Reducing/Optimising Gas Consumption (Central Heating)
Discussion
For those PH'rs in the USA - "Gas" is not Gasoline 
I appreciate there are several threads where PH'rs are sharing cost of living increases, Energy consumption, energy savings etc etc but I wanted a little help on a specific issue and didn't want to hi-jack an existing thread so thought I'd create one
Background
(TL:DR - skip to "Current Work In Progress" or If "tight for time" The Endpoint)
House: 4 Bed Detached built in 1982 ground floor and first floor are each 56m2 (600 sqft) so total 112 m2 (1200 sqft)
(two storey extension in 2006 included)
When purchased 1991 - single glazed windows (including 2 patio doors), leaky wooden doors, loose fill loft insulation, no cavity wall and a void underneath the ground floor (3 feet crawl space where all the CH pipes for the ground floor run wrapped in horse hair tape) with a lot of air bricks
Over the years we have improved the house with double glazed doors and windows, cavity wall, 100mm of loft insulation and boarded most of the loft (yes I know we need more but un-boarding it right now and re-doing it all would be a pain) and wrapped the CH pipes in 10mm foam
Annual Energy consumption (Gas only)
We added a few rads and changed a couple to improve the warmth in a couple of rooms/areas
We did look a few years ago at under floor insulation but the ROI was in decades last time considered it however energy costs means it has potential for 10 - 15% reduction (the floors always feel cold)
So looked again at it last time I was under the floor (June) and whilst it's not going to be a fun job it's doable - I also noticed that the lagging I put on the pipes was now past it's best - now loose fitting and taped joints splitting
Current Work In Progress
I have ordered 56 m2 of 75mm celotex material to put under the floor between the 100 mm joists and 50m of 15mm 25mm pipe lagging and 50 m of 22m 19mm pipe lagging for under the floor and where I can in house (esp airing cupboard and transfer ducts from downstairs to upstairs as it's not got any and has a lot of pipe)
I've made some progress since March in reducing gas consumption by reducing the time the water heating is on for - clearly leaving the water heating time same as central heating time in summer wastes energy (provided you don't need all the water) but the wastage is capped by the HW tank stat saying it's up to temp
However I know that in the three coldest months of the year I will use 50% of my annual gas kWh
So it's Central Heating I need to focus on
Out of 13 radiators 9 are original 1982 and they are all single panel T11 rads (the replaced ones are T22 and the additional ones are T11)
Boiler is condensing 24kW vented system - circulation pump - still have 117 L hot water tank with stat to tell boiler when temp of tank is reached
The boiler flow temp needs to be low 80 deg C in the winter to get the house warm and the return temp is way too high for the boiler to condense (I've tried lower flow temps and the rooms with T11 rads just don't get to comfortable temperature for Mrs BC)
Well with the cost of gas rising and wanting to take advantage of boiler efficiency I think I need to change some of the T11's to help me lower the flow temp and get a resultant drop in return)
Currently "dumb" Danfoss timer (no weather compensation)
Room stat in the hall (that is never anything other than wound right round because 11 out of the 13 rads have TRV's - getting rid of that will stop Mrs BC from seeing when I’ve tweaked it back a bit)
3 speed Grundfos circulation pump that seems to do a good job on minimum speed.
Have a Drayton Wiser Controller, wifi room stat and 9 Smart TRV's to fit to improve control - pretty sure I know which rads I want to control better
In order to fit the smart TRV’s I’ve purchased 9 drayton TRV bodies (out of the 11 original TRV bodies some were sticking/leaking or just plain knackered - don’t buy cheap TRV’s they are a false economy)
With the CH system drained to replace the TRV’s it made sense to remove and flush the rads so I’ve done that now
Magnaclean unit to go in the system and replacement gate valves either side of the pump because last time I replaced the pump they were letting by (so it was a fun “quick swap” with lots of towels)
Have a few other tidy up pipe work jobs in the airing cupboard and with it all drained down it’s the perfect time.
