New wireless thermostat recommendations?

[stevesey]

That's odd I thought this was what he said:

I currently have a Sunvic mechanical thermostat in the hottest room in the house (thanks previous owner!) and it's getting on my nerves having to ramp up the stat to get any heat in the rest of the house and then turn it down again so you don't roast in that room.

Im saying that once the rad is hot and but the sound of the OP's comments there is not flow issue to the rad, that even restricting the rad will not make a jot off difference to the heat in the room.

Simple physics - heat out = heat in (with an allowance for efficency). If you really believe that reducing the heat in will not affect the heat out the challenge is there - patent it, and make youself rich. I await next years Times rich list.

Lets not forget the OP - perhaps we should ask why the room is so hot, what did the previous owner do to make it this way?

 

[gas4you]

But you aren't reducing the heat in! water temp is constant whether full flow or restricted. If you turn valve down or shut lockshield a bit you are just restricting the flow not the temp, therefore letting the pump push the water to the next rad easier

 

[HarrogateGas]

That's odd I thought this was what he said:

I currently have a Sunvic mechanical thermostat in the hottest room in the house (thanks previous owner!) and it's getting on my nerves having to ramp up the stat to get any heat in the rest of the house and then turn it down again so you don't roast in that room.

Im saying that once the rad is hot and but the sound of the OP's comments there is not flow issue to the rad, that even restricting the rad will not make a jot off difference to the heat in the room.

Simple physics - heat out = heat in (with an allowance for efficency). If you really believe that reducing the heat in will not affect the heat out the challenge is there - patent it, and make youself rich. I await next years Times rich list.

Lets not forget the OP - perhaps we should ask why the room is so hot, what did the previous owner do to make it this way?

From what you quoted there it sounds just like im saying....the room stat is knackered or does not have a neutral giving large swings in room temperature.......something easily sorted with a new digital room stat.

 

[HarrogateGas]

But you aren't reducing the heat in! water temp is constant whether full flow or restricted. If you turn valve down or shut lockshield a bit you are just restricting the flow not the temp, therefore letting the pump push the water to the next rad easier

Rejuice......you have just spoken what my fingers couldnt type!!

Rads do just what they say on the tin.....a 2000BTU rad will deliver 2000BTU's or heat when hot whether it has 100000 btus of flow though it or just 3000!!

 

[gas4you]

 

[pannierstan]

That's odd I thought this was what he said:

I currently have a Sunvic mechanical thermostat in the hottest room in the house (thanks previous owner!) and it's getting on my nerves having to ramp up the stat to get any heat in the rest of the house and then turn it down again so you don't roast in that room.

Im saying that once the rad is hot and but the sound of the OP's comments there is not flow issue to the rad, that even restricting the rad will not make a jot off difference to the heat in the room.

Simple physics - heat out = heat in (with an allowance for efficency). If you really believe that reducing the heat in will not affect the heat out the challenge is there - patent it, and make youself rich. I await next years Times rich list.

Lets not forget the OP - perhaps we should ask why the room is so hot, what did the previous owner do to make it this way?

Steve my reasons for my reply are that the OP has actually suggested what he wants to do and its a good corse of action.
Sod the rad, he is better to get a wireless stat and move it to a more neutral zone then by all means fit a TRV on the rad in the room that was too hot in the first place.
I am sure if you fanny around with a lockshield for long enough you might slow down the heat up time of the room in question but the fact is that the stat is either knackered or just in the wrong place!.

Look at the BG homewarm(lukewarm) systems from the late 80's early 90's. The stat was on the landing upstairs! or in a bedroom. No amount of messing about is gonna cure the fact that its just not right to have it there. Upstairs is always gonna be warmer than downstairs so the bloomin thing will shut off while you are still freezing in the lounge.

 

[stevesey]

But you aren't reducing the heat in! water temp is constant whether full flow or restricted. If you turn valve down or shut lockshield a bit you are just restricting the flow not the temp, therefore letting the pump push the water to the next rad easier

Heat output into room = (temp in - temp out) * volume

As the flow/volume decreases the total heat out will also reduce, of course the temp drop increases as the flow decreases so the resultant graph is a curve, not a straight line, but never the less the heat output decreases with flow.

 

[gas4you]

But what you are describing is normal balancing procedure to get your 11C or 20C differentials depending on what type of boiler is fitted. once balanced and rad/heating up to temp this will remain constant.

Volume must remain constant in the rad unless it empties as the heat is reduced

 

[stevesey]

Steve my reasons for my reply are that the OP has actually suggested what he wants to do and its a good corse of action.

Wasn't suggesting otherwise - after all I did offer up the heatmiser as a suggestion.

I was just agreeing with Tony and Chris that the OP should also be able to improve the situation by turning the rad(s) right down so the room warms up slower and therefore the rest of the house gets more time to warm up.

 

[stevesey]

But what you are describing is normal balancing procedure to get your 11C or 20C differentials depending on what type of boiler is fitted. once balanced and rad/heating up to temp this will remain constant.

Volume must remain constant in the rad unless it empties as the heat is reduced

By volume I meant flow (as I said in the text).

I just tried some maths and if you use BTU = Flow(gpm)*500*temp drop(oF). You can work out that a 5000 BTU rad needs about 0.5gpm at a temp drop of 20oF (sorry about the units figures come from a US rad manufacturers spec sheet).

If you then plot the graph for flow vs BTU for this rad you find the BTU output decreases with flow - slowly at first, i.e. 50% flow drop = 25% output drop, then more rapidly until 0 flow = zero output.

 

[pannierstan]

But what you are describing is normal balancing procedure to get your 11C or 20C differentials depending on what type of boiler is fitted. once balanced and rad/heating up to temp this will remain constant.

Volume must remain constant in the rad unless it empties as the heat is reduced

By volume I meant flow (as I said in the text).

I just tried some maths and if you use BTU = Flow(gpm)*500*temp drop(oF). You can work out that a 5000 BTU rad needs about 0.5gpm at a temp drop of 20oF (sorry about the units figures come from a US rad manufacturers spec sheet).

If you then plot the graph for flow vs BTU for this rad you find the BTU output decreases with flow - slowly at first, i.e. 50% flow drop = 25% output drop, then more rapidly until 0 flow = zero output.

Oh my god

 

[Agile]

Oh dear!

The original poster has gone away a long time ago!

Unfortunately a lot of you are forgetting a very basic fact!

I will only name H-G as he started the fallacy! He said that in a properly balanced system all the rads get equally hot.

That statement is correct but ONLY if all the rads are correctly sized for the room they are heating.

In this particular case this particular room seems to have an over sized rad ( or the others are undersized ! ).

In this situation the only way to make it work reasonable well is to restrict the flow into that rad until its heat output characteristics match the other rads. This may mean only opening the rad valve a fraction of a turn so the heat loss means it is not reaching the full flow temperature. An eighth of a turn or whatever is needed!

Tony

 

[Agile]

Oops

 

[stevesey]

Tony - getting really off topic - have you sorted you web pages yet?

 

[pannierstan]

Tony - getting really off topic - have you sorted you web pages yet?

Are you an Agile sponsor or something
PM him.