Storage Heaters

[Stinsy]

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!

[Andy]

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!

It's interesting when you also think of the life time cost of a heat pump. It's almost not worth going for it as the money you save is about the same as the install cost. And with many storage heaters you have a level of redundancy that you don't have with a heat pump. Less to worry about with leaks etc. However, we would't be able to charge them all in the 7 hour window in our house. But for other people it might make more sense.

[Richard77]

Why do I suddenly feel like I need a load of storage heaters even though I haven't got a clue what they are and why I need them!?!

[Joeboy]

As of next week I will have a load of storage heaters for sale. It was an excellent few years with them and if I hadn't jumped the gun into an ashp I'd keep.them. Can do mates rates & delivery in Aberdeenshire. Also a load of hive plugs available too.

[Stinsy]

It's interesting when you also think of the life time cost of a heat pump. It's almost not worth going for it as the money you save is about the same as the install cost. And with many storage heaters you have a level of redundancy that you don't have with a heat pump. Less to worry about with leaks etc. However, we would't be able to charge them all in the 7 hour window in our house. But for other people it might make more sense.

This is an interesting point!

For many years ToU tarifs were seen by energy companies as a place where they could rip off old ladies. The prices were rediculous. Then along came Octopus and cheap off-peak electric was back again.

Certainly, if it is a choice between a HP running on peak-priced (or flat-rate) electric and a SH running on off-peak then there isn't much in it. However if you can power your HP with off-peak electric via a battery then you get double-benefit.

[Andy]

It's interesting when you also think of the life time cost of a heat pump. It's almost not worth going for it as the money you save is about the same as the install cost. And with many storage heaters you have a level of redundancy that you don't have with a heat pump. Less to worry about with leaks etc. However, we would't be able to charge them all in the 7 hour window in our house. But for other people it might make more sense.

This is an interesting point!

For many years ToU tarifs were seen by energy companies as a place where they could rip off old ladies. The prices were rediculous. Then along came Octopus and cheap off-peak electric was back again.

Certainly, if it is a choice between a HP running on peak-priced (or flat-rate) electric and a SH running on off-peak then there isn't much in it. However if you can power your HP with off-peak electric via a battery then you get double-benefit.

You do. But the investment to make it work is significant. But you get gains outside of just the heating so it does work out better.

[Stinsy]

It's interesting when you also think of the life time cost of a heat pump. It's almost not worth going for it as the money you save is about the same as the install cost. And with many storage heaters you have a level of redundancy that you don't have with a heat pump. Less to worry about with leaks etc. However, we would't be able to charge them all in the 7 hour window in our house. But for other people it might make more sense.

This is an interesting point!

For many years ToU tarifs were seen by energy companies as a place where they could rip off old ladies. The prices were rediculous. Then along came Octopus and cheap off-peak electric was back again.

Certainly, if it is a choice between a HP running on peak-priced (or flat-rate) electric and a SH running on off-peak then there isn't much in it. However if you can power your HP with off-peak electric via a battery then you get double-benefit.

You do. But the investment to make it work is significant. But you get gains outside of just the heating so it does work out better.

SHs are sneered upon by almost everyone these days. However they're a simple, reliable, cheap, and efficient way to heat your home!

Sure a HP and battery system will indeed cost less to run. But, as you say, that involves a huge outlay and much complexity.

[Fintray]

I _need_ a 12kw heat pump! At the coldest, it was maxed out at 3.68kW continuously. Not everyone lives in Southern England ;P. We had the 5kW stove on as well.

Respectfully, no normal house “needs” a 12kW HP. If the heat loss calcs come back with that answer, upgrade the insulation and redo the calcs!

As above: there is a decades long tradition of oversizing heating systems ingrained in the trades. Even if they do the calcs accurately they fit the next size up or the one above that. Whereas sizing down is a better idea and augmenting with a secondary heat source in unusually cold conditions.

Two 12kW heat pumps but not a normal house!

[Stinsy]

I _need_ a 12kw heat pump! At the coldest, it was maxed out at 3.68kW continuously. Not everyone lives in Southern England ;P. We had the 5kW stove on as well.

Respectfully, no normal house “needs” a 12kW HP. If the heat loss calcs come back with that answer, upgrade the insulation and redo the calcs!

As above: there is a decades long tradition of oversizing heating systems ingrained in the trades. Even if they do the calcs accurately they fit the next size up or the one above that. Whereas sizing down is a better idea and augmenting with a secondary heat source in unusually cold conditions.

Two 12kW heat pumps but not a normal house!

Sure. I can totally imagine an enourmo mansion with a pool might need 2x 12kW HPs!

Wonder what the DNO had to say about that?

[AGT]

Just picked up another creda6 storage heater tonight
Free uplift was a 2 hr plus round trip but all good