Green Building Forum - Should air conditioning be banned

Should air conditioning be banned

tony — Mon, 28 Oct 2019 23:14:27 +0000

A friend suggested that air conditioning (air cooling) should be banned in the UK as it uses so much energy and in his opinion was unnecessary in both cars and in buildings

Thoughts please

Should air conditioning be banned

MatBlack — Tue, 29 Oct 2019 07:40:20 +0000

Never thought about these before, just a quick Google, I didn't realise how much energy they do use, 3.5kw start up and around 1200w constant use for a medium one. God knows what banks of them use commercially!

Should air conditioning be banned

djh — Tue, 29 Oct 2019 09:36:37 +0000

Posted By: tonyA friend suggested that air conditioning (air cooling) should be banned in the UK as it uses so much energy and in his opinion was unnecessary in both cars and in buildings

I disagree with regard to commercial buildings. It's often the case that the internal gains can cause significant overheating. It's true that many A/C systems could be redesigned to use more efficient systems, such as [solar-powered?] absorption chillers.

I'm afraid I like the A/C in my car too much. Given how hot they can get when parked, I wouldn't want to do away with it.

And if and when I do buy an ASHP for my home, I expect it will be a reversible one. I used to be opposed to the idea, but not so much now.

Should air conditioning be banned

owlman — Tue, 29 Oct 2019 09:57:57 +0000

Is heating banned, - then why should cooling.
Admittedly buildings could, and are, being designed to minimise both but until we have all buildings so fitted then I don't think you can just ban it. You could argue, ( as djh mentions) if its integrated into solar production then why not, especially as it's efficiency can be very high.
Making electricity more expensive might concentrate the minds more.

Should air conditioning be banned

tony — Tue, 29 Oct 2019 13:53:42 +0000

Thanks, a range of opinions

Using lots of energy efficiently is worse than not using it at all.

Commercial buildings use air cooling even when it is cooler outside than inside (this is generally the case)

Cars, yes it is nice but is it necessary?

Heating in particular overly hot heating will need to be banned at some point.....I think

Should air conditioning be banned

dimengineer — Tue, 29 Oct 2019 15:09:27 +0000

Aircon in cars? Essential I'd say. I'm ld enough to remenber without - and you'd boil to death in the summers (or go deaf cos' you had to have the windows open. In the WInter - a major safety feature, as it prevents the wondows fogging up, which is a real problem when its wet & warm.

Should air conditioning be banned

dimengineer — Tue, 29 Oct 2019 15:10:44 +0000

AIrcon in domestic buildings though, like houses - unnecessary in the UK. Totally.

Should air conditioning be banned

djh — Tue, 29 Oct 2019 17:04:43 +0000

Posted By: tonyCommercial buildings use air cooling even when it is cooler outside than inside (this is generally the case)

Because their internal gains are so high. And in some cases you can't open windows. In the last place I worked there were both data centre-type rooms, which need to be sealed so they can flood it with gas fire extinguishant if necessary, and class-4 biological containment labs which need to be both sealed and ventilated even when there's a fire raging. In some places you wouldn't want windows open because of the external air quality.

I'm not saying that commercial buildings couldn't make better use of natural cooling, but there's no way you could ban mechanical cooling outright.

Cars, yes it is nice but is it necessary?

Well, right, but by the same logic we should ban cars themselves; not to mention TVs and an electrical supply grid. None of them are necessary. We managed fine before they were invented.

Should air conditioning be banned

Mike1 — Tue, 29 Oct 2019 18:43:54 +0000

No government would ban it when the newspaper headlines would then blame them for the number of people dying from the heat - and people are already dying from it in our current climate. If you hunt down the NHS 'Heatwave Plan for England 2012', you'll also see that excess deaths occur when the temperature goes above 25Â°C, and particularly above 27Â°C. Despite which I know one recent NHS building that was specified to have a 28Â°C maximum temperature.

This seems to have been a blind-spot in building design. I don't have statistics, but I'd be pretty confident that most UK buildings haven't seriously considered mitigating against heat and minimising aircon requirements.

Also worth knowing that the 1996 DoE 'Review of the potential effects of climate change in the United Kingdom' recommended that buildings â€˜be designed with the probable climate of 2050/59 in mindâ€™ - which is forecast to be considerably hotter than now. Of course nothing happened...

Should air conditioning be banned

cjard — Mon, 04 Nov 2019 16:07:16 +0000

Posted By: djh

And if and when I do buy an ASHP for my home, I expect it will be a reversible one. I used to be opposed to the idea, but not so much now.

