Reef Tank Energy Savings

[TheEngineer]

You are correct I neglected the gas costs as I do not have any data at this point for the gas. I did mention that in the sentences right after my guestimation of monthly savings.

As @Triggreef mentions, I am using the gas water heater so not getting the electrical pull. I agree with you the electric wouldn't make sense because of the inefficiencies and still using electric.



Just looked at my bill. $.13111 per kwh. I don't really have delivery charges. They charge a fee per day, but I am getting charged that no matter what.

You are correct, the water returns to the water heater. So the loop uses no water, just the heat from that water.



You are correct, there is no energy savings. I agree with you that I am actually using more energy to heat my tank because electric heaters transfer basically all the energy into the water. The hot water heater is only so efficient at using gas, holding the heat in the hot water, and the insulation around the piping running through the house also allows heat to leave.

The savings simply comes down to two things.

1. Gas is much cheaper than electricity.
2. The marginal cost of the hot water heater setup is only the difference in what is already being used to maintain hot water for use and what it now takes to maintain that hot water with my system in place. I am repurposing heat that would normally go unused sitting in the water heater.

To your last point, yes a hot water heater is more expensive, but the marginal reduction in the life of the water heater is the cost of using my system. I am not sure what that will be, but I also know that I have replaced a whole lot of electric heaters in the past 5 years. Let's keep my loose math and examples going...

Hypothetical
Hot water heater costs $400 and has a useful life of 12 years. With the added wear and tear from the fish tank heating it now only lasts half as long, 6 years. Cost $200.

Electric Heaters
Cost $30 plus dollars each. 1 per year replaced(I've replaced way more than that, but they get used for various things from QT's to mixing containers, etc.). Cost $180+

Not a whole lot of cost difference there. This is all before we add in the many other benefits I alluded to previously. Electric heaters fail frequently, shock you and inhabitants, break, etc. Hot water heaters still work with the power out and running a pump on a generator in extended power outages is much easier than running a lot of power to keep the system heated. It heats water much faster. Etc. Etc.

Are these setups for everyone, definitely not. A number of variables go into whether setting one up would be worth it, however, in my case I know I will save money, just not to what extent. I look forward to seeing how it plays out and how much I save.

Well said! Good luck!

 

[jsiker]

Has anyone thought to do one large sump and push all tanks (if possible) through this sump and back out? Do you think you would save by having just 1 heater in the larger sump, 1 skimmer, etc? You'd still have multiple return pumps, but you could eliminate a good portion of what you have to run. I know that would mean all the tank's water is shared, with all the potential inherent risks, but if you are QTing everything does that help eliminate the risk and really increase the water volume for the overall health of the tanks?
I'm thinking of doing this with my 90, 40 and 135.

Would this save costs in some way?

 

[sundog101]

I had the crazy idea of having a huge tank in my basement (Never happed) and the electric price would have been crazy, mainly because my basement stays cool and heating would get expensive.

I looked way too much into it though and was trying to do these wild equations to calculate heat loss, insulation, ect.

The one thing I did find was a heater called a heat pump. They're used to heat pools and large volumes of water. Problem is they're really expensive and I've never heard of one being used on an aquarium. But after doing some research I think it's pretty much the most efficient heater available. It works like a reverse air conditioner. I'd love to see someone try it on a tank.

Edit: it would have to be a massive tank

 

[Lowell Lemon]

@sundog101 ,
Not sure but the heat pump system might be available from Pentair Aquatics. They make commercial aquatic filtration systems and related.

 

[ThunderGoose]

While in Bangkok, Thailand I noticed that all their water heating system are tankless. So only a cold water line in to a shower with a 220v instant heater for the shower. This would save so much money and energy in the United States. Think about how much it cost to heat a water heater 24/7/365 in comparison to just as you need it. Most of the units were made by Phillips and cost less than $300.00 with many at or below $200.00. No tank to clog just a simple small exchanger and we never ran out of hot water. Seems this would lower consumption for most of us. Also they use cold water for washing clothes, dishes and related. The heating units are compact and attractive. I almost bought a couple to bring home and install in our house to replace the 60 plus gallon tank we have.

I've used these systems in Europe and they are great. There are similar types of systems in the US but nothing as efficient and cheap.

 

[TheEngineer]

A heat pump is an interesting idea for large systems. I'm not sure about the energy savings... I have a heat pump on my house but it only runs down to 35 degrees before it kicks over to propane.

It would be very efficient at heating when the weather is warm, but when it gets cold it gets much less efficient.

 

[sundog101]

I have a heat pump on my house but it only runs down to 35 degrees before it kicks over to propane.

Ya that's another problem to consider.

 

[johanngh1977]

The " DC " equiptment its the best way for less consume ellectric bill...at least a half = less power, less heat...and the led technology ...good one like kessil, ecotech, maybe aqua illumination...sometimes isn't possible cut consume ellectric without put at risk " succefull"..

 

[mcarroll]

I don't think most folks realize that by switching to more "power efficient" pumps and lights, they are in many cases simply shifting more of the heating load onto their heaters and may not be saving any power at all.

The common refrain on Mag pumps since they aren't the most power-efficient is to "pull em". I laugh at that. Mag's are solid pumps and I think the wattage does not go to waste, it goes to make a stronger pump.

But not only that, when I pulled mine (a Mag 7 skimmer pump, pulled coincidentally with the skimmer) I had to add a large heater to the system to keep the tank temperatures up.

Unless you're running a tropical tank in a tropical location where the system doesn't need added heat, there's only so low you're going to get on power usage.

Or to put it another way...

If the only way you have to run your reef is with a chiller, then you should be upgrading your pumps and other gear to be more efficient until the chiller doesn't need to run anymore and you can take it offline.

