can we change to a combi?

[billy bob]

billybob wrote

as for the 107% efficiencies, all condensing boilers can be calculated to show over 100%, but we know this is rubbish in the UK,

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?.
Yes I know one burns fuel and the other one uses a compression cycle.
But the basic operations of the compression refrigeration cycle are based upon the two heats ,sensible and latent.
So at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

Because that is nonsense, nothing can work beyond 100% of its capability, percentage is out of 100, so it is impossible in the real world to go beyond that.
Condensing boilers are only utilising heat that it has produced that would normally be wasted going out of the flue, it has not magically found energy, so it is only using energy it has produced, just more efficiently, a 30kW boiler cannot produce 35kW of energy, a 30kW boiler could not even produce 31kW so it would be impossible to go over 100%

 

[Doctor Drivel]

Ethos 54C uses 5.6m3/hr gas rate. Anyone who actually installs gas appliances will know the reality of a G4/U6 meter is that you will be VERY lucky to get 6m3/hr flow through it,

Not so, please do some research on metering. They are designed for 100% overload and will pass 12 cu/metres/hr. They make a racket doing it though.

So a U16 would be a must, especially if other appliances are being used simultaneously

Not with just an average gas hob. It designed for that. If a U16 is required, don't they give you that free these days?

 

[Doctor Drivel]

billybob wrote

as for the 107% efficiencies, all condensing boilers can be calculated to show over 100%, but we know this is rubbish in the UK,

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?.
Yes I know one burns fuel and the other one uses a compression cycle.
But the basic operations of the compression refrigeration cycle are based upon the two heats ,sensible and latent.
So at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

Because that is nonsense, nothing can work beyond 100% of its capability,

Please read the threads. In the European tables you go over 100%. 100% ratings is only for sensible heat. Latent heat is not taken into account up to 100%. When latent heat is clawed back then you go over 100%, to approx 109% max. Got it?

 

[Doctor Drivel]

billybob wrote

as for the 107% efficiencies, all condensing boilers can be calculated to show over 100%, but we know this is rubbish in the UK,

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?.
Yes I know one burns fuel and the other one uses a compression cycle.
But the basic operations of the compression refrigeration cycle are based upon the two heats ,sensible and latent.
So at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

Heat pumps efficiencies are not over 100%, OTHERWISE YOU ARE INTO OVER-UNITY. A heat pump moves heat..otherwise we would use them for everything, including generating electricity and moving vehicles.

 

[billy bob]

billybob wrote

as for the 107% efficiencies, all condensing boilers can be calculated to show over 100%, but we know this is rubbish in the UK,

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?.
Yes I know one burns fuel and the other one uses a compression cycle.
But the basic operations of the compression refrigeration cycle are based upon the two heats ,sensible and latent.
So at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

Because that is nonsense, nothing can work beyond 100% of its capability,

Please read the threads. In the European tables you go over 100% 100% is only only for sensible heat. Latent heat is not taken into account up to 100%. When latent heat is clawed back then you go over 100%, to approx 109% max. Got it?

Latent heat is still heat produced by the boiler, so it is not finding extra heat, for a boiler to work over 100% it would have to be producing energy beyond it own max power, if a 30kW boiler uses all of its 30kW energy into the system with no waste that is 100%, to work beyond 100% it would have to be producing more than it maximum of 30kW, the figures are just a marketing idea to make boilers sound more efficient then they actually are, I understand what you are saying about latent heat, but this is still heat that the boiler produced..

 

[Doctor Drivel]

billybob wrote

as for the 107% efficiencies, all condensing boilers can be calculated to show over 100%, but we know this is rubbish in the UK,

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?.
Yes I know one burns fuel and the other one uses a compression cycle.
But the basic operations of the compression refrigeration cycle are based upon the two heats ,sensible and latent.
So at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

Because that is nonsense, nothing can work beyond 100% of its capability,

Please read the threads. In the European tables you go over 100% 100% is only only for sensible heat. Latent heat is not taken into account up to 100%. When latent heat is clawed back then you go over 100%, to approx 109% max. Got it?

