The cheapest type of electric heating?

[geem]

That's what I call a miracle! Where does the extra 2kw come from?

The extra 2kw comes from what ever the heat source is for the heat pump. If it is an air source heat pump it's coming from the outside air. If it is a water sourced heatpump the heat is being extracted from the water around the boat.

 

[ip485]

I thought most reverse cycles systems rely on pumping water through the heat pump? My units produce a continous stream of water pumped from an intake and returned via the heat pump to the sea many degrees colder than when it left the sea.

 

[Poignard]

The extra 2kw comes from what ever the heat source is for the heat pump. If it is an air source heat pump it's coming from the outside air. If it is a water sourced heatpump the heat is being extracted from the water around the boat.

So, if I understand this correctly, you have a system with 1kw going in and 3kw coming out.

Why not then take 1kw of the 3kw output and feed it back as input to the system?

Then you would have a system producing 2kw for zero input.

Where can I buy one?

 

[RAI]

Why not then take 1kw of the 3kw output and feed it back as input to the system?

Might be possible to make one with a Sterling cycle engine?

 

[sailinglegend420]

That's what I call a miracle! Where does the extra 2kw come from?

Why not then take 1kw of the 3kw output and feed it back as input to the system? Then you would have a system producing 2kw for zero input. Where can I buy one?

If you want to waste people's time then please go to The Lounge or Scuttlebutt!!!!

 

[Poignard]

If you want to waste people's time then please go to The Lounge or Scuttlebutt!!!!

Understand this.

All the YBW forums are accessible to any member of the public who cares to register himself. There are no closed forums to which only members of some exclusive coterie have access.

Subject to the rules, anyone may start a thread on any forum, and respond to the threads of others.

Anyone with a grain of commonsense would see that my previous two posts were intended, in a humorous way, to seek clarification of what seems to me to be a basic flaw in the claims made for heat pumps.

It is not my fault if some humourless, po-faced, self-appointed ‘keeper of the flame’, fails to realise this.

If you don’t like what I write the remedy lies in your hands – disagree with it, disprove it, ridicule it, or don’t read it at all.

If you think what I write is offensive (eg ‘humourless, po-faced’) you are free to complain to the moderators and ask for it to be deleted.

Meanwhile, don't try to tell me what I may or may not do!

 

[maby]

Understand this.

All the YBW forums are accessible to any member of the public who cares to register himself. There are no closed forums to which only members of some exclusive coterie have access.

Subject to the rules, anyone may start a thread on any forum, and respond to the threads of others.

Anyone with a grain of commonsense would see that my previous two posts were intended, in a humorous way, to seek clarification of what seems to me to be a basic flaw in the claims made for heat pumps.

It is not my fault if some humourless, po-faced, self-appointed ‘keeper of the flame’, fails to realise this.

If you don’t like what I write the remedy lies in your hands – disagree with it, disprove it, ridicule it, or don’t read it at all.

If you think what I write is offensive (eg ‘humourless, po-faced’) you are free to complain to the moderators and ask for it to be deleted.

Meanwhile, don't try to tell me what I may or may not do!

OK children, lets play nicely!

as far as the serious question is concerned, the heat pump does appear to give you something for nothing, but that's just because you are not looking at all the inputs and outputs. It is cheaper on energy to move heat around than it is to generate it - 1KWH of energy off the national grid may well be able to put 3kwh into your boat, but only by sucking the missing 2kwh out of the water surrounding your boat. If you expand your boundaries to include the boat and surrounding environment, you will arrive at the zero sum that the conservation of energy tells us to expect. Your boat is ten degrees warmer and the marina is a thousandth of a degree colder. Keep it up long enough and the marina will freeze, the boat will boil and the heat pump will stop because the temperature gradient is too steep for it to climb.

 

[sailinglegend420]

Anyone with a grain of commonsense would see that my previous two posts were intended, in a humorous way, to seek clarification of what seems to me to be a basic flaw in the claims made for heat pumps...

My postings on this subject ALWAYS causes similar reactions from those who are ignorant on the subject, which then forces me - or others - to support my claims. You could so easily have gone to Wikipedia to check out the "facts" before trying to "ridicule" my post.

This is not a "Chat" forum, but a "Technical" forum for those "REALLY" interested in understanding the subject. Why wade through 8,600 of your posts to try and get to the facts?

