16 minutes ago, Superfly said:

OK I checked it's called "condensation" apparently I'm sure I'll figure it out once I get the thing - if there is such an outlet I'll connect it to the overflow of the geyser) - BTW there is only 1 inlet in a geyser - that pic portrays 2 albeit it's simplified I know ... LOL

Note sure which of the 3 you refer to as inlets. I only see 1 inlet and that is the cold water. Most geysers have 3 ports. 2 at the top as of the last about 5 years the TP has its own port. Normally 2 at the top and inlet at the bottom. This on horisontal mount. If mounted vertical cold at the bottom and 2 at the top. 

1 hour ago, Superfly said:

 

The heat pump uses the bottom inlet to push hot water... was what I was getting at.

The bottom in blue is where cold water enters the geyser. This point is used by the heat pump to suck cold water in and pushes hot water out to enter at the top of the geyser. 

Only the cold water inlet is not shown in the basic drawing. 

On 2023/05/05 at 11:39 AM, Bobster. said:

I did say that if you had enough in hand THEN you can consider it. 

Here's my system this morning

You can see the heatpump kick in at 6:00. SOC then is 65%. Heatpump turns off just before 7:00 (when the timer would have turned it off anyway). SOC is 51%. The spike at 6:45 is the kettle. 

10kWh battery.

Temperature is set to 55 degrees.

But as I said, I got myself into this happy position by running the pump early in the morning and observing what happens. This may not work for everybody, but it's worth having a go.

So have the exact same situation, I heat my geyser 150l water in the early morning 4-5 with my batteries, I usually end up with around 45% by the time the water gets to 55 degrees  and then my timer(Geyserwise) switches the geyser off. By 9am I’m recharging my batteries and by 12 I am on 100% batteries….what’s wrong with situation? 

On 2023/05/05 at 11:06 AM, Modina said:

If you feel like a hot cup of coffee and use battery power to boil the kettle...  OK, fine.
But using battery power to heat en-mass (geyser water), with or without a heat-pump......  I am just speechless.
 

What’s wrong with heating water with your batteries?

19 minutes ago, Raiden2912 said:

What’s wrong with heating water with your batteries?

That takes battery-privilege too far. What about ROI and those without any solar?

3 hours ago, frivan said:

That takes battery-privilege too far. What about ROI and those without any solar?

Some of us were lucky to get a heat pump many years ago just to save on grid. Now it is a double ++

6 hours ago, frivan said:

That takes battery-privilege too far. What about ROI and those without any solar?

Isn’t ROI calculated over a given period of usage? 
 

Anyway each to their own I guess 😁

1 minute ago, Raiden2912 said:

Isn’t ROI calculated over a given period of usage?

True. But solar panels give energy and probably have an ROI of 3 years based on energy generated. Batteries are there to move energy from generation to later consumption. If you want to heat a geyser, the better ROI would be to do it when the sun is shining with as little as possible battery.

18 hours ago, frivan said:

That takes battery-privilege too far. What about ROI and those without any solar?

I'm mindful of those who can't afford solar, and despite my ramblings elsewhere about the cost of not having solar, most South Africans will never be able to have such a system. But heating water from my battery is not an insult to them. 

As for ROI, if you can heat your water using solar then surely ROI increases? 

Ok... If you used the sun to directly heat water, maybe you need less battery to start with. But this has to be taken case by case. In my case the heatpump was already there, and the installation was always going to be 10kWh of battery. I So once I saw that it was possible, all that was needed was to get an electrician to move one wire from the non backed up to the backed up side of the DB. IE it cost me little. 

Anyone running a heat pump in conjunction with solar water heating? Interest is academic at this stage as I probably use less than 150kWh of power pa (mostly from battery) to boost water temperature first thing in the morning.

Even though I have PV, it still makes no financial sense despite the horrific power price increases of recent times. Similarly I do not believe there is an economic case for a heat pump other than a leaning towards the green brigade.

If we have loadshedding, we have cold water on cold nights unless I remember to choose another timer on the smart geyser switch.

Edited June 16, 20233 yr by Peter V

1 hour ago, Peter V said:

Similarly I do not believe there is an economic case for a heat pump other than a leaning towards the green brigade.

A heat pump's claim to fame is the fact that it can heat a large amount of water for very little kWh. It makes absolutely sense for hotels, guesthouses and large households where they need several hundreds of liters of hot water.  

If you are a single person, then gas will be your cheapest option.

A family of 2 will probably be more cost effective on a 150l geyser.

A family of 4 or more you will have ROI on your heat pump within 3 years (probably closer to 2 years considering at the increased cost of power)

 

If you installed solar the calculation changes completely

If you have excess solar to power the geysers then a heat pump is only useful if you want to heat the geyser early morning running from the battery... one could argue that grid power is much cheaper than battery & heat pump so you are better off running from the grid and avoiding the larger battery too.