It's n ot so effective as you might think, though some of that might be down to the design of my house; I have a reversible one but I suspect it largely ineffective as it removes heat from the floors, which are the coolest part of the room (my UFH in the mid and top floor has insulation underneath). No one designs a fridge with the cooling plates in the base - they're always in the back or the top (and masquerade as a pseudo-freezer compartment)

I've long pondered that it would probably be better to have an ASHP inside the house as well, given that they generate colder air in exchange for warmer water, so the solution to my too-hot house would be to take the heat energy from the air/fabric and dump it into the hot water tank (which I will then use for a shower before dumping the heat down the drain) rather than paying money to dump it outside directly. In winter I'll use the ASHP outside, but in summer I'll use the indoor ASHP to provide the benefits of cooling the house while heating the water

Should air conditioning be banned

owlman — Mon, 04 Nov 2019 20:18:50 +0000

I assume yours is Air to Water, I have Air to Air and it's very effective at both heating and cooling.

Should air conditioning be banned

Paul in Montreal — Wed, 06 Nov 2019 13:16:12 +0000

Posted By: owlmanI assume yours is Air to Water, I have Air to Air and it's very effective at both heating and cooling.

Exactly. Air to water won't remove humidity, which is one of the best features of air-to-air (and water-to-air GSHP)

Paul in Montreal

Should air conditioning be banned

jamesingram — Wed, 06 Nov 2019 17:50:43 +0000

should it be banned ,yes except for medical conditions

Should air conditioning be banned

cjard — Thu, 07 Nov 2019 06:26:32 +0000

@paul running an air to water inside the house should have a slight dehumidifying effect too, as it seems there's always some condensate

Should air conditioning be banned

Paul in Montreal — Thu, 07 Nov 2019 17:43:37 +0000

Posted By: cjard@paul running an air to water inside the house should have a slight dehumidifying effect too, as it seems there's always some condensate

Where does it condense, though, on the floor? That's not good if it's the case! A small A/C that dehumidies well will feel more comfortable than a larger one that short-cycles and doesn't remove humidity. Dry air can also feel comfortable at a higher temperature than damp air - so the sizing of the A/C makes a big difference to comfort levels and energy use.

Paul in Montreal.

Should air conditioning be banned

HollyBush — Thu, 07 Nov 2019 23:31:23 +0000

Banning is not practical and is certainly undesirable in many cases. Enforcing efficient ones would be far more practical.

Tumble driers, oil fired heating, radiators with no thermostatic controls, outdoor gas fired heaters, all get my ban well before aircon.

Gas fired hobs and ovens would be next, along with preventing the building of any new building not meeting established good practice for energy efficiency in use. Same for boats, caravans, cars, lorries, planes etc

Whilst we're at it how efficient are the shop heating things that blow a curtain of hot air at the door?

Should air conditioning be banned

tony — Fri, 08 Nov 2019 07:15:00 +0000

The problem I have with efficient is that they are all very efficient but we need to reduce our energy use and using efficient things does not necessarily achieve this goal, indeed we can and do tend to use more and more energy.

The electric air curtains are 100% efficient at using energy but waste a huge amount of it. Closing the doors would be a far far better option in terms of reducing energy use. The manufacturers of air curtains spin it very differently some how.

Outdoor heaters were discussed on here years ago and should have been banned by now.

Should air conditioning be banned

LF — Fri, 08 Nov 2019 09:21:40 +0000

Holly Bush

Gas fired hobs is on your list of bans, what are you going to cook with instead ?
Wind has massively reduced carbon emissions from Electricity production but it is a long way from stopping them.

40 odd percent efficient gas powered generator is likely to be making your cooking hob electricity kWs instead.
On a non windy, cool day then 2 to 2.5 times more CO2 emissions (more gas) from an electric hob than burning the gas on the hob.

I see the point in limiting new ones in 2027 but until there is something to transition to as heating source there is not enough non gas powered electricity to move everyone across.

Tony - I agree it is all about reducing usage energy usage and consumption of stuff.

AirCon in UK should be a no, except for the vulnerable. On the few days per year it get uncomfortable. Closing curtain and windows to keep the hot out during the day is generally enough.

Wood burners, that by basic chemistry of the fuel, generate twice the CO2 emissions as gas powered heating would be on my list, more in cities where they affect air quality, rather than off grid areas.

Gas fires that are not enclosed and over 90% efficient should go too.

How do you move inefficient boilers and fires out of use ?

Should air conditioning be banned

tony — Fri, 08 Nov 2019 16:19:30 +0000

Nice post Lee, thx.