Rad set up for info
(I like numbers as it helps me to understand things)
T22 = Double panel rad with double convection fins
TR = Towel Rail or Ladder Radiator
All BTU's are T60 Delta (where new rads/towel rails have been fitted post 2008 they might be T50) I've updated a spreadsheet from 2005 when I was planning the extension and what I could do with the original boiler and I think T50 came after that)
If you read thro all that then I'm impressed
The Endpoint
What I'm trying to work out is
1. What rads to replace - I think I have a plan but am not 100% sure.
2. How to factor that in achieving a comfortable room temp with minimum flow temp in order to ensure the targeted lower return temps*
3. Am I missing anything or barking up the wrong tree -thoughts comments (other than you sad b'stard) would be welcome
Note* As low as I can get (AIU lower than 57 deg C is where condensing of the flu gases and heat recovery occurs)
70/50/20 would be nice but can I get 60/40/20
Edited to fix the table errors
I appreciate there are several threads where PH'rs are sharing cost of living increases, Energy consumption, energy savings etc etc but I wanted a little help on a specific issue and didn't want to hi-jack an existing thread so thought I'd create one
Background
(TL:DR - skip to "Current Work In Progress" or If "tight for time" The Endpoint)
House: 4 Bed Detached built in 1982 ground floor and first floor are each 56m2 (600 sqft) so total 112 m2 (1200 sqft)
(two storey extension in 2006 included)
When purchased 1991 - single glazed windows (including 2 patio doors), leaky wooden doors, loose fill loft insulation, no cavity wall and a void underneath the ground floor (3 feet crawl space where all the CH pipes for the ground floor run wrapped in horse hair tape) with a lot of air bricks
Over the years we have improved the house with double glazed doors and windows, cavity wall, 100mm of loft insulation and boarded most of the loft (yes I know we need more but un-boarding it right now and re-doing it all would be a pain) and wrapped the CH pipes in 10mm foam
Annual Energy consumption (Gas only)
| Year | kWh Yr | Comment | Saving kWh |
| 1991 | 25000 | Purchase | 0 |
| 1997 | 22000 | Windows | 3000 |
| 2007 | 20000 | Pipe lag & Cavity Ins | 2000 |
| 2009 | 16000 | Boiler | 4000 |
| 2011 | 14500 | HW Tank | 1500 |
We added a few rads and changed a couple to improve the warmth in a couple of rooms/areas
We did look a few years ago at under floor insulation but the ROI was in decades last time considered it however energy costs means it has potential for 10 - 15% reduction (the floors always feel cold)
So looked again at it last time I was under the floor (June) and whilst it's not going to be a fun job it's doable - I also noticed that the lagging I put on the pipes was now past it's best - now loose fitting and taped joints splitting
Current Work In Progress
I have ordered 56 m2 of 75mm celotex material to put under the floor between the 100 mm joists and 50m of 15mm 25mm pipe lagging and 50 m of 22m 19mm pipe lagging for under the floor and where I can in house (esp airing cupboard and transfer ducts from downstairs to upstairs as it's not got any and has a lot of pipe)
I've made some progress since March in reducing gas consumption by reducing the time the water heating is on for - clearly leaving the water heating time same as central heating time in summer wastes energy (provided you don't need all the water) but the wastage is capped by the HW tank stat saying it's up to temp
| When | HW wkly run time | Daily kWh |
| Mar | 34.5 | 16 |
| Jun | 17 | 8 |
| Aug | 7 | 3.5 |
However I know that in the three coldest months of the year I will use 50% of my annual gas kWh
So it's Central Heating I need to focus on
Out of 13 radiators 9 are original 1982 and they are all single panel T11 rads (the replaced ones are T22 and the additional ones are T11)
Boiler is condensing 24kW vented system - circulation pump - still have 117 L hot water tank with stat to tell boiler when temp of tank is reached
The boiler flow temp needs to be low 80 deg C in the winter to get the house warm and the return temp is way too high for the boiler to condense (I've tried lower flow temps and the rooms with T11 rads just don't get to comfortable temperature for Mrs BC)
Well with the cost of gas rising and wanting to take advantage of boiler efficiency I think I need to change some of the T11's to help me lower the flow temp and get a resultant drop in return)
Currently "dumb" Danfoss timer (no weather compensation)
Room stat in the hall (that is never anything other than wound right round because 11 out of the 13 rads have TRV's - getting rid of that will stop Mrs BC from seeing when I’ve tweaked it back a bit)
3 speed Grundfos circulation pump that seems to do a good job on minimum speed.
Have a Drayton Wiser Controller, wifi room stat and 9 Smart TRV's to fit to improve control - pretty sure I know which rads I want to control better
In order to fit the smart TRV’s I’ve purchased 9 drayton TRV bodies (out of the 11 original TRV bodies some were sticking/leaking or just plain knackered - don’t buy cheap TRV’s they are a false economy)
With the CH system drained to replace the TRV’s it made sense to remove and flush the rads so I’ve done that now
Magnaclean unit to go in the system and replacement gate valves either side of the pump because last time I replaced the pump they were letting by (so it was a fun “quick swap” with lots of towels)
Have a few other tidy up pipe work jobs in the airing cupboard and with it all drained down it’s the perfect time.
