i would like to read one of your guides, my house was built in the 1900 and it's always freezing downstairs. Was trying to find ways of insulating the walls but there's is nothing for double bricks. Now reading this thread I'm going to see what my return temp is......if I can figure out how
How best to run central heating this winter?
- Thread starter darknite
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With Simon on this one.
How can heating your house all day when you don't actually need it be more economical? The greater the temperature difference between the house and outside the greater the rate of heat loss, this heat loss needs to be replaced somehow - i.e burning more fuel to keep the temperature up!
I agree that when you get home from work, that the house thats been kept on 'low' all day will reach a comfortable temp much quicker and with less energy expended, but thats at the expense of you burning fuel all day to keep it at that residual temperature.
Next you will be telling me that my AGA is more efficient than a regular oven as I am keeping it up to temperature all the time!
How can heating your house all day when you don't actually need it be more economical? The greater the temperature difference between the house and outside the greater the rate of heat loss, this heat loss needs to be replaced somehow - i.e burning more fuel to keep the temperature up!
I agree that when you get home from work, that the house thats been kept on 'low' all day will reach a comfortable temp much quicker and with less energy expended, but thats at the expense of you burning fuel all day to keep it at that residual temperature.
Next you will be telling me that my AGA is more efficient than a regular oven as I am keeping it up to temperature all the time!
It's an age old argument 
.
I tried it over a period of time and we used less gas by having it only come on when we're there. Obviously it wasn't an exact science as the temperature wasn't identical outside during the period but it was close enough to be within a margin of error.
You also have the benefit this way of the radiators actually being on whilst you're in the house so it 'feels' warmer. This combined with costing less makes it a no brainer for us. Your experience may be different depending on your house.
. I tried it over a period of time and we used less gas by having it only come on when we're there. Obviously it wasn't an exact science as the temperature wasn't identical outside during the period but it was close enough to be within a margin of error.
You also have the benefit this way of the radiators actually being on whilst you're in the house so it 'feels' warmer. This combined with costing less makes it a no brainer for us. Your experience may be different depending on your house.
How do these smart thermostats work with families? In our house theres me and the wife and then 2 kids at 17 and 13.
Everyone tends to be in/out at different times so I never know the best way to set it and our Thermostat only allows 2 time periods per day so we struggle to find a suitable way to work it!
Everyone tends to be in/out at different times so I never know the best way to set it and our Thermostat only allows 2 time periods per day so we struggle to find a suitable way to work it!
With a nest in a high traffic area of your house. When it senses someone is in the house it will turn the heating on. When it doesn't sense anyone in the house it goes off (well down to your desired away temperature which I wouldn't set too low).
I do like it when my boiler tells me all of its secrets.
Ah, I think I always thought these things connected to an App on a smartphone to determine location.
How do these sensors work?
Sounds like I have some research to do!
Got to watch out though. A lot of it is simply hot air.
The flow rate thing interests me, how do you go about finding out the return temps, is holding a prob next to the return pipe good enough and can a standard pump have the flow rate adjusted?
I have a modern Worcester combi boiler on a terraced house that was built around 1940. It only takes 30minutes to start to make the house feel warm but a family means that we currently run it 5.30am till 8.30am then 3pm to 11pm. Thermos on all the rads. Right now we have the room stat set on 21 but as the winter really bites it has to go up to 23/4 to let all the rad stats take over as the differential between the hall downstairs and the rooms makes the hall stat ineffective.
I have a modern Worcester combi boiler on a terraced house that was built around 1940. It only takes 30minutes to start to make the house feel warm but a family means that we currently run it 5.30am till 8.30am then 3pm to 11pm. Thermos on all the rads. Right now we have the room stat set on 21 but as the winter really bites it has to go up to 23/4 to let all the rad stats take over as the differential between the hall downstairs and the rooms makes the hall stat ineffective.
Return temps only really matter to a condensing boiler.
Condensing boilers condense the exhaust gases to take the energy from phase Chang of gas to liquid of the flue gases.
If you run the boiler cooler to get lower temperatures (and turn on hearing a bit earlier to overcome the lower rad temps ) you can get efficiency gains
This is where weather compensation comes in as it automatically lowers boiler temps in warm weather to ensure return temp is at least below the dew point which is 53C
Here are some examples of boiler efficiency versus return temperatures (This is the best way to run a boiler but not necessarily a house.)
At 65C the efficiency is 87%
At 53C (dew-point) the efficiency is 89%
At 30C the efficiency is 97%
At 25C the efficiency is 98-99%
At 20C the efficiency is near 100%
If you are running in condensing mode your flue will look like a steam train.
Condensing boilers condense the exhaust gases to take the energy from phase Chang of gas to liquid of the flue gases.
If you run the boiler cooler to get lower temperatures (and turn on hearing a bit earlier to overcome the lower rad temps ) you can get efficiency gains
This is where weather compensation comes in as it automatically lowers boiler temps in warm weather to ensure return temp is at least below the dew point which is 53C
Here are some examples of boiler efficiency versus return temperatures (This is the best way to run a boiler but not necessarily a house.)
