Correct. In my case both the heat pump and the old geyser are outside on the side of the building.

The connection is the same as with a solar plate\tubes. In this case the heat pump has it's own circulation pump as part of the unit. 

On 2020/06/20 at 12:29 AM, plonkster said:

So I imagine it is a cool idea, but with limited use.

Now I see what you did there...

15 hours ago, Richard Mackay said:

Is your heat pump unit mounted outside?

With the thread title being ALL about heat pumps, thought I will add the following

Heat pumps apparently  do generate sound so depending what you use and how easily bothered you are with sounds you need to look at the best install location.

Also, while heat pumps are way more efficient than standard electric geysers the heat pump does also consume some electricity while "idle". (this consumption is usually not included in the COP based savings calculations).

A nice comparison here  (https://powersaving.co.za/appliance-tests/powerprophet/heat-pump-simulation/) between a heat pump and standard geyser for a 4 person family.  

Edited June 21, 20206 yr by introverter
spelling

I've had a heat pump for 11 years. Generally I've been happy with it, and it does consume a lot less power than a geyser. I have a Kwikot. The guy who sold it to me reasoned that you'd always get spares.

I have two "cons" though

1) The timer is not very versatile. 3 programs, all by hour of the day only. So no way to have different programs for different days of the week.

2) I am starting to think in terms of service. That's reasonable after 11 years. Apparently Kwikot (or an approved service agent) simply remove the unit and it goes into Kwikot. Turn around in Jo'burg is about a week. They fit or reconnect an element in the geyser so you still have hot water, but that would mean I'd have to have the geyser moved to the non-backed up circuits.

In my previous house I had a traditional solar geyser with tubes on the roof. This got VERY hot in the summer. Sometimes so hot that an escape valve would pop and there would be lots of water running down the roof. I didn't like the waste. Plus you needed an electrical backup if you were going to use it in the early morning or in case of overcast weather.

6 minutes ago, introverter said:

Heat pumps apparently  do generate sound so depending what you use and how easily bothered you are with sounds you need to look at the best install location.

They do. About the same as an aircon. Which figures because they are basically an aircon with the heat flow reversed.

@introverter  thanks a great deal for the link about underfloor heating. It really covers a great many aspects on the subject. 

1 hour ago, ebrsa said:

@introverter  thanks a great deal for the link about underfloor heating. It really covers a great many aspects on the subject. 

I do have a sneaking suspicion that it is not exactly news for you 🤔 ...looking at your profile and posts I doubt you came rushing up to a builder yelling "wait before pouring that slab!...I just remembered I have some left over pipe that is taking up too much space in the shed..." 

But hey, if I don't single-handedly try to keep google afloat who else will?... 🙂

Have also looked at heat pumps before. 

My current setup in terms of geyser is retrofit (circulation pump) with FPC on roof. Geyserwise installed. Grid tops up geyser temp as needed at pre-scheduled times of the day (geyserwise settings). Topping up being a lot more in winter in CPT and as such geyser connected to non-essential. 

Also have solar PV install (2.1kw)  + batteries and inveter. In summer there was actually enough solar from panels and batteries at 100% to be able to run the geyser off the solar and then top up the max 5degrees needed to 55degrees most days, but winter is a no go. 

So the options I have been looking at:

1) 2kw geyser element. BUT will still have the issue with limited solar production in winter.

2) Heat pump to replace the current geyser element. But how will this fit into my current setup with Geyserwise/FPC and Solar PV setup?

The idea is to sometime up Solar PV to 3.2kw which would get us closer to supplying everything in winter as well.

 

The more I am reading on these Heat Pumps, the more I am becoming convinced that it is time to put my Gas geyser on standby and install one of these heat pumps. I am already on my second gas heater in 4 years.

1 hour ago, Tsa said:

Heat pump to replace the current geyser element. But how will this fit into my current setup with Geyserwise/FPC and Solar PV setup?

What you will do will depend on what heat pump you buy. 

