Workshop in this weather..?

24 degrees, but where? Is that at the bottom? Remember, cold water does not start to rise until below 4 degrees Celsius.

Ron, thanks for the calculations, yes an awful lot of energy required for 3,000 gallons. Yes Koi are a cold water fish, in their homeland of Japan they experience very warm summers and very cold winters, the winter is though of short duration for the extreme cold temps, the Koi prefer a very short very cold winter so that they can go into dormancy and then when winter is over they are better suited to a steady relatively short transmission from winter temp to summer temp. It is during this transmission period when the temperatures are warm enough for pathogens and parasites and too cool for the fishes immune system to be fully activated that they are most at risk. Our weather in the UK is far from ideal for Koi because we now have generally mild winters and mediocre summers so the temperature favour pathogens and parasites. Koi can withstand fairly high water temperatures, there are many avid keepers in hot locations such as Oz, the warmer areas of North America and places in the Far East such as Malaysia and Singapore, they successfully keep Koi in very warm waters. The climate in a Japan must be ideal for them as they have recorded ages of 120 for some specimens, the Japanese are however fanatical about Koi it is almost a religion to some.

Dave W

NDIY, my Koi pond circulates the water from a bottom drain and then passes it through the filtration system and returns it to the surface of the pond, so I would think the temperature gradient between top and bottom in summer is no more than one degree. Probably a bit different in winter, the filtration system still operates but heat is lost at the surface of the pond, and the fish all cluster at the bottom because at six feet deep the pond absorbs ground heat making the bottom slightly warmer and the fish recognise that.

Dave W

NDIY

The water in the pond is continually pumped from the bottom of the pond to the top for the filtration system with a complete water turnover of about a hour, the temp is measured on the return to the pond. I was once told that we don't keep Koi we keep water.

The largest rise in temp was 2.4 degrees C in one day, a bit too much for them really

Lionel

Edited By Limpet on 05/07/2018 17:15:35

The day they opened the roads my dad took me back to university in Aberystwyth from Barry. We hardly saw another vehicle and it was 'interesting' in a Volkswagen Beetle! Typical of my dad, he just helped me unload my stuff, turned round and drove back.

Neil

Lionel, a very true statement, water quality is paramount, without good water quality there are no fish.

NDIY, as an experiment to satisfy my own curiosity I lowered the thermometer to the bottom of the pond, six feet down, and took a reading of the temperature there, it was exactly the same 24 degrees so at the moment no temperature gradient in the pond.

Dave W

When we had a pond with mixed koi/goldfish descended from the householder before the householder before us the survived the pond apparently freezing full depth a few years (only a foot deep), but their numbers decreased as a result and eventually a very long hard winter (I think it was -11 round here) did for them all.

Neil, most fish don’t like being frozen. Depth of pond at a foot is a bit shallow for a hard winter survival, I know I live in the tropical south east, (East Sussex), but my Koi pond has never suffered any ice in winter, my goldfish pond at three feet deep has frozen over, particularly this last winter. The Koi pond holds such a large volume of water, 3,000 gallons, and is continually absorbing ground heat so stays ice free. I feel for your fish if you get any more!

Dave W

I do my best to not let the pond 4000 gallon(ish) go below 5 degrees which was hard this last winter even in tropical Devon and keep the pumps running all year (although much slower) as I fear the exposed pipework will freeze and crack. Next winter will be easier as it now has a heat exchanger fed from the c/h boiler if it gets too cold, although I dread the cost if I have to use it.

Lionel

Is the heat exchanger on the return line to the boiler? If it's a condensing boiler that'll be more efficient.

Lionel, I don’t have any exposed pipe work, it runs underground or enclosed in the filter chamber which is gravity fed and located in a large covered chamber set into the ground. The filter chamber is quite large as it houses a Nexus 220 with automatic control. I think the lowest winter water temperature that I have recorded is 4 degrees. I had thought about some method of heating the water during the coldest months, a heat exchanger off a gas boiler would be ideal but I have to tread very carefully our energy consumption is pretty high already, contributed to by 2 pumps, 2 UVs and 2 air pumps running 24/7 365 days a year. I recently installed a wood burner in the lounge which meant that our gas consumption has dropped dramatically when the wood burner is in use, even so I don’t think higher authority is yet ready to sanction heating the Koi pond, perhaps if I got solar panels on the roof that would offset the extra cost with savings on our electric consumption, something I think I will have to work on.

Dave W

Solar thermal panels may be a better option, than PV, for an installation like that. You would need to use the heat energy, collected in summer, somewhere else - or cover the panels. PV would certainly reduce your pumping and purification costs all year round! PV panels have never been cheaper and may go cheaper, now the americans are taxing chinese imports...

I'm still calculating 8-10 years ROI on solar PV...

NDIY, l was thinking of solar PV connected to house system in order to get a return on units generated, although l understand that income is very minimal from units sent to the grid, the solar PV would reduce total units used from the grid throughout the year and therefore reduce annual electric costs offsetting the extra use from my pond systems. Wife says it’s uneconomical use of capital because I won’t live long enough to break even on the investment, does she know something that I don’t and isn’t telling me?

Dave W

My workshop was at 22degrees when I opened the door at mid day by 13.00 it was up to 25 with the door open, as it is being used as a paint shop the drying of smelly high gloss paint is very fast.

Edited By V8Eng on 06/07/2018 13:23:04

Dave W

I only have a few feet of exposed pipes and they're lagged and like you gravity feed from pond, sieve, bead, eazypod on skimmer, 2 water pumps, 2 air pumps but only 1 UV. The heat exchanger is on the return of the shed c/h circuit (separate zone). As I'm just about to enter retirement I'm seriously looking at 2kW of solar to offset the pond running cost. We use a lot of electricity.

Lionel

Dave W,

In 2012 I had 2.2kW of solar PV panels fitted to my house in Hertfordshire - I only had room for 8 panels, on a south facing roof. A delay in fitting them (whilst the local council messed about re planning permission) meant I got a reduced return (as the government assistance paid to generators reduced in the interim).

When I moved in 2016 I was getting 17.4p per unit generated and roughly 5p per unit for half of the total generated. The return I received all came to the grand total of around £250 per annum.

I looked on it as money which offset my fuel bills, but as to whether it was a good return on the capital investment, I think your wife is quite correct (even if there isn't something she's not telling you)!

Regards Tom

Lionel,

You seem to be well set up if you have central heating in your workshop so easy enough to fit the heat exchanger in circuit, my workshop has to rely on an oil filled electric radiator for heating during the cold months but the workshop has plenty of celotex insulation, about 100 mm in most areas, so no problem keeping steady temperature.

Tom,

I need to investigate what current costs would be for solar PV , I could get probably 4kw from my south east facing roof, would have to do the sums to see if its viable, and then present the case to the financial controller.

Dave W

A 3KW PV installation will be giving less than 1KWh per day in February when you need it most.

A bit steamy here in Jockland tonight so doing the annual freezer defrost