what's cheapest to run central heating or Dyson am09?

It is pertinent to point out that if you are only heating a room(s) to prevent damp, it is far more effective and economical to use a dehumidifier. That said a dehumidifier works better in warm air so whilst the humidifier itself produces heat, it might be necessary to warm the room on occasion to get rid of more moisture.

If dampness is a problem, it is important to find the source of the problem - even if it is just a ventilation issue. Warming a room simply means the warm air will hold more moisture, it is not a solution. That additional moisture will appear on any cold surface e.g. windows.

http://www.nhs.uk/chq/Pages/How-do-I-get-rid-of-damp-and-mould.aspx

http://www.maintainyourbuilding.org.uk/pages/getting_to_grips_with_damp.html

Cardew wrote: »

It is pertinent to point out that if you are only heating a room(s) to prevent damp, it is far more effective and economical to use a dehumidifier. That said a dehumidifier works better in warm air so whilst the humidifier itself produces heat, it might be necessary to warm the room on occasion to get rid of more moisture.

Just want to jump in and say that desiccant type dehumidifiers are not bothered by cold temperatures like a compressor type is. Compressor types are most efficient between 15c & 30c and performance is poor below 5c. Desiccant models are happy to work from 0c through to 30c without any drop in performance.

The Dyson heater will use 2kW of energy to produce 2kW of heat. There may be times that it uses less energy (dependant on thermostat or whatever) but then it will put out less heat.

It will be 95%+ efficient (5% is for the fan). It will never produce more heat than it uses in electricity.

Your gas boiler, if modern, is 90% or more efficient. You can, if you like, turn all the radiators off except the one in the desired room. It can also never produce more heat than it uses in electricity.

Except that gas is around 1/4 of the price of electricity, so it's way way cheaper to run than your gimmicky fan.

If you want cheap to run, environmentally efficient, etc, get air source heat pump/air con in every room. As this is moving heat, not creating heat, you can gain 4.0kW of heat in a room from less than 1kW of electricity. You can also cool in the summer. So it's effectively 400%+ efficient.

It's probably about the same to run as gas, as gas is so much cheaper, but can be powered from renewable sources.

rtho782 wrote: »

If you want cheap to run, environmentally efficient, etc, get air source heat pump/air con in every room. As this is moving heat, not creating heat, you can gain 4.0kW of heat in a room from less than 1kW of electricity. You can also cool in the summer. So it's effectively 400%+ efficient.

Not always. The outside temperature will greatly affect the COP.

Being realistic, I would expect to see a COP of about 3.5 in good conditions, reducing to 1 in very cold weather.

You would find it difficult to beat gas with ASHP's.