Storage Heaters

Air source, ground source and associated systems for heating homes
AGT
Posts: 962
Joined: Sat Jan 29, 2022 11:26 am

Re: Storage Heaters

#431

Post by AGT »

Stinsy wrote: Mon Nov 11, 2024 11:20 am
AE-NMidlands wrote: Mon Nov 11, 2024 10:51 am
Stinsy wrote: Sat Nov 09, 2024 8:07 pm It seems to me that it is best to fit an undersized HP and rely on secondary heating (log burner, resistive electric, etc.) on the very coldest days.
The one thing that leaps out at me is that to use cheap-rate power to charge up a SH you need to anticipate the need a day ahead...
Most people's central heating including mine uses a house thermostat to control the (on/off) output from the boiler, so it's just reactive. The programmable thermostat has significantly different settings for different times of day, but it is still reactive, like (I imagine) lighting a WBS.
And electricity for those of us without an EV is still twice the price of gas. So maybe worth having a HP but hanging onto a gas fire for localised heating in an occupied room at the coldest time of year? (Unless you are planning to remove the gas entirely to avoid the standing charge...)
For many decades the much-quoted downside of SHs has been the fact you need to anticipate the weather. Otherwise you face an unexpectedly cold day with no heat, or have excess heat on days when it is milder than you expected. SHs with decent insulation can hold their heat for several days and use thermostatically-controlled fans (or flaps) to manage the rate that heat is allowed to escape. Some have timer and temperature settings just as sophisticated as the central-heating controls you reference. So this "downside" isn't as dramatic as you might think.

A SH is of no use to someone without a ToU tariff. Until recently these offered exceptionally poor value. However along came Octopus and overnight electric is 7p/kWh compared with 5p/kWh for gas. Given the inherent real-world inefficiency of a gas boiler SHs are now cheaper than gas!
Couldn’t agree more
Richard77
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Joined: Thu Sep 19, 2024 3:26 pm

Re: Storage Heaters

#432

Post by Richard77 »

How do they retain heat for days?

So you turn them on and they don't output heat?

:oops:

Edit.... Bricks?
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Stinsy
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Re: Storage Heaters

#433

Post by Stinsy »

Richard77 wrote: Mon Nov 11, 2024 8:59 pm How do they retain heat for days?

So you turn them on and they don't output heat?

:oops:

Edit.... Bricks?
Insulation
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
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Joeboy
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Location: Inverurie

Re: Storage Heaters

#434

Post by Joeboy »

Richard77 wrote: Mon Nov 11, 2024 8:59 pm How do they retain heat for days?

So you turn them on and they don't output heat?

:oops:

Edit.... Bricks?
Some heaters have a bimetal strip which auto opens and closes the top vent to allow heat to flow out through convection rather than conduction from the storage bricks to the metall carcass. Others have a manual control which opens and closes the flap. A SH with manual control will with the flap fully closed continue to radiate heat through the carcass to effectively heat a room (if sized right). On a 6 hr tou tarrif the SH will not emit all it's heat and will store more heat in each 24hr cycle than it releases. When fully charged they will hold and release heat for a couple of days.

Or they will switch off from grid earlier if you just run them as described. There are differing models, insulation levels, retro insulation etc. I found them to be an astonishingly simple way to extend the benefits of tou and Spring solar charging.

The 800W single bank units are a good way start. Once I remove them from our home I'll install a 800W unit in our son's house as he is going onto IO soon. I might also fit one in the cabin. Hard to simply give up such excellence ✨️
19.7kW PV SE, VI, HM, EN & DW
Ripple 7kW WT & Gen to date 19MWh
42kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
AGT
Posts: 962
Joined: Sat Jan 29, 2022 11:26 am

Re: Storage Heaters

#435

Post by AGT »

Joe, happy to take a couple of the small heaters off you, either come to you , or meet in Dundee when your heading to Edinburgh, don’t need the bricks either so easier to transport or catch up anywhere that suits
Let me know
Just picked one up last night in Strachan that’s some drive, didn’t like that road!
Richard77
Posts: 71
Joined: Thu Sep 19, 2024 3:26 pm

Re: Storage Heaters

#436

Post by Richard77 »

Joeboy wrote: Tue Nov 12, 2024 5:51 am
Richard77 wrote: Mon Nov 11, 2024 8:59 pm How do they retain heat for days?

So you turn them on and they don't output heat?

:oops:

Edit.... Bricks?
Some heaters have a bimetal strip which auto opens and closes the top vent to allow heat to flow out through convection rather than conduction from the storage bricks to the metall carcass. Others have a manual control which opens and closes the flap. A SH with manual control will with the flap fully closed continue to radiate heat through the carcass to effectively heat a room (if sized right). On a 6 hr tou tarrif the SH will not emit all it's heat and will store more heat in each 24hr cycle than it releases. When fully charged they will hold and release heat for a couple of days.

