BC29 Stock Fans pt.2

[Robster]

Well…Finally received the Fans for testing replacement of stock fans. To the surgery…

 

I’ll spare you the details of each day of testing; After taking out the stock fan, (I expected that sucker would sound like a jet engine), but to my surprise out of the hood, in free air it was louder than the new fans, but not by much; and dramatically quieter than it was mounted in the hood.

 

Therefore, given the drastic increase in sound could only mean that when the fan is attached to the hood its vibration is coupling with the hood structure which is not very rigid (acoustically speaking) which in turn creates an amplified resonance peaks (modes) Kind of like a really cheap stereo speaker with a poorly braced cabinet that resonates and adds sound that does not belong there (that’s why plastic cabinet speakers a such a piece of junk and you can buy them for next to nothing). So, given that we cannot add bracing to stiffen up the hood (making hood/cabinet more rigid changes the frequency that it will resonate at…lower frequencies are precieved to be quieter at the same sound pressure as higher frequencies). So, that only leaves damping material…hmmm have some laying around from having to fix a vibration issues in someone’s home theater a few months ago, sweet. This is a material that became popular by high-end car audio installers who when adding thousands of watts to a car were left with metal panels vibrating and all sorts of ugliness. Presto…self adhesive high densisty substance designed to reduce vibration in door panels, trunk lids etc... in a handy 12”x12” sheet about 1/16” thick. Here’s a pic with several pieces applied to the hood area:

 

 

Applied some also to the new heat shield (thin metal, yeah that’ll vibrate)

 

 

Off to more testing The best fan from the group is seaming to be the evercool 60x60x25 rated at 26.5CFM at <30dBA (though at full power its not real quiet) however, anywhere from 7.12V to 9V a lot quieter, and still moving decent CFM.

 

 

And check out the difference by damping the hood…The area inside the red line is where the resonance occurred. (the very light blue line is ambient room noise and sound bleeding in from the city. So basically ignore all data to the left of the leftmost red line. The orange line is the original stock fans in the hood as recorded on that dreadful day of firing it up. The dark blue line is the new 60x60x25mm fan running at 7.56V removing 44.5 dBA of hood resonance!!!! **Disclaimer the dark blue line is only one fan not both after I can get the other one prepped I’ll get a measurement of both new fans running, I expect about a 3dB increase of sound, but still nearly 10db less than stock… in lay terms that = about half as loud!!**

 

Oh, almost forgot… I figured with the lower Voltage/slower fan speed should result in decreased air velocity which would almost certainly further decrease the flow by going through the tight vents on the hood, not to mention adding a little more sound (try taking your fan from free air while running and then set it next to an object that is deflecting most of the flow….it the fan gets significantly louder). So Dremel and a small file to increase the vent flow from the back side

 

before:

 

 

And after:

 

 

Added a little more dampening to each individual vent louver that’s why the lines aren’t too straight, not to mention a couple times the dremel gripped the plastic and made some “divots”…oops.

 

At the lower 7.5V, the new fan seems to be putting out at least the same flow if not a bit more, while pushing it up to 9V is definitely more flow. Waiting for my new bulbs to get here, then I can test to see if going to stay with push/pull fan alignment, or go push/push and create new intake vents, plus still have to finish opening the second vent a bit.

 

Cheers

-R

[TEALCOBRA]

Sounds good, great findings... never thought about using the sound deadening stuff..... Let us know what your other findings are....

 

I actually couldnt stand the 60mm fan selections so I just ordered a 80mm fan, and a 15mm thick adapter that will allow me to go from a 60mm to 80mm fan. The fan I ordered is a Enermax Marathon fan, it moves 24 CFM at only 14 dba. Once I get all these items I will be working it into my hood, although with the nanotuner kit, the fan area is pretty cleared out, so I think itll be a straight forward swap out.... That and if I end up getting the MH lighting kit that Chris is in the process of developing im going to need the extra CFMs.... at that point I wont care about the dba's and they have 80mm fans that move up to 84 cfm's.

 

Man I love modding stuff.

[POSSUM]

Thanks for all that work Robster. Is that dynamat? I looks like it. I too am waiting for the MH kit that Chris has talked about for the bc29. It's been hard to wait considering that the pc upgrade is already availableCooling is definately an issue , so this will help with the sound and the heat. thanks guys. Hey, Teal so what about the skimmers? Which one do I get ? The Tunze or Sapphire's? Which one is the most quiet and performance etc?

