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Sign up with GoogleHeat Pump vs Solar Geyser
- Thread starter dj2381
- Start date
I've been using a heatpump for hot water for more than a decade. Everything on the property is powered by solar pv. It works well.
The only issue I've had is from waterborne silt in the municipal supply. Sometimes it's really heavy and the town water is brown. About 5 years ago the hot water pump in the heatpump gummed up with silt and had to be replaced. Fitting a strainer in the cold water line fixed that, and the only hassle now is having to periodically clean the strainer.
There are several threads on MyBB discussing this topic. I'm on mobile now so regrettably not able to find and post links to those discussions.
I was an early adopter and so researched this thoroughly at the time. In the end I went with a locally designed and manufactured system - mainly to ensure proper local support if required - and have never regretted it.
What's suits me well is the heatpump works day and night, cloudy or not. I have hot water all the time, even after a month of heavily overcast weather.
The only issue I've had is from waterborne silt in the municipal supply. Sometimes it's really heavy and the town water is brown. About 5 years ago the hot water pump in the heatpump gummed up with silt and had to be replaced. Fitting a strainer in the cold water line fixed that, and the only hassle now is having to periodically clean the strainer.
There are several threads on MyBB discussing this topic. I'm on mobile now so regrettably not able to find and post links to those discussions.
I was an early adopter and so researched this thoroughly at the time. In the end I went with a locally designed and manufactured system - mainly to ensure proper local support if required - and have never regretted it.
What's suits me well is the heatpump works day and night, cloudy or not. I have hot water all the time, even after a month of heavily overcast weather.
Who is the local manufacturer, if you don't mind me asking? Please send links when you have a chance, much appreciated.
Heat pumps is great, but they still use electrical power.
If you planning on a solar PV system at a later stage, no problem.
The single biggest issue with solar water heating is STORAGE!!!
Make sure you increase storage to about double or triple your normal hot water storage.
Then it would work for you.
The same applies to Solar PV.
Just increasing the amount of PV does not always help you.
Increasing the size of your battery bank is where the gains is at.
This is now for normal residential systems where you not planning to feed back to the grid.
If you planning on a solar PV system at a later stage, no problem.
The single biggest issue with solar water heating is STORAGE!!!
Make sure you increase storage to about double or triple your normal hot water storage.
Then it would work for you.
The same applies to Solar PV.
Just increasing the amount of PV does not always help you.
Increasing the size of your battery bank is where the gains is at.
This is now for normal residential systems where you not planning to feed back to the grid.
It's the Enerflow made by MTech in Potch. They've been making very large commercial heatpump systems for many years, used in hotels, hostels, prisons, etc. The little Enerflow is/was their first machine for domestic/residential use.
ADrunkTeddyBear
Expert Member
- Joined
- Jul 22, 2014
- Messages
- 1,704
Following. Not sure which direction to go next year as well
I have used both.
Neither of them works as well as a traditional geyser if having hot water is your sole purpose.
In the case of the heatpump the house came with it, it was
a) noisy
b) couldn't always get my water up to 55 degrees in the winter
c) plumbing was done wrong so in the winter it quickly cooled the water in the old geyser unless I closed the valves before / after the heatpump.
d) was useless without electricity
I eventually decided to move to a evacuated tube system with a 300l geyser on the roof (we're a 5 person family).
a) in sunny summer days the water is blistering hot, and because it gets so hot it can last another cloudy day
b) overcast weather produces basically no heating
c) when days start out overcast and then later turns sunny, the geyser usually doesn't have time to really catch up, while my PV system does still get batteries to 100%.
d) obviously does work without electricity!
e) I have to be much more careful in the winter with warm water - also had to move my shower for example to the evening instead of the morning.
So I currently have my home automation set set up to run the geyser's 4kw element when the water isn't hot enough and there's enough PV power. But I really do need to reduce the geyser's element to smaller or alternatively actually reinstall my heatpump (which I kept).
Neither of them works as well as a traditional geyser if having hot water is your sole purpose.