Latent heat is still heat produced by the boiler, so it is not finding extra heat, for a boiler to work over 100% it would have to be producing energy beyond it own max power, if a 30kW boiler uses all of its 30kW energy into the system with no waste that is 100%, to work beyond 100% it would have to be producing more than it maximum of 30kW, the figures are just a marketing idea to make boilers sound more efficient then they actually are, I understand what you are saying about latent heat, but this is still heat that the boiler produced..

I can't say it more simply..again,...
"Please read the threads. In the European tables you go over 100%. 100% ratings is only for sensible heat. Latent heat is not taken into account up to 100%. When latent heat is clawed back then you go over 100%, to approx 109% max. Got it?"

Find out the difference between sensible and latent heat.

 

[sooey]

I can't say it more simply..again,...
"Please read the threads. In the European tables you go over 100%. 100% ratings is only for sensible heat. Latent heat is not taken into account up to 100%. When latent heat is clawed back then you go over 100%, to approx 109% max. Got it?"

Find out the difference between sensible and latent heat.

Without trawling through all these pages are you saying that with a condensing boiler you can get more out than you put in?

 

[Balenza]

Doctor Drivel wrote

Heat pumps efficiencies are not over 100%,

Then why is the calculation method similar ?.

Heat pump efficiency is defined as the useful energy delivered, divided by the energy supplied to perform that function.

Isin't this the same basic formula used to define boiler efficiency ?.
Output divided by Input?.

 

[billy bob]

DD, I don't care what some jumped up penpushing suit in Europe says, if you want to be suckered into that nonsense that is up to you, I live in the real world and I know physics, you cannot get more out then you put in, as you put it, sensible heat and latent heat it does not matter, it is still heat that the boiler has produced, the boiler simply uses heat that would normally be wasted, it does not magically find extra heat from no where, so lets not worry about what men in suits claim, lets be real about things.

 

[Softus]

So why can heat pumps operate at efficiencies of up to 300 percent and even higher ?

at the basic level I think the physics are similar.

Why is it impossible for the energy extracted in a condensing boiler from the latent heat not to push the boiler over the 100 percent efficiency thresh hold ?.

 

[Balenza]

billybob wrote

a 30kW boiler cannot produce 35kW of energy

Yes but a heat pump can.
For example, if the equipment has a heating capacity of 20 kW at a COP of 3.0, the power input would be:

20 kW/(3.0 COP) = 6.7 kW

The concept of the appliance COP is mirrored by the energy efficiency ratio, the ratio of the total heat energy dissipated by the heat pump to the total energy supplied to it. Ultimately as in the case of boiler efficiency ,the value of COP that is crucial to the energy use (and cost) and carbon emission of a heat pump is the seasonal COP ,the value that is attained as an average over the whole heating season.
In refrigeration work, the physics of latent heat is especially important.

 

[billy bob]

billybob wrote

a 30kW boiler cannot produce 35kW of energy

Yes but a heat pump can.
For example, if the equipment has a heating capacity of 20 kW at a COP of 3.0, the power input would be:

20 kW/(3.0 COP) = 6.7 kW

The concept of the appliance COP is mirrored by the energy efficiency ratio, the ratio of the total heat energy dissipated by the heat pump to the total energy supplied to it. Ultimately as in the case of boiler efficiency ,the value of COP that is crucial to the energy use (and cost) and carbon emission of a heat pump is the seasonal COP ,the value that is attained as an average over the whole heating season.

But we are not talking about heat pumps, we are talking about gas condensing boilers.

 

[Balenza]

billybob wrote

But we are not talking about heat pumps, we are talking about gas condensing boilers.

I am talking about latent heat and the physics involved links the two in my view.

 

[billy bob]

billybob wrote

But we are not talking about heat pumps, we are talking about gas condensing boilers.

I am talking about latent heat and the physics involved links the two in my view.

Heat pumps work on the priciple that for every 1kW of electricity used to power the heat pump, the heat pump will produce 4kW of heat, the physics are different as the two work in completely different ways

 

[Balenza]

billybob wrote

Heat pumps work on the priciple that for every 1kW of electricity used to power the heat pump, the heat pump will produce 4kW of heat, the physics are different as the two work in completely different ways

I understand that.
As I have already stated I am talking about LATENT HEAT or to use the more modern term " Enthalpy of Transformation".