Rad set up for info
(I like numbers as it helps me to understand things)
- Ext = equals part of extension in 2006
T22 = Double panel rad with double convection fins
TR = Towel Rail or Ladder Radiator
All BTU's are T60 Delta (where new rads/towel rails have been fitted post 2008 they might be T50) I've updated a spreadsheet from 2005 when I was planning the extension and what I could do with the original boiler and I think T50 came after that)
| Room | M3 | House T60 | Orig Rad Size | kW Value | Now Rad Size | Now BTU | Now kW | Rad Age |
| Lounge *Ext | 52.5 | 4229 | 550 x 1400 T11 | 1.239 | 600 x 1400 T22 | 10375 | 3.040 | 2007 |
| Dining | 30.5 | 4229 | 550 x 1400 T11 | 1.239 | 550 x 1400 T11 | 4229 | 1.239 | 1982 |
| Kitchen | 24.1 | 2416 | 550 x 800 T11 | 0.708 | 550 x 800 T11 | 2416 | 0.708 | 1982 |
| Hall | 31.9 | 2416 | 550 x 800 T11 | 0.708 | 600 x 800 T22 | 5226 | 1.531 | 2004 |
| Utility | 9.4 | 2416 | 550 x 800 T11 | 0.708 | 550 x 800 T11 | 2416 | 0.708 | 1982 |
| Toilet | 3.6 | 0 | N/A | 0.000 | 400 x 500 T11 | 1224 | 0.359 | 2008 |
| Front Hall | 7.0 | 0 | N/A | 0.000 | 550 x 800 T11 | 2416 | 0.708 | 1982 |
| Bedroom 1 | 28.9 | 3625 | 550 x 1200 T11 | 1.062 | 550 x 1200 T11 | 3625 | 1.062 | 1982 |
| En Suite *Ext | 10.4 | 0 | N/A | 0.000 | 500 x 1200 TR | 2388 | 0.700 | 2021 |
| Bedroom 2 | 24.3 | 3625 | 550 x 1200 T11 | 1.062 | 550 x 1200 T11 | 3625 | 1.062 | 1982 |
| Bedroom 3 | 23.7 | 3625 | 550 x 1200 T11 | 1.062 | 550 x 1200 T11 | 3625 | 1.062 | 1982 |
| Study | 14.6 | 3625 | 550 x 1200 T11 | 1.062 | 550 x 1200 T11 | 3625 | 1.062 | 1982 |
| Bathroom | 9.8 | 2416 | 550 x 800 T11 | 0.708 | 450 x 1200 TR | 2239 | 0.656 | 2017 |
If you read thro all that then I'm impressed
The Endpoint
What I'm trying to work out is
1. What rads to replace - I think I have a plan but am not 100% sure.
2. How to factor that in achieving a comfortable room temp with minimum flow temp in order to ensure the targeted lower return temps*
3. Am I missing anything or barking up the wrong tree -thoughts comments (other than you sad b'stard) would be welcome
Note* As low as I can get (AIU lower than 57 deg C is where condensing of the flu gases and heat recovery occurs)
70/50/20 would be nice but can I get 60/40/20
Edited to fix the table errors
Edited by B'stard Child on Sunday 4th December 18:39
Hereward said:
Have fun. It sounds like the weak link in the system is Mrs BC!
Oh she is getting better (or more educated) as I've been monitoring electric usage and feeding back the new costs of certain devices Hereward said:
Shame you cannot lower that flow temperature to optimise condensing and manual weather compensation.
I used to run boiler temp 78 deg in summer (have reduced to 68 deg C in Summer - only heating water to 60 deg C so this is part of the reduced kWh achieved with run time changes) The only weather compensation is me so as the temp starts to fall in autumn I'll have to increase the boiler temp to 78 deg C however once winter is here proper I have to max the boiler temp out (82 or 84 is max) and at this point whilst the house is warm the return temp doesn't drop down below 60 deg C according to measurements with my infrared temp device.
The house heating was designed to the 80/60/20 most rads I only see a 10 deg drop across flow and return on the original rads - my thoughts are that in over sizing some of the original rads I can use a lower flow temp and get the same radiant heat output (not sure if the drop across a rad will increase)
I certainly believe that bigger radiators generally help, although it can mean the system takes a while to warm the water, and some temperatures may overshoot.
