Using hot water to heat our tanks

[Harpo]

Here are my answers:
1) I lose power a few times per year and I want to be less dependent on electricity when that happens
2) I'm a engineering nerd and I like to over complicate things
3) hopefully I can find a few more reasons

 

[Fungusamongus]

Here are my answers:
1) I lose power a few times per year and I want to be less dependent on electricity when that happens
2) I'm a engineering nerd and I like to over complicate things
3) hopefully I can find a few more reasons

Sounds like you have all the reasons you need. I will be following your progress. You got this!

 

[BeanAnimal]

What is your goal? Save $? If your HWH is electric there is likely to be no savings over typical resistive aquarium heaters.

If the water heater is electric there will be significant loss compared to an in tank resistance heater. a watt is a watt and the water heater tank leaks heat from the stored water, as well as energy used by the pump to send water through the heat exchanger in the aquarium.

 

[Harpo]

Gas water heater. The internet claims I can save 40% on my electric bill. Even if I can save 1/2 of that I will be thrilled.

 

[BeanAnimal]

Gas water heater. The internet claims I can save 40% on my electric bill. Even if I can save 1/2 of that I will be thrilled.

You can do the math pretty easily. What do you pay for gas?

 

[jman4x]

As a master plumber of 8 years and a reef keeper of 20 years I’ve never heard of or thought of doing this to heat a large aquarium! As well as using heat pumps to heat and cool, I just love where the hobby is headed!!

 

[BeanAnimal]

Looks like in MI you pay ~$1 per CCF
That is ~100,000 BTUs of gas.
if~ gas heater is (new) maybe 60% efficient at getting heat to water.
so 60,000 BTUs per $1

Your heater loses significant efficiency as scale builds up.
Let’s call it 10% to be nice.
so 50,000 BTUs per $1

There is loss in storage and in your plumbing, let’s ignore cold incoming water and consider it a closed loop. Let‘s assume another 10% loss.
40,000 BTUs per $1

1 kWh = 3412 BTUs
you pay ~$0.20 per kWh
Or 17060 BTUs per $1
There is no loss… all BTUs heat the tank directly.

napkin math savings on energy cost is ~2.3x

 

[legionofdoon]

Lol.. I can't imagine living in a climate where I'm worried about heating my tank efficiently, I'm more worried about keeping it cool, living in South Florida where it was 90 yesterday definitely has a different priority. My temperature in my tank is 77 on cold days and 78.8 on more normal ones. If it wasn't so hot here I'd go back to halides in a quick minute.

 

[legionofdoon]

In addition I've lived in the same house for 14 years and I've never had to turn my heat on (had a heat pump until I replaced my AC this January, lol losing your AC anywhere else in January would not be a big deal).