u/not_who_you_think_99

Get a bottle with a cap that you screw and unscrew, and you'll be sure it will never leak.
But you cannot unscrew it and screw it with one hand only.

Bottle caps with a straw top that you fold flat (the first two examples below) or with a flip top (the third picture) can be operated with one hand. But how leakproof are they?

I have never tried Hydro Flask nor GSI, but I have tried other brands with the same tops, and they always leak. Toss the bottle in a bag where it won't stay flat, and it will always leak.

The best leakproof cap for one-handed use I have managed to find is the Kambukka Elton. But Kambukka insulated bottles are heavy.

What is the best leakproof design for one-hand use? Have you had good experience with the straw cap or flip cap of any specific brand?

I don't need to store hot liquids, nor carbonated drinks.

https://preview.redd.it/5ubpqa09hzjh1.png?width=1142&format=png&auto=webp&s=d42ac20ba5e88fcda9899e2884743052d352d085

Get a bottle with a cap that you screw and unscrew, and you'll be sure it will never leak.
But you cannot unscrew it and screw it with one hand only.

Bottle caps with a straw top that you fold flat (the first two examples below) or with a flip top (the third picture) can be operated with one hand. But how leakproof are they?

I have never tried Hydro Flask nor GSI, but I have tried other brands with the same tops, and they always leak. Toss the bottle in a bag where it won't stay flat, and it will always leak.

The best leakproof cap for one-handed use I have managed to find is the Kambukka Elton. But Kambukka insulated bottles are heavy.

What is the best leakproof design for one-hand use? Have you had good experience with the straw cap or flip cap of any specific brand?

I don't need to store hot liquids, nor carbonated drinks.

https://preview.redd.it/adqz06twgzjh1.png?width=1191&format=png&auto=webp&s=1dc73ecb1ee66bde79bfbdbd55ddbe723b29ec8b

Get a bottle with a cap that you screw and unscrew, and you'll be sure it will never leak.
But you cannot unscrew it and screw it with one hand only.

Bottle caps with a straw top that you fold flat (the first two examples below) or with a flip top (the third picture) can be operated with one hand. But how leakproof are they?

I have never tried Hydro Flask nor GSI, but I have tried other brands with the same tops, and they always leak. Toss the bottle in a bag where it won't stay flat, and it will always leak.

The best leakproof cap for one-handed use I have managed to find is the Kambukka Elton. But Kambukka insulated bottles are heavy.

What is the best leakproof design for one-hand use? Have you had good experience with the straw cap or flip cap of any specific brand?

I don't need to store hot liquids, nor carbonated drinks.

https://preview.redd.it/sbnmz2qoezjh1.png?width=1166&format=png&auto=webp&s=7fbbce37cf756be49ea29f30a6418dd41f5d18a7

Installing air conditioning (air source heat pumps which heat and cool) became permitted development only in May 2025.

My questions are:

• is it permitted development only if the installer certifies the MCS noise calculation?
• if the client does the noise calculation, is it not permitted development?
• what if an acoustic consultant does? Some acoustic consultants do a desktop calculation (based on the measurements you provide), while others require professional drawings, which causes the cost to skyrocket

The reason I ask is because it's impossible to find an installer that does this calculation (I have contacted 8). If I search the MCS website for installers, it tells me there are none certified for air-to-air heat pumps yet! More than 2 years after these rules became effective!

Suppose I do the calculation myself. Can the council really force me to remove it not because the calculation was wrong, but because it wasn't signed off by an installer?

If I get an acoustic consultant to do it, surely the council cannot object? Even if the MCS document mentions installers only, and not consultants?

The law

https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises

states that

Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards

MCS publishes the noise calculation methodology here https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.0-Final.pdf and the spreadsheet for the actual calculation here: https://mcscertified.com/?standard=mcs-020-a-calculation-tool

This MCS consultation document states that https://mcscertified.com/wp-content/uploads/2024/11/MCS-020-Consultation-Response-Final.pdf

For installations without an MCS certificate, Planning Authorities will need to consider how to enforce claims of compliance to MCS 020 (a).

So is it basically left to the whims of each council?

