ASHP Recommendations

jamiesw

Hi Guys/Gals,
I am thinking of putting in an ASHP system into my house. I currently use 4x47Kg Bottled Propane LGP, and it is costing a fortune to heat the house.

We live in a 3 Bedroom 2-Storey Semi Detached at the Very North Of Scotland (Near John O' Groats), with Radiators in each room.
Here is some weather stats for my area(Past 3 years):
Coldest Day : -3.9
Lowest Windchill: -12.4

Here is what I was thinking of installing:
Trianco Activair Air Source Heat-pump (5 KW / 18000 Btu) - This will plug into my existing Rads/DHW, however I don't think it will be powerful enough to provide suitable heat/hot water, but should take the chill out of the air in the bedrooms.

[FONT=Verdana,Arial,sans-serif]So in addition I was planning adding:[/FONT]

Mitsubishi Heavy Industrial SCM60-ZG Multi Inverter 3 x 3.5 kW room system.
[FONT=Verdana,Arial,sans-serif]One for the sitting room, one in the lobby/bottom of stairs and one at the top of the stairs.[/FONT]
[FONT=Verdana,Arial,sans-serif]Any Comments\Advice please....[/FONT]
[FONT=Verdana,Arial,sans-serif]Thanks.[/FONT]

anthonykeates

There's a few people using air source heat pumps on the forum, generally the opinion is positive. This particular thread: http://forums.moneysavingexpert.com/showthread.html?t=1310449 is a good one but not the only one.

Those using them have been posting electric usage figures over the recent cold snap, albeit they're down South, and the systems seem to have been coping fairly well with the snowy conditions.

I haven't committed yet to going with ashp but I'm seriously considering it as I don't have gas, so I'm an interested follower of the debate!

albyota

be careful, you must research this technology, you can easily be swept away by the advertising bumph, speak to as many engineers and get loads of advice, know what you want, not led by the shpeel, i have an ASHP works brilliantly with UFH, but temperature is 40 degrees can go to 55 for rads, but you may need to increase sizes a little, do the heat loss calcs, you have to size the heat pump to the building heat load. check how long the warranty is for, where are they made, china or Japan or europe, IMO Japs have it sorted, check the MHI stuff, not bad, but check ambient temps, some systems are -5, some -10, others -15, I spec A/C everyday, and warn people of the underhand tactics by some of the blurb out there, and dismiss some incorrect rumours.... be careful.

Cardew

Most of the people on this forum have simple warm air ASHPs(i.e no radiators or underfloor heating)

As heat pumps catch on, there will be more and more cowboys operating in this field

richardc1983

anthonykeates wrote: »

There's a few people using air source heat pumps on the forum, generally the opinion is positive. This particular thread: http://forums.moneysavingexpert.com/showthread.html?t=1310449 is a good one but not the only one.

Those using them have been posting electric usage figures over the recent cold snap, albeit they're down South, and the systems seem to have been coping fairly well with the snowy conditions.

I haven't committed yet to going with ashp but I'm seriously considering it as I don't have gas, so I'm an interested follower of the debate!

Cardew my electric figures are from the north! Im in Leeds!

albyota

Cardew, I agree there are enough out there already,but, the industry has reformed the way these systems can be purchased, training programmes, accreditation, and closely regulated by local authority building control, you cannot buy these off the shelf, only from authorized installers. there is air to air heat pump which is standard air con and there is air to water air source heat pumps, I have the latter installed, I beleive you thought my post on other threads was to promote a company, this was not intentional, and I did edit them, anyway, I am new to this forum lark, but not new to the industry, electrical or air con, (35 yrs) I do spec this technology, but i am not in sales, and one thing for sure, is, I am fed up with people being ripped off by the energy companies, and not being given the information or choice, thats why I got rid of my oil boiler, which was very efficient but after studying the running costs for the year and being held to ransom with oil prices last august, it was a no brainer to go for the AIR to WATER ASHP, please help, advise people on facts not personal preferences. TA

richardc1983

jamiesw wrote: »

Hi Guys/Gals,
I am thinking of putting in an ASHP system into my house. I currently use 4x47Kg Bottled Propane LGP, and it is costing a fortune to heat the house.

We live in a 3 Bedroom 2-Storey Semi Detached at the Very North Of Scotland (Near John O' Groats), with Radiators in each room.
Here is some weather stats for my area(Past 3 years):
Coldest Day : -3.9
Lowest Windchill: -12.4

Here is what I was thinking of installing:
Trianco Activair Air Source Heat-pump (5 KW / 18000 Btu) - This will plug into my existing Rads/DHW, however I don't think it will be powerful enough to provide suitable heat/hot water, but should take the chill out of the air in the bedrooms.