Or they will switch off from grid earlier if you just run them as described. There are differing models, insulation levels, retro insulation etc. I found them to be an astonishingly simple way to extend the benefits of tou and Spring solar charging.

The 800W single bank units are a good way start. Once I remove them from our home I'll install a 800W unit in our son's house as he is going onto IO soon. I might also fit one in the cabin. Hard to simply give up such excellence ✨️
Cheers for the info Joeboy....

You have 95kWh worth of them?
I can only see some 2/3kw max ones.

Is your 95kWh calculated by 7/8 hours worth of small units (~1kw)?

Sounds like magic!

*Searches gumtree/eBay/Facebook marketplace*

Are there any particularly good old models to look out for? Are the new models just as good? I seem to see most people on here getting old second hand ones.
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Stinsy
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Joined: Wed Jun 02, 2021 1:09 pm

Re: Storage Heaters

#437

Post by Stinsy »

SH capacity is usually calculated as the power of the element multiplied by 7hrs (based on ecconomy7).

If you're using them with vanilla Go you'll get 5hrs of capacity. Therefore 1500W * 5hrs = 7.5kWh. Look for "HHR" (High Heat Retention) models. These have better insulation so hold the heat for a few days. Some have electronic timers, which is useful if your house is unoccupied in the daytime. The older ones weren't particularly good at retaining heat, great if your house is occupied all day but you might need an alternative heat source in the evening...
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Richard77
Posts: 71
Joined: Thu Sep 19, 2024 3:26 pm

Re: Storage Heaters

#438

Post by Richard77 »

Stinsy wrote: Tue Nov 12, 2024 8:21 am SH capacity is usually calculated as the power of the element multiplied by 7hrs (based on ecconomy7).

If you're using them with vanilla Go you'll get 5hrs of capacity. Therefore 1500W * 5hrs = 7.5kWh. Look for "HHR" (High Heat Retention) models. These have better insulation so hold the heat for a few days. Some have electronic timers, which is useful if your house is unoccupied in the daytime. The older ones weren't particularly good at retaining heat, great if your house is occupied all day but you might need an alternative heat source in the evening...
Thanks Stinsy....

I might try and pick a few up. The new ones looks quite expensive though, I gather that's why everyone scours the 2nd hand market!

I'll be honest I had never heard of them until this thread. What other wonders of the world am I missing out on living under this rock?!?

We haven't got flying cars and hover boards yet have we? Have we??

:whako-teapot:
AGT
Posts: 962
Joined: Sat Jan 29, 2022 11:26 am

Re: Storage Heaters

#439

Post by AGT »

Watch out for the sizes as we control them via smart sockets so you can program schedules, I have the one and 2 element units only with each element around 850-900 watts so I’m happy switching 1800watts with them.
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Joeboy
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Location: Inverurie

Re: Storage Heaters

#440

Post by Joeboy »

Richard77 wrote: Tue Nov 12, 2024 7:50 am
Joeboy wrote: Tue Nov 12, 2024 5:51 am
Richard77 wrote: Mon Nov 11, 2024 8:59 pm How do they retain heat for days?

So you turn them on and they don't output heat?

:oops:

Edit.... Bricks?
Some heaters have a bimetal strip which auto opens and closes the top vent to allow heat to flow out through convection rather than conduction from the storage bricks to the metall carcass. Others have a manual control which opens and closes the flap. A SH with manual control will with the flap fully closed continue to radiate heat through the carcass to effectively heat a room (if sized right). On a 6 hr tou tarrif the SH will not emit all it's heat and will store more heat in each 24hr cycle than it releases. When fully charged they will hold and release heat for a couple of days.

Or they will switch off from grid earlier if you just run them as described. There are differing models, insulation levels, retro insulation etc. I found them to be an astonishingly simple way to extend the benefits of tou and Spring solar charging.

The 800W single bank units are a good way start. Once I remove them from our home I'll install a 800W unit in our son's house as he is going onto IO soon. I might also fit one in the cabin. Hard to simply give up such excellence ✨️
Cheers for the info Joeboy....

You have 95kWh worth of them?
I can only see some 2/3kw max ones.

Is your 95kWh calculated by 7/8 hours worth of small units (~1kw)?

Sounds like magic!

*Searches gumtree/eBay/Facebook marketplace*

Are there any particularly good old models to look out for? Are the new models just as good? I seem to see most people on here getting old second hand ones.
If I remember correctly it's based on 6hrs charging. Roughly 15.8kW potential charging but I never did charge them all fully at the same time. We had a few properties and anecdotal evidence fathered that shows the older 800W single standing units generally used in bathrooms took a better charge and outputting more heat than newer ones. No idea if it was a design change but we found that twice.
19.7kW PV SE, VI, HM, EN & DW
Ripple 7kW WT & Gen to date 19MWh
42kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
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