What is weather compensation?

[SimonH2]

Of course it isn't, it's completely different, in the 60s the outside temperature wasn't a factor at all.

You missed the point - it's so 1960s to control the whole house from a single sensor.

The example I gave, 960w vs 3400w, £42 vs £242 on Screwfix.

So what ? It's a one-off cost, amortised over decades. £200 difference, over 20 years is ... £10/year, less than a quid a month, and if you're heating with a heat pump, the ability to run at a lower temperature most fo the time will probably save you more than that.

Of course, I've said that often. But some houses, yours and Eric's at least, sound far for the norm and if you need particular tweaks to make it work better, then great.

I'd suggest "far from the norm" is inaccurate. Unless you have changed the laws of physics, I'd suggest most houses have some of the issues listed for some of the time. Hmm, thinks ... yup, I can recall as a kid constantly being told to shut the door as the living room gets a cold blast from the hall and stairs

Not my experience at all, central stat with opentherm, weather compensation and manual trv's works just fine for me and the ones I install.

Of course, when people don't know that better is available, and they've been told that what they're getting is the bees knees, then they probably accept suboptimal. Like when someone tells them a combi boiler is a great idea - it seldom is, except for the plumber who has an easy time installing it, and the developer who saves a square yard off the required floor area in the new-build showbox.

 

[denso13]

You missed the point - it's so 1960s to control the whole house from a single sensor.

We drove cars in the 60s as well, quite different from today's.

So what ?

Because you queried the 4x cost like I was just making it up. I showed you I wasn't.

suggest "far from the norm" is inaccurate. Unless you have changed the laws of physics,

No need to be snarky. Your house with a vaulted ceiling lounge and lots of glass upstairs and Eric's 3 storey house with a granny flat below are no where near normal.

course, when people don't know that better is available, and they've been told that what they're getting is the bees knees, then they probably accept suboptimal. Like when someone tells them a combi boiler is a great idea - it seldom is, except for the plumber who has an easy time installing it, and the developer who saves a square yard off the required floor area in the new-build showbox.

I disagree.

 

[ericmark]

I've been steadily putting larger rads in as I've been "doing up" rooms.

That is a good idea.

Who said anything about turning off completely ?

Eric has said it often, "no point heating rooms that aren't used".

I really don't know how much is completely off, and how much reduced, I have tested a mechanical TRV head, and set at say 2.5 I have found it will start reducing flow at around 18°C but not fully off until around 22°C but not tested the electronic heads, I don't really know if the timed setting changes from 20°C to 17°C will it close fully?

And I never set a room to zero, it would take too long to re-heat, so around 15°C is the lowest setting.
Radiator size and price.

The example I gave, 960w vs 3400w, £42 vs £242 on Screwfix.

But in real terms to fit a 3400 watt radiator in the space allowed for a 960 watt radiator means moving from natural air flow, to fan assisted, and this opens up a completely new can of worms.

I had a Myson fan assisted in my old house, worked very well, but in mothers house my attempt to use a fan with the radiator was not very successful.

The fan needs to be very low power, and also only run when radiator hot, so used a brewing thermostat as a way to turn the fan on/off. I could set the droop, so it would allow for cooling once the fan started, and the sensor went on the return pipe, a small USB fan with of course mains to USB adaptor was about right, and can nearly double the output, but simply spraying it matt black will do about the same.

The biggest problem, was radiators on outside walls, and the whole idea of air movement, we have all seen the text book pictures. even the text books can't, it seems, make their minds up. One of these can show the real temperatures quite easy, and one quickly learns we can have cold spots near windows which simply do not need correcting, as we simply don't sit right next to the windows, and simply curtains can allow us to have cool spots in the room which do not matter, so any fan to circulate the air can mean we need a lot more energy.

And if we put a smart TRV head on an outside wall, this will cause the boiler to fire before it is required. So we have these

so the TRV does not measure next to outside wall, but on an inside wall, once heating is running, really does not help, it only helps as to when it starts running.

It wasn't so much stored heat, it was gravity systems

It can work either way around, the hot coil can heat the DHW, or the hot coil can contain the domestic hot water, this idea where the DHW is at mains pressure, also allows multi-heat sources to heat the house and DHW, in real terms, likely twin tanks, and the installation cost means only really an option when the home is being built, not really for retro installation. However, there is no need for pressurised tanks, or combi boilers, to get reasonable pressure at a shower, be it a power shower or the way the heat exchangers are arranged, there are many ways to get the pressure up.

With my mothers shower it was far worse after the combi boiler was fitted, and the pump had to be removed. Not sure if I like a power shower, but a shower with side jets like this

can't run off a combi boiler.

