New Gas Fire should save ££££££

Ben84

allisonw wrote: »

So you are not centrally heating your house any more, you are just heating 1 room.

Obviously you will use less gas.

I used to just heat the one room when all I had was a coal fire. Then I got central heating. I would never go back to heating just 1 room.

If you want something you have to pay for it. I would rather pay to heat the whole house.

If you're cold while in a room with a heating appliance, like a gas fire, it generally makes sense to turn on the fire in that room before turning on every radiator in the house.

As for gas fire efficiency, which a couple of people have suggested is low, some are actually very good. The radiant fires with the white bricks tend to be pretty high, maybe 70-80% and some of the new more decorative fires are rated highly too, usually the ones with a glass front. However, some gas fires should be sold as decorative only as they're very inefficient.

uptomyeyeballs

My central heating will come on once the temperature in the living room drops below 16 degC. It's only got there a couple of times so far (in October). This month it's been around 17 deg when I get in from work, so not triggering atm. Otherwise the fire is on of an evening, using about 3-3.5 kWh per hour.

An hour of CH on a morning and evening will return the temperature in the living room to a level where the fire can easily maintain it for the rest of the evening at a comfortable level (I like it in the 19-20 range). As the winter draws on, the CH will be required more, but I will still use much less gas than before.

Oct+Nov last year = 1461kWh
Oct+Nov so far this year = 573 kWh (to 24th Nov)

I've just put some reflective panels behind my external wall radiators as well. My cavity wall is too narrow to take insulation, so i'll see if this improves the performance of my radiators when the CH is on.

uptomyeyeballs

Final figures for November 2011 (Last year in brackets)

Gas 377 kWh (967 kWh) - 61% less.

This month i've only had the fire on (apart from a couple of nights) instead of the CH. i know the weather has been milder, but the different heating strategy will have helped as well. Roll on December (last year 1,797 kWh)

:-)

oldskoo1

Funny this topic came up

I did a similar experiment recently.

My stove burner which isn't quite as efficient as yours, is 78% efficient and uses 25% - 30% less gas than the CH, but it's much much warmer.

Of course if you need to heat the whole house it's a different story. But we only heat the living room and the CH is on 16C 24/7.

uptomyeyeballs

Update

Provisional figures for December usage are projecting around 1080 kWh for December 2011. That is about 41% down on December 2010, to go with :

October 43% less than previous year
November 61% less

grahamc2003

uptomyeyeballs wrote: »

Provisional figures for December usage are projecting around 1100 kWh for December 2011. That is about 35% down on December 2010.

That's sort of in the ballpark of what I expected you to save, also bearing in mind last years weather up mto now compared to this years. I think those who advocate keeping the ch on are missing a couple of important points.

Firstly, quoting 'a decent ch boiler is 95% efficient' or suchlike is a little meaningless in reality - I'm sure if the certification says so, then it is under the circumstances it was tested. But the same boiler could be VERY inefficient when used as some suggest 0 i.e. turn off all radiators in the house except for the room you're in. That would casue the return water temperature to be very high, resulting in a much lower efficiency. Similarly for those using a 18kw boiler just to lose 3 or 4 kw by just heating the hot water tank in the summer.

Another point is that hot water is still being piped all over the house and losing heat from pipework even with the radiators off (obvioulsy that heat loiss heats the house, but it is in rooms where heating isn't required).

So I'd expect a very noticable saving from heating locally one room, rather than driving the ch to heat one room.

The early posts in this thread were saying any flued appliance isn't as efficient as it could be, so you could get even more savings if the amount of room and exhaust air being exhausted was less, or zero, so they were correct imv. You can get unvented catalytic gas fires operating at very high effecinces (theoretical and actual), but I personally wouldn't take the risk yet with those (if they are still for sale?).

SYNERGY

grahamc2003 wrote: »

That's sort of in the ballpark of what I expected you to save, also bearing in mind last years weather up mto now compared to this years. I think those who advocate keeping the ch on are missing a couple of important points.