The OP in this thread did the calculation himself, applied for a certificate of lawful development, and the council accepted it. I suppose each council will be different? https://www.reddit.com/r/ukheatpumps/comments/1msm5lu/lawful_development_for_air_to_air_heat_pump/

Installing air conditioning (air source heat pumps which heat and cool) became permitted development only in May 2025.

My questions are:

• is it permitted development only if the installer certifies the MCS noise calculation?
• if the client does the noise calculation, is it not permitted development?
• what if an acoustic consultant does? Some acoustic consultants do a desktop calculation (based on the measurements you provide), while others require professional drawings, which causes the cost to skyrocket

The reason I ask is because it's impossible to find an installer that does this calculation (I have contacted 8). If I search the MCS website for installers, it tells me there are none certified for air-to-air heat pumps yet! More than 2 years after these rules became effective!

Suppose I do the calculation myself. Can the council really force me to remove it not because the calculation was wrong, but because it wasn't signed off by an installer?

If I get an acoustic consultant to do it, surely the council cannot object? Even if the MCS document mentions installers only, and not consultants?

The law

https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises

states that

Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards

MCS publishes the noise calculation methodology here https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.0-Final.pdf and the spreadsheet for the actual calculation here: https://mcscertified.com/?standard=mcs-020-a-calculation-tool

This MCS consultation document states that https://mcscertified.com/wp-content/uploads/2024/11/MCS-020-Consultation-Response-Final.pdf

For installations without an MCS certificate, Planning Authorities will need to consider how to enforce claims of compliance to MCS 020 (a).

So is it basically left to the whims of each council?

The OP in this thread did the calculation himself, applied for a certificate of lawful development, and the council accepted it. I suppose each council will be different? https://www.reddit.com/r/ukheatpumps/comments/1msm5lu/lawful_development_for_air_to_air_heat_pump/

Installing air conditioning (air source heat pumps which heat and cool) became permitted development only in May 2025.

My questions are:

• is it permitted development only if the installer certifies the MCS noise calculation?
• if the client does the noise calculation, is it not permitted development?
• what if an acoustic consultant does? Some acoustic consultants do a desktop calculation (based on the measurements you provide), while others require professional drawings, which causes the cost to skyrocket

The reason I ask is because it's impossible to find an installer that does this calculation (I have contacted 8). If I search the MCS website for installers, it tells me there are none certified for air-to-air heat pumps yet! More than 2 years after these rules became effective!

Suppose I do the calculation myself. Can the council really force me to remove it not because the calculation was wrong, but because it wasn't signed off by an installer?

If I get an acoustic consultant to do it, surely the council cannot object? Even if the MCS document mentions installers only, and not consultants?

The law

https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises

states that

Development is not permitted by Class G unless the air source heat pump complies with the MCS Planning Standards

MCS publishes the noise calculation methodology here https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.0-Final.pdf and the spreadsheet for the actual calculation here: https://mcscertified.com/?standard=mcs-020-a-calculation-tool

This MCS consultation document states that https://mcscertified.com/wp-content/uploads/2024/11/MCS-020-Consultation-Response-Final.pdf

For installations without an MCS certificate, Planning Authorities will need to consider how to enforce claims of compliance to MCS 020 (a).

So is it basically left to the whims of each council?

The OP in this thread did the calculation himself, applied for a certificate of lawful development, and the council accepted it. I suppose each council will be different? https://www.reddit.com/r/ukheatpumps/comments/1msm5lu/lawful_development_for_air_to_air_heat_pump/

La situazione

Un parente anziano e abbastanza tecnofobo / analfabeta informatico (non ha nemmeno un indirizzo email) mi ha chiesto se ci sono banche dove si possano comprare BOT allo sportello, senza operare on line. O all'emissione o sul mercato secondario.

Questa persona ha ereditato una cifra che vuole investire a breve, un po' per l'età che ha, un po' perché tra 1-3 anni ne avrà bisogno per ristrutturare un immobile.

