5 hours ago, Scorp007 said:

You will read a lot of junk from people bashing heat pumps while they have never used them. Sometimes best to ask those that have been using them. Myself and @Bobster. have been using them for over 10 yrs and do know how little power they use.

There's a lot of deliberate misinformation about heat pumps right now. This is mostly from organisations or trades that have a stake in older technologies that the heat pump is touted as a replacement for, and mostly it comes from the UK and the EU where governments are encouraging the use of heat pumps.

Mine ran for 30 minutes this morning, after being turned off since 15:00 yesterday. It heated the water in the geyser to 57 degrees. That took about 0.8 kWh.

And mine is old. The newer ones will not be less efficient.

5 hours ago, Scorp007 said:

I even heat my geyser from batteries if I have to and I only use a small 2.4kW Axpert. I just ensure I switch off my fridges via smart switches for the 1 hour when heating to prevent overload on the inverter. 

I don't go that far. I do make sure that if we run the dishwasher (our other regular big load, since it must heat water), then that gets done between 9:00 and 12:00. But that is life with PV. You have to watch the peak demand. I have fairly new fridges and a freezer, and they use next to nothing. Which is why I am confident that the new heat pumps will, if anything, be more efficient than my old clunker.

Heatpumps are going into new builds here as well. Or so a guy from Kwikot told me. For new complexes in Jhb they are being mandated (according to the guy from Kwikot) so as to reduce load on the grid.

5 minutes ago, Bobster. said:

There's a lot of deliberate misinformation about heat pumps right now. This is mostly from organisations or trades that have a stake in older technologies that the heat pump is touted as a replacement for, and mostly it comes from the UK and the EU where governments are encouraging the use of heat pumps.

Mine ran for 30 minutes this morning, after being turned off since 15:00 yesterday. It heated the water in the geyser to 57 degrees. That took about 0.8 kWh.

And mine is old. The newer ones will not be less efficient.

I don't go that far. I do make sure that if we run the dishwasher (our other regular big load, since it must heat water), then that gets done between 9:00 and 12:00. But that is life with PV. You have to watch the peak demand. I have fairly new fridges and a freezer, and they use next to nothing. Which is why I am confident that the new heat pumps will, if anything, be more efficient than my old clunker.

Heatpumps are going into new builds here as well. Or so a guy from Kwikot told me. For new complexes in Jhb they are being mandated (according to the guy from Kwikot) so as to reduce load on the grid.

Thank for this. I've now decided this is the way I'm going. Might cost more today but sure it will pay itself in the long run. The misinformation is huge and that's why I've been so sceptical. 

Thank you once again and @Scorp007 thank you too. 

 

Going 5.4kw ITS HP with solar and 300 - 350L geyser capacity after speaking to ITS this afternoon.

2 hours ago, BarendD said:

Thank for this. I've now decided this is the way I'm going. Might cost more today but sure it will pay itself in the long run. The misinformation is huge and that's why I've been so sceptical. 

Thank you once again and @Scorp007 thank you too. 

 

Going 5.4kw ITS HP with solar and 300 - 350L geyser capacity after speaking to ITS this afternoon.

All a pleasure. I just try to give my own experience with enough figures and test to back it up. When I had to do repairs in a steel factory we had a heat pump but all I had to ensure is that the thing is always running. I had no idea how it worked as it was just the inlet and outlet pipe from the pump. I also had the headaches to repair copper pipes in a massive 17kV induction heater that was used to melt the electroplated tin on steel plates at a high speed while the steel strip was going through the coil. These coils were cooled with distilled water. Never knew this tech will one day be used in most homes over time.

@Bobster. and @Scorp007 one last question. What hotwater tank/ geysers are you using? Logic tells me that to a and solar/HP combo you would need a geyser with 7 holes. Cold/hot inlet, HP in/out, solar in/out and an overflow. Not sure if I'm missing something here but see the ones on the market has 3 or 5.

Some hints and tips from others with heat pumps to get to amazing efficiencies.

One day when I finally get my farm, I'll be getting a heat pump too.