[Robster]

Possum- Yep Dyna Mat Hush Mat Ultra... pricey stuff list is $100 for 4 sq.ft., but it says its rated temp is -30 to 400 F and is supposed to handle humidity, even saltwater spray I used about 1 1/2 sq.ft. Edit: Make that about 2 sq.ft. now

 

pdf:

http://www.hushmat.com/new/pdf/hushmat_ultra.pdf

 

 

Cheers

-R

[TEALCOBRA]

Thanks for all that work Robster. Is that dynamat? I looks like it. I too am waiting for the MH kit that Chris has talked about for the bc29. It's been hard to wait considering that the pc upgrade is already availableCooling is definately an issue , so this will help with the sound and the heat. thanks guys. Hey, Teal so what about the skimmers? Which one do I get ? The Tunze or Sapphire's? Which one is the most quiet and performance etc?

 

So far, you cant go wrong with either one.... the Tunze is already totally broken in, but the sapphire isnt... hopefully itll be broken in completely within the next week or so and I can get more accurate results...

[Robster]

Well back to the drawing board a bit… the 25mm fan height is about 4mm too high to allow clearance of the 4th 32watt pc on the 4.32 conversion . In a moment of hey why not, double stacked the 60x60x10 delta fans with a little piece of that wonderful damping material between them to give space and not drag the fan blades against the 1st fan. Bingo!! Happiness is not only found in the bottom of my coffee cup… those few mm difference give just enough room for the 4th light to clear the blades…sweet! Now I have to order 2 more fans hmmm….there seems to be an ever increasing hole in my wallet .

 

On a side note, finally got my new 5500K 96CRI 2800Lumen PC’s in…All I can say is WOW! They have the purest white light I have ever seen from a bulb…Contrast of colors in the room seemed to have exploded… Red’s became vibrant and subtle nuances of color shades became definitive!! And NO over saturation in the Yellow spectrum like the cheapo imitation daylight bulbs.

 

After I get the other two fans I'll get some SPL measurements

 

Cheers

-R

[TEALCOBRA]

Got my fans and everything in today, I am going to try to find some time to mount them tonight and post my findings.... Ill keep you posted.

[Robster]

Tealcobra- So what happened????

 

Still waiting for my second pair of 10mm fans. Picked up the new ballasts today very happy with those at first tests, though I hate not being able to measure things....so ordered a LUX meter today also. Just so happened that the dealer had just received 1st shipment of Tunze Nano-Stream 6025's...couldn't help myself...had him add that to the order too. Can't believe how much I've spent, and it doesn't even have water in it yet All I can say is it better keep fish/corals alive or I'll get real grouchy.

 

Anyway... once the fans and the LUX meter get here then not only can I fine tune/measure the SPL's on the fans, can also get the optimum air flow compensated for, since the ambient temp around the CFL will have a dramatic effect on the light output too hot or too cold drops lumens from its capacity if you are curious and here's a nice little article:

 

http://www.lrc.rpi.edu/programs/nlpip/ligh...s/lat5/pc10.asp

 

it is not as detailed as they get, I but enough to sink yer teeth into.

 

Cheers

-R

[stallen]

http://silenx.com/ixtremaprofans.asp

These fans do not move as much air and they are pricey, but they are almost totaly silent. Anything uder 20dBA is almost totally silent from about 6ft away. I've used them in my computer they are great. The most silent fans out there (dBA vs. CFM).

 

It's what I'm going to use to uprade the fans in my hood and for my fuge light ventilation.

[Robster]

http://silenx.com/ixtremaprofans.asp

These fans do not move as much air and they are pricey, but they are almost totaly silent. Anything uder 20dBA is almost totally silent from about 6ft away. I've used them in my computer they are great. The most silent fans out there (dBA vs. CFM).

 

It's what I'm going to use to uprade the fans in my hood and for my fuge light ventilation.

 

they sound very nice, but if you are going to run 4-36watt bulbs on the BC29, the 25mm height may be problem. when I set the 25mm tall fan I was testing, it put the blades up too high and caused them to drag on the lamp housing

but the company you listed has the right concept: Lower RPM=less noise (combined with de-coupling from canopy, and distance from intake grill).

