Domestic Central Heating volume/temperature/time/energy standard. Is there one?

Post new thread

Discuss Domestic Central Heating volume/temperature/time/energy standard. Is there one? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Status
Not open for further replies.
D

Datanaut

If it takes 10 hours for the temperature to rise by one degree in a windowless room measuring 3x3x3 mts with a 1 kw radiator on a 25 kw boiler one might say that the domestic heating system was failing.

My question:

Is there a standard laid down somewhere for domestic heating and if so what might it be called and where might I look for it?

My guess is that there is a standard and it's something like the temperature of a volume of air needs to rise by an amount over time for a given amount of gas burned.

My guess is that the equipment required is a gas meter a thermometer a stopwatch a tape measure and a lot of calculations and several mugs of strong tea..

My guess is that 'the radiators get hot and it seem OK to me" is not a test but an opinion.

Can I smell burning pants?
 
BS EN 12828:2003 Design for water base heating systems in buildings.
more likely BS EN 12831:2003 Method for calculation of the design heating load.
 
chris watkins said:
I am fairly sure that 5449 is now superseded, it is from memory around 20+ years old now.
Click to expand...

Yes 1990 standard. Superseded, Still not a bad document, Same sort of principles, surpose we must move on though.
 
-- The system is very slow to heat the property --
A company senior heating engineer came around to test the installation.
He measured the rooms and noted the doors and window types.
Counted the number and type of radiators and identified the boiler.


The engineer told me the radiator / boiler combination is correct for the property. He then left telling me that he would return with the correct testing equipment to make measurements. I phone back 3 weeks later and the engineer has written and sent his report to the other party despite never returning to do any testing! Without taking measurements his 'report' can only be opinion.


I've have tried to get access to the 12828, 12831 or the 5449 standard to see if I can do some of the calculations but the prices are prohibitive. Even if I could get my hands on the standards It's likely I might not be able to work out how to do the testing.


I assume you:
Note the room temperate.
Note the outside temperature.
Note the gas meter reading.
Note the time.
( there may be others like boiler temperature of the flow and return pipes? )


After:
A period of time has passed
OR a unit of gas has been consumption
OR the inside temperature has risen has by a fixed amount
OR a fixed time has elapsed


You take all the measurements again and using a formula you get some results which can be compared against the numbers in one of the standards 12828, 12831 or the 5449.


Can anyone point me to that formula or am I kidding myself it's just not that easy?


What I'm up against is a very large company that is taking advantage of my ignorance of domestic central heating systems. Do they not realise that in the long run it's a tactic that's doomed!


Doomed I tell you, DOOMED.
 
Datanaut.
First let me apologise because I am not going to answer your question exactly, there is an answer but I don't know it.
But we could start at some basics.
From what I have read I think you are a tenant and you think your property is too cold most of the time.
Just occassionally we come across poblems like this and find there is nothing wrong with the heating - the problem is with the resident!
The first thing to test - is very simple - is your home really too cold.

If your sitting room is 21 C when it is cold outside and your bedroom is 18C then everything is fine - your heating system is meeting standards.
Then you also need to know the outside temperature.
You living room has to be 21C when it is AA degrees outside. If it gets colder than AA then your living room will not get to 21 but that is OK.
What is AA.
AA is a normal winter low in your area - it is not those exceptional cold spells.
And what exactly is AA?
It is different across the country - I expect someone else can tell you before I find a link to it. Here in the S East I think it is about 3 degrees and as you go further north it gets lower.

Before you waste time and energy just make sure your home really is cold. The people we have seen who complain about their heating in the way you have are complaining it is cold and nothing works when they have their homes at 27C or more!

Of course, your heating system may really be not designed correctly.
 
Last edited by a moderator:
also is the boiler on full i had a tennant complaining the house was cold and she had the boiler on 1 when i suggesated she turn it up she said if she did that it would burn to much gas
 
outside design temp between 0 and -5 normally, 21 degrees in living spaces, 22 in bathing rooms and 18 in sleeping areas and wc.

each rooms heat loss should be calulated and depends on size, u valvues, air changes etc.....


examples of some suggested outside temps.

Belfast
-1.2
Birmingham
-3.4
Cardiff
-1.6
Edinburgh
-3.4
Glasgow
-3.9
 
ask the installation company for the heat loss calculations. Is it a new house?
 
And.
Now I've thought about it - there isn't an answer to your original question because it doesn't take account of heat loss and it assumes the heating system will always raise the temperature.
You give example of 10 hours to rise by 1 degree - but how hot is it in there? If it is only 15C then yes you have a problem and if above 25 not.
 
Dear Tara and Steve,

Thanks for your answers and I'm aware of the issue with cold and that it may well be a tenants perception that is really the problem. I know about the temperate map that varies between areas. I run my place pretty cool in comparison to most at around the 18 C mark.

