Solar-Heat pump or just the geyser

[topflight]

Please help me out here...

Which one will it be…solar, heat-pump or just the geyser as is?

I have heard all the sales pitches, read all the articles and I cannot find any conclusive proof that one is better than the other nor that any one will definitely save me money.
I belief solar is still too expensive for what you get and that the technology of solar are not 100% there yet. Don’t get me wrong…it is a good product but we are paying a lot for a little.
Next will be the heat pump but there are numerous stories that the thing is noisy and needs a lot of maintenance….and water quality is also a problem.
Just the old geyser well insulated?

This is for a 3 bedroom place…family of 3 to 4.

I would really appreciate feedback from experience.

[Alkemac]

I'm installing solar geysers today and will be able to give you some feedback soon. Also looked into the two different products and opted for the solar geysers, in addition to which the rebates were bigger..

[Bundy]

Gotta rush TF....but I will share my experiences with solar later today....pros and cons to all. Cant advise on heat pumps though.

Will jot down some notes when I get back this afternoon.

[topflight]

Thank you for the reply Bundy...I was hoping to get some feedback from you.

@Alkemac, I would appreciate the feedback as well.

I still have till end of Feb to decide.

[topflight]

I think the right decision become even more crucial now.

http://www.moneyweb.co.za/moneyweb-sout ... ty-tariffs

I will love to take my house of the gird but that would probably cost me at the price of another house.

[Alkemac]

something else I want to look at is the fact that I pay a "connection" fee every month for electricity, and I want to reduce it by the number of days in a month that I dont have electricity...anyone else keen to join ?

[Tumbleweed]

The only saving is if the whole family buys into the consept i.e. shower straight after each other early. Your first 18h00 shower is sun aided after which the thing just costs to heats like a normal geyser and in winter dont expect to wash greasy dishes at lunch time.

For me the timer adds most of the value. We hardly save but a small consulation for a luke warm shower for the first two if the electricity is down.

I only changed because my geyser burst and used the rebate.

[Alkemac]

Progress report

The company installing the solar geyser said that they are going to set the timer to run between 4-5 am and then the sun should do its thing. If it is overcast for more than 3 days, you can then overide this. He reckons he's never had to override in the 6 years that he has had his...(dont know if this is just sales pitch though - time will tell)

[Alkemac]

Solar heating for pools.

Really good idea I heard, was that when you build a pool, lay the inlet pipes around the pool, under the paving, and this will also heat the pool, only problem is there is no off switch for heating...

[Dunesand]

Hope my experience is of some assistance.

I've had a solar geyser for 7 years.
If you buy, make sure it is BIG enough. If you use say a 150l electrical unit usually, then go for a 300L.
Reason for this is during the day you will easily heat up 300l with the sun. When you however start using hot water, the cold water inlet rather quickly takes heat away - the more hot water you have the more cold water you can mix with it.
If possible go for a stainless steel tank - I already had to replace a regular steel tank as result of bad water quality - besides for the fact that it was an indirect system.
The electric override is switched OFF at least 6 months of the year - like switched of 24 hours - and we have enough hot water for household of 4 as well as flat with 2 people but we have lots of sunshine here.
In winter I switch on the element for 2 hours in the morning - the termostat is set at 60 degrees in winter and less than 50 degrees in summer and only get switched on if a clouded day or so.
Worst case scenario I ever had through cold winter or clouded days was element switched on 2 hours in the morning and 1 hour in the evening.

Heat pumps works very well and it is said that they are cheaper than solar even - solar has bigger initial capital outlay but surely over time solar is cheaper.

I also have a small swimming pool with solar panels on the roof - when the pump is running water circulates through the panels - makes a huge difference - big pool get's up to 28 decrees - small pool up to 40 degrees!! - but again only in summer. Important to use a solar blanket as well over the pool.

Hope it helps

[topflight]

@Dunesand, where do you stay?

I stay in Pta and we have a lot of sunny days here, I think we have enough sun for a solar geyser…or I might be wrong.

My first thoughts were also to go for solar but then someone else said that a head pump is better. I then started to investigate the options for both solar and heat-pump, but none gave a conclusive result that made me want to buy one.

I would like to get some views on a heat-pump but there is nobody that I know of that is using one. There seems to be more disadvantage than advantages on heat-pumps.

[Dunesand]

I am in Windhoek.
I am of opinion that if you can heat a huge enough amount of water during the day, if possible something like 400 or 500l, then it would be enough to last until the next day for people to shower in the morning even with any electrical element back-up. Only problem here is if you get a few cloudy days in a row and you then have to heat up that amount of water with a geyser element, then it is going to cost you and that is where a heat pump will save you again.
What I know about heat pumps is that it would use say 2kw to give you the same amount of hot water in the same time or shorter that a geyser will give you with the only difference that a geyser would have used 3.5kw that costs more.