Firstly, quoting 'a decent ch boiler is 95% efficient' or suchlike is a little meaningless in reality - I'm sure if the certification says so, then it is under the circumstances it was tested. But the same boiler could be VERY inefficient when used as some suggest 0 i.e. turn off all radiators in the house except for the room you're in. That would casue the return water temperature to be very high, resulting in a much lower efficiency. Similarly for those using a 18kw boiler just to lose 3 or 4 kw by just heating the hot water tank in the summer.

Another point is that hot water is still being piped all over the house and losing heat from pipework even with the radiators off (obvioulsy that heat loiss heats the house, but it is in rooms where heating isn't required).

So I'd expect a very noticable saving from heating locally one room, rather than driving the ch to heat one room.

The early posts in this thread were saying any flued appliance isn't as efficient as it could be, so you could get even more savings if the amount of room and exhaust air being exhausted was less, or zero, so they were correct imv. You can get unvented catalytic gas fires operating at very high effecinces (theoretical and actual), but I personally wouldn't take the risk yet with those (if they are still for sale?).

You can get unvented catalytic gas fires operating at very high effecinces (theoretical and actual), but I personally wouldn't take the risk yet with those (if they are still for sale?)

Yes they are available in many more variations, conventional gas fire type etc, than the original wall hung type, I've had one for the past five years.

I'm off out now but will post later this evening ref using one, their gas consumption, advantages, disadvantages etc.

Richie-from-the-Boro

With 16 million Unvented Catalytic installs in America, I'm not convinced they are unsafe :

- Rumours and Misinformation Answered
- Water Vapour Technical Paper
- Sizing Guide

Regardless of who tests and what their bias is, it seems to me that the traditional undisputed 70%+ going up the chimney on a flue'd fire must convert unscientifically to about three times more efficient per kW input. Safety is always a question, but the track record in so many installs is a good one and any way they are all ODS equipped, in addition to which a secondary good quality ODS monitor is only about £25.

grahamc2003

Richie-from-the-Boro wrote: »

With 16 million Unvented Catalytic installs in America, I'm not convinced they are unsafe :

- Rumours and Misinformation Answered
- Water Vapour Technical Paper
- Sizing Guide

Regardless of who tests and what their bias is, it seems to me that the traditional undisputed 70%+ going up the chimney on a flue'd fire must convert unscientifically to about three times more efficient per kW input. Safety is always a question, but the track record in so many installs is a good one and any way they are all ODS equipped, in addition to which a secondary good quality ODS monitor is only about £25.

I'm not aware of anyone saying they are unsafe have they?

I personally wouldn't install them with what I know (or rather don't know) about them at the moment - that is just a statement of fact and a confession of my ignorance, and my bias of being worried about breathing the results of combustion, and my bias borne of having a house with a tendancy for damp, so don't wish to put more water into the house air.

The thing is that with Google, we can get any references for whatever stance we wish to take on any subject. A few minutes googling doesn't make anyone an expert on anything. For example, here's a paper from Harvard medical school (which is independent, and not industry sponsored) concluding

Despite these limitations, the existing evidence suggests that there may be a modest effect of exposure to gas appliances on respiratory health. In future research we need to identify the pattern of exposure and the subgroups associated with increased risk.

(Just to pre-empt some replies i think likely, I know the conclusion doesn't state unvented gas appliances are dangerous!, and neither do I want to imply they are (or aren't for that matter - I have no idea).

Googling also throws up sufficient references specifically advising to avoid using unvented appliances where babies and children live, due to the quicker build up of co in their bodies due to their higher metabolism. Again, that is not to say they are dangerous at all, just that it is sometimes prudent to avoid the risk, whatever that risk is.

http://thorax.bmj.com/content/52/suppl_3/58.long

Richie-from-the-Boro

HiYa grahamc2003 - #58 - """ I personally wouldn't take the risk yet with those (if they are still for sale?)"""

NOTE : I agree with you neither the BMJ nor the Harvard comments you referenced are even romotely applicable to the product we were debating, I agree with your comments in #60 you are correct .. .. they could equally be directed at anyone burning a 'joss stick' indoors