ASHP and supplementary heating

elljay

Not sure whether to post this here or in energy threads.  However, we are looking to have an ASHP fitted as we have woefully inadequate heating from multifuel stove and wrap around boiler at the moment.  As I believe an additional source of warmth would be needed especially in the living room on cold nights we had thought to add a nice little woodburner to be cosy and a focal point.  However latest news is that even the most eco stoves are really polluting and can cause illness which we certainly don't want, in our 70s.

So what alternatives are there as supplemental heating?  If the fire is that bad we might as well forget the whole thing and install oil fired central heating which is at least nice and hot.  Rural, no gas.

Can anyone advise or recommend the best thing to do?  Thanks.

JKenH

I can thoroughly recommend a wall mounted air to air heat pump. We have one in our lounge and it does a brilliant job of keeping the room warm at very little cost. It also heats the room up very quickly. We also have one in the kitchen and apart from a few minutes with a convector heater in the morning to warm up the bathroom, they are currently providing all our heating needs. This time of year I tend to leave the lounge one running all day and switch it on at 2am to make use of our cheap overnight electricity tariff. We don’t have gas either. My wife loves it and thinks it’s the best money we ever spent.

Have a look at this thread to get an idea of the costs of running an ASHP. 

https://forums.moneysavingexpert.com/discussion/4715287/discussion-ashp-air-air-with-solar-pv/p33

ABrass

elljay said:

Not sure whether to post this here or in energy threads.  However, we are looking to have an ASHP fitted as we have woefully inadequate heating from multifuel stove and wrap around boiler at the moment.  As I believe an additional source of warmth would be needed especially in the living room on cold nights we had thought to add a nice little woodburner to be cosy and a focal point.  However latest news is that even the most eco stoves are really polluting and can cause illness which we certainly don't want, in our 70s.

So what alternatives are there as supplemental heating?  If the fire is that bad we might as well forget the whole thing and install oil fired central heating which is at least nice and hot.  Rural, no gas.

Can anyone advise or recommend the best thing to do?  Thanks.

Why would the living   (edit  ) room be cold? That's a sign you've undersized the system.

Petriix

ABrass said:

elljay said:

Not sure whether to post this here or in energy threads.  However, we are looking to have an ASHP fitted as we have woefully inadequate heating from multifuel stove and wrap around boiler at the moment.  As I believe an additional source of warmth would be needed especially in the living room on cold nights we had thought to add a nice little woodburner to be cosy and a focal point.  However latest news is that even the most eco stoves are really polluting and can cause illness which we certainly don't want, in our 70s.

So what alternatives are there as supplemental heating?  If the fire is that bad we might as well forget the whole thing and install oil fired central heating which is at least nice and hot.  Rural, no gas.

Can anyone advise or recommend the best thing to do?  Thanks.

Why would the loving room be cold? That's a sign you've undersized the system.

It's always hot in my loving room, but that's a different story!

elljay

Thank you for all the information.  Not sure why it would be cold in the living room but from what I've read, an extra heating source would be needed at times, particularly when sitting quietly in the evening, .  Our living room is actually kitchen/diner/living room with currently 2 radiators (one large, one small) and the multifuel stove. So pretty much all of downstairs. Smallish barn conversion.  Definitely not warm enough.

We haven't got as far as having a survey etc done yet, just looking at option combinations though we're pretty sure we want the ASHP.  I would also have liked a nice little log burner for cosiness and focal point, but the latest environmental report has rather put me off.

Thanks again.

Meatballs

Your ASHP should meet the heat demand for the building or you won't get the full RHI payment. As the ASHP is basically run 24/7 the house should be pleasantly warm as the fabric of the building should all be up at a fairly consistent temperature rather than the hot/cold cycles most people use with their gas boilers.

If the room is too cold you want to look at fabric improvements/insulation first before heat source - identifying and blocking any air-leaks can make a big difference to comfort levels (although I guess you need to have an airbrick or something for the stove?)

If the radiators are too small then the installer should be fitting much, much larger radiators than the existing ones. If they are offering to fit an ASHP without changing any of the radiators and pipework I would walk away. There may be some cases where you radiators are big enough but if you say the room is cold I doubt it.

The wood burner stories at the moment are a bit overblown, but they do all contribute to local air pollution. They do actually cause a good airflow into the room they are in. I would also consider as you get older how long you will be wanting to chop, stack and haul in wood from storage rather than just relaxing in your retirement. 

