An Odd Request

JakeCK

On my aquarium I have some very powerful LED lights(powerful enough to reach through 24" of water and still keep the plants happy) that still put off a good amount of heat, I also have a couple hundred watts worth of heater in the sump. And I keep looking at the very smooth top of those lights trying to think of what kind of HX I could affix to the top of the  and plumb into the sump return line. 

Any ideas? Would absolutely need to be stainless. Brass, aluminum, iron would not be a good candidates for various reasons. I had thoughts about some stainless tubing with a thin stainless plate welded to the bottom cut to fit the lights might work. But a off the shelf solution would be nice...

hot_rod

How powerful are the lights, in Watts? Watts X 3.41= btu
So a 150W light X 3.41=511 BTU/hr. Is that worth trying to recover?

If you have a way to weld or braze stainless, but some square SS tubing and make a few trips across the light.

McMaster Carr has SS tube sheets, a bit $$

JakeCK

Yikes that's pricey. 

There is about 100 watts of lighting. Considering it's all LED that's actually a pretty impressive amount of lumens. Imagine how many watts from an incandescent or even florescent light it would take to get the same amount of light. Lol But yea the payback period would probably be a good number of years perhaps... The thing is this tank is heated to 78-79f and the house between 70 and 72 24/7/365. In the winter it's a wash since it helps heat a little bit, although it's not a very economic way to add heat to the house. In summer I'm paying to heat the aquarium and then paying to cool the house with a 150 watt heater that runs almost non stop with that 9f delta and 100 watts of lighting that run 14 hours a day.

The heater is sized very close to what is needed to heat the tank. Close enough that I put a second heater in it if I need to recover or increase temp if I have an outbreak of something like ich. Which brings me to the reason I brought this up today. The heater got shut off last night on accident. Didn't notice until this afternoon when I got home from work. It was almost to ambient and I now have 250 watts going all out to recover at about 1f an hour. The heat from the lights would have bought me a lot more time. Luckily the fish look fine, just a couple swimming a bit slower than normal. 

hot_rod

Seem like someone should invent submersible aquarium lighting. The light and heat is in the tank, a dual purpose appliance.
It might be less $$ to source some underwater lighting.

tim smith

Something like this, heat goes right in water.

JakeCK

The problem with LED's is finding ones that put out light at the best frequency(600-700nm) for photosynthesis. I've spent a lot of money purchasing and repurchasing lights before I found one that actually have both the intensity and spectrum I wanted. 

Putting a HX on top of the lights I have was just an idea and wanted to see if anyone had anything come to mind that would work. And not be prohibitively expensive.

Larry Weingarten

Hi, How about this? https://www.midweststeelsupply.com/store/304stainlesssteelrectangulartube The trick is in creating a fitting at the end that you can attach tubing to. I'm guessing silicon sealant would leach stuff into the water??

Yours, Larry

mattmia2

Wouldn't using a small heat pump to heat the water from the air around the tanks be easier than trying to get enough differential out of the lights to transfer any appreciable amount of heat to the water directly?

JakeCK

Larry Weingarten said:

Hi, How about this? https://www.midweststeelsupply.com/store/304stainlesssteelrectangulartube The trick is in creating a fitting at the end that you can attach tubing to. I'm guessing silicon sealant would leach stuff into the water?? Yours, Larry

There is actual silicone caulk just for aquariums. But yes most types are not aquarium safe.

retiredguy

I would experiment with just running a serpentine tubing over the top of and glued to the lights to see if there is any appreciable heat gain. Why spend a lot of money on a "guessing game" just to find out that there is very little heat gain. If the tubing idea works, you could then try elaborate ideas that cost more.

Mad Dog_2

Is that why my fishies died?  That Silicone in my tool bucket ain't for fish tanks?? Ha ha 😂 🤣 😆 😄.  Mad dog 🐕 

CLamb

Could you make a watertight enclosure for the existing lights and put them underwater?

