Aircon to the rescue

Well, it seems the window film by itself is not sufficient to maintain inside temperature.   Exeter has suffered several days and nights in the mid to upper twenties and the inside temperature monitor – probably combining conducted and radiant values – was always several degrees above these.

So this morning I disinterred the Dalek and it’s plumbing and fired it up in the lounge.  Starting about 7 degrees above external at 1030am, the inside temperature is now (5.38pm) reading  23.6 with an external value of 23.3.  Set to a target of 23, it should soon start throttling back.

Just in time. 40 degrees is forecast for the weekend in three days time.

I don’t know how much energy it’s using,  and I don’t want to find out. For the moment, staving off heatstroke seems more important.

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Iced coffee

Summer is here. Outside 22, inside 26 degrees.   My normal hot beverage is too heating but I found the following in Rachel Roddy’s column in the Guardian.

The third option is caffè shakerato, which involves hot coffee, sugar to taste and ice, blended into a froth that settles into two tones. Claudio suggests making it in a jam jar at home: a single espresso, a spoonful of sugar and five ice cubes, lid on tight and shake like mad.
I use drinking chocolate instead of neat sugar; otherwise as above.   After shaking well, pour the slurry into a small glass ( or pretty espresso cup in my case ) and serve.  The remaining ice chips keep it cool until finished.
The danger with coffee at any temperature in hot weather is dehydration due to enhanced urination.  I  therefore alternate with a pint mug of iced, carbonated water lightly flavoured with fruit squash – currently M&S Raspberry and Cranberry while the supply lasts.
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Summer 2022 – another solution to overheating

Having failed to secure consent for erecting external shutters or sunshields I have fallen back a stage and arranged for solar reflective film to be fitted to the inside of my windows.

The film is called Sterling 40, is neutral in colour and said to reflect most of the UV, and various amounts of the visible and infra-red spectrum.   On first inspection there seems to be no film there at all. Only when comparing the view through the glass with a direct view through an opening can one detect a slight colour shift to blue through the glass combined with a marked reduction in the intensity of reflected daylight.

Since most of my external heat gain is solar this has kept the flat noticeably cooler than previous sunny days,  including one peaking outside at 30 oC. Keeping all my top-hinged  windows open allows air flow without admitting direct solar radiation. The net result is a slow drift of inside towards outside air temperatures, but with no apparent solar component.

Installation of the film involves scrupulous cleaning of the glass and ultra-careful cutting and manipulation of the film. I judged this to be beyond my competence and was glad to pay for a professional installation.   All in all, to supply and fit film to 6 windows over a morning cost under £400 for a local firm.

I will collect performance data and report further.

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Winter 2022

A lot has happened to me,  but not much to the flat. It’s 25th January, so it’s winter. The temperature outside is 6.4oC, inside in the lounge it’s 21.7.  I do have one of the two storage heaters on, but the bedroom has none.  The temperature there is 20.7 and I have to sleep most of the night on top of the duvet under a single sheet to avoid overheating.

As previously reported, this flat is one of 120 retirement flats and surrounded by others, so it has only one outside wall. Even with the windows closed down to trickle vents it seems it should be more responsive to outside conditions.  Goodness knows how I shall manage when summer come again.

A personal bulletin may be relevant.  In December 2021 I completed a year on chemotherapy drugs. As most most fellow sufferers report, we don’t notice the cancer, only the side-effects of the therapy. Mine is called chemical castration and eliminates all traces of testosterone, giving me the chemistry similar of a post-menopausal woman – complete with hot flushes, problems with weight gain etc.

I wonder if this keeps me warmer than before – was it Robert Louis Stevenson who talked about being “lit internally by wine”? Other chemicals may work the same way, I suppose, but the thermometer readings should not be affected.

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The heat wave is back

As I write this in mid-June, summer has arrived with a bang and a blaze. With blinds down all day, by mid afternoon the temperature in my lounge reads 26.5 degrees C, and, attired only in a pair of shorts, I am still reluctant to stray from the beam of the fan.   This slows down my current project – installation of a portable air-conditioning unit.

After my heat complaints of last year I acquired this device, cheaply and second-hand, through my nephew. But by then it was too cold to think about cooling, so I stowed it the hall-cupboard and concentrated on dealing with the emergencies of daily life – and death too, in a way.  Shortly after that post I was diagnosed with advanced prostate cancer. This is incurable and will usher me off the scene in an indeterminate number of years, but my treatment is currently effective with negligible side effects, and since it has no immediate bearing on the purpose of this blog, I shall say no more about it.

I only wheeled the air conditioning unit – now called the Dalek – out of the hall cupboard when the heat wave started and, of course, made it too hot to work on the installation with any comfort.   As a heat-pump, the dalek takes in warm air from the room, extracts heat from it and generates two new streams – one colder than the intake and another one hotter.  The cold air it blows into the room from a lidded aperture on the top, the hot air has to be expelled from the room via a flexible pipe.

