ASHP Recommendations

Cardew

samtheman1k wrote: »

I haven't looked at the Trianco brand in over a year, but last time I looked they were only rated to -5degC. In the north of Scotland I would of thought that it regularly dropped to that temperature and below, making the Trianco system useless just when you need it the most. I has been -10degC once already this year here in london, and it is due to be -9degC on Friday. Though if you don't mind using an electric heater once in a while then I'm sure it's ok, and it is a fairly cheap ashp.

I personally went for the Mitsubishi Ecodan (air to water) as it is rated to -20degC so won't be running at full whack for most of the time. I have a house the same size as yours with radiators, and it is sufficient without any extra heating, though is a little be cold maybe when the temperature is below -5degC, but that should be fixed when I put underfloor heating in in the summer!

Check the specs of what you are buying before commiting as, just like boilers, they vary a lot!

Nice to see you back!

Have you got any figures to publish yet?

richardc1983

Dont forget to read my guide to ASHP's.

http://forums.moneysavingexpert.com/showthread.html?t=1464827

Cardew let me know what you think.

paceinternet

As you might expect with a developing technology, not all heat pumps are the same.
There are certainly differences in what temperature is achieved by the type of refridgerant used inside it. Some are more enviromentally friendly, some can achieve higher temperatures, and others will operate at lower external air temperatures.
You may also find they will operate below their minimum specification temperture, but at a lower COP and lower kw output. Air to Water systems often supplement this lower output with an auxilliary electrical heater.

Read the spec of the Trianco carefully, because when I looked at it, more than 6 months ago mind, it was not using the newest refidgerants, and its efficiency wasn't as good as some others. However, it was priced lower, and may be suitable for some aplications.

samtheman1k

Cardew wrote: »

Nice to see you back!

Have you got any figures to publish yet?

Hello Cardew, I don't have the original figures to hand, but seem to remember I have used around 5-6000 kWH since Christmas 2007, around 13 months ago, with the thermostat set at 21degC (in the living room*). That is for all electricity usage, including cooking, lighting, DHW, heating, PS3 etc!

As I mentioned, it is all going well. The biggest problem seems to be the fact that we are out all day, and thus it only comes on an hour before we come home and thus takes a while to heat the house up, though that isn't an ASHP issue. I am going to put UFH in the entire ground floor of the house this summer as having to oversize the radiators does look a bit unsightly. Everyone I've spoken to says UFH is great and ideally suited to ASHP due to the lower temperatures. We're going to use the polyplumb overlay stuff rather than screed stuff for ease as we already have concrete floors.

In terms of the noise, none of the neighbours have complained, not even the fussy fella next door. You simply can't hear it through double glazing. There are new regs coming out imminately I belive where they are going to recommend no ASHP should create a noise level greater than 45dB at any neighbour's window, which shouldn't be a problem really.

On holiday last month in the far East, I saw many air con units that were boxed in really decoratively, almost making them a feature of the garden, so in the summer we're going to try to hide the HP better and also build a fence behind it to deflect the noise away from the house (it is in the garden, not on a wall), all without restricting the airflow of course!

*although that temerature is relative, not absolute as it obviously depends on where the thermostat is located.

jamiesw

Thanks to everyones replies, giving me lots to think about and research..
Samtheman1k, if you don't mind me asking how much was the ecodan?

samtheman1k

jamiesw wrote: »

Thanks to everyones replies, giving me lots to think about and research..
Samtheman1k, if you don't mind me asking how much was the ecodan?

The Ecodan on it's own is about £2.5k and Boilermate (a thermal store and HP control for DHW/CH) which makes installation a doddle is about another £2k on top of that. I bought mine from https://www.segel.co.uk, mainly because he was fairly local to me rather than another other reason.

AKay_2

Hi,

I have been following the discussions on ashp's on this website with great interest over the last few days as I am about to make a decision regarding the Mitsubishi Ecodan ashp and underfloor heating or radiators.

My husband and I are living in central Portugal (believe me it can get cold here in the winter!) and are renovating a small property. We will have solar panels on the roof and we like the sound of the ashp although this is quite an expensive option.

The house has traditional walls in some places up to 60cms thick and where we had to rebuild walls they are properly insulated. There is also good insulation in the roof and under the floors and we will be having double glazed windows and doors installed.

We were not planning to have heating in the kitchen and the living room will have a large woodburner (we have a good source of wood on our land).

When we were living in England we had gfch with thermostatically controlled radiators and this is the only 'kind' of heating we have experience of.

For the house we are renovating, I like the idea of underfloor heating as it is hidden and doesn't take up any wall space. However, I am concerned that it may not provide enough warmth - my husband works from home and sits at a pc most of the day so I would not be pleased if he complained that he still wasn't warm enough after going to the expense of having it installed! :mad:

It seems to be a very subjective area as we have asked various people for their opinions; their responses ranged from "wouldn't touch it, wouldn't be warm enough".....to....."perfect, as long as the pipework is configured properly to avoid cold spots, etc."

An option we were thinking about is to have underfloor heating in the office and bathroom with a convection radiator (hot water type, not electric) in the bedroom. The idea here is that the convection heater could provide cool air in the summer for our south facing bedroom. However, I was then told that with the ashp we should not mix things up, i.e. either go for underfloor or radiators but not both!

All of our floors will be tiled, except maybe for the bedroom which may have a wooden floor (not 100% sure yet). However, I was then told that if we chose underfloor heating in there we can't have a wooden floor? I suppose it makes sense.....

Please excuse my lack of knowledge, but wouldn't underfloor heating under tiles mean it's a more inefficient way to get heat into a room?

Sorry for the long post, but I would be grateful for any advice. Thanks!

samtheman1k

UFH is ideal for ASHPs as the water temperature is lower. UFH and radiators can be mixed, but you must oversize your radiators to cope with the lower water temperature. I think you can have wooden floors, as long as you leave plenty of expansion room at the edges .

AKay_2

samtheman1k wrote: »

UFH is ideal for ASHPs as the water temperature is lower. UFH and radiators can be mixed, but you must oversize your radiators to cope with the lower water temperature. I think you can have wooden floors, as long as you leave plenty of expansion room at the edges .

Thanks Samtheman1k. This may now help us reach some kind of decision!

paceinternet

UFH runs at a lower temperature, maybe 40 deg C, whereas your radiators ideally need higher than that, typically 70 - 80 deg C.
As said above, you can oversize your radiators or make use of the highest temperature the heat pump can deliver, maybe 55 deg C.

Some heat pumps can include a valve which mixes and delivers the water at appropriate temperature to each zone/type of heating.
Alternatively, have a separate heat pump for each zone.