Jump to content

Home energy use.


markm
 Share

Recommended Posts

15 minutes ago, Scully said:

I don’t know how old the set up of this couple from France was, but they weren’t that impressed. He said that fortunately in the area they lived in, hard frosts weren’t that common. 
They had no intention of installing similar back here. 

I think you get much as expected in that;

  • Where it is correctly planned - and in a suitable property (i.e. very well insulated and ideally with a large area designed for low temperature heating surface like underfloor, or very 'oversized by boiler standards' radiators), it can work quite well, but is never particularly cheap to run compared to say mains gas simply because electricity is expensive per kilowatt compared to gas - and usually expensive to install.  Long term reliability should be much better now as the technology is relatively 'mature'.
  • However, where (as so often seems to be the case) it is grafted into older properties as sold by smart talking salesmen as a 'environmentally friendly' boiler replacement - it is often a disaster and cannot provide enough heat.

One major problem with retrofitting is that the flow temperature of the heating water is quite low - especially in cold weather.  Unless you have very oversized radiators, it doesn't give out much heat - especially when cold - which is of course when you want it most.

When I redid my heating some years ago (ALL new radiators) I did go oversized (typically replacing singles with double convectors) because the wisdom then was that condensing boilers were more efficient at lower flow temperatures.  I think we went for 60 degrees centigrade rather than the 'normal' 75.  It works well on the condensing gas boiler at a flow of 60 except in the coldest weather when I do have to turn the flow up a bit if you want fast warmth.  But a heat pump in cold weather will struggle to get a flow of 50 centigrade.  The area of radiator needed goes up dramatically as the temperature of the fluid falls below about 60 centigrade.  You need to cover almost all walls with radiators(!) and that means bigger pipes ............. all bad news!

Edited by JohnfromUK
Link to comment
Share on other sites

  • Replies 64
  • Created
  • Last Reply

Top Posters In This Topic

28 minutes ago, JohnfromUK said:

I think you get much as expected in that;

  • Where it is correctly planned - and in a suitable property (i.e. very well insulated and ideally with a large area designed for low temperature heating surface like underfloor, or very 'oversized by boiler standards' radiators), it can work quite well, but is never particularly cheap to run compared to say mains gas simply because electricity is expensive per kilowatt compared to gas - and usually expensive to install.  Long term reliability should be much better now as the technology is relatively 'mature'.
  • However, where (as so often seems to be the case) it is grafted into older properties as sold by smart talking salesmen as a 'environmentally friendly' boiler replacement - it is often a disaster and cannot provide enough heat.

One major problem with retrofitting is that the flow temperature of the heating water is quite low - especially in cold weather.  Unless you have very oversized radiators, it doesn't give out much heat - especially when cold - which is of course when you want it most.

When I redid my heating some years ago (ALL new radiators) I did go oversized (typically replacing singles with double convectors) because the wisdom then was that condensing boilers were more efficient at lower flow temperatures.  I think we went for 60 degrees centigrade rather than the 'normal' 75.  It works well on the condensing gas boiler at a flow of 60 except in the coldest weather when I do have to turn the flow up a bit if you want fast warmth.  But a heat pump in cold weather will struggle to get a flow of 50 centigrade.  The area of radiator needed goes up dramatically as the temperature of the fluid falls below about 60 centigrade.  You need to cover almost all walls with radiators(!) and that means bigger pipes ............. all bad news!

The friend I have who has had it installed to his old bungalow with a new extension, is having all manner of control problems with his. 
He says it often comes on during the night when he doesn’t need it, and finds himself throwing off the duvet as he’s too hot. 
He hasn’t experienced a Winter with it yet. 
I think he fell for the over zealous salesman pitch. I told him to talk to my old boss prior to making a decision, but don’t think he did. 

Link to comment
Share on other sites

41 minutes ago, JohnfromUK said:

When I redid my heating some years ago (ALL new radiators) I did go oversized (typically replacing singles with double convectors) because the wisdom then was that condensing boilers were more efficient at lower flow temperatures.  I think we went for 60 degrees centigrade rather than the 'normal' 75. 

The trouble I have at home is that we are 10mm pipework to the rads from a 22mm flow and return - our rooms (downstairs) have hand plastered coving with a metal stop bead at the bottom and even if we surface mounted the pipes (say 15mm) it would be destructive as anything to get it in. I have thought about going triple in the living room and the hallway but would have to stick with the 10mm

Link to comment
Share on other sites

11 minutes ago, discobob said:

The trouble I have at home is that we are 10mm pipework to the rads from a 22mm flow and return - our rooms (downstairs) have hand plastered coving with a metal stop bead at the bottom and even if we surface mounted the pipes (say 15mm) it would be destructive as anything to get it in. I have thought about going triple in the living room and the hallway but would have to stick with the 10mm

I know when mine was redone (ALL new pipework and rads as some was 50 years old) we used a minimum of 15mm, but quite a lot larger.  I moved virtually all rads to inside walls and away from windows, and almost all are double convectors.  I hate rads under windows where the heat ends up behind the curtains!

For condensing boilers to be properly effective and get condensation, the return temperature to the boiler needs to be (ideally well) below 55 centigrade.  We calculated on flow of 60 centigrade, 25 degrees drop and return of 35 centigrade under normal winter cool days - leaving plenty in reserve for the very cold days (as the boiler can be turned up).  It needs not just the next size of rad, but quite a lot bigger rads.

You might get away with your pipe size by having a high capacity pump?

Link to comment
Share on other sites

@JohnfromUK that would then mean that it would be olloxed on the flow amount though 10mm?? I may try one of these radiator fans - of for the want of dot and dabbed and stud walls (we have one stud wall in the kitchen downstairs) and all pipework is plastered in and behind skirting boards cut into the scratch coat(? or bonding?)

