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Green Building and Design => Green Construction/DIY => Topic started by: charlieb on January 05, 2021, 06:26:12 PM



Title: Electric Boiler??
Post by: charlieb on January 05, 2021, 06:26:12 PM
We are refurbishing a cottage on the farm.  It's pretty space limited and the architect has defaulted to an 'Electric Boiler' for heating.  (Replacing a back boiler on the fire.)  This isn't a phrase I've heard before, but seems to just be an inline electric heating element.  Basically direct electric heating, which would be about as un-green as it's possible to be.  (Regardless of wind or solar penetration on the grid, the marginal fuel at heating times in the morning/evening will be fossil for a long time to come.) 

Have I missed something?  I'm surprised by this, as the architect seems pretty clued up and environmentally minded.  To be honest I'm surprised electric heating is even allowed these days. 

C



Title: Re: Electric Boiler??
Post by: Countrypaul on January 05, 2021, 11:00:27 PM
How big and how well insulated is the place, what do you expect the occupancy pattern to be?

If it is a small well insulated place only to be used during summer then his suggestion could work out the best. Ask him to explain his suggestion.


Title: Re: Electric Boiler??
Post by: oliver90owner on January 06, 2021, 06:57:16 AM
Are you sure the architect is not referring  to a heat pump system, or is this refurbishment a real cheapo job?


Title: Re: Electric Boiler??
Post by: chasfromnorfolk on January 06, 2021, 08:32:25 AM
To be honest I'm surprised electric heating is even allowed these days. 

May not fit your rather strict definition of green, but what would you have the households relying on night storage, electric underfloor and even, in extremis, bar heating do for warmth?

Chas



Title: Re: Electric Boiler??
Post by: Philip R on January 06, 2021, 09:53:17 AM
Electric boilers are advertised in the plumbing press as being clean and easy to fit.
I went out to one  a while back on the Wirral. The people had moved from an oil heated house to an all electric one with radiators heated by an electric boiler. Only the nearest two rads to the boiler worked and the place was cold.
I balanced up the radiators and cleared some airlocks in the radiator pipework and soon got it working. The lights started flickerring as the heating elements switched in and out due to voltage regulation,
I told the people to rip it out and get an LPG or oil boiler system installed, or having a choice of being warm or poor! They told me they did not like oil because it smells. I told them that if it is sited correctly and maintained, it should not smell other than startup.


Title: Re: Electric Boiler??
Post by: Ted on January 06, 2021, 10:07:13 AM
You can basically get two types of electric 'boiler' heaters for wet central heating systems.

Something akin to an electric shower 'flow' heater in the 5-15kW range. Takes up very little space and is 1 phase. No DHW just heating.  Seen one in a 2-bed bungalow, fitted in the airing cupboard, alongside the immersion tank.

Or something more like a combi boiler, capable of heating a normal house and DHW, up to 15kW on 1 phase but needs 3 phase for anything bigger.


Title: Re: Electric Boiler??
Post by: brackwell on January 06, 2021, 10:56:50 AM
All depends on usage size,rooms,full time/ air BB etc etc.

A inline HW heater used as "just in time" is green enough when compared to other alternatives. However if you are talking CH then what about Storage heaters on TOU night tariff, the grid is green and cheap at that time, or a air/airHP

Are you actually taking the fire out or does the architect think that is your heating.


Title: Re: Electric Boiler??
Post by: charlieb on January 07, 2021, 03:35:59 PM
Thanks all.
The architect has not really done any proper thinking - she acknowledged this.   It's just a default for her becuase they're easy to fit and don't take up much space.  She knows I work in this stuff so we're not going to go with it.  I'll mention to her (nicely!) that as a serious professional she really should be thinking beyond the smallest/simplest solution. 

Now Ted and others have confirmed what they are I think I stand by my statement that an electric boiler doing central heating is about as un-green as it's possible to be Chas. Other ways to heat with electricity:  Heat pumps obviously increase the kwh of heat compared to kwh of electricity;  Storage radiators time-shift to use cheaper electricity, which is also generally much lower carbon; even bar radiators are much more localised and people are very aware of them and only use what's needed; ditto electric underfloor to an extent.    Inline Hot Water has it's uses too, as Brackwell says.  Fossil fuels:   I reckon just about any fossil heating system is also going to be lower carbon than electric boiler CH, though that obviously depends on grid marginal carbon intensity.  Even coal on a backburner would probably be better, as users would rarely aim to keep a house at a steady 20 0+ so wouldn't get all that much use. 

For us we'll look at heat pumps and biomass boilers.  Possibly also woodstovestove with night-storage-radiators. (Thought there's already a wet radiator system, so that would seem a strange step.)   The cottage is being done up for full-time living, so it needs to be a proper system.  We're adding as much insulation as possible but it will still be miles away from a new build, so it will definitely need heat input. 

CHarlie

PS Does anyone know if there's a scheme in Scotland that might support the heating or insulation bit?  I've lost track of green deal, etc, etc. 



Title: Re: Electric Boiler??
Post by: A.L. on January 07, 2021, 04:02:11 PM

PS Does anyone know if there's a scheme in Scotland that might support the heating or insulation bit?  I've lost track of green deal, etc, etc. 


At least try Home Energy Scotland on 0808 808 2282. (Free)


Title: Re: Electric Boiler??
Post by: oliver90owner on January 07, 2021, 05:43:10 PM
I'll mention to her (nicely!) that as a serious professional she really should be thinking beyond the smallest/simplest

How much were you charged for that ‘default’ advice.🙂


Title: Re: Electric Boiler??
Post by: charlieb on January 10, 2021, 06:29:23 PM
I'll mention to her (nicely!) that as a serious professional she really should be thinking beyond the smallest/simplest

How much were you charged for that ‘default’ advice.🙂

Nothing for specific heating advice to be fair. She just added the e boiler when we went to quantity surveyor for  a ballpark quote on the whole project.


Title: Re: Electric Boiler??
Post by: kdmnx on January 11, 2021, 03:26:47 PM
I'd have serious doubts about the architect. How many other ways has she recklessly spent your money? Where else has she gone with quick-and-lazy rather the well-thought-through?


Title: Re: Electric Boiler??
Post by: charlieb on February 24, 2021, 03:34:59 PM
I'm glad to say we've moved on now and will definitely be putting in a heat pump (AS or GS to be confirmed); or just possibly a farm-level biomass system.

Quick question: what is typical cost difference between underfloor heating and over-sized radiators?  We'd be replacing the floors anyway and rewiring, but I'm assuming UFH installation is still going to be dearer than radiators.

Thanks