Should air conditioning be banned

djh — Fri, 08 Nov 2019 20:44:46 +0000

Hmm, a quick google produced the following link as the first chart to compare fuel types:

https://www.icax.co.uk/Decarbonising_Heating_2022.html

From that it appears that next year even my resistance heating induction hob will be 37% better than a gas hob!

I'm not sure whether heat pump hobs are available?

Either way it looks like electricity is the way to cook.

Should air conditioning be banned

LF — Fri, 08 Nov 2019 22:57:24 +0000

Good to debate. The figures above are from heat pump association so not exactly independent. They state electric heating more efficient than gas heating by 1/0.85 which is about 20% better. Modern condensing boilers are better than this. But back to our cooking ...

Induction hob is likely more efficient than gas hob when boiling a pan of spuds and perhaps a microwave even better.

Government report shows about 50% of electricity is from gas and coal. Mostly gas now thankfully about 4:1 as coal and wood emit twice the CO2 as gas for the same heat output.
So 50 to 60% of electricity uses fossil to generate the electricty, but the effeciency of the fossil bases generators is only about 40 % hence the massive cooling towers dumping waste heat So for a kW of electricity in your house it is 1/0.4 x say 0.55 (fossil gas eqivalent) which is about 1.38 times as much CO2 as a kW of gas

(gas is about 2.5 times cheaper than electric generally per kWh for these type of reasons)

It seems induction hob and gas hob are in the same ball park or gas hob less CO2 emissions ... certainly not a reason to ban gas hobs which was my point as they are just emitting CO2 from different places at the very similar rate ? Gas hob warms your house a bit more in winter ?

figure 3 of report
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/790626/2018-provisional-emissions-statistics-report.pdf

In fact when lots of cooking happens from 4 to 7 PM is when peak electrical demand is and it is likely gas and even diesel systems are pushing in electricity for these peak periods, especially on non windy winter days when solar is not doing anything.

So if electricity is about 1.4 times more CO2 for a given unit of heat/energy then heat pumps with an CP of 2 to 3 are clearly now a low better than using gas for heat. Lets say 2.8 to make numbers easy and then heat pumps have half the CO2 emissions of gas for a given amount of heat assuming and efficient gas boiler etc.

Heating is biggest user of heat in general homes followed by hot water - so heat pumps would have biggest impact there at reducing CO2 emissions. I think that is what the "Fuel carbon factor
gCO2/kWh in 2020" in your attachments table are getting at. Where

There is biomethane in the gas grid these days which has 90 to 50 % less CO2 than fossil natural gas, there is not enough to make a massive difference yet. They are also looking to put hydrogen into the grid to reduce CO2 emissions further as that would burn to make only water. They would try and use surplus renewable electricity to make the hydrogen.

Should air conditioning be banned

HollyBush — Sat, 09 Nov 2019 00:58:40 +0000

"Gas hob warms your house a bit more in winter ?" err, aren't you venting the stuff out doors with an extractor fan? Which is far less necessary with an induction hob.

Each year more and more electricity will be from renewable. Why allow gas hobs, heaters, boilers etc now? Why not announce the phasing out of all, similar to the heat pump v gas boiler.

But if I ever get both solar panels and aircon, I will run the aircon when the sun shines. I would even eat uncooked food to offset. But whilst there are so many other bad ways to pump CO2 into the atmosphere, I'm unlikely to agree to ban it.

Should air conditioning be banned

gyrogear — Sat, 09 Nov 2019 03:00:20 +0000

Posted By: HollyBushBut whilst there are so many other bad ways to pump CO2 into the atmosphere

The idea is to EXPAND the use of air conditioning, using dry ice as the refrigerant...

https://mashable.com/article/ac-units-climate-change-carbon-capture/?europe=true

gg

Should air conditioning be banned

LF — Sat, 09 Nov 2019 11:14:05 +0000

HollyBush,

Gas is being phased out for new builds from 2027 is it not. Should not need heating or tiny amounts by then if housing design was properly energy efficient by then.

Your comment
"Gas hob warms your house a bit more in winter ?" err, aren't you venting the stuff out doors with an extractor fan? Which is far less necessary with an induction hob.

Not sure your comments stack up, but I think gas hobs, will go in new build as CO2 efficient heat pumps come in on the new builds and reason for connecting gas to the house goes away.

I use gas hob and would welcome advice showing it is dangerous or that I need to have an extractor fan on for me to use it. Extractor is used for the steam and smells from food rather than the heat and combustion products of cooking - so extractor is same for both. In modern world extractor should recover the heat anyway of the air being thrown away.

