Since I installed a thermostat into the central heating I have been wondering which is the best (most efficient) way to heat my house.
I have a thermostat in the living room with a timer so you can set what temperature the boiler will kick in at certain times in the day. There is also
a control on the boiler than monitors the temperature of the water coming back to the boiler and if it is above the setting it wont fire up (like most
combis). Finally there are thermostatic valves on the radiators.
What is the best combination? Keep the rad valves fully open and boiler on max to get the house up to temp quickly, keep the valves open but turn the
boiler down so its not always firing, or one of the many other combinations.
I don't pay much for my gas and electricity at the moment but to be honest I find it hard to keep the house feeling warm. I put it down to the
very cold winter we had before Christmas.
you dont want the boiler turned up to max on the c/h system. depending on your rads i would say 70 degrees would be fine. the built in timer i would turn off and just use the heating as and when you need it,controlled by the room stat. thats what i do anyway
Probably not much help but, we use a log burner with a back boiler that feeds the hot water and radiators. We also have thestandard GSH set up but
just fire that up if we want instant hot bath water or while we wait for the log fire to get going.
£800 for the initial set up plus £200 for a hydraulic log splitter, but free wood from the council parks dept and our last gas bill was £15 per
Qtr.
Pay for itself in no time.
Andi
I must be a bit soft as I like the house to be slightly warm when I wake up. I like the idea of the log burner though.
Also interested in this, thought a lot about it but never really know any answers.
Particularly for a house where everyone works during the day so is empty 8till6 every day and has a lot of shared living/sleeping areas.
Currently we have the boiler temp around mid (160deg) , timer set to come on at 5, off at 8, on at four, off at ten.
Using thermostat valves on rads to balance out individual room temps and ignoring the poorly located main thermostat.
But then again, its rented accoms and we don't pay the bills.
Daniel
That's pretty similar to my house. I fitted a thermostat before the winter thinking it would help as most of the time we are all in the living
room, so as long as that room was warm then there was so point the heating being on any more. Haven't really been able to tell if it made any
difference as the winter has been so much colder than the last so far.
My gas and elec bills seem to be pretty cheap, but all 3 of us spend a lot of the time away with work and the house is empty most of Jan so the
heating just keeps it above 5 degrees.
Radiators are more effective at higher temps, but (condensing) boilers more efficient at lower temps (they rely on the return temp of the rads being
<55C to condense and so regain lost energy). So the most efficient way is to have low rad temps, but it'll be slow to warm up for your evening
temp. Either way, the most efficient way is to have it cooling during the day and night and coming back on in the evening. Our lowest gas use seems to
come from about 2 out of 6 on the rad outlet temp. However when it was -20 outside that was unable to get the house above 18C, so I bumped it up to
full temp.
At the end of the day you need to remember the above about efficiency (if you don't have a condensing boiler you don't need the return temp
<55), and you need to remember that heat loss depends on insulation and temp difference across the walls. Time to heat up and cool down depends on
thermal mass in the house and radiator size and temp.
Last year we had the CH turned half way up to keep warm.
For this winter we installed a logburner, room heater only no hot water but its a lot more efficient than the old gas fire and the CH has been on the
bottom notch all through the recent cold weather.
Muttly really appreciates it as well
With a boiler that monitors the water return temperature you a timer, not a wall mounted thermostat. These boilers use thermostatic valves on all radiators, then each room controls itself.
Wind down the water temperature to allow the boiler to condense if it is a condensing type. Dont go below 60 degrees or you will run into legionella
problems in your hot water cylinder.
Wind your main thermostat down in stages over a few days until you reach the lowest setting your comfortable with, for the whole house. Remember that
1 dergree less is 10% off your bill!
Adjust each thermostatic rad valve down until you find the most comfortable temperature for each individual room.
Ive wondered about this too.
in my opinion there are 2 thoughts on the matter...
1. leave heating on all day controlled by the thermostat, this stops the boiler having to work overtime trying to heat the house at set times of day,
using individual rad thermostats to regulate individual room temp (and turn unused rooms off, such as spare rooms)
2. use timer to set heating only when in the house, this stops you heating the home when nobody is in, but causes the boiler to work overtime at set
times of day again still using rad thermostats to control individual room temp.
