Limiting temperature of a conservatory

message from Roly on 17 May 2004

Summer's here and the conservatory regularly tops 100 degrees even on
overcast days.

What are the best ways to keep the temperature within sensible limits
?
I've seen adverts for thermal inserts that are slid into the
polycarbonate roofing. The lack of any pricing structure leads me to
suspect that it's not cheap and will be a high-pressure sale of a
largely ineffective product. Is it worth considering ?

Other obvious solutions might be to use a thermostatically controlled
extracor fan or some sort of shading in the roof.

Has anybody any suggestions or observations ?

It's only a small conservatory, less than 3 metres square and south
facing.

Christian McArdle replied to Roly on 18 May 2004

Stick reflective insulating foil over the polycarbonate. The same stuff that
is used behind radiators or on campervan windscreens. Obviously, the fan can
help too. Install an opening roof light near the apex, so hot air can escape
through convection.

Christian.

N. Thornton replied to Christian McArdle on 20 May 2004

Or maybe have some metallised mylar curtains on a rod, so you can open
and close the reflective curtains when you want.

Thermostatic roof vents are certainly good, as used in most commercial
gerenhouses, but better controlled ones can be much better. Really you
want those vents open at night while its cool out, to store as much
coolth in the structure as possible. This does make a sizeable
difference. Ensure security is not compromised etc.

A deciduous climbing plant on the outer walls is another option: leafs
up in summer to keep most of the sun off, as well as looking lovely,
and deleafs in winter to let the sun in, and provide a display of
stems only. Note that exterior reflectors are more effective than
interior, since reflection is never 100%, and glass transmission is
also not 100%. Make it a nice decorative fruiting climber and how
could you resist?

Regards, NT

geoff replied to Roly on 19 May 2004

That's telling him

it won't make any different though - he doesn't understand words and
complicated things like that

geoff replied to Roly on 20 May 2004

In message <c8gmd9$k5d$1@news8.svr.pol.co.uk>, IMM <abuse-imm@easy.com>
writes
No just **** will do

Ian Stirling replied to Roly on 17 May 2004

You'r looking at a solar gain of up to around 10Kw.
(need more information about total glass area in the sun direction.
for more accuracy)
Air absorbs around 1KJ/m^3/C.
So, to keep the temperature rise down to 10C, you'r looking at
.1m^3/s of airflow.
To keep it within a couple of degres, more like half a cubic meter
a second.

A 30cm fan should easily do this, requiring only an output speed of
1-5m/s or so.

Mary Hinge replied to Ian Stirling on 19 May 2004

Very interested in this thread - in a similar position with the house
we've just moved into recently. This time a large lean-to conservatory
- 5m wide by 3m deep, east facing against a two-storey house so mostly
in shade in the afternoon. Solid walls to south and north sides, fully
glazed to the east. Roof is very shallow pitch triple-wall
polycarbonate.

I would prefer to avoid air con due to high up-front and running
costs. Conservatory blinds seem to cost an awful lot as well. What
sort of air extraction rate might be required in this case? Any chance
one of those 275m3/hr Xpelair jobs might help, or are we talking major
air-shifting?

The inserts for polycarb roofs looking interesting, anyone had these
fitted?

TIA.

Ian Stirling replied to Mary Hinge on 19 May 2004

For ballpark use, the total heat gain is 1Kw/m^2.
This area is measured at right angles to the sun.
As the day goes on, the area rises and falls depending on the angle
which the sun is shining onto it.

I'll assume that the 5m is against the house, and that it's 2.5m tall.
In the morning, you've got some 5*2.5 = 12.5Kw.
As a very rough ballpark, 1Kw raises the temperature of a 1m^3
by 1C in 1 second.

275m^3/h is (/3600) =.08m^3/s.
Heated by 20C, this will absorb .08*20 = 1.6Kw, which is about an eighth
of what you need.