 

1 hour ago, BarendD said:

@Bobster. and @Scorp007 one last question. What hotwater tank/ geysers are you using? Logic tells me that to a and solar/HP combo you would need a geyser with 7 holes. Cold/hot inlet, HP in/out, solar in/out and an overflow. Not sure if I'm missing something here but see the ones on the market has 3 or 5.

The current range of NORMAL geysers do have 2 hot water outlets. One for the hot water to taps and the other for solar collector/heat pump. Then you have the cold water inlet/taps as well as the drain point and lastly the pressure relief to the outside. I had to chat to the manager of the last plumber who had no clue how a heat pump works and luckily for me I saw he put a non return valve between the heat pump hot water T-piece connection and the geyser hot outlet. He did not use the 2nd hot water point for solar/heat pump. This would have meant my heat pump would not have been able to push the hot water into the geyser. Imagine trying to convince the plumber it is wrong and he had to remove the non return valve or connect the heat pump to the correct port. That is how things go. 

The only way for the 2 plumbers to accept they did it wrong was to Google a Kwikot document with drawing to show the connections.

I have been using the standard Kwikot geysers all my working life. These are the normal replacements by the insurance companies.

Edited January 27, 20251 yr by Scorp007

12 hours ago, BarendD said:

@Bobster. and @Scorp007 one last question. What hotwater tank/ geysers are you using? Logic tells me that to a and solar/HP combo you would need a geyser with 7 holes. Cold/hot inlet, HP in/out, solar in/out and an overflow. Not sure if I'm missing something here but see the ones on the market has 3 or 5.

IDK. When I bought this house it had a conventional geyser. I wanted to switch to PV, but there wasn't enough north facing roof near the geyser and thus all the piping. The installer (who I'd used before) told me that they are no longer allowed to fit a geyser on a trestle on the roof. 

This thread has had me thinking about how the heatpump warms the water in the geyser. Obviously there is some loop that takes cold water to the heat exchanger and feeds the heated water back into the geyser. The geyser itself was not changed and not moved, but obviously there must be more connections to it. The element is in place but has no power to it. The cable that was powering the element now powers the pump.

The geyser and the pump are Kwikot. That brand has been traded a bit the last couple of years, but they still seem to be giving good service. They came to attend to a problem with my heatpump in late December. 

He wants to sell me a new pump, but he still fixes the old one.

Edited January 28, 20251 yr by Bobster.

12 hours ago, Bobster. said:

This thread has had me thinking about how the heatpump warms the water in the geyser. Obviously there is some loop that takes cold water to the heat exchanger and feeds the heated water back into the geyser.

If you look at my basic picture of yesterday just below the koekies you will see a closed system and the pump sucks from the cold inlet of the geyser and discharges at the hot  outlet side. Being a closed system this causes the geyser water just to circulate. At all times whether the pump is running or not cold water enters the geyser as hot water is used.

This is very muck like water pumps in cars circulating water through the radiator to cool it down.

11 hours ago, Scorp007 said:

If you look at my basic picture of yesterday just below the koekies you will see a closed system and the pump sucks from the cold inlet of the geyser and discharges at the hot  outlet side. Being a closed system this causes the geyser water just to circulate. At all times whether the pump is running or not cold water enters the geyser as hot water is used.

This is very muck like water pumps in cars circulating water through the radiator to cool it down.

Oh. I thought the pump compressed the gas and moved the gas through a heat exchanger. Ha! Now I'm acting like I do know.

So is the temperature difference between the inlet and outlet sides of the heat exchanger enough to get water flowing? And does that mean that this flow slows down as the water gets closer to the target temperature?

12 hours ago, Bobster. said:

Oh. I thought the pump compressed the gas and moved the gas through a heat exchanger. Ha! Now I'm acting like I do know.

So is the temperature difference between the inlet and outlet sides of the heat exchanger enough to get water flowing? And does that mean that this flow slows down as the water gets closer to the target temperature?

AFAIK the pump is just pumping water (circulating)all the time while the temp is below the set point. Once the set point is reached the gas compressor is also stopped. Yes the compressor pumps the gas just like in a fridge and aircon but the result is just heating instead of cooling. This is why the outlet air from the heat pump is cold as per an aircon where the outlet of the aircon is inside the room and the exhaust is hot air to the atmosphere.

Edited January 29, 20251 yr by Scorp007