Aquarium heating effeciently

[Dylan Grech]

Recently local goverment created a rebate scheme for homes that use heat pumps to heat water rather then the convential electric water heater becauses it uses less electricity and it got me thinking...

Are there more effecient options to heat aquariums rather then normal heaters?

I'm thinking:
- Heat pumps
- Propein water heaters
- any other technology?

 

[Diesel]

Pumps already transport heat in the water.

You better of with the traditional tube heaters as they are proven.

 

[Randy Holmes-Farley]

I've never seen any technology applied to a normal reef tank is more efficient at heating than a submerged electric heater.

That doesn't mean they do not exist or can't be created, but I've never seen someone using one.

My tank took massive heat in the winter. Many 300 w heaters, although i doubt they were all on at once. Some were backups.

 

[315wall]

Yes I use a re-circulation loop on my hot water heater controlled with a pump and my apex controller. Keeps the temp very stable and uses very little power to run the loop, the temp drop on the re-circulation line is only about 10 degrees.

 

[Dylan Grech]

Yes I use a re-circulation loop on my hot water heater controlled with a pump and my apex controller. Keeps the temp very stable and uses very little power to run the loop, the temp drop on the re-circulation line is only about 10 degrees.

That's exactly what I was thinking it should be far more effecient way to heat water but was worried about copper being released in the tank since most of these systems have copper tubing inside.

 

[Randy Holmes-Farley]

Yes I use a re-circulation loop on my hot water heater controlled with a pump and my apex controller. Keeps the temp very stable and uses very little power to run the loop, the temp drop on the re-circulation line is only about 10 degrees.

What sort of heat exchanger do you use? I used plastic tubing for a similar thing using tap water to cool the water, but I wouldn't use the tubing I used with hot water.

Have you ever checked to see if the plumbing code allows this? You are taking potable water out of the system and then adding it back again.

 

[Diesel]

Yes I use a re-circulation loop on my hot water heater controlled with a pump and my apex controller. Keeps the temp very stable and uses very little power to run the loop, the temp drop on the re-circulation line is only about 10 degrees.

Now let me ask you this, is this a tankless water heater or conventional water heater with a 80 gallon tank?
If you apex controls the pump I guess it's done by a temp schedule right?
What is the distance the loop has to travel from your heater to your tank?
I guess the water pipe is going through your sump in some sort to heat your water, what is the pipe material made off?

 

[315wall]

What sort of heat exchanger do you use? I used plastic tubing for a similar thing using tap water to cool the water, but I wouldn't use the tubing I used with hot water.

Have you ever checked to see if the plumbing code allows this? You are taking potable water out of the system and then adding it back again.

I use standard copper to get it near the tank then put in a shut off valve, then switch to pex tubing, then return to the drain on the hot water tank. I've been running on this since about 2004. I have a loop of aobut 10' in my Rubbermaid sump. Depending on the size of the tank you could use much less.

 

[315wall]

This is the same as you could do with a radiant floor heating system. It never leaves the system, it just changes to pex tubing which is within code everywhere I know of in the U.S.

 

[315wall]

Now let me ask you this, is this a tankless water heater or conventional water heater with a 80 gallon tank?
If you apex controls the pump I guess it's done by a temp schedule right?
What is the distance the loop has to travel from your heater to your tank?
I guess the water pipe is going through your sump in some sort to heat your water, what is the pipe material made off?

Conventional water heater
The pump is just in the outlet assigned to the heater.
In my case about 15' from the heater but you could extend a line anywhere.
Pex

 

[Dylan Grech]

This is the same as you could do with a radiant floor heating system. It never leaves the system, it just changes to pex tubing which is within code everywhere I know of in the U.S.

In my country we dont have these sort of codes so its not an issue at all, even more so we never use copper for plumbing, always thick plastic pipes and fittings. Its the internal components of the system that worry me. Wouldn't salt water corrode the system used?

