Backyard Aquaponics
A place to discuss aquaponics

A line from VB or Monya caught my eye in an old thread today Said they had some success warming water with piping running thru their compost heap. Got me thinking.

BSF tend to generate lotsa heat under foam in winter. If we could incorporate piping in a long narrow BSF bed in our return line from gb to fishtank, could we not get some free water heating on a consistent basis? The availabilty of cheap manure and space, may be the only limiting factors in achieving a meaningful heat contribution from these wonderful helpers Anyone got any thoughts?

I feel another "take one for the team" trial coming on.

AM was the one who did the compost trials TT (in Cairns no less - he needs it much less than the rest of us).

He had limited success. The issues are that the heap would need to be large (same pricipal for BSF I imagine) and would need to continually produce a lot of heat to do the job. Give it a go - but I think the sun is a better option because on a sunny day the heat collection will be constant throughout the day, while I reckon the BSF heat would quickly deplete if you had lots of pipe going through the compost.

yeah, just thinking out loud really. For that matter in Australia we could run a heap of black tubing back and forth in our GH exposed to the north in the return line, to perhaps get a similar, less messy effect. Dunno. If space wasn't an issue, cost of tubing was affordable and it didn't block up with biofilm/stuff up pump/drain balance, perhaps it could work.

Really looking to maximize (cost) effective fishtank heating options in my soon to be built greenhouse.

The victorians used compost for greenhouse heating (hotbeds) but the actual heating period is quite short so you`ll need a constant supply and plenty of it as VB said.

The best and most economical first line of defence would be to minimise all the losses, tank to greenhouse and greenhouse to the exterior..otherwise you`ll just be pouring heat (cheap solar or pricey electric) into a bottomless pit.

If you lose less, you don`t need to add as much

I'm reminded of something I read about old houses in some cold region of the world (I know, really vague). The idea was that the house was bermed into the side of a hill. Cows were housed in the lowest level of the house, and their manure and body warmth rose and helped warm the living quarters above. Sounds cozy but stinky. I also think I remember something about running pipes through a manure pile to warm water for the house. You would need a pretty big pile.

a few swiss farm houses are like this for the winter the animals keep the house warm as well they feed fire with biomass

An alternative is to use the local natural resources

88 rabbits would generate as much heat per hour as a 1500w heater,
they`ll also produce co2 and organic waste for composting..
only downside is they`ll eat all your AP veggies

Joking aside, it does add another string to the self sufficiency bow, generating heat, food, co2 and utilising just vegetable waste from the AP system.
It doesn`t have to be rabbits.. any warm blooded herbivore would do.

My girlfriend's a herbivore.... dun know if she's warm blooded though ....

Is that 1500w when the rabbits are hanging out eating carrots or when they're getting busy?

-Stevo

I guess you could probably triple the btu`s when they`re "busy".

If you don`t have any rabbits, 100 cats and 1200 mice will do a similar job.. you`ll have to accept the steady drop in output as the mice get eaten though

Actually, you could also try the same idea with chickens. The biggest difference is that thier poo is high in nitrogen, so, as it decomposes it gets a higher temp than most other animal manures. Other typically high nitrogen manures are horse, sheep/goat, rabbit, and pig. While we always used fresh cow manure for "heat" in our spring hot beds, we would tend to use one year old composted horse manure (otherwise it was too "hot" for young plant roots.)

As far as the idea of the cats and mice, just adjust the ratio to where there are more cats to mice, and then as the prey species is reduced introduce some dogs, that should improve heating efficiency! (Before I get jumped, I love cats, dogs, mice and all living creatures. With the only exception being some of the low life human ones.)

Theretically, you could use those too

If the average low life human weighs about 150 pounds, then approximately 75 pounds is burnable biomass with a yield of (75 pounds * 7500 BTU per pound) = 0.6 Million BTU's, or almost 176kw !

Half a dozen should get you through the winter

oh wow...

Just imagine a world without centralized jailhouses....inmates are spread about the communities into underhome jail-rooms to heat peoples houses...and aquaponic systems... now THATS sustainabilty!

Mines more along the lines of hot tounge /cold shoulder