Octopus Heat Pump

[Bazyle]

On Bazyle Said:

Eeeeek […]

It is quite clear, Bazyle, that you do not realise just how small and interconnected my bungalow is.

That’s no criticism of your suggestions of course.

For the present exercise, however, I did explicitly ask that the house be considered as an unknown constant.

MichaelG.

[Andrew CrowParticipant @andrewcrow91475]

Micheal, I obviously don’t know the exact details of your bungalow, but in general they have a much greater external surface area to internal space compared with a two storey house.

My first checks would be on quality an efficiency of wall and roof insulation ie does your bungalow have cavity wall insulation? Is the roof space of adequate depth, this is easily fixed.

If the walls aren’t insulated that would be my first priority, either cavity fill or install external or internal insulation.

Secondly, if you’re windows have been installed for some years they may not be as efficient as modern double glazing ie breaking down of seals etc, you could always enquire about triple glazing.

My final point would be to look at installing air conditioning which is also used to provide air sourced heating I’m sure it would be cheaper to run than an oil fired boiler.

Andy

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Andy

You analyse the unseen bungalow quite well, but the fact is that I expect it to take at least the next two years to properly insulate it without the risk of condensation.

[ there are many horror stories about such]

Now … although I have ordered the survey by Octopus, I am becoming increasingly convinced that Air-to-Air is my best way forward.

An instantaneous Electric heater should provide adequate hot water to two taps … and is much more compact than the enormous tanks that seem to be required by the Air-to-Water installations.

Air-Conditioning the whole of this little building, as one big room, is now my ambition.

MichaelG.

[Roger HartParticipant @rogerhart88496]

If I understand aright you spend about £2349/year on oil plus some on electricity and live in a smallish bungalow.  I live in a biggish house with a wife who likes to be warm and spend £3372/y on gas&electricity.  My double glazing is a bit old,  the roof is well insulated,  one half the house is older narrow cavity brick the rest modern blockwork and my boiler is pretty old.

I would guess your main problem is the house.  Mucking about with heat pumps (which seem a bit borderline) is not likely to help all that much unless you upgrade the house.  I imagine gas is not an option.

I don’t know about you but I am old and any payback over 5 years is moonshine.  I shall not be doing much.  Asset rich – cash  poor;  and the asset is not looking that great.  Enough cash left for a chipboard box.

And I imagine a great many home owners are in the same boat.  This implies a good number of houses will come on the market over the next decade or so not meeting what seem over-fussy standards.

Which in the absence of many DIY options means builders and doer-uppers will make out like bandits installing whatever they can get past the rules and mortgage inspectors with.  An ill wind etc etc.

 

 

 

 

 

[Roger Hart]

On Roger Hart Said:

[…]

I would guess your main problem is the house.  Mucking about with heat pumps (which seem a bit borderline) is not likely to help all that much unless you upgrade the house.  I imagine gas is not an option.

I don’t know about you but […]

 

 

 

^^^All true, Roger

I am 77 and have severe Heart Failure + crippling  Arthritis in my hands

The story of how I ended-up in this little bungalow is too painful to relate here.

There is much to do, but little I can do … but I have found an excellent contractor to do the hard stuff, and I’m not giving-up yet.

MichaelG.

 

 

[Andrew CrowParticipant @andrewcrow91475]

Michael, you mention condensation, modern window’s are recommended to be fitted with trickle vents to prevent this problem. Another option is a dehumidifier they have the added advantage that in dehumidifying they put some heat into the room and also the condensate can be used in your steam iron or boilers of model locomotives.

Whatever route you go down I’ll wish you the best of luck, anything has got to be better than the cost of oil.

Andy

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, Andy … much appreciated

The condensation-risk that concerns me relates to the eaves of the roof.

The two upstairs ‘bedrooms’ have cupboards [roughly] built into the eaves … These will need to be gutted before I can even assess the scale of the job 🙁

The rooms are all dry at the moment, but badly-installed insulation could easily change that !

MichaelG.

[Andrew CrowParticipant @andrewcrow91475]

I do understand that problem, about 35 years ago I re-tiled my roof which involved installing roofing felt under the roofing laths. Although I installed ducting under the tiles where the bedroom ceilings protrude into the roof space I still had condensation problems in the space above the insulation. I cured the problem by fitting four vent tiles in the roof, it does give a small risk getting a leak as I cut through the felt, not happened yet fortunately. If I had done the roof 10 years later I would have been able to use the more modern breathable  membranes, no problems with condensation with that.

Andy

[BazyleParticipant @bazyle]

A key factor to get concrete figures on from your energy supplier is the night rates and special rates for heat pumps like are available for car charging in the daytime if they have spare wind or solar power they want to sell off. This might give you say 12 hours per day of half price electricty.

Also fid out about the controllability of the heat pump by you rather than always totally automatic and out of your control. The COP of a heat pump is generally taken as 3 for simple calculations. However when used at low power output it can be much better at 6 or more being claimed. This together with a periodic lower tariff might allow you to run lower at the expensive times using the thermal mass of the building to even it out.

A dehumidifier can be a good option to avoid damp in winter as it is a kind of heat pump getting more heat out than energy going in because it condenses water, often quoted as having a COP of 2.