In the case of the heatpump the house came with it, it was
a) noisy
b) couldn't always get my water up to 55 degrees in the winter
c) plumbing was done wrong so in the winter it quickly cooled the water in the old geyser unless I closed the valves before / after the heatpump.
d) was useless without electricity
I eventually decided to move to a evacuated tube system with a 300l geyser on the roof (we're a 5 person family).
a) in sunny summer days the water is blistering hot, and because it gets so hot it can last another cloudy day
b) overcast weather produces basically no heating
c) when days start out overcast and then later turns sunny, the geyser usually doesn't have time to really catch up, while my PV system does still get batteries to 100%.
d) obviously does work without electricity!
e) I have to be much more careful in the winter with warm water - also had to move my shower for example to the evening instead of the morning.
So I currently have my home automation set set up to run the geyser's 4kw element when the water isn't hot enough and there's enough PV power. But I really do need to reduce the geyser's element to smaller or alternatively actually reinstall my heatpump (which I kept).
Athos
Senior Member
- Joined
- Sep 11, 2005
- Messages
- 891
I have this beast:
Costs R 35 000 (approx) to have it installed. It holds 270 litres.
This was my total usage for November:
Hope this info is helpful.
**Edit: Forgot to mention that this is 100% self-contained, this does not feed water to a geyser.
Costs R 35 000 (approx) to have it installed. It holds 270 litres.
This was my total usage for November:
Hope this info is helpful.
**Edit: Forgot to mention that this is 100% self-contained, this does not feed water to a geyser.
Last edited:
This is my 300l evacuated tube solar geyser's electricity usage for the current month (December, 0kWh) and last month (Nov, 31.3 kWh).
So yes, it works and it saves a ton of money.
Rainy day today, so temperature not really going up (as opposed to yesterday this time when it was trending upwards).
So yes, it works and it saves a ton of money.
Rainy day today, so temperature not really going up (as opposed to yesterday this time when it was trending upwards).
Priapus
Honorary Master
- Joined
- Jun 8, 2008
- Messages
- 11,422
I swapped out my 4Kw element for a 2kw element - geyser runs off the Solar now and then at night if it did not reach target temp.
Have considered a heat pump; but with the geyser on the solar, I don't see the need to get a heat pump now
wingnut771
Honorary Master
- Joined
- Feb 15, 2011
- Messages
- 28,146
Why does your temp graph look so jittery?This is my 300l evacuated tube solar geyser's electricity usage for the current month (December, 0kWh) and last month (Nov, 31.3 kWh).
So yes, it works and it saves a ton of money.
View attachment 1205650
Rainy day today, so temperature not really going up (as opposed to yesterday this time when it was trending upwards).
View attachment 1205654
wingnut771
Honorary Master
- Joined
- Feb 15, 2011
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- 28,146
Especially when it costs R35000.
Priapus
Honorary Master
- Joined
- Jun 8, 2008
- Messages
- 11,422
Exactly, just seems wasteful now. If I didn't have the PV system, then a heat pump makes sense.
wingnut771
Honorary Master
- Joined
- Feb 15, 2011
- Messages
- 28,146
R35000? Is it made out of platinum?
Athos
Senior Member
- Joined
- Sep 11, 2005
- Messages
- 891
Ja they are expensive. To be honest I didn't buy it, I bought the property with an old heat pump (same design). Long story short the old one burst and insurance paid for a like for like replacement which was this thing. I love it though.
Athos
Senior Member
- Joined
- Sep 11, 2005
- Messages
- 891
How much did it cost to install? Do you ever not have hot water, during winter perhaps?This is my 300l evacuated tube solar geyser's electricity usage for the current month (December, 0kWh) and last month (Nov, 31.3 kWh).
So yes, it works and it saves a ton of money.
View attachment 1205650
Rainy day today, so temperature not really going up (as opposed to yesterday this time when it was trending upwards).
View attachment 1205654
31 kWh for a month is very nice.
Koosvanwyk
Expert Member
- Joined
- Aug 6, 2015
- Messages
- 1,051
I am having a heat pump installed next week to run off my solar system. About R30k installation included for 5.3kw system (draws about 1kw when heating to 60 degrees celcius).
This is the last piece of my puzzle to move solar and the long and expensive process to reduce our daily consumption from around 26kw to 15kw
Based on experience with the heatpump at my holiday home they work great, but needs to be serviced annually. They don't like standing idle, which requires bi annual services. They are expensive though
This is the last piece of my puzzle to move solar and the long and expensive process to reduce our daily consumption from around 26kw to 15kw
Based on experience with the heatpump at my holiday home they work great, but needs to be serviced annually. They don't like standing idle, which requires bi annual services. They are expensive though