If plenty of sunshine I'd go with a big tank solar, controllable thermostat and definitely a timer as backup.

[HENNING JOHAN]

@Dunesand, where do you stay?

I stay in Pta and we have a lot of sunny days here, I think we have enough sun for a solar geyser…or I might be wrong.

My first thoughts were also to go for solar but then someone else said that a head pump is better. I then started to investigate the options for both solar and heat-pump, but none gave a conclusive result that made me want to buy one.

I would like to get some views on a heat-pump but there is nobody that I know of that is using one. There seems to be more disadvantage than advantages on heat-pumps.

The best is to ask Reuben.He installs heatpumps.Reuben is also on the forum.He stays in Pta.

[Baitbird]

Anyone had a look at these "new" induction type geasers?

Still uses electricity - but so much more effectively ( alledgedly)
And the cost isn't THAT much higher than a normal geaser.

[Bundy]

Hi TF,

Here are my thoughts, I am not an expert but I have Maintained/installed many of these systems in various configurations with one basic thought in mind....the energy from the sun is free, but to maximise it's use, you need VOLUME!

If you buy, make sure it is BIG enough.

100% correct.

The options are vast, so easy to get confused. You must start by asking yourself what you aim to achieve? Do you want to simply reduce your heating cost or do you want to get rid of the need for heating with electricity completely? ("off the grid") Two completely different things.

To get off the grid completely is NOT easy or cheap. You will need at least 300L capacity (based on your family size) and it also depends on your roof structure/sun orientation. I prefer the "Indirect" or "Glycol based geysers (Suntank is the brand I have experience with the most) with either std flat plate collectors or a Vaccume tube collection system. Nothing wrong with a direct circulation system except that I find the exposed pipes/flatplates succeptable to freezing damage in winter...especially up on the Highveld! The Flat plates heat up the water through direct radiation, whereas the vaccum tubes use UV radiation. In bright sunshine, no real difference but in slightly cloudy conditions the Vaccume tubes will still heat the water through UV exposure to a better degree. If you have the space to fit the geysers on top of the roof, then you can use the "thermo syphon" principal to circulate the water/coolant through the panels and geyser. If however you do not have this space/option, then the use of a low voltage solar pump will be required. Thermo syphon is always better...pumps like to fail.
Bottom line.... if you use 150L solar heated geyser you will still need to top up with electricity (usually on a timer set for about an hour in the early morning hours) With a 300L capacity (in Pretoria) you will almost never have to "top up"...but as you can logically think, it is about double the capital outlay. 2 days of overcast and you will be showering cold I promise you.

No real full proof way to get off the grid completely (without massive cost), so I prefer to reduce the cost as much as possible using a technique that was suggested by an engineer (and proven ) I did work for a few years back. He uses the solar geyser as a "pre heater" to his existing geyser located inside the ceiling. The existing geyser (in the ceiling) was put on a Geyser control system, which controls the temperature. It only switches on when the water inside gets to 40 degrees. He took the cold water supply away from the existing geyser and fed that up to the roof where he installed a std 150L geyser "indirect" system with two vaccume tube panel collectors. He then took the hot water outlet on the solar geyser (which would normally go to your taps) and fed that directly into his old geyser's cold water inlet. In effect, what happens is that the solar system on his roof feeds "pre heated" (solar and free) water into his existing geyser everytime he opens a hot water tap. Thus the existing geyser never really has to "turn on" the power unless there has been excessive overcast for a day or two. On a hot day he therefore has 300L capacity... even though he has only purchased one 150L geyser.
This type of installation works very well and you do not even have to have a "geyserwise" management system if you don't want one. Simply switch off the geyser at the DB and if you have a day or two of overcast then you can just manually operate the electricity supply by switching it on for a hour or two just to heat the 150L existing geyser. The advantage of this is that when the day is warm/sunny you will use no power...but should the need arise it is easy to quckly heat up the 150L with Eskom power. In Pta this will be maybe once a month or so? Great way to almost remove your heating cost. You must make sure though that the existing geyser is fitted with a geyser blanket and that all pipes leading to and from roof are well insulated to reduce any heat loss during water transfer between the two!!!

That's the advantage of solar...in this specific example....

Disadvantages to solar heaters....

Aesthetics....they look kak, unsightly (usually) and the birds crap all over them Need regular cleaning too.
Cost: 150L flat plate system...anything between R9000 and R15K (excluding any Eskom rebates)
Very susseptable to Hail/wind damage...we are regularly getting golfballs from the sky these days!
Difference between Summer/winter sun angles (affects heating efficiency)

Those are my thoughts/experience, I hope it helps a bit.

Sorry I cant advise on "Heat pumps" or how they compare.