Air source heat pump problems

ProDave

Your EPC certificate if you read the small print, should give an estimate of your annual heating requirement, what does it say?

hayley54321

ProDave said:

Your EPC certificate if you read the small print, should give an estimate of your annual heating requirement, what does it say?

So it says out house is 110m2 and the primary energy indication is 388kwh/M2/year. Later in the report it states that our expected costs would be about £6500 over 3 years- the things is this report was written in 2016,so obviously those costs are hugely different to what they are now.It didn't mean much tonus atm,like idiots in think we barely read it

Ramouth

hayley54321 said:

ProDave said:

hayley54321 said:

So the house had an EPC of E, it's mixed ages, 1850,1980 and the newest double height extension in 2005. We have lots of loft insulation,and double glazed throughout - I'm not sure what else we could reasonably do, especially with little funds. Even with a bad EPC surely we shouldn't be on 50kw per day when someone else in the Highlands uses this much per week ?!The heat is delivered by radiators and a tiny patch of under floor heating in the bathroom. We've tried so hard to get an engineer out,but I think owing to our location,no one will get back to us

EPC E is your problem.  ANY form of heating in that is going to be expensive, even mains gas if it was available.

I have just read my meter again and in the last 4 days since the weather got really cold, my ASHP has used 13kWh per day so that would be 91kWh for a whole week or about £25 per week.

The poor EPC will probably be the construction, probably stone walls with no insulation.

Safe to say we're feeling pretty foolish at this point then, maybe not a lot we could affordably do to get us near a 'normal' level of consumption

In the short term you can look at eliminating draughts where possible and adding loft insulation if it isn’t already maxed out.  Heavy velvet curtains are surprisingly good for helping with old windows and doors.  Decorators caulk can help around window frames, top of skirting etc.  Fitted carpet will help with draughts coming from floors.  

If you really want to get costs down longer term you will really need to consider adding insulation to all external walls and the loft space, replacing windows, sealing ALL gaps and adding mvhr (but only if you can get the air tightness down enough).  

OR get used to being cold - It really dents productivity though as you get warm somewhere then you don’t want to move!

ProDave

hayley54321 said:

ProDave said:

Your EPC certificate if you read the small print, should give an estimate of your annual heating requirement, what does it say?

So it says out house is 110m2 and the primary energy indication is 388kwh/M2/year. Later in the report it states that our expected costs would be about £6500 over 3 years- the things is this report was written in 2016,so obviously those costs are hugely different to what they are now.It didn't mean much tonus atm,like idiots in think we barely read it

So that estimates your usage will be 42680kWh per year (388 * 110)

If that was gas at 11p per kWh that would be £4694
A heat pump with a COP of 3 when heating would consume 14222 kWh of electricity at 33p per kWh = £4694

So at the moment if your heat pump delivers a COP of 3 then the heat pump will cost the same to run as a gas boiler.

EPC's tend not to be very accurate, ours over estimates usage by a factor of 3, so hopefully your actual bills will be lower

I keep on saying this and will say it again in the hope someone reads it.  People seem to buy a house because it looks nice, ignoring the EPC which was there to tell you the estimated energy usage, and then come and complain when they get high bills that they struggle to afford. 

I would personally not buy a property worse than EPC C unless it was a LOT cheaper than a better performing house, to reflect the higher running cost or costs to upgrade it to improve it's performance.

Just by way of comparison what you can achieve, my self build house with EPC A94 has been using 13kWh of electricity per day to heat it in this present cold snap where it has been down to -7 here at night and not above 0 in the day. 

mattyprice4004

Our EPC is 'D' and we live in a 1970s detached 4 bedroom house - currently spending about £15-£20 per day on gas to heat it (new efficient boiler too, replacing the 25 year old boiler fitted at time of EPC). 

The combination of colder weather (I'm in England), the ASHP being less efficient below zero and 'E' rating means you're going to struggle with this - you'll either need to save up and get radical with insulation this summer, or possibly consider moving to a more efficient / smaller house if this level of use is going to be a problem. 