 

Aside from that if you are not running 4 lamps I would imagine you won't have any issues.

Cheers!

-R

[Robster]

Ok so everythings been a bit crazy busy. but finally got the fans and the lux meter (since we established earlier that optimum amibiant temp around CFL bulbs is critical to achieve highest light output). My solution as it sets now is I'm using 60x60x10mm fans 2 stacked on top of eachother with a little bitty spacer to keep the blades from dragging on 2nd fan. This for a total of 4 fans.

 

After the challenges keeping straight lines when opening the existing vents, I wanted to first try to keep the push/pull design to avoid making new cuts in the hood for intakes. After getting 4 bulbs in mounted/wired/etc... I was able to put the fans to the test!! With the Lux meter probe (waterproof ) at the bottom of the tank (filled with water) began testing as the bulbs were warming up, the lux meter kept jumping up with higher numbers...sweet.. it got all the way up to about 8,000 lux, but then started dropping sharply. Have fans on 3-to-12v selectable power supply, with a variable resistor (rheostat) in line for extra fine adjustments. despite every attempt at different volts (speeds of fan) full throtle to slower the meter settled in at 7,450 lux down quite a bit from where it peaked for 2.5 seconds.

 

So time to invert fans to all push, and cut new intake vents.:

 

Dremel, height adjusting collar (I think it was from a grout removal kit??), straight cutter, small sheet of wood and clamps for guide, and shop vac (lots of little black pieces of plastic on the floor and my work bench...oh, I mean kitchen table....got to try and keep it half clean so my wife doesn't get too grouchy )

 

 

The depth attachment proved extremely usefull!! I found that setting the depth very shallow and taking off a little bit at a time much cleaner cuts, also found that the plastic gets a little melty so after passing over after about 1-2 seconds the melty plastic cooled a little bit, and by running back the opposite direction the melty stuff clicked right out .

 

good hour or so work'in and finally finished:

 

 

 

Not quite Michael Angelo, but close enough for government work. Reversed the second pair of fans now all air being pulled in from new front vents and out throught the two fan vents.

 

Test time

 

Fan efficacy has increased substantially!!!!! Now I'm running into the inverse problem too much flow!! have to keep notching them down...it's now about 3:30am (can't sleep...making too much progress) fan voltage now down to 6.80volts and light output has jumped to 8,660 Lux !!!! That's an increase of 1,210lux (translation: almost like sticking a whole additional light into the mix)!

 

Fan noise is at a whisper about as loud as the Tunze 6025 nanostream and light output maximized!!

 

Goal acomplished!

 

cheers!

-R

[TEALCOBRA]

GREAT work Rob... I was soooo waiting for you to try making both fans pull and then adding new intake slits in the cover.... What was the diameter of the slits that you added to the hood ??

 

Man I need to get off my a$$ and start doing some new mods.

[stallen]

Nice work on the vents! I was thinking abut adding some vents to the front of my BC8, but wasn't sure the best way to do it without messing up the hood. Now I know how to do it!!!

[chuckfullservice]

How long did the lux hold at that output for?

Also great job on the venting even looks better then the stock vents !

[ccjung]

Good work rob! It looks like you got a handle on the Temp vs Output relationship on PC bulbs. The next step would be to determine the best bulb combination to provide the most effective spectrum for your corals.

 

Bear in mind tho, that LUX is a measurement of visible light, and different wavelengths (particularly the blue spectrum) are weighted different, which means that a 5500K bulb would perform better under a Lux meter than a 50/50, etc, but wouldnt necessarily mean the lighting is "ideal" for the species at the depths they would experience in nature. Still, the Lux meter and a known standard reference bulb (ie your 5500K) is the best way to get a fix on the temp-output relationship. When we developed early designs of the JBJ retros, we used 5500K (pee yellow) bulbs to get proper design temperatures.

 

Now on to the right combination of bulbs!!! or a single MH bulb that has been "dialed in". Ideally, to determine the best combination of PC bulbs, you would need a par meter or a radiometer.

 

I think you did a great job on the intake vents for the hood, as stated in earlier posts, the Biocube is not optimal, but performed surprisingly well in the stock Push Pull with upgraded fans. This is great for performance, but not for noise, and many people aren't as skilled as you are with a rotary.