Personally if the room just needed a small boost for comfort after the ASHP is put in, and I had done everything I could including increasing radiator sizes/pipework/insulation, I would maybe consider an infrared heater for the comfort levels - but not something to run for long periods of time. 

Reed_Richards

Meatballs said:

Your ASHP should meet the heat demand for the building or you won't get the full RHI payment. As the ASHP is basically run 24/7 .....

Not mine, it goes off at 22:30 and comes back on at 07:00.  That said, it is set to come on overnight should the house get too cold and in the depths of winter the heating control is set to achieve the desired temperature by 07:00 so it comes on earlier.  If you have an ASHP with radiators, as I do, you can operate it like a normal boiler.  ASHPs are often paired with underfloor heating and it's the underfloor heating that needs to be run 24/7, whatever your heat source.  

Meatballs

Reed_Richards said:

Meatballs said:

Your ASHP should meet the heat demand for the building or you won't get the full RHI payment. As the ASHP is basically run 24/7 .....

Not mine, it goes off at 22:30 and comes back on at 07:00.  That said, it is set to come on overnight should the house get too cold and in the depths of winter the heating control is set to achieve the desired temperature by 07:00 so it comes on earlier.  If you have an ASHP with radiators, as I do, you can operate it like a normal boiler.  ASHPs are often paired with underfloor heating and it's the underfloor heating that needs to be run 24/7, whatever your heat source.  

Normal recommendation is to setback the temperature in the evening 2-3 degrees and not to run it like a gas boiler at all regardless of rads/UFH. The lower design flow temperatures would take a long time to restore a big temperature drop, and if the HP has to run hotter this can decrease its efficiency and potentially increase energy use compared to just leaving it gently topping up the heat overnight.

However every install/house will be different, different flow temps, different insulation, different sized emitters, different lifestyles so a bit of experimentation to work out whats best in individual scenarios is good. It sounds like your house probably doesn't even drop those 2-3 degrees in the evenings anyway and if it does have a smart program to come on early to reach temperature by 7am with its normal low temperatures its probably not any different in practice.

You are also more likely to have a cheap evening electricity tariff if you move to something like Octopus Go, which you would likely plan your DHW heating around.  This could also skew the approach to keeping it going overnight on the money saving side of things.

Hexane

There might be some confusion in this thread?

1. the OP (elljay) is talking about considering an ASHP because of the issues with their current heating installation. Not talking about already having an ASHP and finding that the rooms aren't warm enough.

2. JKenH is talking about the benefits of air to air heat pumps in specific rooms (some people call these "air conditioning units"), not connected to any radiators, not connected to any underfloor heating, not used for domestic hot water heating. A setup like this might meet the OP's needs, i.e. increasing heating capability in particular room or rooms at low cost.

3. Meatballs and Reed_Richards are talking about RHI-approved ASHP systems where the system meets heating and hot water needs throughout the house, with the ASHP connected to radiators or underfloor heating or both plus the hot water. This can attract grants or subsidies, and might be considered a more environmentally friendly whole-house solution, but is also much more costly and disruptive. (Ten years or so down the line, we might all end up having to have systems like this, but not right now...)

I might have misunderstood who is asking or suggesting what!

shinytop

elljay said:

Thank you for all the information.  Not sure why it would be cold in the living room but from what I've read, an extra heating source would be needed at times, particularly when sitting quietly in the evening, .  Our living room is actually kitchen/diner/living room with currently 2 radiators (one large, one small) and the multifuel stove. So pretty much all of downstairs. Smallish barn conversion.  Definitely not warm enough.

We haven't got as far as having a survey etc done yet, just looking at option combinations though we're pretty sure we want the ASHP.  I would also have liked a nice little log burner for cosiness and focal point, but the latest environmental report has rather put me off.

Thanks again.

It sounds like your current set up was always going to struggle.  2 radiators and a wood burner for the whole downstairs doesn't sound enough, even very hot ones.  We had 4 storage heaters plus a wood burner in the same sort of area (accepted I don't know the size of heat loss of your house).  

If you get an ASHP expect to have more and bigger rads.  We now have  three in the living/dining room, one in the hall and one in the kitchen.  All medium-ish sized double thickness.  The ASHP heats the space nicely with these at 35-40 degrees. We also have a wood burner and a coal stove for extra heat if needed and, as you want, a feature/focal point. 

There is nothing wrong with a modern, well installed wood burner using well seasoned wood.

Heedtheadvice

^^^ yes a form of biomass