...which I don't think would be possible without damaging the bulb....it would be a very difficult task. Actually, if there was a coating of some type that does not limit thermal flow but somehow waterproofed the bulb this would be the best solution because the thermal contact would be directly between the bulb and water...there would be no metal to pass through on the way. If this would still be too hot, it would be a good idea to use thermal paste to connect metal fins (to increase the surface area where heat can dissipate) to the surface of the bulb.
If you ask me, any of these methods would take a lot of time and a lot of thought. I think that air cooling would work fine for bulbs, but for the person that just *HAS* to have the projector be dead quiet, watercooling is the solution. (unless you want to submerse the back of your bulb in 3m non-conductive liquid...but that's something else ALL together 😀)
cooling Bulbs
Let Me start by saying that,while I am an electronics Tech(23 years), I am in no way an expert on lighting products, but I do know that a Halogen bulb >Needs< to run hot. It has to do with the tungsten in the filament actually vaporizing(A little) and the combination of the halogen gas and the quartz of the tube helping it to redeposit back on the filament. If You look at a halogen bulb that is old or has been run at a lower voltage(On a dimmer) You will see the metal on the outer tube from the lack of the heat(more so at the support posts). Cooling a halogen bulb would therefore, not only shorten the life of the bulb, but also it would get progressively dimmer as it aged. Sorry to be the bringer of bad news, but I know this to be true.
Tall Shadow
Let Me start by saying that,while I am an electronics Tech(23 years), I am in no way an expert on lighting products, but I do know that a Halogen bulb >Needs< to run hot. It has to do with the tungsten in the filament actually vaporizing(A little) and the combination of the halogen gas and the quartz of the tube helping it to redeposit back on the filament. If You look at a halogen bulb that is old or has been run at a lower voltage(On a dimmer) You will see the metal on the outer tube from the lack of the heat(more so at the support posts). Cooling a halogen bulb would therefore, not only shorten the life of the bulb, but also it would get progressively dimmer as it aged. Sorry to be the bringer of bad news, but I know this to be true.
Tall Shadow
Tall Shadow...thanks for the heads up. I guess watercooling or peltier cooling isn't really a goal any more 
.
I think I still may go with the air cooling idea just to see how it turns out, if not just temporarily. Not so that the bulb itself stays cool, but so the air being blown all over my room isn't quite as hot...
.I think I still may go with the air cooling idea just to see how it turns out, if not just temporarily. Not so that the bulb itself stays cool, but so the air being blown all over my room isn't quite as hot...
Still thinking about cooling.
defmike - thanks for the info about peltiers and cooling.
I'm still in the planning stages for a projection system, but when I build it I would like to make a completely quiet system. My idea was to try to get the bulbs that was mentioned in the previous post. If I am not misstaken the actual bulb is submerged into the water. There is basically a glass tube around the bulb where the water circulates.
If these bulbs are as good as promised and the glass housing has in and out connections for the water then the only issue would be to circulate the water and move the heat away. With the high wattage lamps the water will for sure get very hot so some kind of cooling is necessary. My idea was to connect the peltier so that the water tank gets cooled.
Tall Shadow - Do you know if the same applies to MH lamps?
defmike - thanks for the info about peltiers and cooling.
I'm still in the planning stages for a projection system, but when I build it I would like to make a completely quiet system. My idea was to try to get the bulbs that was mentioned in the previous post. If I am not misstaken the actual bulb is submerged into the water. There is basically a glass tube around the bulb where the water circulates.
If these bulbs are as good as promised and the glass housing has in and out connections for the water then the only issue would be to circulate the water and move the heat away. With the high wattage lamps the water will for sure get very hot so some kind of cooling is necessary. My idea was to connect the peltier so that the water tank gets cooled.
Tall Shadow - Do you know if the same applies to MH lamps?
Re: Still thinking about cooling.
Hi!,
Metal Halide and High Pressure Sodium don't use the same type of system to produce light as a halogen or other incandescent lamps do. Therefore They don't need all of the heat that the They do. This makes Them better suited to air or liquid cooling. As far as using a peltier for cooling the water, You need to remember that a 400w MH lamp is putting out a heck of alot of heat! I'm not sure that peltier(s) would be able to keep up. You will need to dump a bunch of heat...all the time the lamp is on.
