It occurs to me that simply toggling down the pump flow rate would sort that.
Mine has 0,94 sq m surface area of the heating coil...Mmm.
I cant find a UK distributor for Hautec..seems to be ireland only.
Yes - we thought that too ! Trouble is - the pump is most efficient if it's running long periods without stopping/starting - and (unlike a gas / oil boiler) it's either 'on' or 'off' - no in-between.... You end up with fast cycling, or such a slow flow-rate that heating the water tank takes forever - trust me !
Well - on our experience - that wouldn't do...
I was sure I found somewhere on the web - maybe drop the German manufacturer a line... ?
As I said - there's enough 'incorrectness' in what your salesman said to make me concerned.....
Adrian
I could simply use immersion then. Its really not a major expense here.
I went to 'nearests distributor' and got ireland :-)
Ive also been collecting people who do heat pumps.
Not exhaustive but:-
Hautec Danfoss Veissman Dimplex. Nibe
Typical prices for a single phase unit in the 11Kw range seems to be £4k-£5k..
Getting somewhat widely differing figures for the ground loop as well.
One guy says '25W/meter max 100 meters per loop' (i.e 400 meters total) whereas another says 'one 200 meter loop will be enough.
I suspect that on wet clay the salesman's 'Oh: clay? 35W/m' is nearer true, which means a 200m loop is marginal, and a 400meter is better.
Biggest bugbear is the better units with 2 stage compressors (higher output temps) all need 3 phase. BUGGER.
Thats why I am still here talking..trying to distil the real info from the BS.
Tra a Google for "water meter" "pulse output" eg:
Try a Google for PicAxe [sic]
cheers, Pete.
Sounds about right
I guess you could talk to the people @ CAT in N Wales - they've got nothing to gain by their recommendations - so you might some real advice
Ours is single phase...
Wise man
Adrian
I forgot about temperature
RS do a sensor that's good for 125=B0C:
or something like this with a laser and photodiode may do:
cheers, Pete.
Pete C coughed up some electrons that declared:
Heh, I reckon 90C should be safe enough, you wouldn't run a heatbank that high in normal operation.
Not as expensive as I'd imagined, though the water meters are cheaper.
Found the manufacturer's site here:
Cheers
Tim
Got some good info from a man at Nibe..
Essentially you CAN use the existing water tank, but you need an intermediate heat exchanger/heatbank..sort of 200 liter hot water tank that has GOOD conductivity from the heatpump primary: Once thats hot you then pump the cylinder primary from that ones secondary, and when it cools down a bit it fires up the heatpump again. Marginally cheaper than a whole new tank..
Looking hardest at the nibe and dimplex units..
HI TNP
The Natural Philos>> HI Again
Don't know them...
Ah - that's a plan....
Not sure if I mentioned it - but with our system we have our own 'sort of heatbank'.... the c/h and dhw circuit returns end up in a 200litre, well-insulated 'oil drum-sized' store - before going back through the heatpump and round again....
When the heatpump decides it's done enough heatpumping then it turns off, and the warmed water in the circuit and the heatstore is pumped around unti it too has given up enough of its heat....
There's no heat-exchanger in our heatstore - it's just a big 'bucket'. Clown of a plumber who installed our system managed to do so without installing an air vent at the top end of the heatstore - which meant that air became trapped in the store and gave rise to an unfortunate 'header tank overflowing' situation....
One of the jobs for this summer is to install an air vent to prevent this...
Nibe seem to call these tanks 'accumulators'....
Regards Adrian
When I looked into this I came to the conclusion that for me - it was insane, and superinsulation was the right route.
However. The economics might work even better with a very large heat store, and running on economy 7 electricity. This does mean a larger heatpump, sized to output around 3 times the nominal 24*7 figure, but the electricity can be a third of the cost in some cases, taking your cost down to 1.5p or so per Kwh.
The downside is that you need several cubic meters of water to keep the temperature swing low - say 15C. This may be very cheap to implement, or nearly impossible, depending on your situation.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.