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20 November 2009
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Poor house insulation has a double-whammy effect in
Cyprus:
- it causes the house-owner to lose a lot of money in heating and
air-conditioning costs
- it is one of the major reasons why Cyprus has the
very doubtful honour of one of the highest per capita carbon emission
rates in the European Union
This essay light-heartedly describes my feeble efforts over a period of
12 years to identify and reduce these problems in a very
typical house, as built towards the latter half of the 1990s.
Why the problem?
The problem was, in my opinion, plain stupidity and plain cupidity on the
part of the developers. Cupidity because they tried to cut costs so as to
maximise profits. Stupidity because they could see no farther than the end
of their nose. It had not occurred to them that adding a little, say 5%, to
the cost of the house would have allowed them to sell it at a price of 20%
more.
The house itself is almost a cube over two storeys. This was actually one
of the reasons I chose it, way back in 1997, because I knew that the heat
losses would be minimal compared with the two bungalows that were offered at
the same time, with their larger wall and roof areas.
The construction was typical, a reinforced concrete anti-seismic
skeleton, filled in by a single layer of "insulating" terra cotta bricks,
you know the type, where the insulation consists of a few holes. The fact
that terra cotta is porous was ignored. The lot was splashed by a "plaster",
actually a cement rendering, inside and out.
The open aluminium construction of the old
windows, open to the elements, with no insulation.
 The windows, French windows and kitchen door were aluminium-framed with
16 mm (3+10+3 mm) double glazing. The sliding windows had a gap of about 7
mm between the frames, the only thing closing them off being a brush. This
stopped the draughts so effectively that a birthday-cake candle could be
blown out on a stormy night, when held close to the gap. Worse, the windows
could be removed by pushing them upwards about 25 mm and then pulling them
inwards. The gap that you could push them into had about 2.5 mm of aluminium
inside and out and just empty space above the window frame, practically open
to the elements. The gaps were so big that we had bats nesting in them (it
is bat droppings that you can see in the open framework to the left!). The
frame itself had some of the profiles open, as you can see. I once saw the tail of
a scorpion through one of the gaps. On a cold winter's night, struggling to
keep the house warm, just touching the aluminium frame would send shivers
down your spine; the distance between the outside and the inside of the
frame was only about 28-30 mm and aluminium is a damned good heat conductor,
almost as good (or bad!) as copper or silver. Is it surprising that we had
to struggle to keep warm?
The front door was a MDF chipboard monstrosity with a good 1 cm gap at
the bottom. We kept a big "door sock" pressed up against it to try and
attenuate the howling gale that blew through it. Worse, even though I had
fitted plastic and foam draught excluders around the jamb, I could see
daylight infiltrating round the whole door, except at night! As the years
went by, both the door shrunk and the doorframe warped, obviously in
opposite directions, so that the gaps became worse.
The roof required a genius of simplification to think it up. Some wooden
beams were fixed to the anti-seismic skeleton and some cheap
tongue-and-groove wooden planking was stapled to the beams; this was our
insulation, about 10 mm of wood (see below). I believe a layer of roofing felt was fixed
to the planking and some battens nailed along the planking, to hold some
nice terra cotta roofing tiles in place. Yes, it looked great from the
outside. On the inside, the beams and planking were stained and lent a
little character to the interior with exposed beams, as well as the almost
free passage of heat. Who would believe that the house was so badly
insulated? Of course, we didn't realise just how bad the house was
constructed until we lived through a winter in it.
The floor was also monstrous. Of course, the reinforced concrete slab was
cast to the skeleton, directly on the ground, no sanitary cavity or
anything. The pipes and conduits were laid on the slab, on which was placed
a 25-30 mm layer of damp unwashed sea sand, complete with salt. The cement
screed was cast on top of that and finally some beautiful ceramic tiles were
laid. This was wonderful in summer, nice and cool to our bare feet. But it
was as cold as charity in winter, requiring thick carpets laid to keep our
slippered and socked feet almost acceptably warm in winter. The dog loved
the tiles in summer, but he could not get off them fast enough in winter, so
it was not just us exaggerating our discomfort.
