Starting again with heating

grahamc2003

prunus wrote: »

bobmedley,

What make are the MHI and ME units? Googling those alone brought up a variety of different makes.

I think its Mitsi heavy industries, and mitsi electric - two totally separate compaines so I'm led to beleive. I've also narrowed my search down to mhi 'hyper' (whatever that means) inverter models, purely due to the name and the very high cop, and the mhi variants being cheaper than the me equivalents.

The 'problem' in the uk is the undertainty over the rhi. You can either get them fitted by non registered companies (or diy) and lose the fit and pay 20%vat, or wait till the rhi is finalised, pay a premium for registered compay to supply anf fit (and pay 5% vat) and then get the rhi which, as most green subsidies these days, are likely to be very high (the latest thinking that it'll be about a 12 year payback period, and paid for 18 years or so.

I'll search oput a link to the mhe units and edit it in later.

Here it is (bearing in mind other threads, I'd better say I have no connection with the company in the link).

http://www.aircon-shop.co.uk/Aircon-Shop/Mitsubishi_Heavy_Wall.html

bobmedley

The other OP's are correct - MHI is Mitsubishi Heavy Industries and ME is Mitsubishi Electric. Both have excellent reputations in the air con market.

The ME unit is the M Series MSZ-FD25VA with 2.5kw cooling and 3.2kw heating - I dug out the invoice and it cost £811 inc 17.5% VAT from www.carltonsales.co.uk

The MHI unit is the SRK20ZIX-S - this one cost me around £575 (can't find the invoice), but it has been superseded by the SRK20ZJX-S Hyper-inverter which has a slightly higher output but now costs £621. The COP on this can reach a healthy 5.71 (at my leccy unit cost that would equate to 1.6p/kw of heat under the right conditions). Link here

http://www.orionairsales.co.uk/mitsubishi-heavy-industrial-srk20zjx-s-28-kw--9000-btu-hyper-inverter-air-conditioning-220-p.asp

These are the people I bought my unit from.

The ME units do cost more than MHI but apart from a few non-essential bells & whistles and a little bit more style the performance is pretty much equal so I would recommend MHI to save money.

The killer is installation - they can't be done DIY (that's why I suggested the cheap Italian unit so you could see if air to air is suitable) and I was charged £750 to install them both. I think that was steep & you could probably reduce the cost with some shopping around.

I use them to supplement my oil CH (which now only runs for a few hours per day plus DHW) and even in the recent cold spell they kept the rooms easily up to temperature.

As graham2003c states, you might be able to claim back via the RHI scheme making it all even more cost-effective.

Any more questions, please ask

prunus

bobmedly,

Thanks for the info. I should have been able to figure the answers out for myself, shouldn't I?

I've just read a lot of the stuff at energysavingtrust.org.uk. Very interesting, especially the field trials report on heat pump installation. It basically said that a lot of installations are not up to scratch and only about 13% of them return a COP of 3 or more. This seems to me to introduce an element of chance in to the whole business.....

The other thing that leapt out at me is that the RHI will only apply to renewables that replace fossil fuel burning. An all electric place like ours would not qualify which strikes me as potty. But the RHI won't be completed for a few months so that may change.

I quickly browsed the Wind Turbine section. The Energy Trust says that, if a mast is erected in a suitable position, the installation costs would be recouped in about 6.5 years. This seems to be a fair investment, given the current return on most alternatives. We have a fairly windy site here and I'm going to pursue this possibility - as well as getting a few quotes for ASHP installation.

I hope what I've put is right. I'm slightly groggy with lack of sleep and alcohol. I'll check things again tomorrow.

bobmedley

The EST report is not explicit as to which heat pumps are being reviewed, but reading it it seems certain that they are talking about air and ground to water systems (they mention UFH, radiator sizing & DHW).

Air to air systems are different - whether they are more efficient is a moot point, but their COPs tend to be higher than the air/ground to water systems.

prunus

Yes, I see what you mean, bobmedley. A quote or two should clarify things and I've learnt enough from this forum to ask that the guaranteed cop figures be put on paper.

I've just read the wind turbine trial on the EST site and that subject seems even more iffy over practice meeting the theory. Scotland is the place to live as its the windiest place in country but, unfortunately, I'm a fair way from there.

So it's heat pumps here in Shropshire. I'll let you all know how I get on.

Many, many thanks to all who have posted. You help make this forum great.

grahamc2003

Bob - I see the models you have have 'the magic eye'. In practice do you think it does any good? The blurb implies it can save a bit of cash and make the room more comfortable by ensuring the room is heated more uniformly - what's your view? - is it worth the extra complexity?

Prunus - I've read differing views on whether an all electric house will qualify for the rhi. The engineer I had round to quote for a system (who I thought was excellent, as was his report) thought there's no doubt his proposed system would qualify (in my all electric house, and I specifically asked that question). There's an element of 'he would say that', but in this case, he gained my trust. I think the bottom line is that no one can say for certain yet. I also agree that these are quite new developments for homes (at least the the very high cop models), so there's an element of risk there, and some in other threads seems to be having problems in the extreme weather we've had (nothing which puts me off buying though).

bobmedley

Graham

The ME unit has the 'magic eye' & this is one of the bells and whistles over and above the MHI unit. It appears just to alter the vanes/flaps/fan to send the air around the room uniformly, but you can set that on the remote anyway.

Frankly, I haven't noticed any particular benefit so I personally doubt whether ME is worth several hundred pounds more than MHI - I'm mainly bothered about performance and longevity, and as they are both good brands I hope to get both (touch wood):D

Doug_bea

I've been looking at the MHI SRk20ZJX-S and i've been quoted £535 inc vat for supply only! but i think i can do better! the main dealer for MHI is HRP Just trying to open up a cash account with them unless anyone here has one i could use nudge nudge

bobmedley

That's a cracking price - are they Trade only?

Doug_bea

no, HRP arnt trade only, i've used them before, but i know if you've got a trade account apparently they'll give you upto 60% off list price, so i'm guessing i can get them cheaper still, i've filled out an online cash account request form but there dragging there feet!!!