Once the chiller is offline, you don't need to upgrade any more gear.

If you don't run a chiller, then the rest of your gear is simply giving your heaters an easier job – they aren't taking up any extra power.

 

[TheEngineer]

I agree to a large extent, but with one caveat... Not all of the energy wasted by these pumps is converted to heat. I have no idea what the percentage is, but some of that energy is iron loss from the EM field and it is not heating your water. Some energy is also lost heating up things like the wiring in your house due to the copper loss of moving the power. The same can be said of a heater, in theory.

All that said, the largest source of energy loss in an AC motor is to harmonics. Those harmonics will heat up the motor core and provide heat to your tank as mcarroll says.

 

[bwmalloy]

Looks like most people on this thread are in northern locations. I live in South Florida and have the opposite problems. Even during my winter, my chiller is constantly turning on. I was starting to research a new, more efficient chiller when I was convinced to turn my attention to changing my MH's to LED's. I will be changing to LED's soon but I wasn't thinking about the pump before reading this string. I'll switch to a DC brushless motor, too (thanks, trigreef).

Any other good ideas? Should I change out my maxijets? I've got 3 of them running on a wavemaster.

 

[FishGuyBri]

I live in sw FL but I use AC.. am I the only one? With the ac on at 70 I need little heat from heater to keep it right temp. Power out is another story, but that's rare for me in Ft Myers

 

[D_Nyholm]

I recently insulated my sump with 1 inch foam board (6.5 R value). The tank is in my basement so during the winter, the room is about 60 degrees. I went from using 6.5 kw per day to 4. I'm contemplating insulating the sides and back of the display tank since it is a frag tank. Maybe get another 1 kw savings per day. Electric here is about $0.28/kw so any savings is helpful!

 

[bwmalloy]

I live in sw FL but I use AC.. am I the only one? With the ac on at 70 I need little heat from heater to keep it right temp. Power out is another story, but that's rare for me in Ft Myers

MacQac, you might want to consider an efficient chiller so you can not run your AC as much. I can't back this up by numbers but I believe that driving the AC all day long is more expensive than the amount of time the chiller would run to keep your tank consistent. What lights do you have?

 

[mcarroll]

Looks like most people on this thread are in northern locations. I live in South Florida and have the opposite problems. Even during my winter, my chiller is constantly turning on. I was starting to research a new, more efficient chiller when I was convinced to turn my attention to changing my MH's to LED's. I will be changing to LED's soon but I wasn't thinking about the pump before reading this string. I'll switch to a DC brushless motor, too (thanks, trigreef).

Any other good ideas? Should I change out my maxijets? I've got 3 of them running on a wavemaster.

Maxijets are sort of power hogs. Some return pumps are a little worse than others. But...

Don't take your eye too far off that lighting switch.

Pumps use way less power than lighting, so you'll have to make a lot more changes to add up anywhere close to the same. You probably don't have that many pumps. I bet you'd only save 100 watts in switching all your pumps. You can save that or more per fixture on lighting.

I'd make the lighting change first and see if you need to bother with any of the other gear.

Have you decided at all on what lights you might get?

MacQac, you might want to consider an efficient chiller so you can not run your AC as much. I can't back this up by numbers but I believe that driving the AC all day long is more expensive than the amount of time the chiller would run to keep your tank consistent. What lights do you have?

I also can't really prove this, but the chiller will have to work harder to cool the water in an uncooled space vs an air conditioned space.

This might eat up the difference. Of course if you really don't want to run your AC, then any difference might be worth it.

 

[FishGuyBri]

MacQac, you might want to consider an efficient chiller so you can not run your AC as much. I can't back this up by numbers but I believe that driving the AC all day long is more expensive than the amount of time the chiller would run to keep your tank consistent. What lights do you have?

I drive ac all day because of my lovely dogs. They overheat easily, so I have to keep it low. We've finally settled on 70 we have doors and windows open all weekend in the AM and late PM.

 

[bwmalloy]

Have you decided at all on what lights you might get?

I've settled on the GHL Mitras LX7. So expensive, though. And, I will need 3 fixtures so it's going to be ~$2500. Tough to swallow in one shot. But, to your point, the sooner I get them in, the sooner I start to realize savings.

I drive ac all day because of my lovely dogs. They overheat easily, so I have to keep it low. We've finally settled on 70 we have doors and windows open all weekend in the AM and late PM.

Yah, if you must keep your AC low already for other reasons then you might as well keep it as-is without adding a chiller.

 

[bwmalloy]

Bought my Deepwater brushless DC pump yesterday. Hope the install goes smoothly. Man, it would be great if I could simply remove my old Dolphin and drop this new pump in place.

 

[mcarroll]

Which BLDC did you get and which Dolphin do you have?

Looks like at least a few of them share the same plumbing size.

At most a new fitting at the pump-end though, right? Not exactly unscrewing a lightbulb, but not too bad either.

 

[bwmalloy]

Which BLDC did you get and which Dolphin do you have?
Looks like at least a few of them share the same plumbing size.
At most a new fitting at the pump-end though, right? Not exactly unscrewing a lightbulb, but not too bad either.

The current pump is a Dolphin Amp Master 1/15 HP pushing 3500 GPH. The replacement pump is Deepwater Aquatics BLDC10 DC Brushless Pump. The detailed reader will notice that I'm replacing a 3500 GPH pump with a 2650 GPH pump. I'm doing this because I currently dial back the pump using valves, quite a bit, too. I can spend less money on a more energy efficient pump by buying a pump with a lower flow rate. Well, at least that's my thought process.

And, you're right about the fitting. The plumbing was designed for this so it won't be too bad.