My lounge has only one window, facing south east. Half of it can be opened with a hinge at the top, so this window is where the hot air must leave. The opening must then be carefully sealed to stop the hot air coming back in again, and this has been the site of my labour. The supplied exhaust fitting assumes the window is either a sliding sash or side-hinged casement design: engineering a solution for a limited-aperture top-hinged design in the full blaze of the daylight has taken some doing.

My first design was to install complete second glazing over the open window with a circular hole for the pipe, so I ordered a large sheet of  double-walled polycarbonate to cover it. While waiting for this to arrive I cobbled together a trial system using a sheet of hardboard, wheeled the dalek into position, connected the exhaust pipe and power and switched it on.

The slot on the top of the dalek opened slowly over several seconds and then emitted a blast of very cold air accompanied by a fierce roaring sound, roughly equivalent to a motor bike at full throttle.  Letting it run for half an hour brought the air temperature down by several degrees, but the sound level was unacceptable.  I gather from the manual that the fan speed can be adjusted to reduce both noise and speed of cooling, but before I could investigate further my polycarbonate was delivered and I had to dismantle the temporary installation to fit the new one.

I found my original design has a serious fault. The twin-walled polycarbonate lets a lot of light through but blurs the image of the outside world, thus restricting my ability to keep an eye on my neighbours.  Still, the window next to it remains clear for espionage.

Then the outside cooled down somewhat, and I found I could get cool quietly by lowering the blinds over open windows and setting fans to suck cool air into the flat. Over a period of hours this cooled the structure of the rooms to a tolerable level, so I wheeled the dalek back to its kennel to wait for the next heatwave.

19th July.  The heat wave is back – blazing sunshine and tempertures up to 31oC – and the Dalek is out of its kennel.  I connected it up to the polycarbonate window fixture in my lounge and fired it up. I found that it was able to reduce the room temperature down to 23oC over a few hours with the other rooms – bathroom and bedroom at 28 – but no lower.

Setting the fan speed to minimum on the Dalek reduced the noise to a steady whoosh measuring 63.5 decibels – still intrusive but tolerable for the comfort it provided.  I spent most of the day there hiding from the glare outside. At 10pm the outside air temperature was down to 18, so I opened the bedroom window, wedged a fan in the opening and ran it until midnight, hoping to to cool the room enough to sleep in.

No such luck. Not only was the room still too hot for sleeping, the housing for the fan motor had fallen off and down two floors for the ground. Donning dressing gown and slippers I stepped downstairsto reclaim it. I found the housing sitting undamaged on the entrance paving. I picked it up and sat for a while on a handy   bench, enjoying the moonlight and the cool midnight air. After a while, the birds started chattering and whistling to each other.It was so much fresher and cooler than my flat that I wished I could spend the rest of the night there.

I reflected on the continued complexity of thermal comfort – discussed in detail in the blog, but little understood by most lay people. I was perfectly comfortable on that bench just below the gaping windows of my bedroom inside the block. Why was inside perceived to be so much “hotter” than outside a few metres away.

Two factors probably dominate:  firstly, radiant heating from the walls inside was absent in the open garden, and secondly air movement was absent inside the flat which has no through draft able to pick up some of the gentle midnight breeze.

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Dealing with disability

One facet of sustainability is to live in the same place for as long as it’s feasible to do so, thus avoiding the waste of packing up, moving from one place to another, dismantling the new place and furnishing anew.  Avoidable replacement is waste.

Admittedly, some refurbishment is sometimes essential.  The electrician who rewired my flat took pictures first to add to his Chamber of Horrors, as did the plumber who re-routed my hot water supply piping from it’s previous location buried unlagged in the concrete floor.  And this block was built in 1987.

Still, I hope to stay here as long as I can manage to look after myself, and this requires forethought and preparation for forthcoming physical disability, however it develops. Some we thought of before – my new wall-mounted toilet was installed at “comfort height” and all doorways were already wide enough for wheelchairs.  Some are easily added – remembering how Penny dislocated her shoulder in Big Bang Theory I affixed lots of non-slip adhesive plastic sea-creatures to the floor of my bath/shower, not being able to emulate Sheldon’s equivalent ducks.

But others are revealed too late for casual rectification.  Since the ceilings are concrete (like the floor),  all the room lights are mounted on the walls, which suits some people; except that I need to use that wall for bookshelves. Also, my cataracts are now so dark that I need bright task lighting at several places in my long  lounge/diner. I needed a solution that was flexible, didn’t clutter the room with standing lamps and avoided the need for professional wiring and banks of switches.

IKEA and Amazon to the rescue. IKEA produce a low-cost, three-circuit lighting track with a small range of spot and pendant lights to fit in it. As I write this entry my ceiling has three of these tracks serving the sofa, dining table and coffee station.  The dining table and coffee station tracks are operated by conventional  wall switches nearby for short term use. The sofa track is double length and provides most of the general light in the room, as well as two types of task lighting – all controlled by Amazon Alexa All three tracks are plugged into smart plugs which operate by wifi signals sent by Alexa in response to spoken commands.  She also handles the TV, some decorative table lamps and the cascade fountain in the bay window by the same method.

