You pay 35 % of the cost of your hot water heating cost instead of getting it free from the sun is there a choice?

Or was it as well as solar?

Posted By: mikeyb_leedsDoes any one have any idea what proportion of heating one normally spends on heating water vs heating the home?

Some numbers I got from somewhere (sorry, I'm better at noting sources these days):

UK average household annual energy usage:

Space heating: 12 900 kWh
Water heating: 5 700 kWh
Lights, appliances, cooking: 3 000 kWh

So, space heating is roughly twice water heating.

Actually, I wonder about those numbers I just gave. Maybe they're only for electricity usage or something.

Green Building Bible, 3rd edition, Volume I, page 92 says domestic energy consumption is divided as:

Space heating: 78%
Water heating: 11%
Lighting: 4%
Other electrical: 7%

so that puts space heating at seven times water. Quite a range to choose from.

I think I must be quite the most pants contributor on this forum. However, here I go :

- Mitsubishi Electric are organising Ecodan seminars. I was planning on going to the one on 22/9 to see the thing in action but didn't because in the meantime I've 'gone off' Ecodan. You'll be wondering why.

- Ecodan is sold as a packaged (optimised so it all works together) bundle. (I believe) the bundle includes a Gledhill Boilermate and I've seen Gledhill rubbished on this forum.
- There is no bolt on option for solar (see above).
- I'm specifying for France. They are all the rage with French plumbers at the moment (they love them - marketed as Zubadan) particularly with UFH and if you want some element of cooling as well. Cooling would be good for me, but where I'm located, solar is an absolute no brainer.
- The version 'out' at the moment is 9kW. They will launch a 14kW version later in the autumn. My build will require a 14kW version, so when available is an issue for me.
- If I am to go the air source heat pump route, the 'package' that more closely meets my needs is the Daikin Alterma. They have a solar option. Daikin don't actually manufacture the solar panels - just rebadge them but they're chosen to work with their bundle. Unfortunately the solar panels chosen by Daikin are all flat panel and I have my heart set on evac tubes.
- Another issue discussed with the plumber is that in the Ecodan the heat exchanger is in the external condensing unit -> distance away from the house, insulation issues ??? With Daikin, it's inside.

It might be worth your going on one of these seminars? Perhaps report back to the forum what you can glean apart from the hard sell?

Hi everybody,

Thanks for all your comments.

Some more thoughts about the ECODAN.

First Tony’s comment about “free” solar, yes it would be free but solar only supplies about
50% of your hot water year round. If anyone has any better figures for this please let me know.

Doing some simple calculations based on last winters quarter it works out that the
ECODAN would be about £207 more expensive !
This is because a kWh of gas is ~3.21p compared to 16.14p for electric.
I.e. More than 3 times as expensive, and the Ecodan only improves efficiency by 3 times.

The actual figures would be slightly less as my current boiler is inefficient and
I’m adding lots of insulation everywhere (cavity wall etc).

So I think I’m going to stick with solar water.

Here are my calculations, based on today’s rates, just in casee someone spots a simple school boy error !

Energy (kWh) Units £/unit % efficiency Total
Electric 2747 0.1614 £443.37
Gas 23176 0.0321 £743.95
Total £1,87.32

Electric 25923 0.1614 300% £1,394.64

Difference £207.33

Hope this helps anyone else interested.

By the way it looks like a much better deal if you just use electricity but if you use
storage heaters you need to factor in your economy 7 electricity rate.

Mike

A few ideas...

I've been doing my ASHP homework and the ecodan was one of the first I looked at. I like the fact it is pared with a gledhill thermal store but I'm not sure this store is any good... I dont like the heat exchanged being outside. I dont think it uses 410A either... I'm now looking at trianco activair, 12kw for about £2200 and it uses 417A (later version of 410A). I'd couple this to a DPS thermal store.

The latest refrigerant and inverter technology can save up to 70% on running costs so make sure you get both.

Also, air to air heat pumps look like a great idea like the hitachi RAC-35YH5 Inverter Heat Pump System - R410a for about £550 giving 5kw of heat output!