I'd suggest "far from the norm" is inaccurate. Unless you have changed the laws of physics, I'd suggest most houses have some of the issues listed for some of the time. Hmm, thinks ... yup, I can recall as a kid constantly being told to shut the door as the living room gets a cold blast from the hall and stairs

Yes, there is a massive difference between our first house, with just a kitchen and living room downstairs, to the house spread over three floors, yet hardly any change in boiler size, even with a house with 4 times the floor area. There is nearly as much room in my granny flat, as there was in the whole of my first house. And energy use, likely nearly the same. Single glazed windows were better than living in a tent, but I well remember our winter of discontent and how fast the house cooled once the electric was turned off. This to this is quite a jump, using Google Maps photos, and in our first house, we found when the neighbour moved out our heating bill near doubled, clearly we had been getting a lot of heat through the party wall, since now in a detached house, what the neighbour does, hardly affects us.

I asked google for normal house design in UK in whose dreams?

 

[drives]

Not in our house.

I did say most houses, in fairness. Yours sounds unusual.

We cook in our house, and occasionally open the door as well. Weather comp still works fine.

 

[denso13]

We cook in our house, and occasionally open the door as well.

You mean, like they did in the 1960s?

 

[Odds]

I thought maintaining a steady temp in rooms around the house would help to combat damp: it does but now i've got to regulate the humidity to avoid excess condensation.

When God closes a door he opens a window...

 

[ericmark]

Oh, what a web you weave. Like the talk about trickle vents in windows, for a stand-alone heat recovery unit to work, the air blown in one direction must force air to also travel in the reverse direction, and trickle vents would mess this up. But not seen any rules which say trickle vents are not required where a heat recovery unit is fitted.

So single glazed windows, with their troughs and pipes to lead condensate outside, result in better humidity so when changed something needs to replace that function.

How this ties in to weather compensation I don't know?

 

[ericmark]

You mean, like they did in the 1960s?

The kitchen would have louvred windows to remove the heat from the Aga cooker which running on coke, would turn the kitchen into an oven.

The cooker did have dampers to direct the flue gasses, so you could control the ovens heat, but as the song said the smoke went up the chimney just the same.

We had high backed chairs to stop the draft, and got coke from the steelworks coke ovens cheap, as the blast furness could not use small coke.

I remember back then, and as a boy, having to shovel the coke into a wheelbarrow at the gates, and take it around the back of the house into the bunkers, as had to order a ton at a time.

 

[SimonH2]

We drove cars in the 60s as well, quite different from today's.

And ?
You are still suggesting the best way to control heating is by a single sensor, exactly as we did in the 60s. Slightly different sensor, but the same principle of trying to control heating across a property, with varying per-room requirements, by a single sensor which is almost certainly not in the best place.

Because you queried the 4x cost like I was just making it up. I showed you I wasn't.

You didn't specify what was 4x. In the grand scheme of things, the extra cost of a larger radiator is "back of the sofa small change" - especially when it's being changed as part of other works (some people will spend more than that on wall paper for a room.) How much did your heat pump cost ? How much less would it cost to run if all the radiators were larger ?

No need to be snarky. Your house with a vaulted ceiling lounge and lots of glass upstairs and Eric's 3 storey house with a granny flat below are no where near normal.

Not being snarky. "Many" houses have large windows. "Many" (all ?) houses have an upstairs and a downstairs - hence scope for the heat to b***er off upstairs if a door left open. "Many" houses have a room somewhere with a high ceiling - true ours isn't all that common, but it's also not a big part of the problem we are discussing as heat would still b***er off upstairs even if it had a "normal" ceiling.

I disagree.

I think we'll need to agree to disagree - because you aren't going to persuade me that you've changed the laws of physics which is a requirement for a single sensor in the house to be better than a sensor in each room, and even more so that the whole house temperature can be controlled just by the outside temperature.

I really don't know how much is completely off, and how much reduced, I have tested a mechanical TRV head, and set at say 2.5 I have found it will start reducing flow at around 18°C but not fully off until around 22°C but not tested the electronic heads, I don't really know if the timed setting changes from 20°C to 17°C will it close fully?

They do. Not only that, but they can apply PID (proportional, integral, differential) control techniques to maintain the temperature more closely than a mechanical TRV head. I.e., it's possible for an electronic one to settle at different valve positions for the same temperature. So unlike a mechanical TRV that will leave the room cooler if the heat demand is higher, an electronic one (with the right algorithms) should be able to achieve the same room temperature under varying conditions.

And I never set a room to zero, it would take too long to re-heat, so around 15°C is the lowest setting.

Ditto. It also avoids a very cold room "sucking" heat from a warm room in the same way that a very cold room would.