For safety, the light switch at the door operates two small lamps on the shelving, but most of it is controlled by voice alone. Sitting on the sofa – or perhaps one day in my wheelchair – I can control an increasing range of services – including fans in tge current hot weather; but more of that later.

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Cooking with economy

All the energy entering this flat – aside from sunshine – is electric.  This is essential for high-tech kit like TVs and computers, but is also used for less complex activities like heating water for cooking and bathing.

This is perverse.  Most of our electricity is still generated by heating water using chemical or nuclear reactions. The steam produced drives enormous generators feeding electricity through elaborate transformers and thousands of miles of cabling . . . into my kitchen to heat water to cook food.   Why can’t we cut out the middlemen and use the heat directly.

Some of us can. We burn fuel directly in our homes in stoves and boilers; but there are two problems in doing this. Firstly, most of the fuel burned contains carbon and so produces CO2 to drive the global heating that may yet extinguish our civilisation.  Secondly, this flat is part of a retirement complex where some of the residents may not be able to use gas appliances safely. Consequently, the only energy supplied to the premises is electricity – still dangerous, but unlikely to demolish the building.

Admittedly, an increasing proportion of electricity comes directly from wind or sunshine; but fossil fuels are still a major component.  Even hydrogen is mostly produced from hydrocarbon gas, thereby driving CO2 into the air – until the dream of carbon capture and storage becomes a reality – if it ever does.

However the power is generated, it is all going to move around the country as electricity, so it behoves us all to use as little as possible.   I can’t build a fire in my kitchen to cook my food, but heat can be managed to minimise the electricity required . . .  by insulation, assisted by induction.

The picture below shows a pot of chickpeas in water cooking on my black glass induction hob.   An induction hob heats aCooking on an Induction Hob ferrous metal object by generating a current in the bottom. Thus the object acts as its own heating element and nothing else gets hot.  So, I wrapped the sides of the pot with a towel and put a dishcloth on top to keep more heat in and reduce the power needed to keep the water boiling. After 15 minutes the chickpeas were heated through and now needed to be kept hot for an hour or two to continue cooking.

The next picture shows how this was done – without energy  – by wrapping the pot in a thick insulating jacket (called a Wonderbag). After several hours the chickpeas were soft and the water temperature was still 64 oC.

When cooking fuel was scarce and expensive, people used a wooden box insulated with hay to do the same thing.  Fuel may not be scarce nowadays, but it still costs more than we can afford.

 

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After the heat

Last week was terrible. Following the medical symptoms I described below I moved in with my wife (we have separate flats in the same block). Her flat is on the north-west side and has three outside walls, so was much cooler, allowing restful continuous sleep for several nights.  This week is better.  The outside air is cool enough to reduce the internal temperature of my flat, although the walls radiated enough heat at first to make my ears feel hot.

It was a powerful lesson in the complexity of thermal comfort and the role played by building construction and orientation.  The whole block is constructed of concrete floor and roof slabs enclosed by brick and block cavity walls.  My side faces south-east and stored up heat from the intense sunshine: her side faces away from the sun and absorbed much less solar radiation.  Of course she is colder in winter than I am, but winter seems  a long way away.

In the midst of the furnace week I did try to buy a portable air conditioner, but they were all sold out.  I will persist with this and report later.

 

 

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Cooling in a heat wave

My weather station reads temperatures inside and out. Yesterday evening the indoor temperature was 29ºC and outside it was 27ºC.   I only kept going by stripping to underclothes and sponging my skin with a wet cloth in the beam of an electric fan.

This had a noticeable physical and mental effect: feelings of near panic gradually receded and I was able to consider activities unconnected with temperature  regulation. I didn’t take my core temperature but I imagine it came down from the feverish level of before.  It brings home to one how dangerous to the elderly overheating can be.

I am now reading up on portable air conditioners. Delonghi seems to be the brand of choice.

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Residential cooling

British housing needs to be heated to be healthy, but should it also be cooled? Global heating is here and getting worse. We should all do what we can to combat it (see under Energy), but we need to get ready for what is coming. The usual books are not much use to flat dwellers. They emphasise the passive aspects of construction – massive heat-absorbing materials, windows set deep into the structure to avoid summer sun and heavy thermal insulation.

Certainly, insulation helps to keep cool as well as stay warm. My first flat on the seaside needed extensive rebuilding and incorporated lots of insulation in the new roof. In summer whenever the beach hut became too hot (2003 was a scorcher) we retired to the flat to cool down, only returning to the beach for the evening. But no other flat since was so blessed; in general, flat dwellers are not able to make significant changes to structure and insulation – so-called passive measures . We need to fall back on active strategies which consume power, and are usually based on heat pumps. Understanding how these work might help in following current innovations, so I have included a section on heat pumps in the reference menus.

This raises the point of equipment. If you can fit something on the outside of your flat you can look at a wide range of efficient units. However, I  shall assume that – like me – you can’t do that.   Portable freestanding units do exist,  but their problem is how to get rid of the heat. Domestic freezers don’t bother,  they just release it into the room,  but cooling the whole room needs moving the heat out of it.  Portable units do this by blowing hot air through a large hose fitted to a window.

I’ll report back when I have more information.

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