We are in the process of awarding a contract to a company in Leicestershire to fit a central heating system who will utilise 2 Ecodan 14Kw Air Source Heat pumps arranged in parallel to heat our 3 storey Grade 2 Listed 17th c. house in Lincolnshire. At the moment the house is 'heated' by 1940's type storage heaters on economy 7 (the units are the size of single decker buses) and the winter electricity bils are scary as well as we are still cold in the evenings!! There isn't a gas supply in our village nor likely to be! The stone walls, stone and lime ash floors dont allow for much insulation but we wil be looking at a instigating a major Kingspan project in the attics during 2009-2010

My wife is insistent that she retains the aga for cooking and as this also heats the hot water sufficient for us with emmersion heater back up when the hordes descend to visit. So whilst I realise that retaining the oil fired aga is not the most economical way to proceed I will just have to lump the 2 fuel costs unfortunately.

I have been impressed with what I have read on the interwebby about Ecodan and MHI are a huge international cooperation with a decent reputation so I am relatively confident that the product will do what it says on the tin however I am very concerned that the noise levels will cause problems with our tetchy neighbours who complain at the slightest thing (they reported the previous 90 year old lady owner for having a sky dish installed without LBC).

The installer reckons that the units together will produce about 50dcb of noise and they will be fitted in our open to air cart sheds about 25m away from our neighbours. What do you guys think will be noise annoyance factor?

50dB is quite noisy. Windfarms are usually restricted to, in effect, about 40dB. Unfortunately a continuous noise is more annoying to the human ear than the odd random one. Beware, NOTHING, even planning permission, permits you to create a 'nuisance' to neighbours; and continuous noise will receive no sympathy from a judge - the odd much noisier event will be demmed far more acceptable. You are asking for trouble.

A hedge is irrelevant. Noise attenuation is too complex a subject for this post, but essentially you need to site in a heavy masonry chamber with silencers fitted to air intakes /outlets, ande these pointed away from neighbours, to have any chance.

I installed a Mitsibushi Ecodan air source heat pump system last August. I have had a miserable winter.

First the system does work, heat is collected from the outside, even at sub-zero. Noise is not an issue - it is a very acceptable level. However, the good news ends there. It is a new technology and a chose a local installer from those approved by Mitsibushi on a list they supplied. The dealer also featured in their publicity brochure and video. I am a pensioner and have no heating knowledge and had to rely on the installer, particularly with the Mitsibushi recommendation behind him.

I now appreciate how important it is that heat loss calculations are carried out on the property for a retro fit. It has become very clear in hindsight, that this was not done and that the heat pump is under size. My house is well protected with cavity wall, double glazing and well insulated loft, but the installer failed to do the basics, although I gave him all the room sizes when he surveyed the property. The heat runs through the system (assuming a correct size Ecodan) at 55 degrees, instead of around 70 for a oil/gas installation. Therefore, all radiators have to be changed to increase the surface area by about a third.

In addition to an undersized system - the warmest the lounge has got through the winter is 17, on coldest days 14 - the Ecodan comes packaged with a Gledhill tank. This has been nothing but a problem. It is difficult to program times, but more importantly we have had trouble with elements of it, including needing new printed circuit boards and being without any heating or hot water for a week while they were replaced.

My advice, is look very carefully, if it is a retro fit. Check out the installer (I thought I had since Mitsibushi featured them so strongly) and be very careful to look close at the unit which comes with the air pump. This unit drives the whole process and is the 'brains' of the system. Additionally, since it will become a sealed system under mains pressure, you have to be very sure of all joints etc in the existing system – we found this out the hard way!

Despite visits from the installer and Mitsubishi (supposedly their top man on Ecodan/Gledhill) no significant improvements have been achieved – though some tinkering with the system has gone on to very minor effect. My wife and I have suffered chest colds all winter and have been ill, we are now seriously looking at facing the cost of replacing the Ecodan with oil during the summer. We cannot have another winter like the last.