Of course, we were aware that the house had no built in heating or air
conditioning when we bought it. In fact, one of the first things we did was
to install split air conditioning units. We had also brought with us a small
wood-burning stove from Switzerland, when we moved here. This stove kept us
wonderfully warm and cosy in our Swiss living room, burning one or two logs
in an evening, when it was -10°C outside. The room size was about the same,
give or take a little, although the ceiling was lower in our 17th century
Swiss farmhouse - and the windows and doors fitted without draughts. In our
naivety, we thought this would just about keep the whole house warm, with
frosts being very rare, but we had not considered Cypriot workmanship or
lack thereof.
Our first winter
Well, we started with a truckload of olive wood. We thought this
would keep us warm in the evenings. Like heck! We were burning twice as
much wood as we did in Switzerland and still freezing our ..., well, not
feeling comfortable despite thick sweaters. We had brought with us a fan
heater and an oil-filled heater; neither of these seemed to break
through the all pervading chilliness of our house. In the end, we used
the noisy air-conditioning units on heating mode (much more economical
than the fan or oil-filled heaters, relegated to the cupboard under the
stairs). By wrapping up well into cuddly bundles, burning umpteen logs
of olive wood and topping up from the aircons, we just about survived
the first winter. Was it because the house was new and the cement and
concrete were still damp?
Our second winter was no better, so we concluded that the bitter
conditions, much less comfortable than in Switzerland, were something we
had to put up with, as best as we could, and to pay the bills for wood
and electricity to keep the living room at 18-19°C, at least during the
evenings when we were sitting watching TV.
Brainwave!
After the second winter of abject misery (well, almost) we started to
look around at alternative heating. Central heating seemed the answer
but there was nowhere to put a boiler and all those copper pipes looked
like an unhappy idea. We did consider underfloor heating, but the idea
of digging up over 100 m² of tiles and screed and removing all that
salty sand was unappealing, even if we could have a better insulation.
Circulated hot air was also a no-no, as the conduits would be ugly.
Then a neighbour suggested low-tariff storage heating. Looking
around, we found that modern storage heaters were more sophisticated
than the lumpy brick ones of yesteryear, with input and output
thermostats. The only problem was that the house had only a single phase
connection. We contacted the EAC and they told us, in no uncertain
terms, that there was no way that the circuit supplying our house would
support the three-phase load. Back to square one.
A couple of months later, I saw some EAC technicians installing a
supply to some new houses just below us and they had a whopping great
transformer that they were trying to fix up a pole, three times the size
of the one that was already there. I re-contacted the EAC and told them
their refusal was no longer valid as there was a new transformer
supplying our quarter. They gave in and said we could have a three-phase
supply but it was limited to 40 A/phase. Pen, paper and calculator came
out and I worked out how I could fit heating into this limitation. The
best I could work out was just under 40 A for two of the phases and
about 41 A for the third one, by juggling around with different sizes of
storage heater. Thinking that the extra ampere would not be noticed, I
commissioned an electrician to install storage heaters in all the rooms
and to wire them up as I had worked out. No! He knew a better way to
wire them up! No way was he going to be told by a customer how to wire
them. I then called the EAC to install the three-phase supply. They
came, installed the extra meter but didn't connect it and reversed the
phase and neutral of our single phase supply, a very dangerous thing to
do. This was on a Friday afternoon.
The following day, various appliances started playing up, so I
investigated and discovered the reversed connections. I phoned the EAC
emergency service and, to their credit, they were there, on a Saturday
afternoon, within an hour. I explained that their installer had reversed
the phase and neutral. Impossible, saith he! Possible and done, saith I!
To prove my point, I took my multimeter to the breaker box and showed
him that there was 240 V between the neutral and earth. He scratched his
head and finally admitted I was right. "First time I've seen the likes
of that!". A trip out to the meter box showed that the single-phase
meter had been moved. Breaking the lead seals, he found that the phase
input wire had been connected to the neutral input connection on the
meter, presumably because it would no longer reach the correct terminal.
The air turned blue when the technician saw this, with epithets like
malaka, poustis and pesavinkis of an ignorant bastard of an installer!
