Ditching gas, going electric immersion only, a wee project

JKenH

You could run most of the house at a lower temperature and have a wall mounted ASHP to boost the living area. That’s more or less what we do with ASHPs in kitchen and lounge and a convector heater to supplement the bathroom for a few minutes. It means we don’t need the CH on for as long.

1961Nick

Solarchaser said:

I went off on a meandering through the Internet last night and found this type of thing
https://www.ebay.co.uk/itm/234073487501?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=XB6MEzd_Tl6&sssrc=2349624&ssuid=DtbsXk1pRsq&var=533705260790&widget_ver=artemis&media=COPY

A portable gas boiler.
With a bit of fiddling I could put it on an outside wall, with shut off valves connecting it to the radiator circuit, and a gas tank.
For the coldest 3 months it could be on the house, and for the rest of the year stored with the tank in a shed.

I have to not buy it for a week because I'm a terrible impulse buyer for some things.
But if I still fancy it (or similar) in a weeks time, that will be my next plan.

The wife wasn't exactly keen, but the fact it would only be visible when we weren't using the garden at least got me past the straight out refusal of a heat pump.
Progress 😁

Just a couple of considerations..

It's really a hot water heater rather than a boiler so will it work on a closed loop?

How are you going to prevent it from freezing on an outside wall?

Solarchaser

Hi Ken, definitely no heat pumps. Wife says NO.

Nick, yeah that's what I meant by a bit of fiddling, I figure it's likely to have some sort of sensor for water flow, or it's simply a heater regardless of flow.... its cheap.
I figure I'll just insulate the water pipes, the actual burner is unlikely to freeze, and I can't see it having a condensate pipe to freeze.

I'll have a further look into how they work, see if I can find a service manual and that should let me know whether they are able to be fiddled with or not.

born_again

Solarchaser said:

I have to not buy it for a week because I'm a terrible impulse buyer for some things.
But if I still fancy it (or similar) in a weeks time, that will be my next plan.

The wife wasn't exactly keen, but the fact it would only be visible when we weren't using the garden at least got me past the straight out refusal of a heat pump.
Progress 😁

Been watching this thread with interest. What you are doing is way over my head in most cases. So hats off to you 😍
You have highlighted one issue, on the insulation side. Which clearly will help.

This week has not been the norm we have been seeing over the last few years. But what a great test for your system.

So from a Dummies point of view (that's me, btw) why not let it run as is, this winter & see how it pans out. Rather than jumping in and adding permanent extra heat sources, which will add cost & may not show the real results from your base system.
Then come spring next year you will have a very good idea of how the system performed, both heat & cost wise. Then look what idea's have been posted here & how they can improve or not your system in terms of cost effectiveness. Which you seem to have a few of anyway 👍

So if Mrs needs a quick burst of heat, why not a electric heater that you know the running costs on, so you can factor them out. Or another portable heat source for inside, which again you can factor out the costs.

And you never know, Mrs may even relent & go for the Heat Pump come spring 👍

Meatballs

Under MCS heatpumps are sized for the 99% of temperatures, with 1% of days expecting not to meet the full heating demands and requiring additional input. Sizing for that 1% means excessive sizing that cant modulate down as well, and excessive costs etc.

This week has pretty much been the 1% for many households, so having to put on some additional heating isn't a bad thing in the grand scheme of things. 

Solarchaser

born_again said:

Solarchaser said:

I have to not buy it for a week because I'm a terrible impulse buyer for some things.
But if I still fancy it (or similar) in a weeks time, that will be my next plan.

The wife wasn't exactly keen, but the fact it would only be visible when we weren't using the garden at least got me past the straight out refusal of a heat pump.
Progress 😁

Been watching this thread with interest. What you are doing is way over my head in most cases. So hats off to you 😍
You have highlighted one issue, on the insulation side. Which clearly will help.

This week has not been the norm we have been seeing over the last few years. But what a great test for your system.

So from a Dummies point of view (that's me, btw) why not let it run as is, this winter & see how it pans out. Rather than jumping in and adding permanent extra heat sources, which will add cost & may not show the real results from your base system.
Then come spring next year you will have a very good idea of how the system performed, both heat & cost wise. Then look what idea's have been posted here & how they can improve or not your system in terms of cost effectiveness. Which you seem to have a few of anyway 👍

So if Mrs needs a quick burst of heat, why not a electric heater that you know the running costs on, so you can factor them out. Or another portable heat source for inside, which again you can factor out the costs.

And you never know, Mrs may even relent & go for the Heat Pump come spring 👍

You know, I really can't argue with that, it's a very logical response, and i really cant fault it at all 🙌.
As a very logical person, I find this has kind of stopped me in my tracks.
It's funny because other folks have said similar things in the last few pages, and while I've taken them on board, I've still swerved them, but this has hit me head on.

