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NOISE is a big problem.. .

.. .. .. Welcome to the Forums.
Heat pumps (HP) do make a bit of noise and they usually have the dBA (noise Ratings) marked on them.
( Similar to an Air-Cond -- Well, they ARE an Air-Cond of types - They just heat the water not the Air )
MOST - of the normal HP systems are these ones with the mechanics mounted atop the tank.
My opinion - stay away from them.. . The NOISE is then at Window-Height, at fence height etc. etc. right where you or the neighbours, do not want the noise.. If you want to use Off-Peak power, then you need to design for noise abatement.
A HP system with a separate tank and HP will mean greater versatility, and the HP device can be mounted low and away from windows and can be noise-isolated if need be.
Above all - the split system will be more serviceable, as you will not be throwing away the HP when the tank springs a leak.. .
HP - H.W.Systems can also be used to to cool something. In generating the heat for the Hot-Water, it produces Negative Heat ie COLD AIR that can be used to cool a store room or something else.
I cool a kitchen pantry during summer, but that means running it during the hottest part of the day, which is also the most expensive - electricity cost wise. In Autumn and winter, I will heat the HW in the wee-hours, so that I use the Off-Peak rates.. .
It's all a case of . .. . COST/BENEFIT. .. .
garymp wrote:Just wondering what would be better, solar hot water or a heat pump. I live in Qld.
garymp wrote:My roof is facing wsw
Only one roof face???
Clearly the Solar HWS would be better if in Qld. , and with suitable roof space.
Solar energy is generally (semi) FREE, and with electricity going up and up, running cost is highly significant.
A split Solar HWS will need pumps to circulate the heating.
There are ways that you can reduce the final energy cost of a Solar HWS by limiting how you use any boost functions. You can even go to LPG gas booster, as you will likely only need the boost function on a few days a year.
There are a great many threads about your question. Try using the search function for key words.
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PS have a look at...
http://forums.energymatters.com.au/wind-solar-misc/topic190.html?sid=2251048b3f706df1eed70f7dc4fd6ae7.