Keeping your home warm / heating / energy crisis / insulation etc

Cavity Wall Installation - anyone had this done? We're in a 1930s hoose with cavity walls. Just not sure how much of a benefit we'll feel or if the scare stories of damp issues are legit. Thanks!

Haven't had it done but there's a lot of cowboys out there. Ideally you want some open cell stuff like icynene to avoid damp issues.

Probably also want to make sure it's assessed afterwards to make sure the stuff has gone in evenly - with a thermal camera for example.

Thats my fear - the cowboys! We have a company called Locohome coming out in the new year, who are a retrofit assessor that my wife knows. Hoping we can get some legit contacts from them. It seems to be a pre-requisite for getting any kind of grant for ASHP from what I understand.

are you in Glasgow? Or is that a different group?

If it's the same lot, they are great. Would recommend them, they really know their stuff.

Yeah Glasgow (just outside). My wife has done some work in Govan with them and their retrofit projects so we kind of know them.

we got a report from them (the founder lives round the corner). Hopefully the report helps you as much as it did us!

If we lowered the flow temp of our boiler to 55 degrees, would that provide a reasonable approximation of how a heat pump would behave?
We have an unvented cylinder and 55 is maybe a bit low to prevent bugs, but we could run the immersion heater occasionally to boost the temp and kill of any nasties.

For the best efficiency you should be aiming for 45 degrees. HPs are pretty inefficient at anything over 50 degrees. The newer models are engineered to produce higher temps (I guess to mimic gas boilers so reduce the need to modify existing rads, and user behaviour) but they’re still more efficient the lower you go.

For hot water that means you need a bigger cylinder as much more hot water is being used. Instead of mixing 60 degree water with cold to shower at 40 degrees, it’s almost all coming from the cylinder at 45. That just seems like a no brainier anyway, why heat water to a higher temp than you need only to dilute it. Additionally, a tank at 60 degrees looses much more energy per hour than a tank at 45.

ASHP controllers have a disinfection cycle built in where the HP takes the cylinder up to ~55 then the immersion kicks in to hold it at 60 for ~20 mins. Ours is one a week but if I could, I’d set it to once a month. The risk of legionella’s is actually pretty low, especially if you’re cycling almost all the water out the cylinder on a daily basis.

You could drop the flow temp for HW by five degrees every week or so, see how you get on. The limiter will be the cylinder size.

Ok cool. I'll drop it a bit and see how we get on. Cylinder is 200l.

Anyone got any experience with PV-T solar panels? Expensive and complicated or a good option if space is limited?

Is the latest Tado summary that I can either get the Wired or the EU Wireless version if I want modulation?

I don’t understand your English, but ideally you want the EU wireless thermostat version to get the modulation.

just a word of caution for anyone relying on the humidity readings in/on their Nest thermostat, that they may not be accurate and read too high.

noticed the numbers on the dehumidifier (fancypants Meaco Arete) were a good 10-15% off from the Nest, whilst in close-ish physical poximity, so got a cheap hygrometer from Amazon, which matches the Meaco to within 1%.

there’s also this thread with lots of folk reporting similar issues, with the only real fix being getting a new unit.

could be worse i suppose, in that at least this old house is consistently in the low 50s rather than mid 60s %RH-wise!

RH measurements are never particularly accurate, I think+/-3% is usually considered good

so got a cheap hygrometer from Amazon, which matches the Meaco to within 1%.

Those cheap hygrometers can be wildly off, I've had some 10-15% off so you need to calibrate them but it's pretty simple to do.

Put a teaspoon of salt in a bottle cap, add a few drops of water so it turns into a paste, put the lid and the hygrometer in a ziploc bag and leave it over night. The reading should be 75% so if your hygrometer is showing 72 then you know how far off it is, you can't normally change the reading on the cheap ones so you'll just have to remember to subtract or add to what ever it shows.

You can then use the cheap hygrometer to calibrate your other ones.

Think in this thread people have mentioned infra red cameras before, this looks a good deal on a well reviewed budget option
https://www.hotukdeals.com/4275911

I need to lift part of the floor in my kids room to fit a light. I won't be able to lift the whole floor due to the furniture and time constraints.

Is there any value to insulating ⅓ - ½ the floor?

It's a 1st floor of a 1950s semi, wood joists.

I'm just conscious that I've always kicked myself for not insulating my youngest's room when we did the floor and had the chance. So I figured if I could squeeze part of it in, then there maybe a chance of doing the other half down the line.

Upstairs room? Consensus online seems to be don't bother insulating upper level floors because you want some heat from below

Only insulate between warm and cold. Unless it's for sound.

Cheers. That's really helpful.

The youngest's room has the hall and a staircase below so I think that makes sense at some point, but clearly the eldest's room isn't a good idea.

I actually disagree slightly with the orthodoxy that it's not worth insulating between floors.

This is coming from someone who's spent months going down eco insulation wormholes (and I've just finished an online course on it too).

There are a few other advantages to insulating between floors. At the risk of stating the obvious, it helps you zone the rooms by keeping some warm while not heating others, which is more efficient. If you spend most of your time downstairs in your living room/kitchen then you won't be paying to heat upstairs rooms which may not need it in winter.

Current thinking on heating and insulation has fortunately developed past the 'heat your house as one big box' approach to focus the heat where it's really needed (see things like Tado TRVs, energy firms giving out electric blankets), so IMO it only seems logical to insulate between floors and rooms to extend this thinking and only pay for heat where you need it.

It can also help with overheating problems in summer. Our bedroom is at the top of a three story terrace and it gets way too hot. Some of that is heat which is rising up through the house - through the fabric of the building but also up the stairs which are currently open to the living room - so we'll have a lovely cool living room but an unbearably hot bedroom. Adding in insulation between the floors with a high specific heat capacity will slow that heat transfer by storing up the heat and slowly releasing it over time, buffering the overheating effect.

But hoefla is right of course and the main reason to fit it is acoustic. This is another big reason we're doing it and I wouldn't underestimate how much good acoustic insulation can benefit the final feel of a room or building. Objectively it enhances privacy, improves comfort, boosts productivity and there's some evidence it improves your health too, but more subjectively people who've had a lot of insulation fitted tend to perceive rooms as being more cosy and 'softer'. Which is probably not surprising if like us you currently have 175mm joists and nothing in there but dust and a load of old shit - it's like living on top of a drum 🥁

They who shall be obeyed do agree with me because intra-floor insulation is now required in new builds under part E of the regs. Personally with our renovation I'm bringing things up to current regs standards where I can, so another reason it's a no brainer for me.

Worth adding that if you're putting it into an older building it needs to be breathable and ideally hygroscopic to help maintain the health of the building and prevent sagging - just in case kid in said room knocks a drink over in the future...

(and I've just finished an online course on it too).

This sounds interesting, how much was it?

Free! I should have said it was the one @hoefla posted, so thanks to her for that.
https://woodfibreinsulation.co.uk/courses/

I did the retrofit one, which was especially relevant for me as I'm planning on using wood fibre batts for external and internal wall insulation, with hemp flax combi jute in between the floors because it has a higher heat capacity and better soundproofing qualities.

With it being free my expectations weren't high but it was actually really useful.

Similar to fox, I live in a three story terrace, the ground floor is to cold, the top floor with bedrooms is too hot, currently radiators are turned off in bedrooms and I sleep with the window slightly open to manage temperature. The main culprit has too be the staircase but I can't see how insulating between floors wouldn't help with slowing down heat transfer and keeping it where i want it rather than badly relying on trv to control heat in to the room.

That is great thanks (and @hoefla !)

currently radiators are turned off in bedrooms and I sleep with the window slightly open to manage temperature

Are you from the north by any chance?! :P

I'd agree the main culprit is the stairs - we're planning to fix that by changing the stair layout a bit and putting a pocket door at the bottom so belt and braces really. Should also fix the issues with smells and noise - if we leave doors open sometimes we go up to bed and the bedroom smells of dinner!