Rad delta T with wc.

[townfanjon]

Guys , just curious, how do you work out your rad sizes when using WC , rather than a set DT of say 50

 

[Last Plumber]

WC?
I work out the heat losses from room then look at Stelrad Charts to choose the rad. They do charts for 30T, 40T, 50T etc.
Does that help?

 

[townfanjon]

WC?
I work out the heat losses from room then look at Stelrad Charts to choose the rad. They do charts for 30T, 40T, 50T etc.
Does that help?

I think its the only way , as said I was just curious.
I have learnt from WC in my own house that sometimes my boiler flow temp can be lower than 45 C and it still heats the house and is no where near a DT of 40 / 50 .
I have started to leave off a “heat up”% of 1.5 because the heating is always on , would you agree ?

 

[chris watkins]

You just size as normal, the idea being that as the external temp rises from the designed low point, the required output from the heat emitter will be less to maintain the room temp. This is still met by progressively reducing the boiler flow temperature.

 

[townfanjon]

You just size as normal, the idea being that as the external temp rises from the designed low point, the required output from the heat emitter will be less to maintain the room temp. This is still met by progressively reducing the boiler flow temperature.

Cheers Chris , you have confirmed what I thought.
We bought a new house a couple of weeks ago and I am recalculating the rads . Would you agree and knock of the initial “ heat up “ calc from cold , just seems wrong putting it on .

 

[Last Plumber]

Yes, I would size things as per usual.

 

[chris watkins]

Yes, if it is going to be left on for extended periods & not no/off morning & night.
Just a word of warning though for those using time control with the modern construction insulation & building mass, 10 - 15% may not be enough, DHDG recommending up to 20%

 

[doitmyself]

DHDG?

 

[townfanjon]

DHDG?

Go on you will have to help me lol .

 

[chris watkins]

Sorry, Domestic Heating Design Guide.
I thought every one had a copy

 

[SimonG]

Mine's in me oftec handbag. Don't get to use it much.

 

[townfanjon]

Sorry, Domestic Heating Design Guide.
I thought every one had a copy

I thought it was something to do with double glazing lol , my copy is that old it must be edition one , theres no mention of weather comp in it .

 

[chris watkins]

Christmas presents ?

 

[townfanjon]

Christmas presents ?

Lol , me and Mrs TFJ gave up xmas presents years ago , she has everything!!! , Lol , and if the kids buy me anything apart from a bottle or two of jd I play heck with them , I rather they spend money on themselves.

 

[SimonG]

Christmas presents ?

Normally it's socks from the kids and smellies. Wife always surprises me and then i treat myself to drill or some other bitnof kit i need for work.

 

[doitmyself]

Sorry, Domestic Heating Design Guide.
I thought every one had a copy

Not at £28 a copy, just to satisfy my curiosity.

I assume the 20% "heating up" allowance is due to the considerably lower heat capacity of new buildings.

 

[Harvest Fields]

Does nobody use a mears’ calculcator anymore? Or are they classed as too outdated?

 

[chris watkins]

Outdated I would say.
I have always used either Myson or Stelrad Stars, once you get use to them they are good & free. More importantly you have a record & are acting like a pro.

 

[chris watkins]

Heat Loss Manager by MYSON
Stelrad STARS

You don't have to use there heat emitters etc.

 

[townfanjon]

Does nobody use a mears’ calculcator anymore? Or are they classed as too outdated?

I have one , very very basic , I have never trusted it

 

[Harvest Fields]

I have one , very very basic , I have never trusted it

Worked for years though.

 

[Sharp Point]

Is there a superb app out therefor heat loss, free or fee .... I don’t mind

 

[townfanjon]

Is there a superb app out therefor heat loss, free or fee .. I don’t mind

If you want a cheap quick one , Mr combis are ok .
However I have just worked our new bedroom heat loss / rad size etc etc , I did mine long hand and know it was right ( F1 F2 etc )and then compared it to the Mr Combi , quite a bit of difference.

 

[chris watkins]

If you want a cheap quick one , Mr combis are ok .
However I have just worked our new bedroom heat loss / rad size etc etc , I did mine long hand and know it was right ( F1 F2 etc )and then compared it to the Mr Combi , quite a bit of difference.

I like a man who does it long hand

 

[chris watkins]

Not at £28 a copy, just to satisfy my curiosity.

How about Satisfying a thirst for knowledge, doing things right, staying up to date.
It is called CPD.
£28 seems a small price to pay every few years.

 

[Harvest Fields]

I like a man who does it long hand

Mines all short hand

 

[ShaunCorbs]

If you want a cheap quick one , Mr combis are ok .
However I have just worked our new bedroom heat loss / rad size etc etc , I did mine long hand and know it was right ( F1 F2 etc )and then compared it to the Mr Combi , quite a bit of difference.

whose was higher ?

 

[townfanjon]

whose was higher ?

Mine , but I didnt work the bedroom at 18 , I used 21 because nobody in our house can shut doors . So I calc it all at 21 .