Plumbing like this: https://www.google.com.mt/search?q=...AhUF26QKHa39C1AQ_AUIEigB#imgrc=I_nLXKUQlP7YSM:

 

[315wall]

In my country we dont have these sort of codes so its not an issue at all, even more so we never use copper for plumbing, always thick plastic pipes and fittings. Its the internal components of the system that worry me. Wouldn't salt water corrode the system used?

Plumbing like this: https://www.google.com.mt/search?q=...AhUF26QKHa39C1AQ_AUIEigB#imgrc=I_nLXKUQlP7YSM:

Dylan salt water only touches the pex pipe, do not leave any connectors of fittings in your sump just the coil of tubing. The pump is pumping hot freshwater from your hot water heater just like you would use at a sink. You use a pump such as http://www.radiantheatproducts.com/store/cart.php?m=product_detail&p=407

 

[Dylan Grech]

Dylan salt water only touches the pex pipe, do not leave any connectors of fittings in your sump just the coil of tubing. The pump is pumping hot freshwater from your hot water heater just like you would use at a sink. You use a pump such as http://www.radiantheatproducts.com/store/cart.php?m=product_detail&p=407

This is very interesting! I'd love to see some pics of the system and did you ever run some cost savings calculations?

I'm assuming the savings are fairly small as you're still using resistive heating and the heat loss from the pex tubing but obviously since you're heating a lot less water the heater should be on for a less then time then us.

 

[315wall]

Costs
re-circulation pump ~$100
Pex tubing $25
Copper fittings valves etc $20

Running costs $.25 per month electricity cycles 8 times per day for about 10 10-15 min. $ .11 per kwh

 

[tankdave]

I’m all for trying different things, but I don’t understand how a remote heater would be more energy efficient than one in the water.

I can certainly see the practicality if your tank is too big to be served by something from the LFS

 

[315wall]

Well my tank is 300g and was running 1000w for 21hrs a day to keep the 300g and 75g sump warm. So this saved me a bunch of money.

 

[KenO]

Interesting ideas. I have a NG tankless hot water system. I'm working on setting up 2 tanks (250 gallon and a 125 gallon) along with a 150 gallon sump. It would be pretty easy to setup a hot water loop to the sump.

 

[JoeIII]

Joey Mullen (king of diy on youtube and AlexG (here and on youtube) both illustrate methods of using hot water from a residnetial hot water heater to heat their systems.

both are quite large, Joey's is 2000G and AlexG's is ~1700 IIRC, but both will illustrate how these concepts work and should address concerns about contamination, as you can see that the water from the heater and the water in the system never mix.

 

[TheEngineer]

I’m all for trying different things, but I don’t understand how a remote heater would be more energy efficient than one in the water.

I can certainly see the practicality if your tank is too big to be served by something from the LFS

This is my feeling as well. A similar subject came up earlier this year. I think it depends though on what efficiency gains you are trying to achieve. If it is watts expended versus increase in water temperature, I don't think anything is more efficient than a submerged heater. If it is dollars spent versus increase in water temperature, there are arguments that could be made.

For the former situation, there are simply too many losses between an external heater and the aquarium for it to be more efficient in terms of energy usage. The submerged heater transfers (essentially) 100% of the electricity that goes into it into heat for the tank. With a remote heat source like a water heater, heat is lost during the transfer of the heated water to the tank itself. Now, is that amount consequential? I don't know, but it certainly exists and isn't zero.

For the latter situation, it really does depend. If you are in an area where electricity is very expensive and natural gas is cheap, this may indeed save you some money if your process of heat exchange is efficient.

 

[amps]

This is something that I've strongly considered for my larger system (240g total volume with a basement sump). My house is old, drafty and costs a fortune to heat and I've found it's extremely expensive to heat my tank during the winter with my 2x 500w heaters.

I'd love to go the re circulation route since I have an Apex and electricity in Ontario is much more expensive to heat with than natural gas. My concern is about which fail-safes need to be in place and if I have to worry about the temperature running away since the hot water heater is always on and directly attached to my tank.