Bills aren't going to go down in the short to medium term, so while it seems impossible you'll need to act now to make sure next winter isn't even worse. 

ThisIsWeird

hayley54321 said:

So the house had an EPC of E, it's mixed ages, 1850,1980 and the newest double height extension in 2005. We have lots of loft insulation,and double glazed throughout - I'm not sure what else we could reasonably do, especially with little funds. Even with a bad EPC surely we shouldn't be on 50kw per day when someone else in the Highlands uses this much per week ?!The heat is delivered by radiators and a tiny patch of under floor heating in the bathroom. We've tried so hard to get an engineer out,but I think owing to our location,no one will get back to us

Is the 'small patch' of underfloor heating in the bathroom 'wet' or wired? Ie, is it driven by the ASHP or completely independent? If the latter, then it'll likely cost the full electrical rate to heat, so won't even benefit from the ASHP.

What rooms are in your new extension? Can you 'live' in this? It will surely be far better insulated than the rest of the house, so much easier to heat up. So, as far as you can, try to stop using as many rooms as possible that are not essential (you've already done this with the sitting room), and have these set to just background heating, enough to prevent it freezing and no more. Close the doors to them, and forget about them until the weather warms up again

If the ASHP is just too blunt a tool to heat individual rooms (I don't know much about them, tbh), then you may be able to use a similar amount of electricity heating up oil-filled radiators, and at least get a couple of 'living' spaces warm enough to be comfy, rather than most of a house being too cold. But you'd need to be able to compare the sums.

Do you have fireplaces? A wood burner? Access to cheap logs?

Perhaps also worth doing research into Biomass - wood chip boilers. Yes, these are costly to buy and install, and require a decent amount of (ideally outside shed) space for the boiler and woodchip storage, but I think they are similar or cheaper than oil to run. Grants may also be available.

Mutton_Geoff

For comparison, I live in a 4 bed open plan modern new build. My ASHP is using 65kwhr per day to heat the house & water. The heating is on 24 hours a day. Cost £12 a day over last 10 days (got a fixed rate of 18p for leccy).

Mrcsmrs

Came here to post something similar and have learnt a few things from your thread so thank you. Can’t help much as we don’t have any answers yet but we’ve had the ASHP stuff down as low as we can and luckily we have an oil fired Rayburn for cooking at one end of the house and a wood burner at the other. That said our usage is still costing us £1000 a month plus. But the place is a barn conversion and has an EPC of D, with no gas and only the electric to heat the water too. We have solar and get about £2300 a year back on that but we’ve still been shocked at just how bad the bills here are. We only moved in 2 years ago so it’s been a steep learning curve.  

Interested to try to work out how we could improve the EPC though. Might have to look into this. 

Mutton_Geoff

welly_59 said:

Same as @Ramouth stated, if there's no heat in the air to be extracted then ashp's are terribly inefficient 

At any temperature above -273C (absolute zero) there is always heat to be extracted. In general though ASHPs are designed to work at temperatures down to about -5C, below which they just become less efficient (ie COP falls).

In most of England, extended periods of sub zero temperatures are not usual even though it has been like this over the last week, it's not something that ASHP designers have planned for.

https://www.viessmann.co.uk/en/heating-advice/heat-pumps/what-temperature-is-a-heat-pump-not-effective.html

Lots of useful ASHP videos on the Freedom channel on You Tube.

https://www.youtube.com/@freedomheatpumps1868

ripplyuk

Are there open fires? Or the possibility of reopening them up? This sounds like an old house with solid, stone walls. IME, in that type of house you need to get those walls warm. Otherwise they will instantly suck out whatever heat you have. Other options like dry-lining are a possibility but these old houses were designed to have open fires in every room and I believe that is still what works best in them. It sounds like you live in a rural area so hopefully there are sources of free wood nearby. 

An electric blanket and an eiderdown on the bed is the cheapest way to stay cozy at night. A vintage eiderdown is best. You can get them on eBay.