The Grand Cafe

Sorry. Its an Air Source Heat Pump.

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:+1:

Seems to increase your electricity consumption just looking at the charts.

Yup, but the reduction in gas caused to have much lower bills. Avg. Euro 100 per month less.

I donā€™t understand the graphs, what are they showing?

The left graph is electricity consumption per year (5 year history) and the right graph is gas consumption per year (5 year history).

We got the heatpump last year and the gas consumption dropped from almost 2400 m3/year to 750m3 whilst the electricity consumption went up from 4451kWh to 5664kWh. Winters were similar here.

I must add that we have been very conscious with energy consumption and used our new fireplace too.

All in all a very significant financial result.

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Itā€™s an electric heat pump and you had gas heating before, is that it?

So your electricity went up due to powering the heat pump but your heating costs dropped as a result?

Is it a reversible air conditioning system powered from the grid?
Iā€™m planning to install something to cool my house in the summer and possibly replace the electric heaters for what passes for winter here, which my wife seems to feel more than me. (January can occasionally produce a little frost in the morning but even compared to the south of England I struggle to call it winter). As the highest load on it is likely in the summer months Iā€™m thinking of using solar power for a substantial portion of the energy requirement. The choice for me is between photovoltaic with reversible electric heat pumps or a thermal based system but Iā€™m at the start of looking into the costs and how much weā€™d need.

Off to the big smoke to babysit our fur granddaughter till Sunday night. Gives Mrs Pete the chance to catch up with friends and me a chance to see my mum.

Also gives us a chance to eat out at some of our favourite restaurants. I was hoping my speakers would have arrived but think thatā€™s a few weeks away.

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Sounds like a nice break from the norm.
Cheers.

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DC Ceiling fans are worth considering, when its hot overnight here in Canberra, the fans in our bedrooms make a huge difference and being DC they are almost silent and take 20-50 watts/hr to run. We barely used the aircon at night last summer. Although we have a solar array, the 4 fans halved what was left of our electricity bill. By my calculation one (good) hour of solar runs a fan for over 100 hours. We get a lot of sun here and I imagine you do too so solar makes sense.

We installed an air to air heat pump in our conservatory last winter.

This is basically an air conditioning unit which also heats.

Ours is a 3.5kw model but only uses 850 watts maximum. The newer units are very efficient and once going ours ticks over a 200-300 watts.

We bought it primarily for heating as we realised that the electric convection heater was using too much energy and wouldnā€™t be sustainable with prices rising. One October day we had used 15kw heating the room by just after lunchtime using the 2.5kw convector heater! Thatā€™s more than our full daily consumption for the whole house.

We donā€™t generally use it to cool as itā€™s unnecessary and wasteful but when we have done itā€™s been very effective. They are very quiet too and you can set the fan speed to a quiet mode or leave it to do its own thing.

For your use case these would be ideal. You can get multipoint outside units that can feed several units inside the house.

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The electrician doing my hifi spur said he was fitting a lot of these units and as you say they are getting very efficient.

Iā€™m starting to wish we had had a multipoint outside unit installed so we could have added to it later.

I can see heating our kitchen diner and sitting room during the day with these, I.e. downstairs heat, supplemented using gas central heating to boost and during the evening.

This would also allow cooling in summer for downstairs which would be nice.

Weā€™re having solar panels fitted so this could be a cost effective way of reducing our energy requirements and increasing comfort at the same time.

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We have a large heat pump in our open plan lounge/dining/kitchen that was installed 10 years ago when we did an extension. This year we added two more in our bedroom and our daughters bedroom than run of a single outside pump unit.

The bedroom ones are mainly for air conditioning in summer and we added a solar array this winter, so they should be able to run off the solar. At the moment we run them for heating in the morning - the lounge one for 2 hours and the bedrooms for a quick burst before 7am on the low night rate. This morning that was 4.7kWh of power, half at the night rate and half at the peak rate. Today was quite cloudy and the solar array produced 22kWh and we have consumed 33kWh.

Which is a long winded way of saying that the heat pumps are very efficient.

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I seem to read mixed reports ref. how much ā€˜air sourceā€™ costs to run. Reports on 'tinternet seem to suggest one thing but, elsewhere, I get a different answer. For example, this is from one of the UK heat pump installer web sitesā€¦

At 27p/KWh this Ā£1350pa; god knows what it will be come Oct. Sounds not so cheap to me and certainly not if you add in the huge initial outlay.

The alternative for most people is Gas. Now, thatā€™s cheap :slight_smile:

In my experience most installers advise against a heatpump - because (insert a silly reason here). The reason why I posted my graph above is that they are simply wrong. Heatpumps do work fantastic as long as its not freezing too much.

I had an 11kW heat pump fitted about 4 years ago at home. My house is only electric, no gas or oil, and was entirely heated by electric oil filled individual radiators and in some rooms supplemented a by an electric ā€œbar heaterā€, or a coal fire.

At the time, the calculation was roughly as follows:

Electric radiators are roughly 60% efficient (ie. For every kW of electricity input, they produce 0.6kW of heat)

Air source heat pumps are (at best - depends on ambient outside temp) about 300% efficient.

So, the ASHP is about 5 times more efficient (at best) than the electric radiators.

However, at the time, gas cost was about a quarter per kWh cf. electricity. Also, gas boilers are pretty efficient iirc. The end result being that moving from gas to ASHP at that time was pretty neutral but with a significant up front cost.

Of course, since then the world has moved on and gas/electricity prices have changed significantly and more people are investing in solar to generate their own electricity (whereas not many people are generating their own gas, wellā€¦ you know what I mean).

Since having the ASHP fitted, I have seen a reduction in electricity usage (no graphs though :slightly_frowning_face:). AND - this is the biggest difference - parts of my house are actually warm in the middle of winter!!

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A software update!

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