JakeCK

CLamb said:

Could you make a watertight enclosure for the existing lights and put them underwater?

That's just asking for trouble.

WMno57

The heat may be coming from the LED's power supply and not from the LEDs,
Maybe you could use a liquid cooled gamer computer power supply to run the lights? Then you could plumb the coolant from the power supply to a heat exchanger for the fish tank.

hot_rod

Would copper tube work. I could bend a serpentine of 1/4" od copper tube and put the small barbed ends on to match the pump tubing size. My bender is 1-1/2" radius

I have some scrap pieces of .024 copper roof flashing I could solder it to. Then lay some insulation over the top of it.

JakeCK

Copper is bad news for aquariums, at least for invertebrates.

If you want to really p*** off the owner of an aquarium throw a penny into one of their tanks that has any invertebrates in it, either fresh or salt water, but especially salt water with coral. Depending on how much money dies one could find themselves subjected to a civil lawsuit or even criminal if it was intentional. 

Stainless, PVC, PEX, ABS, glass, acrylic, and aquarium safe silicone are about the only things I trust in an aquarium... Oh and oddly superglue, specifically cyanoacrylate is safe. 

Was curious just how hot the LEDs are at peak output. Thermal camera comes in handy again:

JakeCK

Another option to reduce the run time of the heater at least is insulation. The back, and bottom of the display tank can be insulated, all six sides of the sump, and the return lines.

Larry Weingarten

Hi, How about using some 1/4" PEX tubing? Make loops that cover both lights. Maybe glue it down with silicone and add some thin insulation on top, both to insulate and to hold the tubing in place. Then slowly pump water through it. 😊🐠🐳
Yours, Larry

mattmia2

Maybe a pealtier device to take the heat lost from the tanks and from the lights from the ambient air and put it back in the tank.

JakeCK

mattmia2 said:

Maybe a pealtier device to take the heat lost from the tanks and from the lights from the ambient air and put it back in the tank.

I had a thermoelectric cooler we used for camping. worked great for keeping drinks cool as long as the ambient temp wasn't too high. Leave it in a hot car in the sun and forget it. It stopped working this summer unfortunately.

JakeCK

Larry Weingarten said:

Hi, How about using some 1/4" PEX tubing? Make loops that cover both lights. Maybe glue it down with silicone and add some thin insulation on top, both to insulate and to hold the tubing in place. Then slowly pump water through it. 😊🐠🐳 Yours, Larry

This was my first idea but would probably look like poo unless I built a cover. I have seen some very nice wood covers for aquariums. I built the stand for my tank, but a nice looking cover might be beyond my woodworking skills tho.

EdTheHeaterMan

Have you considered getting rid of the fish? Seems like a lot of trouble for a pet that you can't even pet. A dog will keep you warm when sitting on your lap. No need for a heat exchanger

JakeCK

I grew up with dogs, multiple dogs. Trust me, dogs are an order of magnitude more trouble then some fish. I only have to spend about an hour or so a week doing maintenance on the tank. And even that can be deferred for several weeks if need be if the setup is good enough.

If by trouble you mean being aware of the requirements, it's no different than being aware of the requirements of dogs. Like not giving them chocolate, or chicken bones. Or with cats and how sensitive their kidneys are. Better keep things like Lysol away. 

ChrisJ

My first thought is a PC CPU water cooling pump and block or several of the cooling blocks and heatsink compound of course.

JakeCK

ChrisJ said:

My first thought is a PC CPU water cooling pump and block or several of the cooling blocks and heatsink compound of course.

That idea I like. But I wouldn't need the pump. I could just run a bypass off of the return from the sump and use a valve to throttle the flow. 

I just wish I could find a block that was 24-30" long. And instead of thermal compound thermal transfer tape. 

ChrisJ

JakeCK said:

ChrisJ said:

My first thought is a PC CPU water cooling pump and block or several of the cooling blocks and heatsink compound of course.