At 65C the efficiency is 87%
At 53C (dew-point) the efficiency is 89%
At 30C the efficiency is 97%
At 25C the efficiency is 98-99%
At 20C the efficiency is near 100%
If you are running in condensing mode your flue will look like a steam train.
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On a related note to this, is anyone able to confirm that the figure shown on the LCD display on a Worcester Bosch Combi is by default?
It is two figures and numeric so I am presuming it is a temperature of some sorts but I am not sure if it is output or return temperature. It's usually in the mid 60's on ours so if it is return was planning to turn down a little to try and improve efficiency.
Have googled this but no-where seems to explain this.
Thanks,
With a new build modern house with a modern condensing boiler it is most likely to be more energy efficient not to let your house cool down too much when not home.
There is going to be some threshold time period. If your whole house work super long hours, hitting the gym/pub after work such that you are all out of the house for bear 12 hours then this is a different scenario than when peoples schedules don't align exactly and the house is only empty 6-7 hours.
it will also deepnd on how cold it is outside, on a bitter winters day the house may fall to 10-12 *C and that will require a lot of energy to heat back up to 20*C.
We don't really touch the heating/AC much at all, it is set to 20*C 24-7 in winter and summer. Our utility bills are considerably lower than people in older houses half the size so don't worry about it.
We have forced air heating and cooling and I can hear when the heating is on or off. In the day it is really only once every hour or two for 10 minutes at the most. Really doesn't take much energy at all to keep it at 20*C.
If we are away for the weekend we drop the temperature to 16*C for the cats.
There is going to be some threshold time period. If your whole house work super long hours, hitting the gym/pub after work such that you are all out of the house for bear 12 hours then this is a different scenario than when peoples schedules don't align exactly and the house is only empty 6-7 hours.
it will also deepnd on how cold it is outside, on a bitter winters day the house may fall to 10-12 *C and that will require a lot of energy to heat back up to 20*C.
We don't really touch the heating/AC much at all, it is set to 20*C 24-7 in winter and summer. Our utility bills are considerably lower than people in older houses half the size so don't worry about it.
We have forced air heating and cooling and I can hear when the heating is on or off. In the day it is really only once every hour or two for 10 minutes at the most. Really doesn't take much energy at all to keep it at 20*C.
If we are away for the weekend we drop the temperature to 16*C for the cats.
Highly dependent on insulation though. A good thermosflask can keep water at near boiling point for days.
Sure a house isn't built inside a vacuum but good insulation from a modern build will ensure the energy loss to the outside is very slow.
Which is why i said it depends on the house.
I have heating on maybe 4 hours a day as I'm in a 1902 house.
Keeping it on 24hr a day is crazy in my case
Mine is set to a timer, whether i'm on nights or shift work.
If i'm on nights, it set to come on @ 6.30am for an hour and that's it for the day.
If i'm working shifts, it will come on at 4.30am and be off at 5.45 just as i leave the house, and that will be it, if i'm on 2-12 it will come on at 11.30pm.
No way would i leave it running all day, we have a log fire that heats all of downstairs in around 30 minutes.
If i'm on nights, it set to come on @ 6.30am for an hour and that's it for the day.
If i'm working shifts, it will come on at 4.30am and be off at 5.45 just as i leave the house, and that will be it, if i'm on 2-12 it will come on at 11.30pm.
No way would i leave it running all day, we have a log fire that heats all of downstairs in around 30 minutes.
Last year, when we moved into our new pad, I splashed out £120 on a wireless thermostat with loads of options to configure, to replace the basic, temp-only one. However, with 3 young kids, me working shifts (4 on/4 off) there's not much of a routine to work with. We don't have a standard, day, night, weekday, weekend, so I've set one routine for one day, then copied it to all the other days.
Heating was perm off until last month. Now it's coming on throughout the day & night: iirc, it's 17C overnight, 19C in the morning, 18C during the day, 19C evening; rinse & repeat.
End result - it's sometimes on when we're out and sometimes off when we're in.
I need something smarter.
Heating was perm off until last month. Now it's coming on throughout the day & night: iirc, it's 17C overnight, 19C in the morning, 18C during the day, 19C evening; rinse & repeat.
End result - it's sometimes on when we're out and sometimes off when we're in.
I need something smarter.
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Soldato
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Sorry, this is just rubbish. Whatever the insulation value, the energy loss is proportional to the square of the temperature difference between the house and the outside.
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One thing I think a lot of people ignore is that air temp is one thing and comfort is another.
Our house is not that efficient to be honest, 1930's, takes a while to warm up and cools down really fast. However heating on a lot and it feels a lot warmer, I think it things like the furniture feeling warmer etc. Heating only on for short bursts and I hear the thermostat click off but it doesn't feel as warm.
Our house is not that efficient to be honest, 1930's, takes a while to warm up and cools down really fast. However heating on a lot and it feels a lot warmer, I think it things like the furniture feeling warmer etc. Heating only on for short bursts and I hear the thermostat click off but it doesn't feel as warm.