Anyway, he corrected the problem.
On Monday, the technician came to connect the three-phase supply
after inspection of the electrician's work. No way can he do this! The
current on two of the phases was about 46 A and on the third one about
27 A. I showed the guy my schematic and calculations and he agreed that
they were OK. I called the electrician back and told him to correct the
installation. Chunter, chunter, chunter, the EAC were a bunch of idiots
etc. He finally wired it up as I told him to in the first place and the
EAC guy came back, tested and connected it up.
That winter, we appreciated that the storage heaters gave us a good
background heat throughout the house. With the wood fire, we were
comfortable most of the time, with a little supplement from the aircons
in really cold weather. The cost of the electricity, on the reduced
tariff, was about CYP 0.024/kWh (€0.041), all extras included. Overall,
we paid about 35% less for this electricity plus the wood, than a
neighbour with a similar sized house of identical construction, who had
installed oil-fired central heating at the same time, so we were happy
that we had an acceptable solution that would not break the bank.
The bank broke
The bank got itself broken when I received the first bill with
heating as a Christmas present in December 2008. I hit the uninsulated roof. The
heating tariff (before all the extras) was still the modest €0.0281/kWh
but the fuel adjustment was a whopping €0.092302/kWh. By the time VAT
and all the extras were added, we were paying €0.1433/kWh for the
reduced tariff, 3½ times what we paid initially, in just a few years.
Even our full tariff had more than doubled.
Enough was enough! At that price, something had to give. It was then
that I decided to have a new look at the house construction and see what
I could do to reduce our heating bill and our carbon emissions at the
power station, something approaching 5 tonnes of carbon dioxide/year.
Fortunately, the "fuel adjustment charge" had dropped to €0,06 by the
time the next bill came in February 2009, as we paid a massive €485.39
for our storage heating during the coldest part of the year. We were
still slightly cheaper than our oil-fired neighbours, but there was
little in it for this past winter.
Where did all our joules go?
Well, I'm darned sure we heated the air outside the house more than
we heated the air inside. I had no instruments to know exactly where and
how we were losing energy, but I stuck a wet thumb in the air and
decided that the windows were the place to start. Why did I conclude
this? Well, our refrigerator, oops, sorry, living room had a ceiling, so
the heat there was not being significantly lost through the roof. OK,
that cold floor counted for something, but we had rugs down which
helped. That left our badly fitting front door, two French windows and
three ordinary windows, all of abominable quality, and as air-tight as a
sieve.
I contacted a company that advertised UPVC windows and asked them to
pay us a visit. A bloke came with a sample. Instead of 28-30 mm of
ill-fitting single cell aluminium frames, he proposed 70 mm of sealed, multicellular frames in an insulating plastic, UPVC. Instead of 3-10-3
mm double glazing, he offered 5-16-4 mm double glazing. He offered us
doors that were just about a hermetic seal. I was convinced and I took
the plunge.
For the moment, I ignored the roof, other than vaguely discuss it;
more of that later.
Stage 1 towards Nirvana
70 mm width of UPVC window frame, which is
divided into insulating cells.
The windows were changed at the end of February. The house was
virtually windowless for most of the day for a whole week while the work
was carried out. During that time, I was glad I wasn't a brass monkey,
having no desire for emasculation. When the work was finished, the first
thing we noticed was that outside noises were vastly attenuated, by a
guestimated 30 dB. I thought this was almost incredible. We could hardly
hear it when our dog barked at the front gate (we try to stop him from
barking for neighbourly relations, but he really is an excellent
watchdog, so we keep a watchful ear open to stop him).
Our second reaction was to notice that we were burning only half the
quantity of wood after the new windows were put in, but we were
comfortable and we were able to turn the input and output thermostats of
the storage heaters down, and we needed no complementary aircon heating.
The first electricity bill (April) was meaningless, as the windowless
house really did mean that, during the period of the work, the heating
was going full blast, plus, plus, for a full week.