So, if this was the only means of cooling, it'd heat to some 160C.
The polypropylene will probably melt, and let the heat out first :)
(or more accurately, it'll simply go out through the walls.

Set Square replied to Mary Hinge on 19 May 2004

I once considered putting solar-powered fans (similar to
http://www.gardencentre.co.uk/solar-solutions/pages/fan.htm but not
precisely this) in my conservatory - but never actually pursued it. There
seemed to be a certain logic in having a system whose extraction capacity
increased in line with the solar input. Don't know how well it would work in
practice.

Simon Gardner replied to Mary Hinge on 20 May 2004

Actually, air con doesn't seem to have terribly high running costs and has
the advantage of (a) working and (b) keeping humidity to comfortable
levels.

The planting geraniums thing, of course, doesn't work and is bugger all use
on the humidity front.

IMM replied to Simon Gardner on 20 May 2004

Totally correct.

It does.

Andy Hall replied to Mary Hinge on 19 May 2004

I am not sure which ones you mean here.

Short of fitting air conditioning, there are four main things that
can be done:

- Fit roof vents which can be opened to allow the warm air to convect
out. This is very effective and also pulls in cooler air through
the door, windows or from inside the house.

- Fit fans in the roof. I used two large 54" types which are run at
low speed and are hence silent. They can also be run in either
direction. In the summer, they further assist the vents and in the
winter circulate the warm air.

- Fit blinds. These are not inexpensive if you want good ones.
For maximum exclusion of inbound heat, the reflecting type - typically
concertina on wires give the best results but are not a thing of
beauty. I used pinoleum blinds, which are still quite effective but
look a great deal better.

- Fit curtains or window blinds. How useful this is depends on the
relative position to the sun.

.andy

To email, substitute .nospam with .gl

Mary Hinge replied to Andy Hall on 19 May 2004

Oh you know, the extractor thingies more commonly seen in kitchens.
Vent Axia also rings a bell. Pull a cord or push a button and off they
go, commonly wall mounted. Marvellous.

Roof vents sound like just the ticket, didn't realise they could be
fitted to polycarb roofs. I assume they close, got any links for
visual examples?

Ta.

Andy Hall replied to Mary Hinge on 19 May 2004

Generally these are part and parcel of the roof construction.

Ultraframe are among the largest of the UK manufacturers, and their
roof structures are used by other suppliers as well.

.andy

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Lawrence Zarb replied to Mary Hinge on 20 May 2004

Try http://www.casupply.co.uk

IMM replied to Andy Hall on 19 May 2004

A double negative. An attempt to confuse or make out you are cleverer what
your are. I suspect the latter. It should be:

These are expensive

tsk, tsk.

Mary Hinge replied to IMM on 19 May 2004

<a load of bollocks>

**** off IMM, if you can't add anything constructive to the thread
then don't bother.

Jesus what a ****.

IMM replied to Mary Hinge on 19 May 2004

news:<c8fqmh$u18$1@news5.svr.pol.co.uk>...

My name is not Jesus.

Owain replied to IMM on 20 May 2004

Mary Hinge replied to Owain on 20 May 2004

I see your point, and I must admit a certain disappointment in having
to go for such a basic choice of insult. However I do feel, and I'm
sure that most would agree, that '****' could not be bettered in this
instance.

I should point out that I wasn't inferring that Jesus Christ, Our
Lord, Son of God is a **** (after all he died for our sins you know),
but of course the International Man of abject stupidity.

MH

IMM replied to Mary Hinge on 20 May 2004

news:<1085064713.13614.0@sabbath.news.uk.clara.net>...

I suggest the word C**T is most apt to you too my dear. You lack
intelligence that is clear.

Owain replied to Mary Hinge on 21 May 2004

"Mary Hinge" wrote
| I should point out that I wasn't inferring that Jesus Christ, Our
| Lord, Son of God is a **** (after all he died for our sins you know),

Yes, but on the third day he rose from the dead, so it wasn't exactly the
ultimate sacrifice :-)

Owain

PS Do you have a sister Evadne who lives in Stackton Tressle? I used to love
her radio programmes as a child.