 

People are quick to dismiss the JBJ nanocube family, but their hood design is superior to all on the market at this time, since they already have the slats cut into the front and sides, which is why we have been able to come up with such high performing upgrades.

 

When we talked on the phone, you mentioned you wanted the best of both worlds (noise level and output) and liked the challenge of tinkering.. You have proven successful.

 

You should bring that badboy up to the shop someday, we'd like to see it.

 

Chris

[Robster]

Thanks all for the kind words

 

 

 

What was the diameter of the slits that you added to the hood ??

 

Teal- The bit seems to be just at 1/8 of an inch, leaving the new vents almost identical to the originals (within a few 100'ths), except they do look a breath bigger since they don't have the downward plastic molded to it like the original ones which from a profile kinda make a "Z"shape...except I have trimmed the underneath side so mine look more like say a "7"

 

In Hind sight the two LONG cuts across the front I'm not the most happy with...It far enough in-front of the mid bolt for the spalsh guard, so structural integrity is not compromised in that regard, but the length of cut and remaining material lost a lot of "shear" strength, so If I had it to do again, I think I would have skipped the long cuts, and compensated with more shorter ones, to leave a bit more material between the vents. it works, but the long piece between the two long cuts is somewhat flimsy...so too much fuss'in around with it it might break... not too worried on other factor bringing it to demise... the surface temp after 5 hour of running the lamps was cool as a cucumber... so no worries of heat degredation to that little strip (unless fans sieze )

 

 

 

 

 

How long did the lux hold at that output for?

 

My testing time was done this morning pitch black (relatively for the city) outside, so no unknown ambiant light influence...Before each reduction to fan speed light had stablized out the enitre time from 11:30 to 5 am when I went to bed the Lux didn't drop below 8,380 (and when it was down that low, was when the fans were running too fast!) I made adjustments with the rheostat typically 0.10volts at a time...after about 15-20min temps would stabilize unless there were dramatic volt adjustments made...which was the cause of the big swing down to 8,380 cause as I was fiddling each time i tweeked down the temp light went up, so being a little impatient dropped fan speed to about 6 volts and light was climb'in....but came back 15 min later and it was like the Titantic... then over compensated the other direction...then finally realized must do tiny at a time, so would adj. down til started to see the meter bouncing toward up, then be patient and let it stabalize before making next adjustment. the window for 8,500 - 8,660 was roughly 0.6 volts. The fluorescents crest their light output at the temp they want, then too hot or too cold light output suffers easily asmuch as 20% within a few degrees either direction.

 

Now day time ambiant temp has not been accounted for doing a little playing with that today....between grout and seal on the bathroom...but I fired up the bulbs at last nights 6.8v fan speed and initial measurement jumped by 260lux that would be due to the ambiant light bleeding into the room from outside... but have a couple base-lines now

 

 

Chris- Great points as always

Yes, I agree the lux meter doesn't give me all the info I would like PAR meter would be great....you don't happen to have one at the shop??? and yes, the blue spectrum does get kicked around a bit from what I understand with the lux meters, but there must be some (obscure at best) relationship between them as PAR is measured from the visible light spectrum, though green and yellow spectrums are supposed to be less productive in the PAR realm, but I also understand the Red's are along with Blue's in the more dominant NM's harvested by the photosythesis world...Regardless....love to see the PAR output of these balanced white lights cause they look Marvelous!

 

I would agree with your point on the JBJ design...proof is in the pudd'in as they say! It confirmed my initial hypothesis about the air flow, though like you said the BC push/pull can work with the right fans for the temp output occuring. Which would completely explain the noise level of the Stock BC. (Reminds me of the old F-4 Falcon...engineers described it as proof you can make a brick fly if you give it enough power )

 

I was extremely nervous about cutting the top especially with my first free hand venture on the under carriage when I opened flow for the fan ports was marginally acceptable (couple slips, wavy lines etc...)...Thankfully I don't have a big shop with a big table saw so I had to learn from a friend (sweet carpenter) how to square-up and clamp down a guide piece with the added distance of the blade gaurd for cutting. Clamp and hold tight against the guide, and make shallow passes otherwise the melty plastic wants to grab onto the bit a pull in funky directions.

 

Thanks for the invite....sounds like fun....(especially if you have a PAR meter ) grab an espresso/machiato etc...,etc... I won't have any LR in the tank till after Christmas so no one will miss hood and lights for a day!!!

 

Cheers!

-R

[Robster]

Quick update:

 

Ran the lights, pump and circ. power head 14 hrs straight at the end of the time took measurements...Tank temp 78.6 lux slipped to just a bit over 8,000. I expect the overall ambiant temp of the house being up higher from the day had an effect on the light output I can see that being a never ending battle, but overall I can't be too disapointed, still better than the 7,450 though surely that would have dipped also.

 

over all looks in good shape lots of light and should be able to avoid a chiller I noticed that having the lights on all day seemed to heat up the room a bit...well one more thing to deal with at some point

 

Cheers!

-R

[TEALCOBRA]

Question for you Rob....

 

On the subject of LUX and PAR, would I be better off keeping my 144w of PC lighting from nanotuners, or would the 70w MH from them get me a better PAR number.... I just wonder about those kind of things... I was waiting for their double HQI setup because I would like to keep a small clam and maybe a few small SPS in my BC29, but didnt know how much more PAR the 70w MH would give me than 144w of PC....

[Robster]

Question for you Rob....

 

On the subject of LUX and PAR, would I be better off keeping my 144w of PC lighting from nanotuners, or would the 70w MH from them get me a better PAR number.... I just wonder about those kind of things... I was waiting for their double HQI setup because I would like to keep a small clam and maybe a few small SPS in my BC29, but didnt know how much more PAR the 70w MH would give me than 144w of PC....

 

Those are the questions that keep me pondering through the night, as I'm also hope to be able to keep a small vivid clam and some LPS can't say as I've seen any SPS's that make me think I gota have em, but a saw a piece of birds nest that looked pretty cool. I have not gotten a chance to get over to LFS to try and get LUX measurements off their tanks...that will be an interesting number to know.

 

I am having optomistic outlook for the full spectrum bulbs I'm trying. I found an interesting article on LUx/PAR:

 

http://ncr101.montana.edu/Light1994Conf/5_...text%20only.htm

 

Kinda brain twist'in

 

little more:

 

http://www.advancedaquarist.com/2002/2/aafeature/view

 

and

 

http://www.advancedaquarist.com/issues/july2004/review.htm

 

If your anything like me, my head was spinning like a top after these

 

so with the useable spectrums of light graph in second article, and my knowing that my total lux output is not heavily weighted in the green/yellow spectrums, I think I've got a pretty good chance of generating great PAR values while maintaining crisp white light with the slightest hint of blue

but that will remain to be seen.

 

also, IMHO I don't see much benefit for jumping to 70watt MH vs. 144watt FL Typical efficiencies of MH are not that much higher than those of good quality CFL (maybe 10-30 lumen/watt) and lumens makes its way down to lux which makes its way down to PAR then eveen further to PUR (like PAR except Useable not just Avail radiation). **this is losely translated and simplified, actual output has more variables as you see in those articles listed** So, 144watts x 65lum/watt=9,360 lumen vs. 70watts x say 100lum/watt=7,000 lumen

 

Cheers

-R

[Randy]

Do you think with the added vents and larger fans it would be safe to put a 150 mh bulb in there with just two 28w actinic pc bulbs? With Evercool fans it would have ~32 cfm and with Thermoflow fans there would be ~20-48 cfm flow.

 

I'm asking for myself, because I have an electronic Icecap ballast and want to upgeade to mh in my BC29. I'm considering buying the 70mh kit, but I can use my ballast and do it myself I will.

[Robster]

Do you think with the added vents and larger fans it would be safe to put a 150 mh bulb in there with just two 28w actinic pc bulbs? With Evercool fans it would have ~32 cfm and with Thermoflow fans there would be ~20-48 cfm flow.

 

I'm asking for myself, because I have an electronic Icecap ballast and want to upgeade to mh in my BC29. I'm considering buying the 70mh kit, but I can use my ballast and do it myself I will.

 

 

That is a reeeaaly tough call. MH put out soo much heat, and the plastic splash guard really is not designed for it. It seems like it took Chris a couple years over at Nanotuners, I have not had a chance to see what that install/cooling etc... looks like. I would be extremely hesitant, as you don't find plastic parts in conjunction with MH. they are not well known for getting along together.