I've felt under pressure this week because I've felt it's not quite keeping up with the demands of the house, and as I've "done" this, I'm putting myself under pressure to resolve it and resolve it quickly.
It's my fault for doing this and I need to resolve it now!

That's the thing though, the pressure is all from me. My good lady pointed out that the reason we have the wee electric fake fire in the livingroom is because the gas central heating could never keep up with the demands of the house, and that was on normal winter days, not the real cold snap we have been in recently, and so actually the tanks are coping better than the GCH has historically.

If I add more on now, I won't know how the system has coped as is.

So yeah, thanks very much for your contribution, it's very much appreciated.

Reed_Richards

Meatballs said:

Under MCS heatpumps are sized for the 99% of temperatures, with 1% of days expecting not to meet the full heating demands and requiring additional input. Sizing for that 1% means excessive sizing that cant modulate down as well, and excessive costs etc.

Actually it's 99.6% of temperatures so only 0.4% of days when the heat pump might be undersized.  That's about 1.5 days a year on average. 

Solarchaser

Received my octopus bill for mid November to mid December and so compared it to last year's bill.
2021 bill was 715kwh
641 off peak and 74 peak at a total of £47
Gas for the same period was 1500kwh @3.6p so £64
So £111 combined

This year its 1940kwh
1700kwh off peak and 240 peak
No gas, so total is £118, so looks like a increase of £7 over last year

However if I was still on gas, the gas bill would have moved from 3.6p to 10.3 so the £64 would now be £154 which would have taken me to £201, and in that respect I've saved £83

A bit of positivity

70sbudgie

As someone else has said, a lot of the detail about how you are doing this has gone over my head, but I have also learned loads, thank you.

I had a conversation with my oh about heating and he explained something that made me think of you and this project. I don't know if it falls into the category of detail that has gone over my head or whether it might be of help?

My oh was explaining to me why radiators have ribs in them - without the ribs, you get laminar flow; the ribs cause turbulence, which leads to better heat transfer out of the water in the radiator.

This made me think of your destratification pump and wonder if that would increase the heat losses from your tank? I've lost track of whether not using it was one of the recent tweaks you made, but if not, could not using the destrat pump be an option to get a few more kWhrs out of your system on colder days? 

Solarchaser

That's interesting,  I was always under the Impression that the ribs and fins were to Increase surface area and so heat transfer and the airflow over them would still remain laminar.

The destrat pump, erm I guess the simplest explanation of why I need to destrat is 2 fold.
1. The tanks are horizontal, not vertical, and so the coils in the tanks are on either side of the almost 2 meter long tank and also run top to bottom, if I have all of the heat coming out of one coil, then one side of the tank gets cool, while the other (to some extent) remains warm, this would lead to no heat transfer to that coil in time and so I'd lose central heating.
The pump circulates the water meaning the whole tank should be at the same temperature. 
The piping for the destratification all has 19mm insulation around it.
At the same time though, yeah I probably do lose a bit of heat through pumping for destratification.

2. I have two tanks, and the central heating only runs through a coil in one tank, and so the destratification pump also brings the heat from the other tank into the main tank to aid with heating, and from the opposite point of view,  the smaller tank heats up much quicker as it has 3/5ths the size of the main tank, but the same 6kw of heating elements, and so during the heating cycle, if I don't pump some of the heat out of the smaller tank, it reaches its max heat and stops the elements after only 2 hours of my 3 hour Heat cycle,  whereas if I pump the water round it pumps some of the heat into the larger tank and allows the elements to keep heating, for this reason, the destratification comes on for 5 mins every half hour of the heating cycle. 

Moving back the the laminar flow point, there was one day during the week where the house was cold, and in particular the livingroom was cold.
The single radiator in there is restricted by the window above it, so I can't really go any bigger.
It also has a couch in front of it, which no doubt restricts the amount of airflow to it.
I've already removed it, cleaned out the little sludge that was in it and fitted insulation foil behind it to reflect the heat better, and so the only thing left really is to force more air through the radiator, and so on that cold day I decided to buy a speedcomfort set :-
https://www.sndelectrical.co.uk/products/speedcomfort-duo-set-standard-radiator?currency=GBP&utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping&gclid=CjwKCAiAkfucBhBBEiwAFjbkr7vZNMQdxyEnoonM2Qw1e721j9V6h_EY7YWUI5K4oBikVWf8Owk4JRoCZpIQAvD_B:-1:

It seems really expensive for a set of fans and a temperature sensor, but it *might* be worth it if it makes a significant difference to the heat up time of the livingroom. 

I'll report back on hopefully the positive difference... I'm skeptical, but hopefully I'm wrong to be skeptical.