UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

matelodave

Here's another - https://www.daikin.eu/en_us/product-group/air-to-air-heat-pumps/multi.html . A2A systems have a better COP than Air to water, up to a COP of 4 but as Richardc1983 says,always go for mains gas if you can get it especially in older properties unless you are prepared to invest in insulation and the effort to learn how to use a heat pump.

Gerry1

danrv said:

New storage heaters would need E7 wiring installed.

Nope.  Dimplex Quantum can be programmed to run from a 24h circuit: all consumption on E7 is at cheap rate during the relevant period(s).  Just make absolutely sure that they're slaved correctly to the meter's actual hours, and remember that radio teleswitch times can vary by +/- 15 minutes.

Rodders53

danrv said:  Just wondering with air to air ASHP multi split, how many indoor units can run from one outdoor? 

Wouldn’t want too many of these on the house exterior.

Officially, you'll need Planning for more than one outdoor unit (one is usually OK under permitted development).  
RHI incentives are available for air to water systems but not air to air.  Worth doing the sums?
I have air to air to supplement the oil heating (and replace it in autumn/spring) and for cooling in summer.  Not everyone likes the 'fan heater' effect they can give.

richardc1983 said:

if you don't have mains gas and are using oil or electrical resistive heating (fan heaters, convectors etc) then fit some form of heat pump. 

Kerosene oil prices are extremely low at the moment and as cheap, or cheaper, than gas.  Heat pumps are not normally economic replacement for existing kerosene oil installations.

If your talking oil-filled electric radiators... get the terminology right?

richardc1983

Rodders53 said:

richardc1983 said:

if you don't have mains gas and are using oil or electrical resistive heating (fan heaters, convectors etc) then fit some form of heat pump. 

Kerosene oil prices are extremely low at the moment and as cheap, or cheaper, than gas.  Heat pumps are not normally economic replacement for existing kerosene oil installations.

If your talking oil-filled electric radiators... get the terminology right?

My understanding was that oil has only come down in price recently following the Covid situation, at one point last year it was expensive. I don't think I would be replacing an old oil fire system with a new oil fire system given the previous cost of oil. THat being said if oil was cheap at present then I would try keep the oil system running for a bit longer. 

GGSid

I'm looking to replace an oil CH system. When fitting an air to air system: how do you decide how many indoor units to fit? Smaller rooms probably don't need their own units, larger open plan areas can probably all be heated with one unit. 
Do you aggregate the heating requirements into a few bigger units (and leave some doors open) or get lots of smaller units (and have more control and maybe more efficiency?). The equip and install costs will be quite different. Is it just a compromise between more control and more budget? Do I really need 8 units in a four bedroom house, or would two 5Kw units in the communal spaces and leaving the doors open do more or less the same job with less finesse?

Also does anyone have an air to air heat pump that also heats DHW. I see monobloc units exist although I am finding it difficult to even get a price for unit. Looks like Daikin have a tank with built in split unit that could be on a multi-split system... Anyone got one or any advice or knowledge here?

richardc1983

GGSid said:

I'm looking to replace an oil CH system. When fitting an air to air system: how do you decide how many indoor units to fit? Smaller rooms probably don't need their own units, larger open plan areas can probably all be heated with one unit. 
Do you aggregate the heating requirements into a few bigger units (and leave some doors open) or get lots of smaller units (and have more control and maybe more efficiency?). The equip and install costs will be quite different. Is it just a compromise between more control and more budget? Do I really need 8 units in a four bedroom house, or would two 5Kw units in the communal spaces and leaving the doors open do more or less the same job with less finesse?

Also does anyone have an air to air heat pump that also heats DHW. I see monobloc units exist although I am finding it difficult to even get a price for unit. Looks like Daikin have a tank with built in split unit that could be on a multi-split system... Anyone got one or any advice or knowledge here?

For the small cost of the units get units in as many rooms as possible. You can get away with leaving internal doors open to heat hallways/landings but individual rooms will need their own units. If you have a large open plan area then sometimes fitting a unit at each end is better than one big unit dumping heat into one side although depends on the layout as to how the air will flow. 

Fitting ducted units means you can heat the main area and then you could allow a portion of the air from that unit to heat say a bathroom etc but having a multi split system myself I really only allow internal doors to remain open to allow it to heat the hall/landing area with natural overspill. I have ducted units upstairs and down but used to have wall mounted units all work just as well but the ducted units are nicer and not visible apart from the grills. 

LG do an air to water unit and instead of using radiators you can use fan coil units which will also give you the cooling aspect in the summer.. this system will also heat the hot water. 

https://www.lg.com/uk/heating-awhp 

Rodders53

richardc1983 said:

My understanding was that oil has only come down in price recently following the Covid situation, at one point last year it was expensive. 

It was cheap enough last year, albeit significantly cheaper this year. http://www.mychieveley.co.uk/chieveley-oil-club has the historic prices of one place's oil club on the right side.  2012/13 was the expensive years. Early in Covid they couldn't get any bulk orders fulfilled - hence the gap.
https://nottenergy.com/resources/energy-cost-comparison/ while never 100% accurate compares the prices of different fuels.  Double the kerosene price and it's still cheaper than ashp per kWh into the home on their numbers.  Electricity prices do vary of course.

People need to do their own sums for the supply, install and running (inc maintenance) costs for the different forms of heating and make some judgement calls on future fuel prices.  Not forgetting the cost of Planning for multiple heat pump installs.  {Which may be refused in some places?}  But insulate, insulate, insulate more and draught-proof the home first - then whatever fuel is used will be minimised!


EDIT:  Just seen you've spammed the exact  same post on three places here.
Must be against the T & Cs ?... 

GGSid

Rodders53 said:

richardc1983 said:

My understanding was that oil has only come down in price recently following the Covid situation, at one point last year it was expensive. 

It was cheap enough last year, albeit significantly cheaper this year. http://www.mychieveley.co.uk/chieveley-oil-club has the historic prices of one place's oil club on the right side.  2012/13 was the expensive years. Early in Covid they couldn't get any bulk orders fulfilled - hence the gap.
https://nottenergy.com/resources/energy-cost-comparison/ while never 100% accurate compares the prices of different fuels.  Double the kerosene price and it's still cheaper than ashp per kWh into the home on their numbers.  Electricity prices do vary of course.

People need to do their own sums for the supply, install and running (inc maintenance) costs for the different forms of heating and make some judgement calls on future fuel prices.  Not forgetting the cost of Planning for multiple heat pump installs.  {Which may be refused in some places?}  But insulate, insulate, insulate more and draught-proof the home first - then whatever fuel is used will be minimised!


EDIT:  Just seen you've spammed the exact  same post on three places here.
Must be against the T & Cs ?... 

Oil is very cheap at the moment. Even when it's not buying at the right time of year makes a big difference. If it were only about costs oil is cheap, but it's a very carbon intensive solution to heating.  

Edit: And yes for sure insulation is important. 

mrmmhf

This might be of interest regarding the installation of an air source heat pump and new water tank: https://youtu.be/c3V0k_GeFOo

ASHPs are much to run than oil. Granted oil is very, very cheap at the moment.

GGSid

Currently oil is extraordinarily cheap per cost of energy. It's expensive from an environmental point of view, but no one is billing me for the environmental damage my heating does.
I am eliminating oil from my life because that's the right thing to do. I am pretty sure it is going to be expensive since I will first have to install a new heating system. 
Anything that uses (daytime) electricity needs to achieve a COP somewhere >5 to reduce the running costs - Entirely possible, but I don't expect to reduce my running costs a great deal.