by ericmark »
Sat Jan 30, 2021 3:00 pm
Gas it far cheaper to run than electric, so is oil, been rather surprised on moving on price paid for oil, lot cheaper than expected, however electric can be over 100% efficient when using heat pumps, gas around the 95% and oil around 85% so much also depends on installation cost and control.
Oil boilers are more expensive than gas, so it would seem gas is the way to go, but the % efficiency depends on the install. I know nothing about use of heat pumps for heating, but not cheap.
As for gas the modern boiler gains the latent heat from flue gases, to do that it has to modulate (turn flame up/down) and keep the return water under a critical temperature, this means the radiators today are larger, as they do not get as hot, and also the boiler is likely sized at under half the output of radiators to keep the minimum output low.
So using electronic TRV heads you can program when each room is heated, and you can have geofencing (it works out where your family is from position of mobile phone and turns the heating on as you drive home) and a sequence of heating so rooms used first are heated first.
However you have to look at the installation cost, my brother-in-law had a multi-fuel system using solar panels, log burners, electric and LPG gas which one looked at and said what a good idea, and he did say his heating costs were very low.
However £20k takes a lot of getting back. I was fitted when he bought the house so on the mortgage, but my central heating fuel bill around £300 a year, so if that was halved then over 130 years to pay for its self, and with interest on the money likely will never pay for its self.
OK your not going to those lengths, but heat pump is not cheap, and neither is gas, and it depends on the building, it is so easy to say you should do xyz because it worked on my house, but I have lived in 4 housed in North Wales, first was gas hot air, expensive to run, easy to control and was before double glazing, the problem with using a fan is it blows air at cold windows.
Second used water to move heat around, heating added as an after thought, was open plan and design with to heat with single 4.5 kW gas fire, but with no thermostatic control, so until central heating fitted no heat over night, the open plan mean upstairs got too hot, but TRV heads up stairs stopped that in the main, but leaving bedroom door open or closed did alter temperature.
Third was mothers house, original coal, then coke (doors on fires), then gas fires with back ground central heating, then full central heating, I returned to house with full gas central heating and the major problem was the sun on the bay windows, needed fast acting TRV heads so swapped to electronic.
Fourth is this house oil fired plus one open hearth fire, as yet open hearth not used, chimney boarded off with hole to put the AC exhaust into during the summer. Problem is control, wall thermostat in hall, and hall is slowest room to cool, but with 9 electronic TRV heads it is not bad.
Point is every one was different, and the heating was altered to suit the building, so first big question, is what is it like in the summer? May seem daft today with snow coming down, but heat pumps both cool and heat, so if you need air conditioning in the summer, then even if more expensive a heat pump may be better.
This also impacts on radiators, the ivector myson radiator is fan assisted so it does not matter where it is put, it is smaller than conventional and as long as vents not blocked putting a chair in front of it does not really matter, and it can be used for heating and cooling however better if plumbed in series not parallel when using a modulating boiler as output controlled by fan speed not the water flow, with one for example in kitchen as kick space heater OK, but also the sound of running, and the cost.
So even if best system, most people just say too expensive to install, so in the main central heating is a compromise. As to stand alone heat pump for main room and maybe gas fire in another room, much down to personal preference, with a gas fire with glowing coals one feels warm in minutes, one is the inferred heat, and the other is the ambience of the glowing coals.
There may be a case not to have central heating, but independent heating in each room. We all seem to jump to idea of central heating, so why was central heating considered as being so good? In the main it removed draft, the old fire in the main drew it's combustion air from the room, so we all sat in high backed chairs looking at the fire with the back protecting us from the draft from under the door. The main advantage with central heating was the balanced flue which got rid of drafts. That also resulted in damper homes, which were not as healthy, gas cooking was the worst, no flue for gas hob and oven so loads of moisture plus combustion products in the air.
