The energy crisis

[Mr K]

Originally Posted by Mad Max

Your boiler is past it's sell-by date, it's probably costing you money, I know they're pretty expensive to get a new one, but, if you can afford it you will save in the long run.

New boilers break down, old ones keep going.

[Taf]

Originally Posted by Mad Max

Your boiler is past it's sell-by date, it's probably costing you money, I know they're pretty expensive to get a new one, but, if you can afford it you will save in the long run.

The new regs demand boilers run radiators at 50c. For this to work, you may have to have ALL your radiators and pipework upgraded.

That won't be cheap. Our local council is replacing end-of-life condensing combi boilers with the new standard, and are warning tenants that "installation will be very disruptive in most rooms of your home".

[nomadking]

Originally Posted by Taf

The new regs demand boilers run radiators at 50c. For this to work, you may have to have ALL your radiators and pipework upgraded.

That won't be cheap. Our local council is replacing end-of-life condensing combi boilers with the new standard, and are warning tenants that "installation will be very disruptive in most rooms of your home".

With radiators having to be 3 times the size, heat pump systems are not going to be great.

Originally Posted by nomadking

With radiators having to be 3 times the size, heat pump systems are not going to be great.

If you need to triple the size of your radiators for a heat pump installation, then your radiators are inadequate even with a gas boiler. They’re probably very old, not at all efficient and ought to be replaced anyway.

Worst case in a UK home is likely to be a 2.5x increase, but don’t forget that in many cases that can be achieved by using double or triple panelled radiators with convector fins.

[nomadking]

Originally Posted by Chris

If you need to triple the size of your radiators for a heat pump installation, then your radiators are inadequate even with a gas boiler. They’re probably very old, not at all efficient and ought to be replaced anyway.

Worst case in a UK home is likely to be a 2.5x increase, but don’t forget that in many cases that can be achieved by using double or triple panelled radiators with convector fins.

With a heat pump system, the radiators operate at a much lower temp. The tank of water used is lukewarm at best.

[1andrew1]

I just want a decent electric boiler that I can just swap over for my gas boiler and everything else stays as is. Not sure how far off we're at getting something like that?

Originally Posted by nomadking

With a heat pump system, the radiators operate at a much lower temp. The tank of water used is lukewarm at best.

Heat pumps operate better at lower output temperatures. The best balance between temperature and practical radiator size is 50*c. This, as it happens, is the same temperature the latest regulations require gas boilers to be operable at. 50*c is also definitely not lukewarm and is easily hot enough to burn your hands. 50*c is more or less what you’d want coming out of the hot tap in your kitchen.

So if you’re getting a new gas boiler and it’s running at 50*c you’re going to have to match the radiators in the house to the new, lower operating temperature. And that’s the same operating temperature as a heat pump.

All this ‘yeah but no but heat pumps don’t work’ is nonsense anyway. Heat pump usage in Europe is highest in some of the coldest places, including Norway where 60% of homes have one. Heat pumps absolutely do work, they do however require an attitude that heat energy should be conserved, rather than carelessly leaked out of the walls.

The British problem is that we burned coal in our homes for two centuries, and that coal was so cheap we never really had to think about keeping the heat in.

[Sephiroth]

Originally Posted by 1andrew1

I just want a decent electric boiler that I can just swap over for my gas boiler and everything else stays as is. Not sure how far off we're at getting something like that?

Ah - an electric boiler that can put out 35KW as the radiator water passes through! Good luck with that.

I chatted with a local authority housing officer a good few years ago about ‘wet electric’ boilers, which he had had installed in some council houses that were off mains gas. They exist, they work, but they’re expensive to run. Some larger houses require a three-phase supply when they have an electric boiler because the boiler by itself can be drawing as much power as a standard single phase domestic supply could handle. Some premises with a big heat demand but where three-phase power was impractical, had smaller boilers installed which proved to be inadequate. They were removed.

I’ve seen them installed in flats and caravans and in those small situations they work ok. But if you’re going to use electricity to heat a house, these days you really ought to be installing a heat pump. A wet electric boiler will draw 10kW of electricity and deliver slightly less than 10 kW of heat to the house. A heat pump will draw 4kW of electricity and deliver 10kW or more in heat. It’s a no-brainer.

[nomadking]

Originally Posted by Chris

Heat pumps operate better at lower output temperatures. The best balance between temperature and practical radiator size is 50*c. This, as it happens, is the same temperature the latest regulations require gas boilers to be operable at. 50*c is also definitely not lukewarm and is easily hot enough to burn your hands. 50*c is more or less what you’d want coming out of the hot tap in your kitchen.

So if you’re getting a new gas boiler and it’s running at 50*c you’re going to have to match the radiators in the house to the new, lower operating temperature. And that’s the same operating temperature as a heat pump.

