Heating multiple tanks - Central system, heaters, or room?

[Burks]

Hello,

I am working on setting up roughly 30 - 10g, 6 - 20g longs, 6 - 40/65g tanks, and a 150g for my fish room. I am going to run the smaller tanks off a piston type air pump capable of running 60+ outlets in a loop. The larger tanks will either be canister or HOB's (depending on bio-load). Now using 40+ heaters sounds a bit excessive in cost and safety. That's another 40 things that can short and burn.

Now I'd love to go a central system and just use two medium sized heaters for every 15-20 10g tanks but that's a lot of drilling, and a lot of breaking of 10g tanks (I've drilled them before, I break 1 out of 5). It's still an idea. I just hate overflows. Too risky for water damage IMO.

My final idea was to heat the room itself. It's about 15x15, has two new windows, and a joined bathroom. Just turning up the thermostat isn't a great idea. Our heating bill was $250 last month and the house is set on 62F. So imagine turning it up to even 70F! What about those oil filled radiators? Maybe a 1500w one of those and a couple fans to circulate the heat? Being air driven I'd think the tanks would heat up fairly well since I'd be basically injecting heated air.

All the tanks will have glass tops as well. Keep evaporation down and maintain a more constant temperature. Air exchange is no issue since I'll be using air to filter them!

Any help is greatly appreciated. Thank you!

[MatsP]

To heat X gallons of water Y degrees will require X * Y * C Watts, where C is a constant value. It doesn't make any (big) difference which way you do this. So basically, if you want to keep a certain water at a certain temperature, then the energy needed will be the same no matter which method you use.

There are some side-effects of using one method over another - for example, if you heat the whole room, you will have less condensation, because the walls will be heated by the room-heating. And you will probably use a little bit more heat because the room needs to be kept at the tank temperature + a tiny bit, whilst if you heat the water in the tank, you will have a room temperature that is slightly under your average tank temperature.

Using heaters in the water will not heat the room us as much, and you may get condensation problems. It makes very little difference if you use one central heater, many small ones, or something in between. The only main difference is the number of heaters/wires/plugs/sockets you need - but the power consumption to heat up the water will be so little difference that you won't be able to measure it.

Keeping tanks warm is expensive. It's a bit less so if you have very good insulation in the fishroom (and keep the door closed, etc), as it will keep the warmth in the fish room, rather than heating your whole house.

There are financial aspects of choosing one over another - which is better depends on which is cheaper - your central heating source (if that's electricity, then it's pretty much the same anyways), but if you use oil/gas to heat the house, it may be more or less than the same amount of heating in electricity.

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Mats

[2wheelsx2]

I would just heat the room and try to insulate it better. But you may also have to run a dehumidifier if you don't have covers on the tanks.

[MatsP]

I think that's meant to be a DEhumidifier - a humidifier is something you'd run in a room that is too dry.

And to clarify, if you heat the tank, the tank will act as a radiator in the room - it will release heat into the room and cause the overall temperature to go up, until the loss of heat from the room equals the input from the heater(s). So no matter what you do, you end up heating the room.

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Mats

[2wheelsx2]

Thanks Mats. That's what I meant. Shouldn't need to humidify a room that's full of water.

As for heating the tanks vs. heating the room meaning always heating the room. That's only true to a certain degree in a physical world. In a hypothical world, the heat transfer is inefficient, but convection and conduction both produce losses. ie, my 125 gallon tank in my 20x12' basement is at 26 C while my basement is at 18 C max in the winter, but the heaters are not on 100% of the time and the temp always has a gradient for a number of reasons:

a) the glass is an insulator
b) convection is inefficient, so the air immediately around the tank is quite a bit warmer than the tank
c) the heat loss from the huge volume (actually the surface area exposed to the outside of the house) is much much greater than the conduction and convection from the tank.

Otherwise I could convince my wife that we should heat the entire house with radiant heating from having a big tank in each room.