 

[geem]

OK children, lets play nicely!

as far as the serious question is concerned, the heat pump does appear to give you something for nothing, but that's just because you are not looking at all the inputs and outputs. It is cheaper on energy to move heat around than it is to generate it - 1KWH of energy off the national grid may well be able to put 3kwh into your boat, but only by sucking the missing 2kwh out of the water surrounding your boat. If you expand your boundaries to include the boat and surrounding environment, you will arrive at the zero sum that the conservation of energy tells us to expect. Your boat is ten degrees warmer and the marina is a thousandth of a degree colder. Keep it up long enough and the marina will freeze, the boat will boil and the heat pump will stop because the temperature gradient is too steep for it to climb.

Good description.
For those unfamiliar with heatpumps, remember this is how your fridge works. You are extracting heat from the food you put in the fridge and rejecting it through the condenser coil on the back of the fridge. The process is achieved with an electrically driven compressor I. Much the same way.

 

[Poignard]

Understand this.

Anyone with a grain of commonsense would see that my previous two posts were intended, in a humorous way, to seek clarification of what seems to me to be a basic flaw in the claims made for heat pumps.

It is not my fault if some humourless, po-faced, self-appointed ‘keeper of the flame’, fails to realise this.

My postings on this subject ALWAYS causes similar reactions from those who are ignorant on the subject, which then forces me - or others - to support my claims. You could so easily have gone to Wikipedia to check out the "facts" before trying to "ridicule" my post.

This is not a "Chat" forum, but a "Technical" forum for those "REALLY" interested in understanding the subject. Why wade through 8,600 of your posts to try and get to the facts?

I rest my case

 

[Poignard]

Maby and Geem

Thank you for taking the trouble to explain how heat pumps work. It would be pleasant if everyone was as helpful.

 

[sailorman]

What electric heating is the cheapest to run?
The electricity in the marina is on a card system and it can get a bit expensive when it's really cold.
I have a couple of oil filled radiators at the moment but are they the cheapest type?
Or are the halogen lamp type cheaper or fan heaters? Or????

If you want to waste people's time then please go to The Lounge or Scuttlebutt!!!!

Pls take time to read the Op`s question.
How much does your miracle machine cost to purchase initially

 

[ip485]

Actually you can buy reverse cycle marine a/c units on fleabay from time to time for not fortunes. To be fair there is more cost and time installing them but with the cost of electricity in some marinas you might get close to pay back over five years or so. So its not a great solution if cost is the sole consideration but threads always have a tendency to wander around the subject adding to the interest.

 

[sailinglegend420]

Pls take time to read the Op`s question.
How much does your miracle machine cost to purchase initially

Originally Posted by purplerobbie
What electric heating is the cheapest to run?

That is exactly the question I answered!

For my system see:http://www.dometic.com/enuk/Europe/United-Kingdom/Marine-Equipment/Dometic-Air-Conditioning/

Their link to dealers does not work but I reckon 6 years after I bought mine the price must be £2500 ++. Not cheap, but then neither is an alternative hot air and less powerful Erberspacer diesel driven heating only system - may be about £1500.

The OP doesn't say what his location is or give any info in his profile, but since this is a liveaboard forum he could be in sunny climes and needs Air Con in the summer months also. That begins to make reverse cycle systems attractive. They also have a dehumidifier setting.

 

[Gerry]

Originally Posted by purplerobbie
What electric heating is the cheapest to run?

That is exactly the question I answered!

For my system see:http://www.dometic.com/enuk/Europe/United-Kingdom/Marine-Equipment/Dometic-Air-Conditioning/

Their link to dealers does not work but I reckon 6 years after I bought mine the price must be £2500 ++. Not cheap, but then neither is an alternative hot air and less powerful Erberspacer diesel driven heating only system - may be about £1500.

The OP doesn't say what his location is or give any info in his profile, but since this is a liveaboard forum he could be in sunny climes and needs Air Con in the summer months also. That begins to make reverse cycle systems attractive. They also have a dehumidifier setting.

£2500!!!

My dehumidifier was £129 from Lidls and the fan heater £19.99 from Sainsburys!Last months electricity bill for the boat, which includes everything else too, was £7........................ Even in the colder weather I estimate a maximum of £1 a day.
Think I'll be sticking with my solution.

 

[Marsupial]

We use reverse cycle air con units to heat our apartment in the winter, we get a COP of 3.8 so for every 1 KW we use to run the plant we get 3.8KW out in heated air, that is a good average for an air to air unit operating with feed air above freezing point. For the boat why not try one of these:

http://www.ebay.com.au/itm/Reverse-...umidifier-Heating-10-000BTU-NEW-/221192736301

expect a COP of around 3 for feed air at 0 deg C

COP = Coefficient of performance - (the way heat pumps and air con is rated)