3 Air to Air heatpumps WITH hot water tank. But are they any good?

[sharpener]

16 minutes ago, JamesPa said:

Confused by this statement.  The digram in fig 4 above shows the pump (I assume the open circle is a pump) in the heated DHW circuit essentially taking it out from and returning it to the bottom of the tank and thus needing to be WRAS compliant/bronze.  What am I missing?

 

You are right. Brain fade! So they must exist, but a further search has drawn a blank. From the pic here it looks like a miniature immersed rotor ch pump (unless that is only an artist's impression). There are various 12V 100C bronze/plastic pumps on amazon but I wouldn't want them near my hw tank. I don't know why the pumps sold for secondary hw loops are so big, the pump doesn't need to handle the main hw demand. You don't need to move 4m^3/hr just to keep the pipework hot and they consume a significant amount of power running 24/7, though I notice in passing some now incorporate timers.

[JamesPa]

14 minutes ago, sharpener said:

 

You are right. Brain fade! So they must exist, but a further search has drawn a blank. From the pic here it looks like a miniature immersed rotor ch pump (unless that is only an artist's impression). There are various 12V 100C bronze/plastic pumps on amazon but I wouldn't want them near my hw tank. I don't know why the pumps sold for secondary hw loops are so big, the pump doesn't need to handle the main hw demand. You don't need to move 4m^3/hr just to keep the pipework hot and they consume a significant amount of power running 24/7, though I notice in passing some now incorporate timers.

I've got a 12V pump that looks a bit like that on my narrowboat https://www.midlandchandlers.co.uk/products/johnson-compact-water-circulating-pump-12v-18-5lpm-20mm-10-24502-03, rated for 24*7 use at 100C.  Its pumping the CH water not potable water, and I don't honestly know if it meets WRAS rules for potable water (its OK for fish tanks apparently).  Not cheap, £180, but perhaps an example of a small, reliable, 12V pump. Check out Midland Chandlers and you will find a range of small robust 12/24V water pumps for boats.

[sharpener]

Yes, we had a Shureflow 12V freshwater pump on our Rival 32, and following the line of thought about leisure applications I looked at ch pumps for caravans, touring or static, and came across this which looks better made than some of the chinese imported stuff. But quite expensive so maybe the answer would be a normal bronze pump with the valves almost shut.

 

ATM I am killing time while still chasing Daikin installers and waiting a callback from GE so I can see if they will do a survey without an EPC, as you mentioned elsethread.

[Iceverge]

8 hours ago, DanDee said:

That's what daikin thinks more or less.

 

Interesting I hadn't seen that. 

 

I had it pictured as a variable intake duct.