[Burks]

Thanks for the replies.

I do always keep the door shut and it is somewhat well insulated. It's about 8F warmer than the rest of the house at any given time. Keeps the cats out too. Room is sort of messy so it isn't exactly something I want house guests to see either.

I'm still having a trouble figuring out which way I want to go. I decided NOT to go the centralized sump idea. Don't want to worry about diseases. Plus the fish/shrimp I want to breed need a wide array of water parameters. So that is out.

Now on to the heating the room idea. Would you think a 1500w oil-radiator with a fan would be enough and not cost an arm and a leg to run? Only looking to get the room to 76F or so, as that will leave my tanks pretty close to that temp. Any fish need a higher temp will get a heater but 90% will be fine at 74F+. Anyone done this before? I'm thinking the $50-$60 investment here is better than (Number of tanks) x $13-$15 for heaters + electrical cost. Just to do ten tanks I'm looking at $150 for heaters alone.

Already have a dehumidifier, so no issues there.

[MatsP]

Yes, of course, that is all true. My point, however, is that if you have a temperature difference between the tank and the room, it will leak heat. Depending on the circumstances, this may be a lot of not so much.

The bigger the difference, the more efficient the tank will be as a "radiator". But as you say, if you want a comfortable 22'C in your house, then you need a very big tank at 28'C to keep the whole room heated with that on it's own - and if it's cold outside, it probably won't be enough. That's why we have radiators that are hot to the touch - they radiate a lot more heat than if they are lukewarm. And convection (movement of air due to the air being warmer/cooler than the surrounding air) works best if you have a large difference too.

As I see you have just posted a reply: An oil filled radiator will heat the room. Whether 1500W is enough or not, I can't say - that depends on how much leakage you have in the room.

I agree on not having all tanks into one centralized system - I do have centralized sumps, but only two, three or four tanks per system, both so that I can have different water conditions, different temperature, etc.

Of course, if you are heating the room as a whole, you have a "floor" temperature for all tanks. So you can't turn off the heater in one tank, to lower the temperature. If you have individual heating (per system), you can to some extent control the temperature in each tank. But I guess that's not really a big issue if you are OK with 74'F in all your systems...

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Mats

[2wheelsx2]

My seat of the pants guess is that the oil filled 1500 w heater will not be able to handle heating a 15x15 room from 62 to 74 F. My bedroom is probably about twice that size, and in the winter when the temperature drops, I use it to keep the room at 19 C, which is 2 C above what the temp would be if I didn't have the heater. The heater is on an awful lot. To boot, I still have centralized heating; it's just that my bedroom is in an exterior corner of the house which is exposed quite a bit more and has a flat roof separate from the rest of the house (it was an addition). Anyway, to make a long story short, with a 1500 W oil filled heater, if you open the door and temp drops 5 degrees, it'll likely take an hour to get back up to temp. It wouldn't be as big a deal if the temp differential was smaller, say 5 F or less, but 12 degrees is an awful lot to compensate for.

[Burks]

Mmmmm gotcha. Guess I'll have to put off any further progress for quite some time. Nothing really financially possible right now.

Oh well.

[Bas Pels]

My fishroom is well insulated, and full of tanks. As a result, it is quite warm - the pumps and lights do need a lot of power, which ultimately turns into heat. I don't heat it, it is warm by itself. This is what I expected

However, due to the fact that i don't heat the tanks, but the room, the tanks are just as warm - or cooler - as the room, resulting in far less evaporation then in a situation with heated tanks in a cool room

Now, 6 years after building it, there is still no fungus anywhere. I did not dare hoping this

[Burks]

Maybe I'll just run with what I can afford, heater wise, and see how the room reacts to more gallons at higher temps. It might be *just* enough to keep the water where it needs to be.