Upstairs we have the problem of 3 tiled floors and 3 rooms with laminate although most of the radiators upstairs are oversized for the rooms (builder bought a job lot I think) - our bedroom is twice the size of other bedrooms at least - and it is the same size radiator in all bar my office which is half the size.

The living room has a job at times - I think that it is down to it being all block and two external walls and it has trouble getting the thermal mass into the room - perhaps hampered by not having the heating on during the day or through the night (that is what good quilts are for :D )

 

Link to comment
Share on other sites

24 minutes ago, discobob said:

that would then mean that it would be olloxed on the flow amount though 10mm??

You would need to talk to a heating engineer for that as it depends on lengths, bends, rad sizes etc.  You can get greater flow from a bigger pump, but whether it would be enough I cannot say.  Parts of my downstairs where either it was a solid floor, or tongued and grooved I didn't want to disturb, we plumbed from above and came down through 'utility' areas (e.g. porch, storeroom etc.)  In an old house there is always a compromise between cost and hidden pipes - we managed to hide most, but not quite all - and I can live with that.  Could you plumb from the loft and come down through cupboards, behind curtains etc?

Link to comment
Share on other sites

23 hours ago, JohnfromUK said:

You would need to talk to a heating engineer for that as it depends on lengths, bends, rad sizes etc.  You can get greater flow from a bigger pump, but whether it would be enough I cannot say.  Parts of my downstairs where either it was a solid floor, or tongued and grooved I didn't want to disturb, we plumbed from above and came down through 'utility' areas (e.g. porch, storeroom etc.)  In an old house there is always a compromise between cost and hidden pipes - we managed to hide most, but not quite all - and I can live with that.  Could you plumb from the loft and come down through cupboards, behind curtains etc?

Not really an option - all routing is done though the void of the floors - with everything going either down or up if you get my meaning - just wouldn't be practical - might as well remodel the whole house

 

Link to comment
Share on other sites

We needed to eliminate condensation from a small house we moved to after ditching our big family home. Some ofthe lessons we learned about souces of moisture dropped our fuel bills as a side effect.

Weigh your kettle and know what its hould weigh for a cuppa or two. 1350 grams in my house and then dont leave a load of hot water in it after you make a cuppa that will fill your house with moisture. typically we were boiling nearly twice what we needed. Better still microwave your cuppa from cold, take abouthalf the energy and nothing over to steam away.

wipe water down off shower walls and screen. Drying anything in the house uses huge amounts of energy which leach from your building, then goes out of the vents. Anything drying in doors is action as a swamp cooler and cooling your house.

Spin everything at 1600 rpm  or higher if you can, peg out washing nearly everyday, if the ground is drying, even a bit so will your clothes. If the basket comes in a kilo lighter thats a litre of water you didn't pay to evaporate.

Washing machines run on cold cycle only, it like a huge kettle belching out steam and all detergents work fine cold.

There prob a few more I cant remember but after a while they became new habits. My d/d  is now under £100.

Cheapy remotes for all the house electrics means everything goes off on one button, no stanbys!

Link to comment
Share on other sites

4 minutes ago, harpoonlouis said:

Better still microwave your cuppa from cold, take abouthalf the energy and nothing over to steam away.

Or get a Breville One Cup  :) no boiling excess water - done this years ago with the wife - the description can still be found on a post of mine somewhere but the basics was - boil the kettle - realise it was just about empty - fill the kettle and boil it - meanwhile phone her mum - on for an hour - boil the kettle - call the sister while waiting - repeat ad infinitum 🤬

4 minutes ago, harpoonlouis said:

Spin everything at 1600 rpm  or higher if you can, peg out washing nearly everyday, if the ground is drying, even a bit so will your clothes. If the basket comes in a kilo lighter thats a litre of water you didn't pay to evaporate.

Tumble dryer is on pain of death and we have no more clothes to wear (or fit in since lockdowns 😁)

4 minutes ago, harpoonlouis said:

Washing machines run on cold cycle only, it like a huge kettle belching out steam and all detergents work fine cold.

You have to be careful with some detergents as they gunk up the tubes etc....

5 minutes ago, harpoonlouis said:

Cheapy remotes for all the house electrics means everything goes off on one button, no stanbys!

Alexa and smart plugs - tempted to do the internet router but that can cause havoc with your line speed.

Link to comment
Share on other sites

18 minutes ago, mossy835 said:

my electric is £40 a month, gas £36 a month,

My Electric is £24.80 this month thanks to my solar .just bought a hot tub to use up my power rather than feeding it back in to the grid🙂

Link to comment
Share on other sites

21 minutes ago, mossy835 said:

my electric is £40 a month, gas £36 a month,

Just a thought, but as a figure in £, this is a bit ambiguous.  We will all be on (wildly at present) different pricing tariffs because may people have a 12 or 24 months fixed price tariff.  Standing charges and 'per unit' charges also vary somewhat both by supplier and regionally.

What I mean by that is we don't know if you are on an old 'fixed' tariff, a new fixed tariff, or a variable tariff. 

For example my current monthly is £106 for both gas and electricity but on a 24v month fixed tariff from May 2021 so MUCH lower than it would be on current tariffs.  IF I was on current tariffs I would expect to be paying about £160 a month, or near £200 on the predicted October tariffs.

I look at mine in KWh where I use

  • 19,500 KWh per 12 months on gas
  • 3,700 KWh per 12 months on electricity
Link to comment
Share on other sites

We had an old fridge freezer that was using 760KWH per year. I’ve ordered a new one that will use 200KWH. 

 

Pay for itself in a year. 
 

Surprisingly a 20 year old small chest freezer uses very little and would take 5 years to pay for itself. 
 

Most important, my beer fridge has cost 5p in the last 24 hours. 
 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...