All this ‘yeah but no but heat pumps don’t work’ is nonsense anyway. Heat pump usage in Europe is highest in some of the coldest places, including Norway where 60% of homes have one. Heat pumps absolutely do work, they do however require an attitude that heat energy should be conserved, rather than carelessly leaked out of the walls.

The British problem is that we burned coal in our homes for two centuries, and that coal was so cheap we never really had to think about keeping the heat in.

Link

Hot water tank
The heat pump should heat your hot water tank to around 35-40°C. However this is not hot enough to kill any bacteria within the tank. Therefore the tank should be timed to heat up to 60°C once a week - you will notice a corresponding spike in your electricity usage.

37°C is body temperature, ie lukewarm. A person will output more heat than that, mainly by breathing out of warmer air.


The heat pumps that are used in Norway heat the air, not a tank of water.
Link

In the period 1987 – 2020, almost 1.4 million heat pumps were sold in Norway.

• Air-to-air approx. 1.25 million
• Air-to-water over 50,000
• Brine-to-water over 55,000
• Ventilation heat pumps over 20,000

I once lived in a house that had a central heating system that relied on the warm air being distributed to the rooms.

Originally Posted by nomadking

Link

37°C is body temperature, ie lukewarm. A person will output more heat than that, mainly by breathing out of warmer air.


The heat pumps that are used in Norway heat the air, not a tank of water.
Link


I once lived in a house that had a central heating system that relied on the warm air being distributed to the rooms.

You may want to try using sources that aren’t 10 years old. I’m heading out shortly so no time, but suffice to say that modern installations need not provide 40*c at the cylinder. They can reach 50*c with an adequately sized cylinder, or 60*c or higher if you add an additional pump inside the house to convert room heat to hot water.

With a heat pump it’s never about whether it can or can’t ‘do’ something. It almost always can. It’s always about the systems installed to manage heat storage, distribution and retention in the home.

The means by which heat is delivered to houses from Norwegian heat pumps is irrelevant to my point - they work, and they continue to work at far lower external temperatures than most of us experience in the UK. The reason people in the UK think they don’t is because our houses are appallingly badly insulated. That’s why warm air ducted heating was only ever a passing fad in the UK, almost invariably replaced by wet radiators after the system became life-expired. If your house is draughty, full of open flues (or badly sealed ones) and with inadequate wall insulation, then the warm air fed through the system is too quickly lost to the outside.

[nomadking]

Originally Posted by Chris

You may want to try using sources that aren’t 10 years old. I’m heading out shortly so no time, but suffice to say that modern installations need not provide 40*c at the cylinder. They can reach 50*c with an adequately sized cylinder, or 60*c or higher if you add an additional pump inside the house to convert room heat to hot water.

With a heat pump it’s never about whether it can or can’t ‘do’ something. It almost always can. It’s always about the systems installed to manage heat storage, distribution and retention in the home.

The means by which heat is delivered to houses from Norwegian heat pumps is irrelevant to my point - they work, and they continue to work at far lower external temperatures than most of us experience in the UK. The reason people in the UK think they don’t is because our houses are appallingly badly insulated. That’s why warm air ducted heating was only ever a passing fad in the UK, almost invariably replaced by wet radiators after the system became life-expired. If your house is draughty, full of open flues (or badly sealed ones) and with inadequate wall insulation, then the warm air fed through the system is too quickly lost to the outside.

My issues were with the disruption from installing a heat pump system. Larger radiators, larger tank, location of external equipment.

Water temps are irrelevant to the Norwegian air-to-air systems. No water tanks or radiators involved.


This year.

Most air source source heat pumps and ground source heat pumps operate at a maximum flow temperature of 55°C, but in order to be efficient they are much better suited to running at flow temperatures of around 35°C to 45°C.

[Itshim]

My" garage" looks like a NASA control room , between solar panels/ batteries and heat pump , happy to pay engineer to keep it set to optimum , still have combi boiler no idea why he thought to leave it , said it's a backup. Any way house is comfortable , and bill very low , waiting to see is sky rocket when fixed rate dies in may . Would like to move off grid but just love my gas range!

[Taf]

I asked my Norwegian and Swedish friends about heat pumps, and the general answer was that they did their job, but if you get one with a squeaky fan in the neighbourhood, you'll be wearing earplugs until it is sorted. Most civil buildings run on very large heat pumps installations that can take up "several parking spaces" or are installed on rooftops.

Water heating for sinks all tend to be on-demand electric boilers right next to the sink. All washing machines are cold fill and tend to be used at night, and all showers are electric.

[Mad Max]

Originally Posted by Mr K

New boilers break down, old ones keep going.

I can assure you, Mr.K, that old boilers do break down and are inefficient, unless you're talking about her indoors. lol