Opzione ideale

Il parente vorrebbe poter andare allo sportello, dire: compro questo BOT, e comprarlo, senza operare online. Ci sono banche che lo fanno? Anche se le commissioni sono più alte. Senza passare per consulenti o promotori finanziari

Opzione alternativa

L'opzione alternativa potrebbe essere aprire un conto online e dare al figlio la delega per operare.

Ci sono banche o broker che lo fanno? Mi pare Fineco? Directa? Ve ne vengono in mente altri? Deve essere in regime amministrato, quindi Interactive Brokers non va bene.

Da evitare

Non vuole consulenti finanziari e non vuole conti cointestati

Qualunque suggerimento sarà benvenuto. Grazie!

Since there have been many questions and posts on installing air conditioning in London, many of which with incomplete or imprecise information, I wanted to summarise the current rules.

Aircons are heat pumps

Air conditioners are reversible air to air heat pumps, which are a subset of air source heat pumps. Reversible means they can heat and cool. In fact, there is a green argument in favour of aircons because using them in the winter would pollute less. I had posted about the environmental impact here https://www.reddit.com/r/unitedkingdom/comments/1vbnh8m/comment/p0up3ls/

Permitted development

Aircon became permitted development in May 2025. Before then, only heat pumps which heated without cooling were permitted development. The law is: https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises

Permitted development - noise

In theory, to qualify for permitted development, the external unit must meet the MCS noise regulation. This means max 37 dB at each neighbours' window (excluding bathrooms corridors etc), calculated based on this tool https://mcscertified.com/?standard=mcs-020-a-calculation-tool and this methodology https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.0-Final.pdf

Noise - in practice

The calculation is based on the maximum theoretical noise produced by the unit at maximum power. In reality, the external units will be much much quieter most of the time. Many installers either don't know the rules or lie about them to push a sale

So how do you prove you meet the permitted development criteria on noise?

It's unclear to me if you can do the calculation yourself. I suspect that many people are fudging it (eg it doesn't pass because the neighbour's window is 5 metres away, but you put down 6 so it passes, hoping no one will check)

What to do if someone complains?

Modern units are very quiet and the noise in real life situations will almost always be much lower than the theoretical maximum. With minimum planning, it should be easy in most cases not to cause nuisance to your neighbours. I have no idea if councils will check whether the theoretical MCS noise calculation was correct or not.

What if you don't qualify for permitted development?

Then you must submit a planning application. Each council has its own rules: some require a maximum noise, but most require the unit to be 5 or 10 dB quieter than the background noise. This requires an expensive assessment by an acoustic consultant. This installer has a good summary of the rules in many London boroughs https://micro-climate.co.uk/air-conditioning-noise-regulations-london

Why are the rules inconsistent?

Because permitted development allows 37 dB, but without permitted development the limit can be as low as 21 dB: many back gardens are about 31 dB at night, so 10 dB less = 21 dB. That's an impossible hurdle to meet. It's hard to shake off the suspicion that it's a way to say: we cannot ban it outright but we can make it so bloody hard and expensive that very few will get it

How about flats?

As the law states very clearly (see first link), permitted development applies to flats, too. But only one external unit per block of flats. In practice it's a moot point, because leaseholders in theory need the freeholder's permission, which is very very rarely granted

Can a council override permitted development?

Only in limited cases. PD doesn't apply to conservation areas, and councils can remove permitted development rights from certain properties with an Article 4 Direction. But they cannot say: permitted development allows 37 dB but we want it to be 30 dB in all our borough

How ideological are some councils?

Very. Camden is one of the worst. They have a home improvement policy on their website https://www.camden.gov.uk/documents/20142/4823269/Home+Improvements+CPG+Jan+2021.pdf where they say that aircon is discouraged and that overheating is not a valid reason to get it approved. As per the first point, they fail to acknowledge that aircons are heat pumps and that using them to heat in the winter would pollute less than gas boilers.

If you need to speak to a council about it, NEVER say aircon - always say "air source heat pump".

I want to (get a roofer to) paint my south-facing flat roof with a white, solar reflective paint.

Has anyone done it? Any specific brand / type / feature you recommend?

Forgive my ignorance - do you use a different type of paint for a flat vs pitched roof?

I understand there is an SRI - solar reflective index, where black = 0, white = 100, but some reflective paints have certain chemicals that cause the SRI to be > 100, ie to reflect more heat than standard white.

The highest SRI I found was this Mapei (105) https://www.mapei.com/gb/en/products-and-solutions/products/detail/aquaflex-roof-hr

I want to replace the windows in my south-facing rooms with proper solar control glass, i.e. windows with low g-value (u-value: insulation, e-value: reflecting heat back into the room; g-value: solar gain).

Can you recommend any installer/manufacturer in the London area, selling sash windows with proper solar control glass with low g-value?

I have contacted as many as 8, and only found one which sells proper solar control glass.

They sell Saint Gobain solar control glass https://www.saint-gobain-glass.com/COOL-LITE-SKN-176-176-II#benefits---applications I contacted Saint Gobain to ask about other installers but got no reply.

The level of ignorance / sloppiness . cowboiness with all the other installers was beyond shocking:

• some didn't know what g-value is
• some said I don't need solar control glass
• some said theirs is low g-value but then refused to share the technical specs
• some confused g-value with e-value

It's no surprise that our houses and flats are greenhouses which overheat, if no one seems to know what is needed to limit overheating!

This may differ elsewhere, but in Europe virtually all air conditioners are reversible air to air heat pumps which can also heat in the winter.

Does any one use air to air heat pumps (air conditioning) for heating in the winter?

If I understand correctly:

• A2A is more efficient than gas boilers + radiators. In theory, it's about 4x more efficient, electricity costs ca. 3.5x more than gas (at least where I am), so, in theory, switching from gas boilers + radiators to a2a should result in a slight saving
• They heat a room much more quickly than radiators do, especially if the insulation isn't great
• However, rooms also tend to become colder once you switch a2a off. Instead, radiators keep a room warm for longer because hot water remains in the radiator even after you switch the boiler off.
• Modern a2a heat pumps with inverters consume relatively little to keep a room at target temperature (whether cooling or heating), so you shouldn't be shy about setting a target temperature and keeping it on for longer

My question is:

How do all these factors balance out? Does heating a house with a2a end up being cheaper than gas boiler + radiators? More expensive? Hard to tell?

For example:

• warming up the kitchen in a winter morning takes forever in my home. Maybe that's a case where a2a is cheaper? We turn it on while we have breakfast (not 1 hour before like we do now), then switch it off when we leave
• but how about other rooms? Eg we typically time the radiators so that they are on in the living room for 2 hours in the afternoon. Maybe with a2a we'd need to keep them on for longer?

Does any one use air to air heat pumps (air conditioning) for heating in the winter?

If I understand correctly:

• A2A is more efficient than gas boilers + radiators. In theory, it's about 4x more efficient, electricity costs ca. 3.5x more than gas, so, in theory, switching from gas boilers + radiators to a2a should result in a slight saving
• They heat a room much more quickly than radiators do, especially if the insulation isn't great
• However, rooms also tend to become colder once you switch a2a off. Instead, radiators keep a room warm for longer because hot water remains in the radiator even after you switch the boiler off.
• Modern a2a heat pumps with inverters consume relatively little to keep a room at target temperature (whether cooling or heating), so you shouldn't be shy about setting a target temperature and keeping it on for longer

How do all these factors balance out? Does heating a house with a2a end up being cheaper than gas boiler + radiators? More expensive? Hard to tell?

For example:

• warming up the kitchen in a winter morning takes forever in my home. Maybe that's a case where a2a is cheaper? We turn it on while we have breakfast (not 1 hour before like we do now), then switch it off when we leave
• but how about other rooms? Eg we typically time the radiators so that they are on in the living room for 2 hours in the afternoon. Maybe with a2a we'd need to keep them on for longer?

Do you have experience with TCL split conditioners?

My preference would be for Daikin or Mitsubishi Electric, but they are out of stock everywhere, whereas a local shop has TCL in stock.

My main concern is on reliability and availability of parts.

Do you have experience with TCL split conditioners?

My preference would be for Daikin or Mitsubishi Electric, but they are out of stock everywhere, whereas a local shop has TCL in stock.