That idea I like. But I wouldn't need the pump. I could just run a bypass off of the return from the sump and use a valve to throttle the flow. 

I just wish I could find a block that was 24-30" long. And instead of thermal compound thermal transfer tape. 

You could use the rubber tape but it won't work as good.  Maybe good enough though over such a large area.

But last I saw the rubber sheets etc were far from cheap

hot_rod

At the most 5,000W per day if the heater runs 24/7.
What do you pay for a Kwh?
At .30/ kw= $1.50 per day.
That has to be about the cheapest livestock upkeep cost, as far as power consumption

JakeCK

ChrisJ said:

JakeCK said:

ChrisJ said:

My first thought is a PC CPU water cooling pump and block or several of the cooling blocks and heatsink compound of course.

That idea I like. But I wouldn't need the pump. I could just run a bypass off of the return from the sump and use a valve to throttle the flow. 

I just wish I could find a block that was 24-30" long. And instead of thermal compound thermal transfer tape. 

You could use the rubber tape but it won't work as good.  Maybe good enough though over such a large area.

But last I saw the rubber sheets etc were far from cheap

I know it wouldn't be as good but I would want something would both hold the block in place and transfer heat efficiently. 

JakeCK

hot_rod said:

At the most 5,000W per day if the heater runs 24/7. What do you pay for a Kwh? At .30/ kw= $1.50 per day. That has to be about the cheapest livestock upkeep cost, as far as power consumption

Yea this isn't looking like a cost effective endeavor. But its fun to think about ways to conserve energy. 

That said overall power consumption can run between about 30 watts at night between heater cycles when only the return pump and air pump are running to almost 300 when everything is running.

Two lights, return pump, air pump, CO2 solenoid, heater, and the auto feeder which uses like 2 watts.

ChrisJ

JakeCK said:

ChrisJ said:

JakeCK said:

ChrisJ said:

My first thought is a PC CPU water cooling pump and block or several of the cooling blocks and heatsink compound of course.

That idea I like. But I wouldn't need the pump. I could just run a bypass off of the return from the sump and use a valve to throttle the flow. 

I just wish I could find a block that was 24-30" long. And instead of thermal compound thermal transfer tape. 

You could use the rubber tape but it won't work as good. Maybe good enough though over such a large area.

But last I saw the rubber sheets etc were far from cheap

I know it wouldn't be as good but I would want something would both hold the block in place and transfer heat efficiently. 

Oh I see so you mean double sided tape. I was thinking the expensive thermal pads that don't have any adhesive.

hot_rod

JakeCK said:

hot_rod said:

At the most 5,000W per day if the heater runs 24/7.
What do you pay for a Kwh?
At .30/ kw= $1.50 per day.
That has to be about the cheapest livestock upkeep cost, as far as power consumption

Yea this isn't looking like a cost effective endeavor. But its fun to think about ways to conserve energy. 

That said overall power consumption can run between about 30 watts at night between heater cycles when only the return pump and air pump are running to almost 300 when everything is running.

Two lights, return pump, air pump, CO2 solenoid, heater, and the auto feeder which uses like 2 watts.

What are you paying for power?
If this were something you could fab yourself, go for it. If you have to buy, or pay someone to custom fab it???

Annealed, bendable 1/4" ss tube isn't very expensive 6 or 10' lengths. A stainless shop would have a piece of stainless sheet, break both edges to keep it flat and in position over the light. Some silicone rubber hose from the pump, up and down. 50- 60 bucks worth of parts, plus some TIG or brazing for the tube to plate and adapters on the ends.

t-

JakeCK

Power for me is free with the solar panels.

CLamb

I think you will find it easier to make an LED lamp which can be submerged. You can make one with the same spectral power output as your current one. You can find suggestions on how to do this in this Facebook group. https://www.facebook.com/groups/211979028997564