Results 21 to 31 of 31
-
08-07-2020, 10:23 PM #21
-
RS2OOO Thanked / Liked this Post
-
08-07-2020, 10:26 PM #22
yes in an unheated pond it would cool slightly faster as the ground heat built up over the summer would be insulated against the water.
but insulation only slows the heat transfer and does not stop it.
so all the ground heat would still be built up in the summer, and then given up to the pond in the winter, just more slowly...
at certain depths the ground temp is stable and stays above air temps even in the depths of winter.
even in december most of the country has average soil temps between +5 to +7C at only 30cm deep
and it gets warmer the deeper you go
those that live further south are luckiest and have the warmest ground temps
this info is from ground heat source reclaimation data
you can check your own areas max, min, and mean ground temps at 1mtr down from page 16...
http://nora.nerc.ac.uk/id/eprint/512...ept%202015.pdf
-
RS2OOO Thanked / Liked this Post
-
08-07-2020, 11:25 PM #23
Interesting discussion here.
I researched similar before planning and starting my pond construction. I still couldn't get my head around the variables, but went with insulating the floor (as well as the walls). My logic was based on the following:
I'm building in ground fully (to a depth of 1.8m), my requirements for the pond are to heat the water above the ground temperature (mildly) during the coldest months. I will also be covering the surface with a polytunnel hopefully.
Since during the time or heating requirement, the ground temperature will be lower than the desired water temperature, I would want to minimise the amount of heat loss / increase efficiency. Insulating I believe is preferable in this case.
With regards to stability, pond volume is quite large compared to typical ponds at approximately 70+k litres, in addition, since I will be running an air source heat pump, this will have temperature control and will regulate output accordingly. I do understand however that the stabilisation your referring to is a "natural" source.
At other times of year, when the benefit of the temperature in the ground being transferred to the pond will still happen, albeit more slowly because of the insulation. Further to that, because of my heating regime in the colder months, I am not strictly in need of the ground heat in the same manner that others without heating would benefit from it.
I appreciate that there are a number of swings and roundabouts here, in my circumstances and pond build particulars, I hope that I have made the right choices!
I've also applied the same logic to the swimming pool that I built using the same materials as the pond (insulated concrete forms for the walls and 100mm installation slab installed on the floor). My last guidance towards the insulation was the building regs requirements for indoor pools which have to be insulated. Mine is outside, as is the pond, so I didn't need to follow this, but figured the logic was sound.
Im looking at installing a 34kW ASHP, this will be used to heat the swimming pool during the warmer months and then transferring the connections over to the pond for the cold months. I know my energy usage is going to jump, I've been dreading it as my usage is already very high, but I have a 26kW solar array which helps in the summer months and I have plenty of spare energy which should cover the pool heating / running. Just need to limit the costs of keeping the pond temperatures stable in the winter time.
-
RS2OOO, davethefish1 Thanked / Liked this Post
-
09-07-2020, 07:49 AM #24
Yes.
As discussed and eloquently put by Dave: "so maximum stabliity bare floor, maximum energy saving insulate floor."
My thinking that stability is good is that it reduces the yo-yo of temperatures as the fish enter hibernation or awake. It's not only the koi immune system but parasites and bacteria that follow the temperature. So yo-yo may allow nasties the upper hand and larger koi need slower environment changes,14000l, my mutts: Chargoi (2010), Doitsu (2022), Tancho (2022), Kujaku (2022), Hi Utusri (2022)
-
davethefish1 Thanked / Liked this Post
-
09-07-2020, 11:42 AM #25
70,000 litres
reckon i could get 4 carp swims on that....about the size of yateley pads lake
but i'd agree with your decision, insulate everything...or as much as possible especially if applying any kind of heat.
i've never heard anyone on here in winter complaining that they put too much insulation on thier pond...
-
09-07-2020, 12:00 PM #26
sounds spot on to me
if not heating ever, leave the floor bare.
but i think a lot of people are put off heating by either expensive and noisey air heat pumps,
or direct electric heating costs.
but i've not seen a build that really goes to town on insulation treating it as if it were an eco house build.
with maybe 4"-6" or more of celotex all round...
and a fully insulated filter house/equipment to the same spec.
and good fitting thick winter covers.
...ahh well ideas for the next pond build...
-
09-07-2020, 12:23 PM #27
my build thread has ICF walls, which is a 2” layer of insulation on the outer skin and inner skin, so 4” total with concrete poured between. And then we have a 4” slab of insulation in the floor.
filter pit and filtration tanks all built the same so heavily insulated. Hopefully it works well!
-
davethefish1 Thanked / Liked this Post
-
09-07-2020, 01:49 PM #28
sounds spectacular!
you get the best of both worlds with insulation on both sides of concrete then, good thermal mass and and a total of 4" insulation.
is the 4" floor insulation above the concrete slab or below?
as i would think it might compress a bit under all that weight?
-
09-07-2020, 02:09 PM #29
In between! The pool has a 400mm slab of c35 concrete with waterproofing with 2 layers of 12mm rebar in it. The walls were built on top of this and then then 4” floor insulation laid inside the walls tight to the wall insulation. Then another 4” slab of c35 on top of this with more rebar inside.
with that said, I think the pond was done a bit different, but I need to look at the photos now to check.
-
davethefish1 Thanked / Liked this Post
-
09-07-2020, 02:25 PM #30
i'll have to have a look at your build thread...
sounds like how you build a nuclear bunker
-
GadgetBazza Thanked / Liked this Post
-
09-07-2020, 06:02 PM #31
[QUOTE=davethefish1;341260]i'll have to have a look at your build thread...
sounds like how you build a nuclear bunker
It is.................
-
GadgetBazza, davethefish1 Thanked / Liked this Post
Best plants to remove Nitrate
pug has a very impressive veg filter on his pond, have a look at some of his his youtube videos....