As I rambled on in another thread, I found it useful to attempt to reconcile the outputs of rads against the heat losses of walls, ceilings etc.
If you understand where the heat is going, then you can attack that.
If there is a gulf between what the losses are and what U-values say they should be, then that's something to look at.
Where I live, we don't get many actual freezing days, so consumption is mostly driven by a few months of ~5degC at night, so the system would ideally be efficient during mildly cold weather, yet still effective during freezing weather if you get the difference.
September's jobs for me include adding some more loft insulation and sorting some draughty windows by replacing the hinges.
Beyond that, I think the big savings may be 'operator re-education', as in shut the bloody windows BEFORE the houses cools down in the afternoon, and don't fanny around with the front door wide open etc.
As I rambled on in another thread, I found it useful to attempt to reconcile the outputs of rads against the heat losses of walls, ceilings etc.
If you understand where the heat is going, then you can attack that.
If there is a gulf between what the losses are and what U-values say they should be, then that's something to look at.
Where I live, we don't get many actual freezing days, so consumption is mostly driven by a few months of ~5degC at night, so the system would ideally be efficient during mildly cold weather, yet still effective during freezing weather if you get the difference.
September's jobs for me include adding some more loft insulation and sorting some draughty windows by replacing the hinges.
Beyond that, I think the big savings may be 'operator re-education', as in shut the bloody windows BEFORE the houses cools down in the afternoon, and don't fanny around with the front door wide open etc.
deanobeano said:
Can you increase your circr pump speed to med or max? (noise permitting).
If the flow rates are increased, then the heat devolved to the room should increase (?) therefore allowing you to reduce flow temps and possibly hit condensing temps on the return?
Bloody hell - I though it was the reverse of that if you speed the pump up the water doesn't stay as long in the rads so heat transfer to the room is reduced If the flow rates are increased, then the heat devolved to the room should increase (?) therefore allowing you to reduce flow temps and possibly hit condensing temps on the return?
When we had the Boiler replaced the fitter set the pump to mid position and said if it's too noisy try low and if heating is unaffected leave it there - it was too noisy and I noticed no change on low so it's stayed there.
OutInTheShed said:
I certainly believe that bigger radiators generally help, although it can mean the system takes a while to warm the water, and some temperatures may overshoot.
As I rambled on in another thread, I found it useful to attempt to reconcile the outputs of rads against the heat losses of walls, ceilings etc.
If you understand where the heat is going, then you can attack that.
If there is a gulf between what the losses are and what U-values say they should be, then that's something to look at.
I get that however not much we can do with losses we have now As I rambled on in another thread, I found it useful to attempt to reconcile the outputs of rads against the heat losses of walls, ceilings etc.
If you understand where the heat is going, then you can attack that.
If there is a gulf between what the losses are and what U-values say they should be, then that's something to look at.
I obviously sourced the spreadsheet I have from somewhere but it takes room dimension in m3 multiplies that by 153 to get the BTU/Hr required to heat the space
It then has factors you can apply for reduction/increase shown below
- 25% for bedrooms
- 20% for Cavity wall
- 5% for Double Glazing
+ 15% for two external walls
+ 40% for three external walls
+ 10% for north facing
Once the relevant ones are applied you get a BTU/Hr requirement for the room which you can then compare to the existing rad output
Most of my original rads are only just above the suggested sizing using T60 Delta if I drop boiler temp some will be undersized
- I know I need to un-board the loft floor - add Joist stringers and more insulation and then re-board
- We could get more efficient windows - they were installed in 1997 but still look good, all the seals are in good condition and no drafts from them
- I am going to insulate under the ground floor
OutInTheShed said:
Where I live, we don't get many actual freezing days, so consumption is mostly driven by a few months of ~5degC at night, so the system would ideally be efficient during mildly cold weather, yet still effective during freezing weather if you get the difference.
I'd like to achieve condensing temps all year round if I can and I'd like to not have to run the boiler at max temp for the three coldest monthsOutInTheShed said:
September's jobs for me include adding some more loft insulation and sorting some draughty windows by replacing the hinges.
Idea time to do the loft hopefully not too hot up there we will do ours in the spring and use the winter to clear out some of the crap that is up there so we don't have to move stuffOutInTheShed said:
Beyond that, I think the big savings may be 'operator re-education', as in shut the bloody windows BEFORE the houses cools down in the afternoon, and don't fanny around with the front door wide open etc.
