PDA

View Full Version : Can my pumps really be adding this much heat?


Gudhjem
04/20/2012, 11:14 AM
I have a 57g with a 30g sump; total water volume about 65gallons.

My Apex controls turns my heaters on at 78 and off at 79, which has kept my tank in about that range since I set it up in October last year. The past few days we've had warmer weather - not a heat wave, just warmer, so the house is at 73 during the day. This has resulted in my tank hitting 82 (!). This has me worried about what's going to happen in summer, when the house will be more like 80.

I checked the logs and the heaters turned off when they were supossed to. I double-checked the temp with a different thermometer and it's correct. Other than the heaters, the only sources of heat are the lights and the pumps. The lights are 2 AI Sol Blue LED modules in an open canopy that I run at well under 50% power. I expect these impart close to zero heat to the water (their fans never even come on). I figure it has to be a pump. My pumps are:

(1) Eheim 1262 (80w) return submersed and working against 5' of head
(2) Tunze 6055 (24x x 2 = 48w), programed and so do not run 100% power
(1) pump that sits in my Nac7 skimmer. Don't know brand, but it's small and quiet

I am wondering if anyone knows if these pumps could really be adding that much heat to my tank. It seems so unlikely to me, but I can't think of another explanation. Thoughts or experience?

I'd really like to avoid using a chiller. I could drop to an Eheim 1250. I have one, but it doesn't really move enough water since my return also diverts to my fuge and GAC and GFO reactors (though it is a lot quieter than the 1262, which I find dissapointing in terms of noise)

I'm wondering if placing a small fan blowing across the water surface might help. It would be ugly, and the surface is already very turbulent due to the Tunzes. Any thoughts on that?

--Steve

tkeracer619
04/20/2012, 11:30 AM
Submersible pumps add their rated wattage directly as heat. A 80 watt pump is the same as a 80 watt heater.

tkeracer619
04/20/2012, 11:33 AM
A fan across the tank and/or sump will remove a considerable amount of heat. More so in dry climates. You might consider a small chiller if you do not have an ac

aleonn
04/20/2012, 12:05 PM
I'd lower your Apex temperature ON/OFF points, and program a fan to blow across the sump if temperature reaches a certain point.

atreis
04/20/2012, 03:16 PM
The skimmer pump is 28W. So, that's probably somewhere on the order of 130 Watts - same as a 130W heater that is on all the time. Yes, they really do add that much heat. As others have suggested, fans can help. Most people end up getting a chiller.

Gudhjem
04/20/2012, 03:26 PM
Thanks for the replies.

I'll try some fans first and see where that gets me.

rl225
04/20/2012, 03:29 PM
External pump and power heads? (mp10s)


Sent from my iPhone using Tapatalk

HV1990
04/20/2012, 03:30 PM
I would change when your heaters turn on. Have them turn on if your temp is < 76. and turn off if > 77.

cobra9
04/20/2012, 04:02 PM
try a couple of these (http://www.frozencpu.com/products/12687/fan-ac-30/Fantec_120_x_120_x_38mm_Dual_Ball_Bearing_AC_Fan_Kit_w_Filter_-_CAB_703_-_80_CFM.html?tl=g36c265s668&id=LWWrNiCW)

aleonn
04/21/2012, 11:53 AM
If you have your lights running in the daytime hours, the tank would heat up more during that time too. I run my lighting at night (when I'm home), which helps with heat issues as well as electricity costs (off-peak hours).

chadfarmer
04/21/2012, 02:07 PM
what are using to get temputure readings?

Gudhjem
04/21/2012, 04:40 PM
what are using to get temputure readings?

Apex temp and a seperate digital probe (reads within 0.4 F)

symon_say
04/22/2012, 07:06 AM
I don't wattage of equipment equals wattage of heater, simply because equipment use the power to do their work, and the efficiency of the equipment determine how much heat it puts out, the higher the % of efficiency the less heat it puts out.