[FONT=Verdana,Arial,sans-serif]So in addition I was planning adding:[/FONT]

Mitsubishi Heavy Industrial SCM60-ZG Multi Inverter 3 x 3.5 kW room system.
[FONT=Verdana,Arial,sans-serif]One for the sitting room, one in the lobby/bottom of stairs and one at the top of the stairs.[/FONT]
[FONT=Verdana,Arial,sans-serif]Any Comments\Advice please....[/FONT]


[FONT=Verdana,Arial,sans-serif]Thanks.[/FONT]

THe mitsi you mention there will be perfect for you, in fact I would just have the MHI equipment as your main heat source.

Keep the other heat pump just for your hot water.

One thing to note is the hot water heat pump you mention doesnt appear to have inverter. This means it will consume and run at full power even if it doesnt need to.

Whereas the MHI equipment will modulate depending on load and conditions!

Check out the link cardew mentioned. Some very useful posts in there.

richardc1983

I would have one in the lounge, one at the bottom of the stairs, heat should naturally rise upstairs! Then perhaps one in the bedroom.

You may find heat from the unit down stairs will rise to the landing and the unit on the landing will fight the unit down stairs and you may find the unit on the landing thinks its warmer than it is then heat wont get into the bedrooms.

jamiesw

Thanks for the information Richard, think maybe then 2 x 5kw units to provide whole whouse heating. One downstairs one upstairs.
As for heating my hot water what would recommend?
If using an air to water system which make/model?

richardc1983

Depending on size of upstairs you will find that 5kw of heating for upstairs is far too much!

If its a standard sized semi dettached house 3.5kw for each unit more than sufficient. GIve me details on how many rooms upstairs.

In my 2 bed victorian flat which is a house converted, no insualtion and high ceilings etc I have 2 x 3.5 kw units and it heats the whole flat.

I reckon same would be fine for your place my flat is huge and has same floor space as a standard semi.

I would get the 3 x 3.5kw units from MHI. Reason being is that have one installed in your main bedroom and use this if you only want to heat your bedroom or too boost heating when its very cold.

have the 2nd unit downstairs pointing towards your kitchen other rooms downstairs and your 3rd unit in the lounge. This then means warm air rises heating your landing and stairs and eventually getting into the other rooms. You then can use the 3rd unit in your main bedroom also to boost the heating upstairs should it be very cold. Air from downstairs and from your main bedroom will mix and this will inflitrate into the other rooms.

Heres some info about inverters, the same applies across all manufacturers however efficiency levels are different but the operation side of things is the same.

Click here to view more info on heat pumps... its the mitsubishi new zealand/australia site but some interesting articles.

http://www.bdt.co.nz/comfortmaster/support.asp#info

PLease do also read our long ongoing post on here as well

http://forums.moneysavingexpert.com/...html?t=1310449

Some copied and pasted info on inverter technology.

Location:

Indoors:

Don’t locate units with obstructions in front.

Result:


Short cycling of air back to units room sensor making the unit think its wamer than it actually is.
Air is not circulated correctly leaving cold areas in room.

Try to locate the indoor unit where the airflow is pointing to the other areas of the house that may require residual heating.

Outdoors:

Avoid paved areas unless a drain kit is fitted. Result: Units condensate and drip water. May cause slime build up or ice. If no other place please advise customer.


Inverter System or Fixed Speed System?

What is a Fixed Speed Split System?

This system only has a single speed compressor motor that is either on or off.

It works similar to a fan heater that switches off when the desired temperature is reached and on again when the temperature drops to a set level. It speeds up or slows down to calculate the heat loss from the space to be heated ensuring it is only putting in the same ammount of heat that the space is losing.

What does Inverter Mean?

Inverter technology uses a variable speed compressor motor similar to a car. It simply slows down and speeds up as needed to hold a selected comfort setting.

Inverter technology provides a more precise room temperature without the temperature fluctuations of fixed speed systems.

Inverter vs Fixed Speed:

Inverter Systems are Approximately 30% more efficient than fixed speed systems.

Inverter systems reach desired room temperature quicker.

The speed control of the outdoor unit also means quieter operation, this is important especially at night in residential areas.


Inverter Systems

• Increased output to achieve set temperature faster.
• Then varies the output to maintain a constant room temperature.

Fixed Speed Type

• Slowly gets to temperature as output rating is fixed.
• Then turns on and off to maintain room temperature.

samtheman1k

jamiesw wrote: »

Here is what I was thinking of installing:
Trianco Activair Air Source Heat-pump (5 KW / 18000 Btu) - This will plug into my existing Rads/DHW, however I don't think it will be powerful enough to provide suitable heat/hot water, but should take the chill out of the air in the bedrooms.

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!