My main concern is on reliability and availability of parts.

Can having solar panels + battery affect home insurance? In England - no idea if it's any different in the rest of the UK.

I ask because common sense and insurance don't always go hand in hand.

Eg Axa cancelled my home insurance policy when I asked them if they would cover my e-bike: not only did they refuse to cover it, but they cancelled my policy because they consider it a high-value item, which makes it more likely that burglars would try to break into my home. Ah, they make no clear mention of this anywhere in their policies.

Of course I don't expect anyone to try and steal my solar panels, but can insurers refuse to cover a house with solar panel and battery? Or consider the battery a fire hazard?

I have a common mid-terrace Victorian house:

• north-facing pitched roof
• south-facing flat roof (because of the extension)
• to access the flat roof, roofers open the Velux which opens onto the pitched roof, climb out, climb up the pitched roof to the flat roof, then come back
• The flat roof overlooks the back garden. It will probably be 10ish m high. You can put ladders onto the back garden but I have no idea if they'd get all the way there.

I imagine that installing solar panels on the flat roof would require scaffolding.

My questions are:

• can periodic servicing of the solar panels be done without scaffolding?
• do engineers climb up the pitched roof, the way roofers do, to service and clean the solar panels? Do they use ladders? Do they require scaffolding?
• Apologies if it's a silly question, but do only "cowboys" climb up a roof? How common is that? I ask because a friend has the external unit of an aircon on a similar flat roof (placed by the previous owner, not him), but now can't find anyone willing to service it without scaffolding

Of course putting up scaffolding every time I have to service the panels wouldn't be feasible, nor would I want to install them to then avoid periodic servicing

EDIT: Thank you all for confirming that they rarely, if ever, need servicing or cleaning. Sounds like I was worrying about what is, in fact, a non-issue!

Do you have any specific advice on installing the external unit of a multi split system air-to-air heat pump on the brick wall of a Victorian mid-terrace house? Basically a bog standard aircon which can also heat.

The kitchen has doors which open onto the rear garden, and an awning. The external unit would be installed just above that.

Of course I would get a professional installer to do it. But it's full of cowboys, and I know nothing about DIY or construction.

What are the things I should demand or watch out for?

Can all Victorian walls take the weight? Is there any way to test?

• The unit would be close to a small window in a storage room in our house. We are not worried about noise, but, structurally, can that be a problem?
• any specific anti-vibration mount I should ask for?
• is any kind of canopy needed against the rain?
• any specific way they should / should not drill through the walls?

Do you have any specific advice on installing the external unit of a multi split system on the brick wall of a Victorian mid-terrace house?

The kitchen has doors which open onto the rear garden, and an awning. The external unit would be installed just above that.

Of course I would get a professional installer to do it. But it's full of cowboys, and I know nothing about DIY or construction.

What are the things I should demand or watch out for?

Can all Victorian walls take the weight? Is there any way to test?

• The unit would be close to a small window in a storage room in our house. We are not worried about noise, but, structurally, can that be a problem?
• any specific anti-vibration mount I should ask for?
• is any kind of canopy needed against the rain?
• any specific way they should / should not drill through the walls?

There are many cowboy installers out there, who either don't know the rules, or know them but lie to their customers about the law on permitted development, in order to push the sale.

My questions are:

• for those of you who installed aircon / heat pumps with an external unit, do you have an MCS noise calculation done by your installer or by yourselves? Or do you have nothing at all?
• Of the installers you contacted, how many explained the rules and how many were like: "don't worry, guv"?

MCS publishes the calculation methodology here https://mcscertified.com/wp-content/uploads/2025/07/MCS-020-a-Issue-1.0-Final.pdf and the spreadsheet for the actual calculation here: https://mcscertified.com/?standard=mcs-020-a-calculation-tool

The law is here: https://www.legislation.gov.uk/uksi/2015/596/schedule/2/part/14/crossheading/class-g-installation-or-alteration-etc-of-air-source-heat-pumps-on-domestic-premises

This is for England - I think there are slight differences in the other parts of the UK but I have never looked into it