Tall Shadow
exipnos said:
Hi!,
Metal Halide and High Pressure Sodium don't use the same type of system to produce light as a halogen or other incandescent lamps do. Therefore They don't need all of the heat that the They do. This makes Them better suited to air or liquid cooling. As far as using a peltier for cooling the water, You need to remember that a 400w MH lamp is putting out a heck of alot of heat! I'm not sure that peltier(s) would be able to keep up. You will need to dump a bunch of heat...all the time the lamp is on.
Tall Shadow
allternative to HID?
As far as I recall the water cooled bulbs "are" HID.
I came across these today, I'm looking at allternatives to HID lighting for my PJ. I've considered the LED route but dont want the hassle of "clustering" a couple thousand REALLY expensive LED's.
Then I found these http://www.sunstreamer.com/index.htm if they can be run on a regular Flouro ballast then all that is special is the tube. Granted at 2feet long/tube it would mean a PJ box of probably 26 inchs or so square...but the distance to the LCD panel could concieveably be quite close (still with some fan venting and an insulating sheet of glass (low E?) I think).
The "end mounts" for a flourescent tube are available in many config's so they could be custom mounted allowing for VERY close together spacing of the tubes (thinking ohh maybe 12 or 14 tubes?).
Any thoughts?
if your not livin on the edge...you're takin up too much space!
zardoz
As far as I recall the water cooled bulbs "are" HID.
I came across these today, I'm looking at allternatives to HID lighting for my PJ. I've considered the LED route but dont want the hassle of "clustering" a couple thousand REALLY expensive LED's.
Then I found these http://www.sunstreamer.com/index.htm if they can be run on a regular Flouro ballast then all that is special is the tube. Granted at 2feet long/tube it would mean a PJ box of probably 26 inchs or so square...but the distance to the LCD panel could concieveably be quite close (still with some fan venting and an insulating sheet of glass (low E?) I think).
The "end mounts" for a flourescent tube are available in many config's so they could be custom mounted allowing for VERY close together spacing of the tubes (thinking ohh maybe 12 or 14 tubes?).
Any thoughts?
if your not livin on the edge...you're takin up too much space!
zardoz
I am by no means an expert on the subject of building a projector. The heating issue if it can't be solved by ventilation of the hot air, perhaps a barrier between the LCD and bulbs could be fashioned. Not cooling the bulbs directly, but effectively wicking the heat away from the LCD screen, by building a baffle of sorts the 2 sides being made of glass. The 1st pane should go to side of the bulb(s) that readily absorb heat, the other side to the LCD that does not take on heat easily. In between an air gap, or water gap should be placed as water works better, and a nice little set up for computers that pumps out the water, as long as no air bubbles are trapped between the two I don't see a problem with clarity of light. If I remember science and history correctly water was used much like crystals today to both focus and clarify images. Just thought I would add a different perspective...
any thoughts?
any thoughts?
MLR
I do think the idea of a water cooled panel seperating the bulb/s from the LCD is a decent one, however I'm fairly certain that a 400 watt metal halide HID would boil the water prety fast if it were'nt recirculated to a radiator. I'm also concerned that before very long you would find an algae buildup in your cooler panel giving you a lovely green hue to your projection. The bulb would still need a fan to move air, so you dont loose the noise factor. The bulbs I posted were water cooled, special enclosures that surround the lamp itself with water (recirculated to a radiator), thus removing heat allmost entirely from the PJ. If only they were afordable 🙁
zardoz
Mad Lab Rat said:
I do think the idea of a water cooled panel seperating the bulb/s from the LCD is a decent one, however I'm fairly certain that a 400 watt metal halide HID would boil the water prety fast if it were'nt recirculated to a radiator. I'm also concerned that before very long you would find an algae buildup in your cooler panel giving you a lovely green hue to your projection. The bulb would still need a fan to move air, so you dont loose the noise factor. The bulbs I posted were water cooled, special enclosures that surround the lamp itself with water (recirculated to a radiator), thus removing heat allmost entirely from the PJ. If only they were afordable 🙁
zardoz
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