 

Maybe an open top where the MH reflector is and some heat disapation fins, combined with the increased flow of air through the canopy might. The fans I am using along with the flow change modifications have the ability to over-cool the CFL bulbs, so I have to keep the voltage between 6.8 to 7.1volts on these 12v fans. I do not have any reference or testing against MH, and would advise to proceed with caution!!! and a fire extinguisher!

 

-R

[newtanksmell]

Robster, setting aside the fact that I feel like I just spent an hour in physics class, awesome work, sir. I learned a ton.

 

Please let me know when the Robster modified light hood is available for purchase.

 

 

That is a reeeaaly tough call. MH put out soo much heat, and the plastic splash guard really is not designed for it. It seems like it took Chris a couple years over at Nanotuners, I have not had a chance to see what that install/cooling etc... looks like. I would be extremely hesitant, as you don't find plastic parts in conjunction with MH. they are not well known for getting along together.

 

Maybe an open top where the MH reflector is and some heat disapation fins, combined with the increased flow of air through the canopy might. The fans I am using along with the flow change modifications have the ability to over-cool the CFL bulbs, so I have to keep the voltage between 6.8 to 7.1volts on these 12v fans. I do not have any reference or testing against MH, and would advise to proceed with caution!!! and a fire extinguisher!

 

-R

[Robster]

Too kind

 

My High School physics instructor would be so proud, seeing as how I never did any of his homework....I think it was just too boring!!!

 

Tealcobra was getting to have fun with rock and water, while I was still stuck on this project. So now, I wish I had His rock & fish & corals; and He's prob wishing he had my awesome light!!!! (wishful thinking on my part...I'm sure He's happy as lark)

 

And now for a little bit of bragging.....finally got some measurements of LFS....they had a viper 150mh sitting about 1ft above a NC24 and at tank bottom it only measured about 4,300lux... right above the surface of the water it was running something like 15,000lux, but its penetration didn't seem too impresive, about 1" below surface light dropped to about 8,500lux. This compared to the approx 8,000lux I'm getting at tank bottom!! (I know, I know these aren't lab grade measurements, and not fully indicative, but WOW comes to mind!!!)

 

-R

[TEALCOBRA]

WHOA, youre not kidding... thats a ridiculous amount of LUX dropoff... I wish I had one of those meters to measure how much I was getting at the bottom of my tank.... I like to think theres alot, but Im probably wrong.

 

As for the MH in the BC29, you still need to run a piece of UV glass between the MH bulb and the tank, and I think (dont quote me here...) that goes between the bulb and the plastic lens cover.

 

I was seriously thinking about going to a MH just to see if I can pull it off, but havent heard back from Oceanic about buying a new hood and lens cover.... And I just got a notice in the mail from ComEd (local power company) that rates will be going up 22% starting the month of January... prolly not the best time to start a MH project.

 

A 150w MH along with 36w of actinic would be SWEET. Im still mad I cant use the MH's from work because the kelvin rating isnt even close to 10K.....

[Robster]

WHOA, youre not kidding... thats a ridiculous amount of LUX dropoff... I wish I had one of those meters to measure how much I was getting at the bottom of my tank.... I like to think theres alot, but Im probably wrong.

 

As for the MH in the BC29, you still need to run a piece of UV glass between the MH bulb and the tank, and I think (dont quote me here...) that goes between the bulb and the plastic lens cover.

 

I was seriously thinking about going to a MH just to see if I can pull it off, but havent heard back from Oceanic about buying a new hood and lens cover.... And I just got a notice in the mail from ComEd (local power company) that rates will be going up 22% starting the month of January... prolly not the best time to start a MH project.

 

A 150w MH along with 36w of actinic would be SWEET. Im still mad I cant use the MH's from work because the kelvin rating isnt even close to 10K.....

 

Just pickup a spectrumeter, and see what its putting out. cause the 10k coralifes and jbj I've looked at don't look anything like the spectrum output of 10k heated blackbody. Every reference to 10k light color doesn't have the enormous spike in the green/yellow that all these aquatic bulbs seem to have (according to thier packages, and thier light output from what I've seen)

 

But no sense putting the elec meter on hyperspin when rates hike!!!

-R