Gas v Open v Burner question

grumpyoldgal

Hello

Currently we have a Stovax 5 multifuel burner which we have had for some 4 or 5 years. It is OK - when it gets hot it is lovely, but when we have had the really cold weather it doesn't do much to touch the room, and sometimes find the quality of wood has caused problems. We have quite a large open plan lounge - we have looked at having a door put in but decided it will ruin the flow. It is currently in a marble hole in the wall effect opening.

Therefore, currently doing some work in the house. We wish to knock the marble out and open up to have a nice rustic brick fireplace with a nice little hearth. I have always wanted an open basket fire, Mr grumpy isn't that keen on keeping the burner and I have also looked at going back to a gas fire because there are some damn nice ones out there.

So, just looking online generally for designs and I wondered if you can help me with which appliance is the most effective in heat output into the room?? Given that although we have the open plan the seating area is at a right angle to the fireplace. I do miss having the option to just ignite the gas fire and get warm. even if just for the time to have a brew in the morning, but not sure if the heat for a prolonged - eg evening use is as good as open or burner.


Thank you in advance x

matelodave

For heat output you cannot beat a wood burner. If you've got a Stovax 5 then you should be getting between 4-5 kw of heat out of it. I'd doubt you'd get anywhere like that from an enclosed gas fire.

In the end if you want more heat then you need a bigger fire - more kw = more heat, so if 4-5kw doesn't do for you then perhaps 7-8kw might be more appropriate, although it will eat more coal or wood.

Open flame gas fires and open hearth coal and wood fires send about 80 % of the heat straight up the chimney so although they may look good they aren't efficient and you'll need a big one to produce the sort of heat you are craving.

If your stove is in a recess then a lot of the heat from the sides, top and back are heating the recess, perhaps a stove fan to help circulate the warm air out of the enclosed space would help.

We've got a free standing 6kw Mendip Churchill Stove in our lounge and it does a pretty good job of heating our lounge, dining room and hall - we have to have to door to the hall open except when it's exceptionally cold outside.

Gloomendoom

My sister has a Morso gas fired stove that looks like a woodburner. 84% efficiency.



I had a gas fired log fire in the sitting room fireplace when I moved in. It looked good and was convenient but most of the heat went straight up the chimney. I removed it a replaced it with an open log fire which seems to give out much more heat. That said, that may be due to it not contributing to the gas bill when I crank it up.

grumpyoldgal

Thank you both.

When we open the door of the burner the heat is fabulous, but I don't want to burn with the door open because of the risk - particularly as it is high up. We did get a fireguard to place in front of it when we leave it at the end of the night so that the dog doesn't burn his nose if he goes snuffling around! But we can't open the door and use the fireguard because it is just the one door and doesn't fold back, but opens to around 120 degrees.

silverwhistle

I don't think an open fire will give you much heat, for the reasons matelotdave has given. I've a 5kw stove burning wood and my gas bill at the beginning of April for my three bedder was £35 as the stove keeps the whole house warm.

You mentioned quality of wood: at what percentage moisture are you burning it, and from where do you source it? I normally collect and season my own wood (and burn a few briquettes) but at the end of this cold winter I tried a sample bag of wood from a low cost retailer. Absolutely pointless doing so as when I put one of the blocks on a reasonable fire it didn't burn, sat there smouldering slightly on one edge and effectively killed the fire. I hoiked it out with the tongs and later tested it with my moisture meter and it was so utterly bad I burst out laughing, felt sorry for the guy I saw who bought a trolley load and chucked the bag in my store to season for next winter (or the one after that!).

I find if I use plenty of kindling and small bits to start with I get up to an efficient burn and good heat quickly and my lounge is soon warm enough for me to then open the doors to the hall and dining room. This is all helped by a stove fan to circulate the heat.

Before you do any building work I'd be inclined to give it another winter, buy a stove fan and make sure you're burning dry wood efficiently. You really shouldn't need to open the door of your stove to get warm, and the Stovax is a reputable heater.

Ectophile

If your stove is designed to burn with the door closed (and most are), then opening the door will make it less efficient.

When my central heating broke down last Christmas, I was heating the whole house using a 5kW Stovax stove.

From experience, if I have damp or poorly seasoned wood, then it isn't even worth the effort of burning it. If I use properly seasoned wood, the stove can put out a fierce heat that can make the room uninhabitable unless I start opening doors to let the heat circulate.

zeupater

Hi

As per above posts - an open fire or a stove with the door open can operate at negative efficiencies in a property with central or other form of additional heating .... effectively you could be heating the house with one source and then using the chimney as a really efficient extractor fan to pump the heat out of the house ...

The additional efficiency of a log burner over an open fire is provided by the fuel combustion temperature ... controlling the airflow allows the chamber temperature to rise and increase the percentage of volatiles which are burned as opposed to being carried away up the chimney - this is why there's far less smoke with a controlled burn in a combustion chamber ..

With the door open it may feel like there's more heat because you can feel the directly radiated heat on your skin, but that doesn't account for convected heat, combustion efficiency & up-chimney heat-loss ...

HTH
Z

A._Badger

As it's a multifuel burner, try using solid fuel instead of wood. Follow the instructions for your stove (mainly, if it has a rocking grate, set it so that air can move up through the bars and then keep it well riddled). There may be other instructions and they should be followed.

Pound for pound, solid fuel generates a lot more heat than wood and you may well find it makes the difference. In my case, while wood does for Spring and Autumn, when it's really cold, I switch the solid fuel.

FreeBear

One question: How large is the room (i.e. Length, Width, Height).

I have an Aarrow i500 rated at 6.4Kw heating a room of approx 35 cubic metres (3.6x3.6x2.7) - Whilst not initially impressed with the heat output, I have been getting the room up to a very toasty 24°C most evenings over the winter. My routine was to light the fire in the morning with a mix of wood and smokeless coal. Once well alight, turn the air vent right down, and then feed a log as the last one burnt away over the course of the day.

This keeps the temperature of the room up, and the chimney breast acts as a thermal store - Even after the fire has gone out overnight, the room was still at around 18°C in the morning. Just lighting the fire for a few hours in the evening didn't seem to be worthwhile...

Th OP may benefit from a stove top fan to circulate some of the heat - Usage may also be a factor as well.

Davesnave

I'm not sure what constitutes "quite a large open plan lounge," but there must be something fundamentally wrong if you can't heat it for much of the time with a wood stove rated at 5kW.

Ourliving room and adjoining conservatory are both about 23m2 and the room height is in the house 2.8m. We're well insulated, but the conservatory still has a lot of glass and wouldn't meet building regs for heat loss because of that. On the worst day of the extended winter this year, when it was -6c outside our 5kW wood burner kept both of those spaces warm enough without additional help.

We were working on something that needed the open floor space in the conservatory, otherwise we'd have closed it off, but to our amazement, the temperature in there was a 19c all day.

We run the wood burner 24/7 in winter, but we don't have any extras, like a fan; just very dry logs and a fire which is quick to light and control.

As others have said, the quality of the logs is fundamental, but so also is the fitting of the fire and the state it's in. Before this one we had something about 8kW in size, with dodgy seals, all married badly to a chimney, not a flue. It used much more wood and gave out less heat. We also had less ceiling insulation at that time (bungalow) and doubling that has made a large improvement too.