If you buy a heat pump that can be controlled by the current Geyserwise controller, you will just set it to use the heat pump instead of the normal element.

Or it will be separate. My heat pump has it's own controller. In this case you will set GeyserWise to not heat at the pre-scheduled times, but you will set the heat pump to heat at those times instead. 

On 2020/06/19 at 10:19 AM, Jaco de Jongh said:

Like with everything, there are cheaper, not so efficient units and quite a few claiming exceptional COP ratings, but only a few of them can deliver on their products. One trusted brand that I would strongly recommend is ITS solar's range especially their 5Kw Super unit that can off 10 degC higher outlet water temp than most of its competitors.  

Note: A COP rating of 3 for example means that the unit is 300% efficient and 4 is 400% and so on, and the only way that is possible is because the heat-pump is not producing the Heat, its is merely moving it from the environment into the water. It takes less energy to move the heat compared to producing the heat. (The process is a bit more complicated, but this is the simple explanation of things.)

Is a higher COP rating an indication of a better product?

On 2020/06/21 at 11:25 AM, Bobster said:

1) The timer is not very versatile. 3 programs, all by hour of the day only. So no way to have different programs for different days of the week.

Nice post Bobster.

Fully agree with the statement above, this is my only frustration at the moment.

I have had a ITS  (as previously mentioned) for the last 7 years and services it last year. Still going well and ROI was roughly 4 years ago already.

Anyone know, or have any thoughts on, how to change the control panel to make it "smart" IE: get it into HASS.IO with a sonoff device or DI mini or something similar to such?

On 2020/06/21 at 11:25 AM, Bobster said:

2) I am starting to think in terms of service. That's reasonable after 11 years. Apparently Kwikot (or an approved service agent) simply remove the unit and it goes into Kwikot. Turn around in Jo'burg is about a week. They fit or reconnect an element in the geyser so you still have hot water, but that would mean I'd have to have the geyser moved to the non-backed up circuits.

OK... I just found a guy who services on site. He says that the guys who take the unit away know diddly about pumps, so they just remove it, drop it off at a Kwikot branch and add a markup and charges for disconnecting and reconnecting. 

Mine is still heating, but it's taking longer. He says it is likely a loss of gas, but there may be other factors.

NB.... the date stamp on the covers says it is 9 years old.

TIL that in Canada heat pumps are used to heat rooms in the winter.

9 hours ago, Richard Mackay said:

Is a higher COP rating an indication of a better product?

Not always, a few brands claim unrealistic COP's as a sales pitch, and in some cases its true, but the test was done in 40degC ambient conditions, then you go and  install it in Sutherland in the winter and the unit just cant deliver on the manufacturers promise. 

Most units claiming a COP of 5 and above, i will personally investigate before I buy it. 

I had a conversation with the owner of ITS last year and although his units states a COP of 3, it is a case of under promise and over deliver. He gives you the worst case scenario although his units are capable of delivering cop's of up to 5 it hotter areas of the country. 

On 2020/06/20 at 12:29 AM, plonkster said:

I've had that thought too. The only issue is... when would you use it? In summer, you're water will be hot by noon... but your house is still hot (so you still need to run the AC), and in winter... well you want hot water... but you really don't want to cool any part of your house down!

So I imagine it is a cool idea, but with limited use.

Know of one that use cold water for AHU for cooling in summer while heating the pool and generating hot water. And in winter he heats the underfloor and dump the cold in the pool.

Heat pump in general is a water to air system capable of delivering 60C hot water.  You take 1kW of electricity and put 3kW of heat in the geyser (COP=3) and dump 3kW of cold air outside.

With a chiller/hydronic unit you have water to water system.  Normally hot water is around the 40C mark and cold water below 10C.  Some units can deliver both +-40 and 60C for use of building heating and geyser/domestic hot water.  Now you use 1kW of electricity to get 3kW to cool your house and 3kW to heat your geyser or pool and effectively have a COP of 6.