As we all know, April can be chilly and we did consume 69 kWh during
the month. This compared with an average of about 80 kWh in previous
years, but no conclusion can be drawn from this, as the weather varies
so much from year to year, and we gave up fires much earlier this year,
as I was in hospital during three weeks during this period. What I do
know is the house was generally more comfortable.
From the fact that we had turned the thermostats down, we knew our
energy consumption was down, but we don't know really by how much. We
hope to get a better numeric idea over this coming winter. My guess is
that we are obtaining a better winter comfort with perhaps a 30-35%
reduction of energy, but this is not yet substantiated.
What about aircon in the summer? We are fairly modest with our use of
air conditioning. Our summer electricity consumption on the normal tariff rises for
two reasons: air conditioning and pumping our irrigation water. This
year we irrigated somewhat more than the critical 2008, so we expected a
higher bill, but our consumption for June to August was down from 1593
kWh to 1403 kWh (it was 1873 kWh in 2007, with more irrigation, and 1690
kWh in 2006). I think the fact that this consumption being lower than
any of the previous three years is probably due to less air conditioning
being used, despite this summer having a slightly higher average
temperature.
Stage 2 towards Nirvana
Schematic sketch (not to scale) showing
original roof construction (top) and how the insulation was
added (bottom) with the batten-thick air gap between the
aluminised bubble insulation and the added tongue and groove.
As I mentioned earlier, our very uninsulated roof has apparent beams
and wooden tongue and groove planking (upper sketch above). This is quite attractive and adds character to the
house. I didn't want to spoil this. My initial idea was to fill the gaps
between the beams with glass wool or expanded polystyrene, place new
planking onto the bottom of beams and add new beams just for show. The
roofs were all high enough to allow this to be done. The only problem is
that it would cost a small fortune.
Then a supplier came up with another solution, perhaps not quite as
good from the thermal point of view but a lot better for our bank
balance. You all know what bubble-wrap looks like. Now imagine
bubble-wrap with a layer of plastic sheet glued to each side and those
two plastic sheets have a layer of shiny aluminium deposited on each.
This is a description of what a Chinese aluminised bubble insulation
looks like. According to the publicity blurb, the 7.5 mm thickness of
this is equivalent to 55 mm of expanded polystyrene foam.
Anyway, we had a strip of this insulation stapled to the gap between
the beams. A 20 mm square batten was then fixed to the sides of the
beams on top of the insulation and some tongue and groove, cut to the
width between the beams, fixed on top of the battens. To make it look
tidy, a quarter beading was run along the beams to close off any gap
between the beams and the tongue and groove. This looks very neat,
actually better than the original, because the tongue and groove is less
crude than the original planking (lower sketch above).
We don't even notice that we have lost about 35 mm of the
depth of the beams; there is still a good 100 mm or so visible.
Does this insulate well enough to make a difference? Well, I haven't
a clue, as this job was finished only a week ago and the weather hasn't
been exactly that which would inspire us to switch on either heating or
the aircon. However, I do think it will make a difference and it has
actually made a very noticeable one, if accidental. The sparrows have devised a dance
somewhat crossed between an eightsome reel and the Irish River Dance,
which they perform every morning on our roof, just after dawn. This is
accompanied by a group of pigeons roo-coo-cooing to provide the music.
Believe it or not, since our bedroom roof was done, we have not been
woken up by this choreographic or musical masterpiece. The other
morning, I had an urgent need to rise just before dawn. I then crawled
back between those warm sheets, just as Aurora was showing her face. I
lay there, listening for those damned birds, sure enough, with both ears
wide open, I could appreciate their artistry; nothing had changed,
except that the sound level had dropped from loud enough to wake us up,
down to barely perceptible. A great
improvement, if accidental, and almost unbelievable.
Stage 3 to Nirvana
Insulating the walls or the floors? I think not. In fact, not on your
Nelly! (I bet you don't know the origin of this phrase: in full, it is
not on your Nelly Duff, which is Cockney rhyming slang for puff, meaning
breath or life!). I believe Buddha took seven stages to reach Nirvana.
I'll miss out on the last five, thank you very much. However, I'll
update on the energy savings, as I hope they will be revealed.
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