Backyard Aquaponics
A place to discuss aquaponics

Way to go Charlie.... good to see you getting results... and that you're spreading the word about AP....

Re : your heat pump system... and the data logged... looks to represent the common problem... that heat gain through the day is lost through the night...

Have you looked at any ways to address this problem??

this is an amazing set up.....geeze I would love something like you have built....and the planning out.... ...awsome

With the level of insulation it doesn`t look like theres much more you could do to reduce the heatloss.
If theres 16KL of water in the system its losing around 2kw/hr over the 19hr period. Pulling the water temp up by 2C in 2.5 hours would take around 14.85kw/hr input or 37kw overall..probably a little more to overcome the losses. Daytime solar gains will be more limited in winter which could mean heating the water during the day as well as night.

hi there the main thing is that with the air source heat pump it has a `cop coefficient of performance that relates to the kilowatts in (electricty) to kilowatts out (hotwater) at a ratio... for this heat pump it has a COP of 3.3 at A2W35 meaning air temp 2oC and outlet water at 35oC, however the airsource heat pump has a COP of 4.8 at A25W35, meaning that the 37 kw required, is derived from 7.7kw of input energy to the heat pump/day.... which is its justification for being there...air source heat pumps work at their very best with warm, and humid air which is exactly what we have in the greenhouse..

but the second feature (asides from heating) is dehumidification (which we can recycle) and also that the exhaust air is 5oC colder than the intake, and there is a VCD to direct air either inside to cool the greenhouse or outside to maintain temperatures...

hope that makes sense....

charlie

Hi Charlie
You may be looking at 11kw of electrical power per day in the winter then? ouchy
Its likely to be more due to lower air temperatures increasing the heat loss from the building and the water. I guess you have a wind turbine or PV providing the electrical power otherwise you`ll probably need a lot of 50p`s for the meter

Thanks for the update!!!!
I think there was mention of possible use of bio-mass for electricity or heat production on at least one of his projects.

For this project, the RAS systems are heated from a biomass boiler feed by around 30acres of willow coppice, however the idea for the aquaponics greenhouses was to have them operating as potentially self contained units, (even at 11kw a day it would be under 0.95p) and with production of 7 lettuces and one 500g tilapia per day, plus the use of the system as an educational resource its relatively low, especially when considering the indirect costs associated with importing out of season salad crops into the country....