[Michael GilliganParticipant @michaelgilligan61133]

For Bazyle, and anyone else remotely interested:

https://octopus.energy/smart/cosy-octopus/

MichaelG.

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Edit: … and if you are really keen [or bored] … here are all the available smart-tariffs:

https://octopus.energy/smart/

[MacolmParticipant @macolm]

An ordinary dehumidifier has both evaporator and condenser in the same thermal space. It merely removes heat to achieve condensation, then adds the same amount of heat (plus operating energy, see next). If it has a COP at all, it is “one”.

But heat from the electricity used to operate it is indeed added to the output and so provides heating, though the more efficient the dehumidification, the less the additional waste heat output.

[BazyleParticipant @bazyle]

Dehumidifier – not quite. Think of it the other way around. If you had to re-evaporate that water in the dehumidifier tank you would have to provide the latent heat of evaporation so that is what you get by condensing it.

[MacolmParticipant @macolm]

Well yes, provided you keep the water as liquid and prevent re-evaporation, or you pipe the condensate outside. You could always put the condensate in a bucket, freeze it, and discard the block of ice outside. That would add about 14% to the heating effect, provided the freezer is in the same thermal space. You would get about 0.8kWh of heat per litre, assuming none is allowed to leak back.

[Michael GilliganParticipant @michaelgilligan61133]

Window Glass

This is interesting … and is sure to be increasingly relevant as the U.K. weather gets more extreme:

 

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MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

[ UPDATE ]

I have just cancelled the Octopus ‘Survey’ that I had booked for13-October

… it has become self-evident that the paraphernalia associated with their cuddly little ‘Cosy’ Heat-pump cannot be accommodated in my small bungalow.

https://octopus.energy/heat-pump-help/hot-water/

I have now engaged with a local, award-winning, installer … who might have some better proposal.

MichaelG.

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Thanks for the discussion

[Mark RandParticipant @markrand96270]

Most of the installers seem to have a fairly limited ‘script’ that they follow.

Twats installed a 3 bar pressure reducing valve after I explained that I already had one feeding the supply to the HW cylinder they replaced. Also installed two circulation pumps. One of which I had to remove, then turn the output down on the remaining one to achieve the designed flow rate. 😮

 

The point is don’t assume that the installers or specifiers know what the hell they are talking about unless you’ve had full and frank discussions with them, backed up by accurate measurements and verification of the calculations and design. They get the job done in an hour, you live with it for 20 years (if you’re lucky 🙂 )

 

PS:- In case this sounds too negative, we’re still saving a few hundred quid a year on the running costs (compared with a 30yo condensing gas boiler) and wouldn’t have paid much less to get a paid plumber to replace just the boiler.

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for your thoughts, Mark

My initial contact with the local firm was very encouraging

I will report further when I have met their Surveyor.

MichaelG.

[Michael Gilligan]

On Michael Gilligan Said:

[ UPDATE ]

I have just cancelled the Octopus ‘Survey’ that I had booked for13-October

… it has become self-evident that the paraphernalia associated with their cuddly little ‘Cosy’ Heat-pump cannot be accommodated in my small bungalow.

https://octopus.energy/heat-pump-help/hot-water/

I have now engaged with a local, award-winning, installer … who might have some better proposal.

MichaelG.

.

Thanks for the discussion

I didn’t want to say anything but Octopus were a nightmare when we switched to them a while back. They also seem to waste a lot of money on “styling” their products for some strange reason. Some of them look quite ridiculous to me but I guess it’s a matter of taste …

Good luck with your new potential installer. 😉

[duncan webster 1Participant @duncanwebster1]

Octopus is my energy supplier, no problems at all. I also got them to supply and fit my EV charger.  The chap came up with a much better route  for the in house cable than I had thought of, and again I’ve had no problems

[Michael GilliganParticipant @michaelgilligan61133]

Vic … Please always feel free to speak your mind

Duncan … Like you, I am generally happy with Octopus as an energy-provider.

The recent problem is mostly down to incompatibility … Their preferred range of hot water tanks are all too big to fit in the space I could provide.

MichaelG.

[Mark RandParticipant @markrand96270]

We’re with them as well.

They must be doing something right, they’ve gone from starting up in 2015 to being the UKs largest energy supplier…

 

[VicParticipant @vic]

Michael, aesthetically you may have dodged a bullet?! 😮 🤣

I know which one I prefer.

[Mark Rand]

On Mark Rand Said:

We’re with them as well.

They must be doing something right, they’ve gone from starting up in 2015 to being the UKs largest energy supplier…

 

Apart from clever marketing and financial incentives (£50 if you recommend them) there’s also this.

[Michael GilliganParticipant @michaelgilligan61133]

Vic

I have just asked Google a couple of questions 🙂

who was responsible for the styling of the octopusenergy ‘cosy’ heat- pump … We deserve to know ,

followed by

no, I just wanted to identify the culprit !

MichaelG.

 

 

[Adrian R2Participant @adrianr2]

Octopus bought the smaller company who designed it. It might have been OK if they had kept the shiny painted finish.

 

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