Cheapest way to heat a large room.

Happy_Sloth

We have a large front living room that we every Saturday night for guests. (about 41 m²) 

I understand all the things we can do you keep individuals warm and most of the time as a family we bundle up.  However on a Saturday night when we have 5-6 guests we want our living area to be comfortable for a large group.  After all who wants to go to a friends house to visit and be cold?  

I know it's coming into warmer weather but over this year we intend to renovate that large living space and would like to plan how to heat it for next winter without breaking the bank.  

Currently the room has 1 large radiator and 1 small very inefficient electric fire.  The Radiator is large and it does certainly heat up the room, but the room is never really warm in winter it's simply tolerable. 

when we decorate i intend to put big heavy curtains up and good underfloor insulation (The floorboards are exposed to the basement and it's often below freezing down there in winter)  

Is having a gas fire installed cheaper to run?  Apparently we need a balanced flue due to not having a chimney and we've been quoted for a 3.5 watt gas fire? is that big enough to heat the room given that we have a radiator and central heating as well?  Are modern gas fires still cheaper to run than modern electric? 

what is the most economical way of heating such a large space.  (We can't have a log burner in that room sadly ) 

I just want to make sure that i have a good plan and next winter we are toasty without breaking the bank given current energy prices.  

Gerry1

Forget electric heating, nothing else is more expensive.  A gas fire might be useful for occasional top ups, but it will cost more than gas central heating because it's less efficient.  3.5 watts is a thousand times too small !

Basically you need bigger CH radiators and / or more of them.

QrizB

Happy_Sloth said:

We have a large front living room that we every Saturday night for guests. (about 41 m²)

That's almost half the area of my 1950s 3-bed semi

Yes, more/larger radiators connected to your existing gas CH should be your first choice for extra heat. Gas fires look attractive but are less efficient and, from what I recall, your energy bills are already on the high side.

Insulation & draughtproofing is also well worth it; it's cheaper than heat and has no running costs!

FreeBear

Gerry1 said:

Forget electric heating, nothing else is more expensive.  A gas fire might be useful for occasional top ups, but it will cost more than gas central heating because it's less efficient.  3.5 watts is a thousand times too small !

Basically you need bigger CH radiators and / or more of them.

I suspect the 3.5W is a typo - More likely to be 3.5KW.

A second suitably sized radiator would probably do wonders to heat the space a bit more evenly. Perhaps look at a fan assisted one https://smithsep.co.uk/catalogue/ecovector-low-radiator-fan-convector/

ProDave

So you are renovating this room?

PERFECT opportunity to do it properly.  As it is a large room I would batten it out with 4 by 2 timber, insulation between the timber (Frametherm 35 or similar) plasterboard and re decorate.  That will drastically reduce the heat loss.  And Insulate the floor probably best done from below with solid Kingspan type insulation between the joists.

Then think about how to heat it, new radiators off the existing system would probably be cheapest.  Do some upgrading to the controls so that room operates as a separate zone to the rest of the heating on it's own programable room thermostat so you set the times and temperatures in that room just for when you want to use it.  And keep the door shut when not heating or using it.

The mantra we all have to get used to is you buy insulation ONCE, you buy energy to heat a property continuously.  Spend on the former, saves cost on the latter, forever.

Happy_Sloth

FreeBear said:

Gerry1 said:

Forget electric heating, nothing else is more expensive.  A gas fire might be useful for occasional top ups, but it will cost more than gas central heating because it's less efficient.  3.5 watts is a thousand times too small !

Basically you need bigger CH radiators and / or more of them.

I suspect the 3.5W is a typo - More likely to be 3.5KW.

A second suitably sized radiator would probably do wonders to heat the space a bit more evenly. Perhaps look at a fan assisted one https://smithsep.co.uk/catalogue/ecovector-low-radiator-fan-convector/

Yes sorry 3.5KW!  

Happy_Sloth

ProDave said:

So you are renovating this room?

PERFECT opportunity to do it properly.  As it is a large room I would batten it out with 4 by 2 timber, insulation between the timber (Frametherm 35 or similar) plasterboard and re decorate.  That will drastically reduce the heat loss.  And Insulate the floor probably best done from below with solid Kingspan type insulation between the joists.

Then think about how to heat it, new radiators off the existing system would probably be cheapest.  Do some upgrading to the controls so that room operates as a separate zone to the rest of the heating on it's own programable room thermostat so you set the times and temperatures in that room just for when you want to use it.  And keep the door shut when not heating or using it.

The mantra we all have to get used to is you buy insulation ONCE, you buy energy to heat a property continuously.  Spend on the former, saves cost on the latter, forever.

Yes our aim for 2022 is to get this room done and i do want to do it properly. I'd much rather get this room right than do half a job of 2-3 rooms.  

We already haver this room on it's own zone,  but the radiator which even though it's about 15ft long isn't quite upto the job on it's own.  

It issue we have with plasterboard is that we have original coving on the walls, plasterboard would hide it and i don't really want to lose the feature.  

Phlik

Happy_Sloth said:

We have a large front living room that we every Saturday night for guests. (about 41 m²) 

I understand all the things we can do you keep individuals warm and most of the time as a family we bundle up.  However on a Saturday night when we have 5-6 guests we want our living area to be comfortable for a large group.  After all who wants to go to a friends house to visit and be cold?  

I know it's coming into warmer weather but over this year we intend to renovate that large living space and would like to plan how to heat it for next winter without breaking the bank.  

Currently the room has 1 large radiator and 1 small very inefficient electric fire.  The Radiator is large and it does certainly heat up the room, but the room is never really warm in winter it's simply tolerable. 

when we decorate i intend to put big heavy curtains up and good underfloor insulation (The floorboards are exposed to the basement and it's often below freezing down there in winter)  

Is having a gas fire installed cheaper to run?  Apparently we need a balanced flue due to not having a chimney and we've been quoted for a 3.5 watt gas fire? is that big enough to heat the room given that we have a radiator and central heating as well?  Are modern gas fires still cheaper to run than modern electric? 

what is the most economical way of heating such a large space.  (We can't have a log burner in that room sadly ) 

I just want to make sure that i have a good plan and next winter we are toasty without breaking the bank given current energy prices.  

Same size as our living room. We have two large radiators (on separate walls to spread the heat) and the room warms quickly and maintains the heat well, if you've access from your cellar this might be quite a straightforward addition for you, it'll also be the cheapest way to improve the room temperature along with insulation.
Our floors are suspended so similar situation to you with your cellar, I insulated under the floors last October/November and the rooms feel noticeably warmer since. We already use heavy curtains and again you can tell if you haven't closed them on cooler nights.

Ally_E.

ProDave said:

So you are renovating this room?

PERFECT opportunity to do it properly.  As it is a large room I would batten it out with 4 by 2 timber, insulation between the timber (Frametherm 35 or similar) plasterboard and re decorate.  That will drastically reduce the heat loss.  And Insulate the floor probably best done from below with solid Kingspan type insulation between the joists.

Then think about how to heat it, new radiators off the existing system would probably be cheapest.  Do some upgrading to the controls so that room operates as a separate zone to the rest of the heating on it's own programable room thermostat so you set the times and temperatures in that room just for when you want to use it.  And keep the door shut when not heating or using it.

The mantra we all have to get used to is you buy insulation ONCE, you buy energy to heat a property continuously.  Spend on the former, saves cost on the latter, forever.

To insulate around the externals walls, you need to leave a gap to avoid cold bridging, can be a real pain and depending on how wide the room is, can also mean it will become too narrow.

Mstty

I suspect the cheapest answer is use a smaller room for only 5-6 guests in the winter and use this larger room for the 5-6 guests in the summer.

The next cheapest answer is to keep what you have to make the room tolerable but add a multi fuel stove to that room.

matelodave

Instead of guessing, do a proper heat loss calculation based on the size and construction of the walls floor, ceiling, windows etc and then work out how much heat you actually need.

As others have said, you'll benefit from insulating under the floor and two rads, one at each end of the room would likely help it heat faster and more evenly than one big one.

A gas fire really isn't very efficient (about 80% for a good one) and the cost of having it installed is likely to take a long time to recoup.