I would love to know which one is more efficient, I get different answers from different heating engineers.
Fitted this to our house;
Honeywell CM927 Wireless 7 Day Room Stat
It made a huge difference. Boiler is set at 3/4 max on the low flame setting and it never achieves this.
The thermostat learns about the heat output the system delivers and tailors the on off cycle of the boiler.
It's set to 16 during the day 18 over night and 19 when we are in. Our fuel bills have been reduced and the house feels much cosier. Each room
can still be adjusted using the TRVs.
Next summer I'm going to install a tank stat so we don't overheat hot water.
JC
Many years (20) ago my Dad did an OU maths degree jsut for the interest. They had to come up with a mathematical modelling project as the final
assessed part of the course, and he chose to do one focusing on the most efficient way to heat a house - boiler on and off at certain times,
thermostatic valves, boiler runing all the time on low etc. (this was before condensing boilers were comon though). The model allowed for different
rooms at different temperatures, and covered a variety of domestic building sizes and boiler types/efficiencies. It also covered a selection of
building styles and levels of insulation. The conclusion:
Run your boiler for a few hours twice a day with thermostatic control on the individual radiators, but turn the stats up and down as you use the rooms
IF the outside temperature was above a certain value. If the temperature was below this value run the boiler continuously at a low setting and adjust
the thermostats as before. The surprising thing was that the switching temperature between these two options was between 6 and 8 degrees in
practically every case.
Regards
Hugh
hmmmm...
so basically I want a new thermostat that can do the following.
1. read outside temp
2. be able to adjust the internal temp based upon external temp (would need to program some sort of matrix as i dont want it to be 25 degrees outside
and 35 in my house)
3. it should have a button on it for when someone is in the house and when someone leaves the house
4. from the above data it should 'learn' our patterns
I should then set my boiler to the lowest setting and adjust with thermostatic valves?
I bet nobody makes on of these.
also if i was to redo all my plumbing without doubt I would ditch the TRV and zone each room instead with its own thermostat
I just found....
Worcester FW100 Weather Compensation Controller
that must save some money straight away, doesnt do my clever programming thing though.
Get rid of all those radiators and fit underfloor heating
Ok so that's not a cheap option (unless you work for the company that makes it (which I do)) but it seems to be the most comfortable.
A friend who was doing a degree had been set a task of seeing which was better and cheaper when heating a house. The conclusion was its best to leave
it all on, but controlled by the stat in the hall (or living area).
We first use to have it on a timer, so it was warm in the morning when we got up and also warm when we came home from work, but now its left on all
the time, but set at 11 degrees (when she hasnt turned it upto 18!). Its a combi boiler in a small 2 bed.
We never use the gas fire either and with no radiator in the living area as it was moved to the conservatory it seems ok most of the time, i feel that
wooden floors seem to be the main problem as my feet get cold quickly.
ps, i wear woolen socks over my norm sock in the winter round the house but found that a newly cleaned wooden floor and woolen socks dont mix, i went
comedy stile arse over tit the other day (feet above head) and ripped the door off its hinges trying to stop it. Really knocked the wind out of me
too, but i was trying to laff it off and trying to breath.
Just a small point I'm sure you've already realised. Make sure your thermostat is in the room you use most and want the warmest - not the
hall. And make sure your rad valves in the main living room are fully open all the time so the thermostat controls them. Then set the temp in the
other rooms with their rad valves.
We have ours set to a minimum of 16 degs, apparently it cost more to heat a house if you don't keep it to this sort of minimum temp. We've
also found in the very cold weather it can take a few hours to bring it up from 16 deg to the 21 we like in our living room so use a small electric
fire to boost it up quicker.
quote:
Originally posted by SeaBass
Fitted this to our house;
Honeywell CM927 Wireless 7 Day Room Stat
JC
That Honeywell one looks excellent.
My local plumbers merchant has it in stock, so I'm gonna connect it up before I go away - cheers chaps
[Edited on 28/1/11 by Jasper]