<div dir="ltr">> <span style="font-size:12.8px">though I think the efficiency and therefore CO2-saving gains are mainly</span><div><span style="font-size:12.8px">> from reducing flow and return temperatures during milder weather.</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px">Have we considered a way to add sensors to measure the flow and return temperatures? (even if we can't control them). I may be mis-remembering, and may be showing my lack of knowledge, but I'm sure that I read somewhere that many condensing installations were not efficient as the return flow was always too high for them to actually do the condensing bit.</span></div><div><span style="font-size:12.8px"><br></span></div><div><span style="font-size:12.8px"><br></span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 22 December 2016 at 13:43, John <span dir="ltr"><<a href="mailto:john@stumbles.org.uk" target="_blank">john@stumbles.org.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Damon<br>
<br>
On 22/12/16 12:57, Damon Hart-Davis wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I have always assumed that weather compensation is simply the part<br>
that adjusts settings (eg flow temperature) based on current external<br>
temperature, ie reactively.<br>
</blockquote>
<br>
Yes, that's what the boiler schemes I've fitted do. Worcester's Wave also senses internal temperature at the controller (as per regular programmable thermostats) which I think they describe as "influence" but I don't know exactly how they combine the factors.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
There are opportunities to do more than that with the forecast,<br>
getting heat into the house early/late/whatevs if the next little<br>
while is going to be especially hot/cold/windy depending on the<br>
thermal time constant of your house. Potentially especially good for<br>
those with (say) UFH for example.<br>
</blockquote>
<br>
There's possibly some scope for some smart tweaking there, though I think the efficiency and therefore CO2-saving gains are mainly from reducing flow and return temperatures during milder weather.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Note that the compulsory compensation suggestion is out for<br>
government consultation right now, and I voted against it given the<br>
long payback times and the other rather lower hanging fruit (ie<br>
better places to spend the money to save energy first), and even<br>
against compulsory timers since most people don’t use them:<br>
</blockquote>
<br>
Why do you think weather comp would have a long payback time? Even at the price manufacturers charge for their thermistor-in-a-box sensors and the labour required to fit them the total cost should be in the £100-£200 range which should give a payback well within the lifetime of the kit.<br>
<br>
In my experience as a heating installer most people do use some form of time control on their systems, even if a significant minority don't. I think the Regs could do a service by assessing and mandating a usability factor for controls: there are some that even I struggle to set (looking at you Drayton!). But even if some people don't use their timers the building regs are there to mandate what installers provide: if time control isn't compulsory then cheapskate installers won't fit them and even householders who want and would use them won't have them. And given that a timer costs the square root of sfa there seems no justification for omitting them.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<a href="https://beisgovuk.citizenspace.com/heat/heat-in-buildings-online-consultation/consultation/" rel="noreferrer" target="_blank">https://beisgovuk.citizenspace<wbr>.com/heat/heat-in-buildings-<wbr>online-consultation/consultati<wbr>on/</a><br>
<br>
Guess what I thought *would* be a good solution that policy should<br>
support? B^><br>
</blockquote>
<br>
Intelligent TRVs? That would mean mandating Honeywell and a few other mfr's currently very expensive (and in some cases rather flakey) kit, which would surely have an unviably long payback time?<span class="HOEnZb"><font color="#888888"><br>
<br>
-- <br>
John Stumbles <a href="http://stumbles.org.uk" rel="noreferrer" target="_blank">http://stumbles.org.uk</a><br>
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