Operator education in progress 
Might be worth trying a set of these on one of your radiators, could move them around to see where might benifit from more output before changing radiators.
https://www.speedcomfort.co.uk/
Bought a set for my mums last year to try, just bought another two sets from Amazon, made a massive difference to the speed at which the room I tried it in would heat up. Her house is mid 1970's, I think with original radiators. When it is cold the radiators just cannot put out enough heat to get the house up to temperature, means the return temperature is too high so the boiler keeps stopping even though the set temp has not been reached. Didn't used to be an issue but as she has got older now wants the temp at 20C rather than 18C.
https://www.speedcomfort.co.uk/
Bought a set for my mums last year to try, just bought another two sets from Amazon, made a massive difference to the speed at which the room I tried it in would heat up. Her house is mid 1970's, I think with original radiators. When it is cold the radiators just cannot put out enough heat to get the house up to temperature, means the return temperature is too high so the boiler keeps stopping even though the set temp has not been reached. Didn't used to be an issue but as she has got older now wants the temp at 20C rather than 18C.
Tymb said:
Might be worth trying a set of these on one of your radiators, could move them around to see where might benifit from more output before changing radiators.
https://www.speedcomfort.co.uk/
Bought a set for my mums last year to try, just bought another two sets from Amazon, made a massive difference to the speed at which the room I tried it in would heat up. Her house is mid 1970's, I think with original radiators. When it is cold the radiators just cannot put out enough heat to get the house up to temperature, means the return temperature is too high so the boiler keeps stopping even though the set temp has not been reached. Didn't used to be an issue but as she has got older now wants the temp at 20C rather than 18C.
Well I never knew they existed - thanks for the link - I can think of one room where that might help a lot long room with one massive radhttps://www.speedcomfort.co.uk/
Bought a set for my mums last year to try, just bought another two sets from Amazon, made a massive difference to the speed at which the room I tried it in would heat up. Her house is mid 1970's, I think with original radiators. When it is cold the radiators just cannot put out enough heat to get the house up to temperature, means the return temperature is too high so the boiler keeps stopping even though the set temp has not been reached. Didn't used to be an issue but as she has got older now wants the temp at 20C rather than 18C.
B'stard Child said:
Something in funny US units.
Rooms don't lose heat due to their volume, it's more a matter of areas of various surfaces and the thermal resistance/conductance of those surfaces.Volume matters of course, when the air is being changed a significant number of times.
It's also useful to have an infra red thermometer.
Knowing whether it's the wall, ceiling etc that's cold can tell you a lot.
i mean christ at full pelt your only radiating 8.568 KW of energy sorry that was your old output doh
12.128kw now i do wonder how some of your rads that havent changed are now higher kw than they used to be!
replace all with t22 will net you a huge improvement and allow you lower flow rates you will double the heat output pretty much
those fans are an odd one 95 euro for some fans that cost x amount to run or you can get a 600x1400 type 22 for what £160 the rad seems a better idea as it will lower your running costs rather than the fan that costs you more when you use it
what boiler do you have?
12.128kw now i do wonder how some of your rads that havent changed are now higher kw than they used to be!
replace all with t22 will net you a huge improvement and allow you lower flow rates you will double the heat output pretty much
those fans are an odd one 95 euro for some fans that cost x amount to run or you can get a 600x1400 type 22 for what £160 the rad seems a better idea as it will lower your running costs rather than the fan that costs you more when you use it
what boiler do you have?
Edited by Trustmeimadoctor on Thursday 25th August 14:06
Edited by Trustmeimadoctor on Thursday 25th August 14:13
Trustmeimadoctor said:
i mean christ at full pelt your only radiating 8.568 KW of energy sorry that was your old output doh
Add 3 KW for water heating and then have a nice 1982 Vintage Glow Worm Space saver 20 - 30 (Old money BTU in K or 8 to 12 kW in new money)Trustmeimadoctor said:
what boiler do you have?
Glow Worm Flexicom 24HX Original one only needed a thermo couple every couple of years - apart from that faultless
Both previous houses had glow worm boilers too so I bought another - not been disappointed by it either
seems that the boiler modulates down to only 10kw so unless your operating every rad flat out you are wasting energy
so in theory you really wont benefit with trv's as you need all your rads open to get rid of the energy
i have the same issue mine only goes down to 12kw some now get down to 1 or 2 kw
so in theory you really wont benefit with trv's as you need all your rads open to get rid of the energy
i have the same issue mine only goes down to 12kw some now get down to 1 or 2 kw
Edited by Trustmeimadoctor on Thursday 25th August 14:59
Trustmeimadoctor said:
i mean christ at full pelt your only radiating 8.568 KW of energy sorry that was your old output doh
12.128kw now
Plus water heating at say 3 kw12.128kw now
Trustmeimadoctor said:
i do wonder how some of your rads that havent changed are now higher kw than they used to be!