 

@introverter  I saw no reason to pay a so-called builder to hire a few bricklayers so managed building of my house myself. You are right, embedding pex pipes in the floor slabs was planned. I based heating plans on a system of someone in Tasmania. The Australians seems to embed pipes in floor slabs and thus heat up the whole slab. Europeans use a 50mm or so insulated slab containing the heating pipes. I wanted to use solar heaters for the floor but ran out of roof space when photovoltaic panels were installed. Hence the search for an alternative heat source.

Perhaps you could use your spare pipe by looping it around the edge of the room with suitable covering to let  cold air in at the bottom and let natural convection let the heated air out the top. 

The article that your link pointed to was still very useful, particularly when researching use of heat pumps for hydronic floor heating. 

On 2020/06/22 at 1:33 PM, Louisvdw said:

What you will do will depend on what heat pump you buy. 

If you buy a heat pump that can be controlled by the current Geyserwise controller, you will just set it to use the heat pump instead of the normal element.

Or it will be separate. My heat pump has it's own controller. In this case you will set GeyserWise to not heat at the pre-scheduled times, but you will set the heat pump to heat at those times instead. 

Thanks, any ideas on brands which would support the Geyserwise control? Then also I guess one would replace the current element in the geyser with the heat pump one? or is there an option of running both?

Also, totally different question, but do you guys have any suggestions on doing a switch on the geyser between using PV OR using grid? Basically in winter I would have it running on grid and in summer flip it to use the PV/batteries setup to run the geyser where it is mostly a topup in summer. This option vs moving the wiring inside the DB from inverter to grid and vice versa every time. 

 

41 minutes ago, Tsa said:

Then also I guess one would replace the current element in the geyser with the heat pump one? or is there an option of running both?

You leave the current element in place and switch it off at your DB. 

The plumber will add some extra pipes so that the heat pump will get cold water from your geyser tank and circulate it to put the hot water back in. Most tanks have these connections already 

My heat pump packed up this week. 
it was from a company called power tech ist as part of rebate program in 2012.

 I heard that they closed down and no longer do heat pumps. 
 

im based in Jhb , sandton, rivonia. 
Are there any guys out there that can fix these units? 

There must be but you want to get the right outfit to do this work. I was not impressed when I bought an up market "made in Germany" fridge and when it packed up under warranty some outsourced guy in a bakkie arrived to do the service. 

I'm sure this industry isn't  quite the same.  Let's wait for Jaco to provide the heads-up..

Edited June 28, 20206 yr by Richard Mackay

8 years is on the high end for lifespan for a heat pump as I understand. Probably better off just replacing it?

On 2020/06/28 at 6:36 PM, midnightcaller said:

im based in Jhb , sandton, rivonia. 
Are there any guys out there that can fix these units? 

 

23 hours ago, Richard Mackay said:

Let's wait for Jaco to provide the heads-up..

Hi Richard, sorry, I dont know someone, had a call today from a guy who needs two repaired. I will send ask around and let you know. 

On 2020/06/28 at 6:36 PM, midnightcaller said:

My heat pump packed up this week. 
it was from a company called power tech ist as part of rebate program in 2012.

 I heard that they closed down and no longer do heat pumps. 
 

im based in Jhb , sandton, rivonia. 
Are there any guys out there that can fix these units? 

Air conditioning contractors can normally repair these units.
But it is a minefield to find someone who does a good job, charge a fair rate and have some experience with heat pumps.

On 2020/06/21 at 11:25 AM, Bobster said:

The timer is not very versatile. 3 programs, all by hour of the day only. So no way to have different programs for different days of the week.

The guy who came to service my pump confirmed what I suspected, namely that the timer does more than just turn power on and off. It sends signals to the electronics mounted inside the main unit which initiate start up and shut down sequences. These don't take very long, but they do need to be respected. He gave his appy a bollocking for just turning off at the breaker, and then told me to never do anything like that - always turn it off from the control unit used to program the timer.