Heaters on the other hand use all their wattage to produce heat.

James77
04/22/2012, 07:11 AM
I don't wattage of equipment equals wattage of heater, simply because equipment use the power to do their work, and the efficiency of the equipment determine how much heat it puts out, the higher the % of efficiency the less heat it puts out.

Heaters on the other hand use all their wattage to produce heat.

All ofa submerged pumps wattage/energy will turn to heat. Yes, some is converted to water movement, kinetic energy. That kinetic energy will convert back to heat from the friction of the water hitting itself as it slows. Same with a 100 watt fan in a room-it will add 100 watts of heat to the room, and the same reason why 100 watts of whatever light has the same heat as 100 watts of another light....energy cannot be destroyed only converted.

Gandolfe
04/22/2012, 07:43 AM
I had a problem with my tank staying at 84 to 86 all the time after i upgraded to T-5 HO's in an enclosed canopy. My chiller wasn't working so I added a 8" fan with a hole cut in the side wall of my canopy blowing in across lights and water surface. At the other end is another hole with 2 4" fans blowing out(gonna replace them with 1 - 8" fan soon). I run a mag 7 submersible,a skimmer,a 250 GPH submersible for my fuge,and a 320GPH submersible for my phosban 150
. I also have a 1000 GPH quietone pump external on one closed loop, and a 2600 gph mag pump external on another loop. I keep my house at 76(in florida) and my tanks stay at 79 now. I also have 4 cfl on an algae scrubber in my sump and 1 8" fan blowing on those, and 1 cfl on my fuge with no fan. so fans can control your temp without a chiller. i do not have a heater on my tank at all

flipteg
04/22/2012, 07:55 AM
i did a test on this matter a few years back... although a pump and heater will heat the water at the same rate, it only does this when the water temperature is below ambient air temperature. once the water temperature reaches ambient air temperature and above, a heater is much more efficient at overcoming the gradient between temperatures of water and ambient air.

http://www.reefcentral.com/forums/showpost.php?p=16296292&postcount=52

James77
04/22/2012, 08:32 AM
i did a test on this matter a few years back... although a pump and heater will heat the water at the same rate, it only does this when the water temperature is below ambient air temperature. once the water temperature reaches ambient air temperature and above, a heater is much more efficient at overcoming the gradient between temperatures of water and ambient air.

http://www.reefcentral.com/forums/showpost.php?p=16296292&postcount=52

Were the buckets/containers sealed in any way? Just curious if the water moving around played a role in the container with the pump being able to dissipate heat better than the less flow in the water in the heater container.....

flipteg
04/22/2012, 08:40 AM
the buckets were covered but not sealed. the goal was not to totally isolate the water from the environment. i was trying to replicate similar aquarium conditions which are not sealed.

yes, in the vacuum of space with the containers totally isolated, both will probably act the same.

that's actually the same conclusion i reached... the water movement helped the pump heated water pick up heat from the ambient air when the water temperature was still below ambient air. but once it went over ambient air temp, the water movement was helping dissipate the heat away from the water and into the environment.

jscarlata
04/22/2012, 01:11 PM
One pump could be making more heat than it should. When I first setup my 90 I had a mag 9 on the return and a mag 7 on my skimmer. The mag 7 was older...when I swapped the 7 out for a new skimmer pump, the heat issue went away. Be careful how you program your heaters, if you adjust the program and the issue is with your pump, you could have other issues..

symon_say
04/22/2012, 03:34 PM
All ofa submerged pumps wattage/energy will turn to heat. Yes, some is converted to water movement, kinetic energy. That kinetic energy will convert back to heat from the friction of the water hitting itself as it slows. Same with a 100 watt fan in a room-it will add 100 watts of heat to the room, and the same reason why 100 watts of whatever light has the same heat as 100 watts of another light....energy cannot be destroyed only converted.

You get the point i made, and the experiment flipteg did confirm what i say, a 100w pump won't heat the water like a 100w heater can, pump convert power into work and heaters convert all the energy into heat, the 100w are there but not like heat only.

James77
04/22/2012, 04:10 PM
You get the point i made, and the experiment flipteg did confirm what i say, a 100w pump won't heat the water like a 100w heater can, pump convert power into work and heaters convert all the energy into heat, the 100w are there but not like heat only.

The 100 watts are there, and they all go right to heat. The test flipteg did shows that, hence the temperatures going up the same in both containers. What changes is when the temperature in the containers surpasses the ambient room temperature. The reason it does that is the water is moving(quite a bit if it was a 93 watt pump), so the surface is being agitated and being exposed to the cooler air. The water in the heater only container is just sitting there, so it is losing much less heat to the room.

But, there is still 100 watts of heat going into the container and it is heating the water exactly the same as a 100 watt heater. Hopefully you will agree on the fact that energy cannot be destroyed. So after the pump converts a small amount of the energy it uses into water movement, aka kinetic energy, where does that energy go?

Just like 100 watts of LEDs and 100 watts of halides put out the exact amount of heat. A 100 watt fan and a 100 watt powered speaker, all will heat a room the exact same. Please explain to me how it can possibly be otherwise, and please take it a step further than the energy being converted into light or sound in my examples....tell me where that converted energy goes?

Tmoriarty
04/22/2012, 06:37 PM
MP10's/MP20's, puts the pump outside the aquarium and will help keep your aquarium cooler. Also you can put your return pump outside your tank if you have the room to help remove some more temperature.

flipteg
04/22/2012, 07:07 PM
James77 and symon_say, you are both correct!!! all the energy goes in to and through the water. the big difference is how the energy is dissipated to the environment.

at the temperatures that we keep our reef tanks (~75F) relative to room temperature (~72F), pumps will do a descent job at heating the water to the point that it will be exactly the same as a heater. so yes, in practical terms, a pump and heater will heat the water the same.

but if you like to keep the temperature inside your house at 40F and you're trying to maintain 75F water temperature, pumps will not be enough to maintain that because the gradient between water and room temperature is too great. a pump and heater (although both will put the same energy into the water) are not and can not act the same due to what they do to the water and the environment they are sitting in.

same thing if you live in the desert and your air conditioning broke and your house is at 100F. the pumps and environment will quickly bring your tank temp to 100F.

really, the argument of where all the energy goes is irrelevant because we are not operating our tanks in the vacuum of space. we, as human beings, have a temperature comfort zone where we like to keep our house temps at... which also happens to be very close to reef tank temps

Tat2demon
04/22/2012, 09:18 PM
Go with a small fan. I have a medium size desk fan that will drop my 240 almost 4 degrees.

Janet92
04/22/2012, 09:41 PM
http://www.heritems.info/avatar3.jpgSubmersible pumps add their rated wattage directly as heat.

atreis
04/23/2012, 03:47 PM
You get the point i made, and the experiment flipteg did confirm what i say, a 100w pump won't heat the water like a 100w heater can, pump convert power into work and heaters convert all the energy into heat, the 100w are there but not like heat only.

It all goes to heat eventually - some can dissipate more effectively to the surroundings when those surroundings are cooler (due to water motion, which has much the same effect as blowing a fan over the surface). It's still heating the water.

Aside from that, we generally don't care that much about the heat a pump produces when the ambient air temperature is substantially below the temperature of the water. It's during hot weather (when the temperature of the ambient air is above, or well above, the temperature of the water) that these things end up becoming a concern.

moondoggy4
04/23/2012, 06:56 PM
I have a Seio 1100 in a trash can with 15 gallons of new SW and it heated the water from 70deg to 80 deg without a heater.

drtrash
04/23/2012, 08:38 PM
Small fan is all you need. Running a 1260 W MP40 & AI in AZ all summer. AC is set at 81 deg. Tanks runs no hotter than 83.