jack

Guys, can we please tone it down a notch?

I think the other thing is that they run on 24V so you don't need an electrician to install them.

I was talking only about IR heaters relative to, eg, fan heaters. As I said above, other than how thin it is, I can't see any advantage of this NexGen product over, eg, ordinary electric UFH mats.

IR panel manufacturers claim their products are more efficient because of how they heat. Instead of heating an entire room, you heat just the surfaces in the area where you actually need the heat. They aren't saying that their products are more efficient in the sense of more energy out per watt. I'm not saying I agree with this.

The efficiency claims are pure hype. All electrical heating is practically 100% efficient. The main advantage this product has is that it's very thin (0.5 mm).

Yes, but also because we already had a couple of cracks in our polished concrete layer and I didn't want to make those worse or add any more.

From memory, it took several days to warm up our slab from around 14°C to 20-ish when we returned from several weeks' holiday having left all heating off over a cold, dull and windy Christmas. That was only allowing a 27°C maximum flow temp. It might have worked faster with a high temperature flow, but I didn't want to heat things up too quickly.

I called your claim "extraordinary" because it contradicts basic physics (or at least what I understand of it). I didn't say you were a liar, I said that your arguments as to why there might be variations in measured O2 don't hold water, so "clearly something else is going on". Nothing you've said changes my opinion. I'm done with this thread. Apologies to the original poster for contributing to it drifting so far from topic.

Yes, exactly that.

Just because you don't see the point doesn't mean there isn't one. I'm not married, largely because my partner is firmly against the concept of marriage for socio-political reasons. Civil partnerships don't come with all that baggage.

Exactly. But none of the things you mention could possibly contribute to a 10-15% reduction (21% to 18-19%) in the amount of oxygen in the air. No-one's calling you a liar, but clearly something else is going on. You're the one making the extraordinary claims.

More than she likes the planet, it would seem.

@Bitpipe has an insulated basement and I'm sure his experience is that it doesn't overheat. I use our ASHP in reverse mode to cool the (insulated) slab on the ground floor. We have concrete floors so this is very effective. It's a far more natural "coolth" than that provided by aircon. I'm convinced that this helps keep the upstairs rooms slightly cooler too.

I've had a very quick look and can find only a single source that suggests there are significantly lower oxygen levels in cities: https://www.theguardian.com/commentisfree/2008/aug/13/carbonemissions.climatechange Maybe you're right, but everything else I found talks about the dangers of all the other crap in city air, and the hypoxic effects of high absolute humidity and temperature, but these don't affect the proportion of the oxygen in the air, just its effective availability to humans.

The rate for ASHPs went up last April I think.

We really need one of those emojis where the head actually rolls as it laughs.

Sure, but no-ones disputing that changes in air density/temperature cause changes in power output. That's notoriously well known to anyone who's read car mags for any length of time, or been involved with flying planes However, everything I've read says that the proportion of oxygen doesn't change much out of doors anywhere on the planet. I can't find anything to support the idea that as soon as you move from a built-up area to the country the oxygen level consistently increases 2-3% as you suggest. I'm not questioning what you've seen, but there could well be all sorts of other factors involved.

But there isn't going to be a 2-3% difference in oxygen levels between places in the UK. It's more likely to do with machine calibration.

I just leave it overnight and drain it in the morning. No idea what temp it reaches but I'm sure most of the temperature difference is captured this way. Life's too short to think any harder about it than that!

Interesting. That's one of those weird double-think moments where I held two opposing pieces of knowledge at the same time without realising the contradiction!

On the odd occasion we use a bath during the heating season, the water is left to go cold before draining.

Welcome!

Oxygen levels outside are more a function of altitude than country v city. Of course, cities have other components floating around that are less of an issue in the country (although those with certain allergies may disagree!) MVHR can absolutely make a difference to air quality, especially in relation to CO2 levels (which affect perceived air freshness far more than the O2 level). Re: per room temperatures, I don't zone our downstairs UFH. There's just one thermostat and that controls the whole house. However, you can set up the flow rates per room so that, say, the kitchen is cooler than the living room (or however you like it). Less flexible, sure, but has the big benefit of simplicity, with only a single thermostat and no need for per-loop controls. I haven't bothered, as I'm perfectly happy with it running with all loops wide open.

Yes, that's the stuff. I've been looking into it for my garage but I think it's going to be too expensive.

Thin layer of self-leveling topper perhaps? Not cheap but neither is grinding.