Mary Hinge replied to Owain on 21 May 2004

No, alas I have no siblings but my dearest friends Mary Huff and Betty
Swollocks are like sisters to me.

MH

IMM replied to Mary Hinge on 22 May 2004

news:<1085155931.28372.1@iris.uk.clara.net>...

Great Scott! Sounds like a right old Mary.

IMM replied to IMM on 20 May 2004

Maxie, book the Far East flight now. You are deteriorating by the day.

IMM replied to Mary Hinge on 19 May 2004

Maxie, when are you going to the Far East to get your rocks off?

IMM replied to IMM on 20 May 2004

Maxie, you need some R&R.

Andy Hall replied to IMM on 19 May 2004

Based on your performance in the heatbank thread, that is a truly
amazing comment.

Wrong. Something can be inexpensive, of medium price or expensive.

Saying that something is not inexpensive merely indicates that. It
could be of medium price or expensive.

All three are ultimately in the opinion of the buyer.

To you, anything that can't be bought on a market stall for a fiver is
expensive, and you seem to lack an ability to relate value to price.

.andy

To email, substitute .nospam with .gl

IMM replied to Andy Hall on 19 May 2004

< snip tripe by a snot >

Nick Brooks replied to IMM on 19 May 2004

I know it's a long shot but I'd be really grateful if you stopped doing
this as it adds nothing to the conversation and even though I've onbly
been reading this group for a few months, it's getting a bid dull and
certainly doesn't give an impression of the thoughtful intelligent
person I'm sure you are really

Thank you

Nick Brooks
(expecting snip tripe by xxxxx)

IMM replied to Nick Brooks on 19 May 2004

As you have probably assessed by now, I don't suffer fools gladly.

Ian Stirling replied to IMM on 19 May 2004

That'll explain the attitude.

Christian McArdle replied to IMM on 19 May 2004

Actually, "expensive" and "not inexpensive" have subtly different meanings,
particularly when regarding any middle ground.

Christian.

IMM replied to Christian McArdle on 19 May 2004

Sop you are saying he was trying to confuse.

Andy Hall replied to IMM on 19 May 2004

There's only one person in this NG who causes confusion....

along with a number of other things of course...... :-)

.andy

To email, substitute .nospam with .gl

Christian McArdle replied to IMM on 19 May 2004

No. I was saying that your statement equating "not inexpensive" with
"expensive" was incorrect. Clearly, he did confuse you, though.

Christian.

harry8611 replied to Andy Hall on 19 May 2004

Question: On a hot day, with say the vents open but the fans off and
the blinds up, what's the internal temperature like?

Brian

Andy Hall replied to harry8611 on 19 May 2004

That really is a "how long is a bit of string" question.

A lot depends on how much of the conservatory is in sunlight, for how
long and which part of the day. It also varies seasonally of course.

Mine faces north west and so only receives major sun from mid
afternoon onwards.

Use of the blinds and vents make a big difference.

I tend to open the doors on particularly hot days which effectively
makes the internal temperature virtually the same as outside, under
shade.

I would suggest taking it one step at a time and seeing what suits
you.

.andy

To email, substitute .nospam with .gl

geoff replied to Roly on 20 May 2004

In message <c8gmgm$g72$1@news6.svr.pol.co.uk>, IMM <abuse-imm@easy.com>
writes
None of your business ****tard

mrcheerful replied to Roly on 17 May 2004

I thatch mine for the summer using reed stuff on a roll, most garden centres
stock it, I got mine from Costco, stapled to a light wooden frame, this
stops the sting of the sun, reduces but doesn't black out the light inside
and makes the conservatory usable, several friends have copied the idea, all
think it works well, it is also very cheap.

mrcheerful

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