Radiator size and price.

But in real terms to fit a 3400 watt radiator in the space allowed for a 960 watt radiator means moving from natural air flow, to fan assisted, and this opens up a completely new can of worms.

Obviously there are variables. As I mentioned, in our lounge we had a "wasted" space that would take a 10ft long rad. In our dining room, I was constrained by the height of the window cill. There's also the simple fact that going back half a century it was common to have basic single panel rads with no fins - switching to one with fins, or a dual panel, or even a triple panel, takes no more wall space but sticks out from the wall more. What works best for any situation depends on a whole load of factors - of which available space is just one.

I had a Myson fan assisted in my old house

I've worked with them in the past in a commercial environment. Very good in terms of heat output for the size of unit, but not sure I'd want one in (say) a bedroom. And as I recall, sticks out from the wall a lot more than a (say) K22 radiator.

It can work either way around, the hot coil can heat the DHW, or the hot coil can contain the domestic hot water, this idea View attachment 421820 where the DHW is at mains pressure, also allows multi-heat sources to heat the house and DHW

Indeed, and I fitted a different Torrent store in our rental flat nearly 16 years ago. I have a custom store in our house. But thermal stores are still not all that common, and going back to the 60s they would have been quite rare - the standard vented cylinder and header tank in the loft would be more or less standard.
And guess what ? Now people are being pushed to get rid of their gas combi boiler and switch to a heat pump which ... tada ... needs a cylinder for DHW. And what don't new build houses built in (say) the last 1/4 century lack ? Yup, space for anything like that.

 

[denso13]

You are still suggesting the best way to control heating is by a single sensor

I'm suggesting it sometimes is, you are the one suggesting it always isn't. There is no doubt that some layouts need more thought, but in general, in my experience, most work perfectly fine with an opentherm room stat and weather compensation. Even with both, or none, they work perfectly well in the right situation.

How much did your heat pump cost ?

I don't have a heat pump.

How much less would it cost to run if all the radiators were larger ?

No idea, my heating systems work perfectly well as they are.

Not being snarky.

"Unless you have changed the laws of physics"? Ok.

I think we'll need to agree to disagree

That's ok.

 

[Roddy Young]

We have a Vent-Axia heat recovery ventilation unit in our house built in 2011, well insulated and draught proofed.​

There are no trickle vents anywhere. We rarely open the windows for ventilation.

Towels dry on the rail in the bathroom and toilet smells disappear in reasonably quick time.

According to :​

Trickle Vents & Part F: What to Know

Understand how Part F affects ventilation and trickle vent use in your window plans.

www.norrsken.co.uk

​

​

"What are the new regulations on Trickle Vents?​

The new Part F requires all homes to meet minimum requirements for Background ventilation through either mechanical ventilation with heat recovery (MVHR) or background ventilators (trickle vents). Requirements for MVHR are measured by whole-dwelling ventilation rates in litres per second and are discussed at the bottom of this article. Trickle vent requirements are measured in 'Equivalent Area"

 

[Odds]

Oh, what a web you weave. Like the talk about trickle vents in windows, for a stand-alone heat recovery unit to work, the air blown in one direction must force air to also travel in the reverse direction, and trickle vents would mess this up. But not seen any rules which say trickle vents are not required where a heat recovery unit is fitted.

So single glazed windows, with their troughs and pipes to lead condensate outside, result in better humidity so when changed something needs to replace that function.

How this ties in to weather compensation I don't know?

I guess it's all within the knock-on affect of changing the way we heat our homes in the 21st century, compared to the way they did when the houses were originally built - up to fifty years ago and over a century in some cases. These houses were designed to allow air-flow between brickwork which we now try to block using different insulation techniques, causing other issues such as condensation and mould, which we then attempt to tackle using filters and units like PIV, requiring all manner of monitoring devices.

If your phone has 'an app for that', all is well, but many older people don't have access to this technology leaving them vulnerable to rising costs without adequate compensation or funding to change the way they heat and ventilate their homes.

Thirty years ago, a single control fitted to an individual radiator was seen as a progressive step to only heating a room in which you were living but nowadays people prefer to lag their loft and heat all their rooms using modern thermostats. The argument here, it seems, is where to place the thermostat to achieve the best effect for reducing a heating bill.

 

[Razor900]

Its all a little irrelevant to the OP though as his oil boiler won't take very kindly to much lower flow temps...

 

[denso13]

Its all a little irrelevant to the OP though as his oil boiler won't take very kindly to much lower flow temps...

That's right, he did only ask what weather compensation is.

 

[Odds]

Its all a little irrelevant to the OP though as his oil boiler won't take very kindly to much lower flow temps...

furry muff.