I have a "feeling" but no evidence that induction hob uses a little less energy to heat food than a gas hob but differences are likely small. I therefore gave advantage to electric hob in trying to work out which emits less CO2 overall. They seems effectively the same give or take.

Induction hob uses electricity which emits more CO2 by something like 1.4 times per unit of energy as burning gas.

Cooking hobs are very small energy user compared to heating and hot water, so hobs are not going to have much effect either way. If the electricity grid were bigger and green in winter then electric heat pumps would be a greater impact on reducing CO2. If the major use of gas in house is removed with the boiler replaced by a heat pump then small cooking hob becomes pointless and will go to electric you would think.

Many more knowledgeable people on here, know about building energy efficient houses which reduce needs to almost no heating being needed, so the debate on new build should be why is a heat source needed over a couple of kW.

There is not enough electricity generation in middle of winter when wind and solar, are off to power the country so a dash to electricity for heating would leave a gap in supply of electricity. There are fleets of diesel and gas powered micro generation sites on CHPS helping to bridge these sort of gaps as well as big gas fired power stations ramping up.

I take your point on when sun is shining and PV is producing electricity then surplus can be used to power AC, but good building design should limit the need for aircon. The surplus electricity is stored or the surplus electricity is used to get rid of CO2 from the air or something then you are better to design out the need for air con in houses in the UK. New build should not need aircon of done correctly.

In big populated buildings where you have lots of 100W/person heat sources inside the if it is hotter than say 24 C outside ventilation and solar shielding are not going to be enough to stop inside temperature getting to hot.

In hot countries the waste (60%) heat from gas fired electricity generators is used to power air conditioning in co generation schemes and do the hot water on hotels and the like.

It is quite striking when you visit houses in Malaysia where they have open windows and grills and fans. With Gekos on the ceiling to eat and stray insects / mesh on windows but very limited AC. You sleep well enough even in the very high heat.

Should air conditioning be banned

owlman — Sat, 09 Nov 2019 12:53:45 +0000

Posted By: LF
"There is biomethane in the gas grid these days which has 90 to 50 % less CO2 than fossil natural gas, there is not enough to make a massive difference yet."

Industrial Anaerobic Digestion,-- IMHO now there is something that should be banned.

Should air conditioning be banned

tony — Sat, 09 Nov 2019 13:11:31 +0000

As I see it biomethane contains exactly the same number or carbon atoms as normal methane

Is all carbon equal or is some more equal than others?

Should air conditioning be banned

LF — Sat, 09 Nov 2019 14:20:51 +0000

If the carbon bonds are from "this year" and not prehistory then there is a benefit to AD. Food waste and pooh are good sources of gas which overall release much less CO2 than fossil based gas. They are true waste.
Stuff that uses maize and sugar beet is nearer to only 60% better than fossil fuel.

LNG imported by shipping and liquidating, consumes energy and so I think is 20 to 30 % worse than natural gas from North Sea.

So not all gas burned is the same CO2 impact overall.

Should air conditioning be banned

djh — Sat, 09 Nov 2019 14:24:37 +0000

Posted By: LFThe figures above are from heat pump association so not exactly independent.

I don't know where you got this idea from? The page they are on is published by Icax, which is a firm that is involved in designing and supplying ground source heat pump systems, and it clearly states: " Using the predicted Carbon Grid Factor for 2020 of 136 gCO2/kWh published by BEIS on 11 April 2019". BEIS is of course the government's Department for Business, Energy & Industrial Strategy. So I'm not sure where you got the idea of a heat pump association from? My point was simply that what you said, without supporting evidence, might well be wrong.

Should air conditioning be banned

djh — Sat, 09 Nov 2019 14:25:08 +0000

https://mashable.com/article/ac-units-climate-change-carbon-capture/?europe=true

Love it :)

Should air conditioning be banned

owlman — Sat, 09 Nov 2019 14:45:30 +0000

Posted By: LF Food waste and pooh are good sources of gas which overall release much less CO2 than fossil based gas. They are true waste.

Agreed, and I have no qualms about us using this waste stuff, especially as a lot of it is used local to source to drive other processes etc.

"Stuff that uses maize and sugar beet is nearer to only 60% better than fossil fuel.

This stuff may have nice headline "better than" figures but when you start factoring in all the peripheral consequences; land usage, pesticides, herbicides, fertilizers, mono-culture habitat loss, rural traffic, haulage in general, pollution, subsidies, etc etc those "better than" figures look decidedly ropey, in fact they are a myth.