But when I go crazy and turn the temperature up to 21 for the belly dancing high teas I have every Wednesday we have a problem as the place never get's to 21 C like it used to. I believe that there is a restriction in the system. The 20 year old boiler worked fine until last summer. Then it started kettling and a new, more powerful A rated Viessmann boiler was installed. The 20 year old system should have been power flushed before the new boiler was commissioned. But it was not. And since the new improved boiler has been installed the house never makes it to 21 degrees and after 8 hours shuts down because it's lost all it's pressure. I've bleed the radiators and looked for leaks to explain the failing BAR pressure.

Got an engineer round to 'test' the system but as I said. He never actually did any test.

Is the system under strain because the flow round the system restricted by a blockage?
Is the BAR dropping because the pipework is losing water where I can't see it?

How does 'the radiators get hot' answer either of these questions?
 
Mrs Tara Plumbi said:
You give example of 10 hours to rise by 1 degree
Click to expand...
I just picked them crazy numbers out of my head. If I knew what sort of performance I was looking for I'd be in a better position to do my own test. I run the place pretty cool most of the time about the 16 C mark.
 
AWheating said:
ask the installation company for the heat loss calculations. Is it a new house?
Click to expand...
The house is end terrace and over 100 years old. I've lived here for 12 years. I've got the energy efficiency numbers, for that HIP thinf, from a identical house in the next street.
 
I'm aware that it's been very cold this year but so was last at the old boiler performed wonderfully. There is double glassing but the house is solid wall construction being an 1890's London town house.
 
If your rooms are not getting to the temperatures as described 21 22 18 etc. On a cold day then you have reason to complain.
Tae it up through what ever channels are available to complain to your landlord.
Sorry can't help any more but other might be able to.
 
I bought a medical, digital thermometer today that is accurate +- 0.3 c
The Honeywell thermostats is out by 2.2 c. Honeywell says 18 when it's actually 15.8
So the house has never actually made it to 21 C
My guess is inner London outside design temp -1.5
 
As said a heating system in the south east
designed to meet Minimum standards will not reach 21 C
when it is Minus C outside.
It should meet 18 bedrooms and 21 in living room when outside temperature is +3.
Different outside temperatures apply in other parts of country.

Sorry - not sure where to find reference for this and I am going from memory.

As for power flushing - it is not common when fitting a new boiler - a chemical flush is more likely to have happened on your installation.

Of course there may still be something wrong and I am not a technical heating engineer - good luck with your problems.
 
Mrs Tara Plumbi said:
As said a heating system in the south east
designed to meet Minimum standards will not reach 21 C
when it is Minus C outside.
It should meet 18 bedrooms and 21 in living room when outside temperature is +3.
Different outside temperatures apply in other parts of country.

Sorry - not sure where to find reference for this and I am going from memory.

As for power flushing - it is not common when fitting a new boiler - a chemical flush is more likely to have happened on your installation.

Of course there may still be something wrong and I am not a technical heating engineer - good luck with your problems.
Click to expand...
Domestic Heating Design Guide is the bible for this, unless you are half way up a mountain then it is -3 C in England with an internal temp in all rooms of 21 (including beds) except bath/shower rooms which should be 22 (housing for the elderly at 23). A heat up allowance is always added to the straight losses of 10% older housing & 15% newer builds. Also any selected heat emitter is likely to be over sized, so there is a likely hood that a steady outside temp of > -4 / -5 C the internal temp would be maintained with the heating left on.
The truth is they can be designed to what ever you like that is they you were advised to in early posts to request there design figures which you can then yous to check where a) it has been installed correctly & b) the design / heatloss are reasonable / acceptable for your dwelling.
 
Sorry.
I am talking rubbish - Chris is right.
I probably had a different 3 degrees on my mind!

If it any help about 40 years ago the standard was 18C in your living room when it was 0 outside!
 
Start with some basics as you have now bought a thermometer, turn the heating on full leave for an hour them measure and note down the temp of the glow and return coming out the boiler ( the 2 fat hot pipes, haha)
Then go round the rads and measure the temp at the pipe where it goes into valve, do both sides, then measure the temp of the rad, top and bottom in the centre, start nearest the boiler and work away to the last rad
Armed with this info we may be able to offer some guidance
Eg if the rad is too cool there is a prob with the system, if the rad is hot enough to fry eggs on the system is fine so either the rad is too small or the room is losing heat quicker than it is being replaced
 
The design is fine. I have had the calculation done independently. The house requires about 10.5 kw. The boiler is rated at 27 kw and I believe lose about 3.5 kw because the carcass is in concrete screed wrapped in hair felt and the whole house carcass is about 50 mts. The radiators are the correct sizes for the rooms.

I'm going to run my own test: Taking outside temp, inside temp, gas reading. Note the time. Set the heating thermostat to 25 c. ( Note that the heating thermostat is switching at 2 c lower that the digital thermometer is showing ). turn all radiators to fully open. Take new recordings ever 30 minutes for 4 hours.

Then I'll have some real numbers.
 
Started taking measurements and then the battery ran out on the digital thermometer. I'll post results when I have some.
 
Status
Not open for further replies.

Reply to Domestic Central Heating volume/temperature/time/energy standard. Is there one? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Newest Plumbing Threads

Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock