What Size Fluval Tronic Heater?

[zennzzo]

OK then...based on that explanation , I see how that is possible...
Thanks for the clarification...

BTU's would make more sense for heater ratings, just like any home heating or AC unit...



Nice edit BTW...but I still have the original

 

[jschall]

TL;DR.

You're seriously trying to deny that 2 heaters dissipating 150 watts of power each in a body of water will heat the body of water the EXACT SAME AMOUNT as one heater dissipating 150 watts of power?

From the top of your gigantic mess of copypasta I read that you looked up what a watt is and what a joule is, and then you started spouting off about BTUs which are really units of energy same as joules.
Don't believe me? http://www.google.com/search?q=btu

Approximately 4.2 joules will heat one gram of water one degree Celsius. A joule is 1 watt second.
Lets just say we have a 1-watt heater submerged in one gram of water, in a box that's perfectly insulated from the outside world. The temperature of the water will increase by 1 degree Celsius every 4.2 seconds.
Now lets say we submerge another 1-watt heater in there. What happens? We're dissipating 2 watts of power into the water, which will heat the water by 1 degree celcius every 2.1 seconds.

You realize that your heater might have two or more elements in it, right? You might want to check on that, you could be wasting more than half your power!

I still can't believe I'm bothering to write this. You just copied a bunch of paragraphs from the Internet and then spewed some crap about how I should take a fluid dynamics class. Have you?

 

[jschall]

Let’s make it more difficult for some who have a larger Delta T to overcome (as some keep their aquariums’ in their unheated basement in Minnesota, real life example later). Delta T=30, heat loss due to ambient air temperature through the glass on at least 4 sides, the top (assume no top) and yes the bottom. Let’s use two 50 watt in-line heaters and let’s assume one 50 watt heater can only heat a given volume of water to 60 degrees. Notice this is not 60 watts like you assumed.

The 60 degree water output is now sent to the second 50 watt heater (which can only heat water to 60 degrees also). According to you the water temperature output would now be 120 degrees. If this were true the worlds’ energy problem would be solved.

But we know that can’t be. 60 degree water sent to the second heater (which can only heat to 60 degrees remember) will output the same 60 degree water. OK… let’s add a third 50 watt heater in line now. What do you think the water temperature will be, 180 degrees? I don’t think so.

WHAT THE **** ARE YOU TALKING ABOUT? ARE YOU RETARDED?

How would one 50 watt heater heat water 10 degrees, and the next two 60 degrees each?

Assuming you have good insulation, the first one would heat it maybe 10 degrees, the second one would heat it another 10 degrees and you'd have 70 degree water.

That's unrealistic, however, because the temperature difference between the surrounding air and the water goes up as you increase the temperature of the water, so the amount of heat dissipated to the air would go up with the second heater and you'd have diminishing returns. So, the first one would heat it 10 degrees to 60 degrees, and the second one would heat it (completely depends on insulation) 7 degrees.

 

[vyperboy]

If you need 300 watts that's what you need. 2 - 150 watt heaters do NOT equal 300 watts! Two 150 watt heaters will only heat to 150 watts! They are not in series!

Heater Guide Example:

If you need to raise the temperature of a 55 gallon tank 15 F, simply use the guide below to find out what wattage is needed. The corresponding wattage is 190W, therefore you would select a 200 watt heater. For me, my downstairs theater room may get down to 60 at night for my 75 gallon. Therefore a 300 watt heater is used.

DeltaT____10F____15F____20F____25F
Gallons-------------Watts----------------
10________53____80____106___133
20________80____120___160___200
30________93____140___187___233
40________107___160___213___265
55________127___190___253___316
75________147___220___293___367
90________160___240___320___400
120_______180___270___360___450
150_______200___300___400___500
180_______213___320___425___533
200_______220___330___440___550
250_______233___350___467___583

Let's say the guide above says you need a 400 watt heater. This does not mean you can use 2 - 200 watt heaters. You would still need 2 - 400 watt heaters (but they would cycle less often).

Otherwise, you could have 8 - 50 watt units and your tank would be at temperature right? Wrong, it would only heat up to the value of one (1) 50 watt heater. If I heat water to 100 degrees and heat another pot to 100 degrees and then combine them, I would have 200 degree water right? Sorry, it's still only 100 degrees. Unfortunately it is not additive.

Dual heaters (or more) are for redundancy, lessen the duty cycle and eliminate cold spots that's all.

WOW!!! That was an excellant explanation! Always wondered myself why people often used 2 heaters instead of just buying the correct wattage for their tanks and you just knocked that one right off the shelf!

Thanks for the explanation and clerification.!

 

[knicks791]

WOW!!! That was an excellant explanation! Always wondered myself why people often used 2 heaters instead of just buying the correct wattage for their tanks and you just knocked that one right off the shelf!

Thanks for the explanation and clerification.!

Read the whole thread.