Convert a solar DHW tank (or fuel oil) into a thermodynamic water heater with a small swimming pool heat pump

[Christophe]

There you seriously worry me Izy ...

I proposed to add a thermostat with probe in the thermowell located just above the coil of the balloon (on your map), which would allow to set an independent setpoint for the circulator and thus prevent ...

Are you suggesting what I wired and you take my counter example from your (bad) idea ??? It's really WTF there !! And that I had to explain at least 3 times above that a thermostat in the balloon controlled the circulator which starts the heat pump (in deep standby) by detection of the flow !!

The diagram that you repost has nothing to do with what I just did: it just indicates where the exchanger of the balloon that I used is (indicated as "reserve") ...

I can not be clearer than the explanations of points a) b) and c)

[GuyGadeboisTheBack]

On this subject, obviously, less than YOU!

Hey bham!

Except that I'm kidding, not him, and bhim!

[Christophe]

If if if if he too!

Izy is just kidding, between 2 good messages, I'm afraid he's not going well anymore ... but I think he doesn't even notice it ...

[sicetaitsimple]

ps: I switched to high speed (22W instead of 7W since 13:00 pm today) but I have little hope that this will improve the already very good COP ... to be continued!

What are the trends after 48 hours? At least for the heat pump inlet / outlet temperature and cycle times?

[izentrop]

If if if if he too!
Izy is just kidding, between 2 good messages, I'm afraid he's not going well anymore ... but I think he doesn't even notice it ...

It's not nice ... If I quote all the bullshit you wrote on this forum, a 10-volume encyclopedia would not suffice.
For Guitou it's different, he's so in his world, can't stand contradiction. His modus operandi is to always attack the one who does not think like him, rather than to argue intelligently.

Given the current figures I think the optimum is not far away ...

It's possible, but trying slightly different settings and seeing can't hurt.
The current setting which leads you to cycles of "a few minutes", may be very penalizing for the life of your pool heat pump, which was not designed for that. Increasing the circulation flow should go in the right direction from this point of view with longer cycles, remains to be confirmed by checking at the same time that the temperatures remain acceptable.

Of course you can do a test at max flow to see.

That's the catch, the lifespan shortened by frequent restarts.
This type of heat pump is designed to run continuously for several days until the inlet temperature reaches the set temperature.

Here are the readings / photos ... the heat pump works well beyond 40 ° C when it is set to 39 ° C regulation! Since the maximum temperature measured at the outlet is 44.4 ° C ...

Perhaps a safety shutdown because of the water circuit too short compared to the inertia of the probes.

Have you tried to reduce the set temperature?

[GuyGadeboisTheBack]

For Guitou it's different, he's so in his world, can't stand contradiction. His modus operandi is to always attack the one who does not think like him, rather than to argue intelligently.

Argue intelligently according to Izy:
post476492.html # p476492
Get a grip on yourself, old man, you're a total pickup.

[Christophe]

a) High circulator speed readings after 6 days:

kWh: 6,85
Hours: 141
Pu avg. : 48.5 W

So it looks like we have a slight improvement in overall consumption despite the Pu of the circulator which goes from 7W to 22W ... since I was at 55W on average on the previous calculation water-pumping-filtration / transforming-a-solar-DHW-tank-into-thermodynamic-water-heater-with-a-small-pool-t17035-90.html # p475995

But difficult to conclude since I did not draw exactly the same amount of water ... necessarily!

Good I leave on high speed for the next test see b)

b) I passed the Delta, parameter H from 3 to 5 ° C the heat pump will therefore turn between 39 and 34 ° C ... I will have to monitor because if the cold DHW return temperature is higher than 34 ° C then the heat pump will never go into light standby and the compressor will run continuously ...

parametres_nano_poolex.png (98.16 KiB) Viewed 1592 time

delta_temperature.jpg (116.42 KiB) Viewed 1601 times

c) Otherwise it condenses quite a bit as I thought ... it will be necessary to evacuate the condensates, for 6 days I have this quantity, not measured but it must be in about 3-4 L ... (it is a old 20 L paint jump):

condensats.jpg (85.55 KiB) Viewed 1601 times

[Christophe]

Preparation of the condensate drain ... finally I did well to make the wooden support! I simply force-fitted a double nipple of a garden hose in the wood of the support:

condensat.jpg (94.59 KiB) Viewed 1580 times

I hope that this will evacuate quickly enough not to spill over onto the table ... normally yes ...

[izentrop]

difficult to conclude since I did not draw exactly the same amount of water ... necessarily!

A meter on the hot water circuit would have been needed for a valid measurement.

Does this increase the cycle time and does the cycle always stop when the outlet temperature reaches 44,4 °?

In which case, I would have tried to lower the set temperature and checked if that increases the duration of the cycle, while reducing the speed of the pump to the lowest.
The goal is to maintain an outlet temperature around 43 ° or more, just below the cutoff threshold. The goal would be for the heat pump to stop only when the temperature of the water in the tank reaches this temperature and not before ...

The setpoint will perhaps be at 35 °, but as the destination of the heat pump is deviated, this would be normal, since the volume of the water circuit is much smaller.

[Christophe]

b) I passed the Delta, parameter H from 3 to 5 ° C the heat pump will therefore turn between 39 and 34 ° C ... I will have to monitor because if the cold DHW return temperature is higher than 34 ° C then the heat pump will never go into light standby and the compressor will run continuously ...

I just watched a cycle, it's ok.

The return is at less than 31 ° C (which means that the exchanger plunges low enough into the tank) and the cycle is done "normally" the time of "pause" (light standby) and heating and pause are necessarily longer than with a delta of 3 ° C ... see the influence on consumption.

If ok at the consumption level, I think I could increase the delta to 6 ° C without worries, maybe 7 or even 8 ° C ...