I just checked my tanks with open tops, HOB filters, and no heater (most are only a few inches off the ground....so colder air and they are just cycling), they are 68F. COLD but not *that* cold considering the house is freezing. Fish room is comfortable. I only have about 120g worth of water being heated at this time, so not that much really.

My electrical bill is only $36 (which includes a 500w worth of MH's on 10 hours a day), so I can afford to have maybe 7-8 100w heaters added. Doubt that would use any more electricity than the MH's which are going bye bye at the end of March.

What I might do is toss our EdenPure knockoff (you know, those ones on TV made by the Amish) in there today and see how it does heating the room. They aren't that expensive. My only concern is it's electrical and how long one might last in such a moist environment.

[Shane]

Air flow will need to be a consideration as well. My fishroom shelves are three tanks high, and in the winter in South Africa, the difference in temp from the top row to the bottom row could be as much as 8 degrees F. I was able to mitigate this to about 2-3 degrees with a simple ceiling fan to push down the rising warm air. This should also make your space heater much more effective and cheaper to run.
-Shane

[Bas Pels]

Temperature differneces can be much larger than we expect.

Yesterday I happened to take the temp in 2 tanks: standing in the same closet, with the doors always open, near the door to my grarden, in the livingroom

Top tank 19 C, bottom tank 16 C
Top tank is around 1.80 meters from the ground, bottom tank 30 cm

Obviously, the tanks are not heated, and contain fishes which can stand this kind of temperatures (bottom row: cich lids from southern Uruguay, meeting 10 - 22 C in nature, top row: swordtails and Uruguayan Rhineloricaria F1)

[apistomaster]

1. I prefer some centralized room heating source which is capable of maintaining the lowest temperature you may want for any unheated tanks.

2. Keep all tanks covered and equip each tank with it's own heater if you need truly tropical water temperatures.
a. Use a central water heater on banks of tanks on a centralized filter so you can keep the bank at the same temps.
b. Use individual heaters on any tanks not on a central filter system; this allows the most control.

3. Do use a fan to circulate room air to prevent stratification. In most cases the heated tanks contribute a good deal towards keeping the room temperatures up. It is as MatsP said. There are immutable laws of physics which determine how many watts are needed to maintain a desired set point regardless of your heat source. I believe in using my aquarium heaters for more exacting control over water temperatures but I also depend on the radiative heat losses from the tanks to help maintain room temperatures. You are getting more efficiency/watt if you do this. Keeping your tanks covered results in the most efficiency not to mention keeping fish in and dirt, cats and kids out for the most part.

4. Do use some circulating fan to distribute heat and reduce thermal stratification in the room.

5. Look up those space heaters on Google under scams. You will find explanations as to why they are a very inefficient mode of heating spaces.

[bronzefry]

If you choose to go with oil, please read the specifications carefully prior to purchase. Check to see if you need to ventilate the unit. Some units, fan or not, need to be ventilated in some manner. A domino effect of costs could ensue from this. Please check ahead before purchase!

Some folks in New England don't use heaters at all. Ambient room temps is all they go by. If a certain species requires a higher temperature, that tank gets a heater. This is rare. In the winter, the tank temps go lower, but the insulation of the room keeps it from going too low. The summer can be an issue with temperatures rising too much. Many New England homes don't have central air conditioning. I know other folks who do heat their fishrooms with electric baseboard heat. It costs, but it costs less than having 85 individual tank heaters for guppy tanks.

Wow! $10/month? Can I be you? Check out the specifications of some of the baseboard heaters, electrical. Some are much more energy efficient than those from the past. Your electricity supplier may even have a calculator on their website to help you figure out usage if you increase/decrease, etc. Please let us know how you do! Sounds like an awesome fishroom.
Amanda

[jimoo]

Some folks in New England don't use heaters at all. Ambient room temps is all they go by.

Really? I haven't run into this. Of course, I couldn't imagine paying to keep a room at the upper 60s or into the 70s. My bill is high enough as it is and we keep it at 60-62 (gas heat).