If you are completely off-grid and do not have access to grid power the calculation changes once again, you might need to consider a gas geyser for those overcast days

 

There are also heat pump you can install to heat your home, but here in South Africa our winters are not cold so most people would not consider them

 

To answer your question, yes I have a heat pump, installed it a year before I got solar. It helps to reduce demand on those overcast days so the units I need to buy is close to zero

Edited June 16, 20233 yr by iiznh

6 hours ago, iiznh said:

A heat pump's claim to fame is the fact that it can heat a large amount of water for very little kWh. It makes absolutely sense for hotels, guesthouses and large households where they need several hundreds of liters of hot water.  

If you are a single person, then gas will be your cheapest option.

A family of 2 will probably be more cost effective on a 150l geyser.

A family of 4 or more you will have ROI on your heat pump within 3 years (probably closer to 2 years considering at the increased cost of power)

 

If you installed solar the calculation changes completely

If you have excess solar to power the geysers then a heat pump is only useful if you want to heat the geyser early morning running from the battery... one could argue that grid power is much cheaper than battery & heat pump so you are better off running from the grid and avoiding the larger battery too.

If you are completely off-grid and do not have access to grid power the calculation changes once again, you might need to consider a gas geyser for those overcast days

 

There are also heat pump you can install to heat your home, but here in South Africa our winters are not cold so most people would not consider them

 

To answer your question, yes I have a heat pump, installed it a year before I got solar. It helps to reduce demand on those overcast days so the units I need to buy is close to zero

Perhaps few people as crazy as me to have and keep stats. Here we can look at actual figures over the 12 years that I have my ITS 4.7kW heat pump. Only one repair 5 years ago because the installer never fitted a strainer. Servicing done by myself accept for the supply and install of the failed pump. Servicing only blowing out the dust once a year from the unit and keeping the PC board relatively clean.

Price of power is the actual. Over time my consumption did come down. I have excluded the saving due to PV. 

For the last 7 of the 12 years we are only 2 in the house. For 5 years we were 3-4. We do bath about 2-3 times a week and shower the other days. Savings after initial cost is a pure % gain and not only for high use of hot water.

I only need to run the pump about 2 hrs a day and also directly after a bath as the geyser drops down to 26 degrees.

Summary of power used is per month/year.

Total saving of power cost works out to about 5 times the cost of the installation. No element is connected and we have never had the need for back up heating.

 

 

Edited June 16, 20233 yr by Scorp007

I got rid of my heat pump. The problem is that when it runs, it completely recirculates the water in geyser so the stratification is lost. So if the water was at 50 deg let's say and you use hot water and the water temp drops to 45 deg and the heat pump kicks in, then the temperature drops to 35 deg in a flash due the stratification being lost. I also monitored the electricity consumption for about 6 months and the heat pump didn't save anywhere near enough to pay for itself. I also found that it takes much longer than a normal element to heat the water. I was advised by the installer to raise the target temperature to 60 deg but then it is so inefficient that it doesn't save a cent.  

2 hours ago, gthorn said:

I got rid of my heat pump. The problem is that when it runs, it completely recirculates the water in geyser so the stratification is lost. So if the water was at 50 deg let's say and you use hot water and the water temp drops to 45 deg and the heat pump kicks in, then the temperature drops to 35 deg in a flash due the stratification being lost. I also monitored the electricity consumption for about 6 months and the heat pump didn't save anywhere near enough to pay for itself. I also found that it takes much longer than a normal element to heat the water. I was advised by the installer to raise the target temperature to 60 deg but then it is so inefficient that it doesn't save a cent.  

It's sad to hear that you removed the unit. 12 yrs ago a seller also decided to install another make when I asked for a ITS. I had the same problem so his unit was removed the next day and the ITS was installed. 

Although too late now the problem is the installer for not fitting the special valve to prevent mixing the water and only discharge hot water from the heat pump. Most systems had this problem but a lot of them have the special valve these days. 

If interested you can Google ITS loading valve to read the detail of this specific integration and also see the difference with and without it. 

As a refrigeration engineer and owner of a company for 25 years plus, I would just like to say that the wrong people are marketing and selling heat pumps without understanding the actual concept and principal of how it works. It is based on the refrigeration cycle and not direct heat , the refrigeration cycle removes heat from one space and moves it to another the energy required to do this for every 1kw in you get 3 Kw out which is one third of your 2kw element therefore a heat pump will heat your water far quicker than an electric element also what people forget is the cold side of the refrigeration cycle can also be used for cooling in air conditioning or refrigeration doubling the efficiency. To explain this if you have a heat pump there is a figure rating the COP of efficiency Google it. I have a heat pump installed at home and never run out of hot water. I also have air conditioning for dehumidifier and cooling.