That will be my error when I was putting the table together - I'll check my calcs and go back and fix itTrustmeimadoctor said:
replace all with t22 will net you a huge improvement and allow you lower flow rates you will double the heat output pretty much
Yeah that's a bit too spendy for me right now - rads aren't cheap and some areas of the house I wouldn't want to put a double rad because it wouldn'tExamples
Front hall is a small space shut off by a glass door from main hall way - that one is never past 1 on the TRV to keep the chill off the area - even if I had to increase the TRV to 2 due to lower flow temps it would be fine
Downstairs Toilet tiny single rad but not a lot of space to add bigger and what's there is assisted by the main hall rad because the door is never shut
Kitchen - it's due for replacement - apparently 27 years is too long to have same kitchen and she'll want a ladder type rad to increase space for cupboards so anything I do to that will be money down the drain when it gets all re-done next year
Trustmeimadoctor said:
those fans are an odd one 95 euro for some fans that cost x amount to run or you can get a 600x1400 type 22 for what £160 the rad seems a better idea as it will lower your running costs rather than the fan that costs you more when you use it
I'm trying to keep to same width on the rads so I don't have to do too much floor removal (to adjust the tails to suit and keep it neat as well as not screw up wood floor or carpet - or create weird pipework extensions to convert above floor)B'stard Child said:
Trustmeimadoctor said:
i mean christ at full pelt your only radiating 8.568 KW of energy sorry that was your old output doh
12.128kw now
Plus water heating at say 3 kw12.128kw now
Trustmeimadoctor said:
i do wonder how some of your rads that havent changed are now higher kw than they used to be!
That will be my error when I was putting the table together - I'll check my calcs and go back and fix itTrustmeimadoctor said:
replace all with t22 will net you a huge improvement and allow you lower flow rates you will double the heat output pretty much
Yeah that's a bit too spendy for me right now - rads aren't cheap and some areas of the house I wouldn't want to put a double rad because it wouldn'tExamples
Front hall is a small space shut off by a glass door from main hall way - that one is never past 1 on the TRV to keep the chill off the area - even if I had to increase the TRV to 2 due to lower flow temps it would be fine
Downstairs Toilet tiny single rad but not a lot of space to add bigger and what's there is assisted by the main hall rad because the door is never shut
Kitchen - it's due for replacement - apparently 27 years is too long to have same kitchen and she'll want a ladder type rad to increase space for cupboards so anything I do to that will be money down the drain when it gets all re-done next year
Trustmeimadoctor said:
those fans are an odd one 95 euro for some fans that cost x amount to run or you can get a 600x1400 type 22 for what £160 the rad seems a better idea as it will lower your running costs rather than the fan that costs you more when you use it
I'm trying to keep to same width on the rads so I don't have to do too much floor removal (to adjust the tails to suit and keep it neat as well as not screw up wood floor or carpet - or create weird pipework extensions to convert above floor)Trustmeimadoctor said:
move
We did look at that back in 2004 and decided the moving costs plus increase in mortgage payments for a new build, better insulated, a little larger but with a double garage, it would be cheaper to extend the garage and the house It's less than a mile to work for both of us - we have a short walk to local town centre (it's s
t but I've lived in worse) until we lose mobility then the move will be downsize and free up capital to support our retirementOutInTheShed said:
Something in funny US units.
Funny US units?OutInTheShed said:
Rooms don't lose heat due to their volume, it's more a matter of areas of various surfaces and the thermal resistance/conductance of those surfaces.
Volume matters of course, when the air is being changed a significant number of times.
But the volume has to be heated - like I said in the original post it's an old spreadsheet but there are similar tools on line for determining BTU or kW requirements of rads that require volume and correction factors and the numbers come out similar (except that they are all using T50 delta rather that T60 but I'm in the ball parkVolume matters of course, when the air is being changed a significant number of times.
OutInTheShed said:
It's also useful to have an infra red thermometer.
Knowing whether it's the wall, ceiling etc that's cold can tell you a lot.
I have one I mainly use it to balance the rads - never thought to point it at walls,floors and ceilings thanks useful tip Knowing whether it's the wall, ceiling etc that's cold can tell you a lot.
Edited by B'stard Child on Thursday 25th August 16:03
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