Our house is about 7 years old. Outer red brick walls, cavity
insulation, aero type blocks for inner wall, dot and dab plasterboard
finish.

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Anyone know why this is and how we might stop it?

We have added an extra layer of insulation in the loft but this has
not helped much.

On Sun, 08 Jul 2007 23:37:52 -0700 someone who may be garym999
wrote this:-

Our house is about 7 years old. Outer red brick walls, cavity
insulation, aero type blocks for inner wall, dot and dab plasterboard
finish.

For a full diagnosis the orientation of the house, shading and room
layout would be needed.

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Anyone know why this is and how we might stop it?

It is probably simply the hot air rising over the day and you notice
it when you go upstairs to bed (presuming the bedrooms are
upstairs).

If it is then try opening some of the windows on the ground floor
and top floor slightly during the day. Opening them wide is not
necessary. This will produce a gentle current of air which will
limit temperature rises. In particular try opening the windows on
the shaded side of the ground floor and sunny side of the top floor.
Obviously leave the internal doors open. This may be difficult if
the house is unoccupied during the day, but opening them this way in
the evening may help and you can experiment at the weekends.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Sun, 08 Jul 2007 23:37:52 -0700, garym999 wrote:

We have added an extra layer of insulation in the loft but this has
not helped much.

Insulation keeps heat in... But I guess you close the windows at night
even if they are open during the day. This will also trap any heat. As Mr
Hansen says open windows a little low down on the N side and high up on
the S. Draw the curtains on the south side during the day.



--
Cheers
Dave. pam is missing e-mail

On Sun, 08 Jul 2007 23:37:52 -0700, garym999
wrote:

Our house is about 7 years old. Outer red brick walls, cavity
insulation, aero type blocks for inner wall, dot and dab plasterboard
finish.

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Anyone know why this is and how we might stop it?

We have added an extra layer of insulation in the loft but this has
not helped much.

*envy*
How do you get the house so warm?

Does the conservatory act as a heater? Can you close the doors to it
to prevent heat flowing into the house?
--
http://www.orderonlinepickupinstore.co.uk
Ah fetch it yourself if you can't wait for delivery
http://www.freedeliveryuk.co.uk
Or get it delivered for free

Dave Liquorice wrote:
On Sun, 08 Jul 2007 23:37:52 -0700, garym999 wrote:

We have added an extra layer of insulation in the loft but this has
not helped much.

Insulation keeps heat in... But I guess you close the windows at night
even if they are open during the day. This will also trap any heat. As Mr
Hansen says open windows a little low down on the N side and high up on
the S. Draw the curtains on the south side during the day.



The key to keeping houses cool in summer is to SHUT the windows by day -
and the curtains - and OPEN them at night.

The rear of the house, with the conservatory faces NNW. Of the four
bedrooms one is to the rear, others to the front. The master bedroom
windows are open all year and the radiator is never on.

Upstairs by day is fine. Early evening is OK but by late evening the
difference is staggering. I know heat rises but I thought extra
insulation in the loft would help prevent the build up in there. As we
use the loft and it is boarded out I stapled Airtech to the joists.
And that has knocked the temp in the loft down a lot.

"*envy* How do you get the house so warm?" Wish I knew. We brought the
house off plan and I don't think it was built to any exacting
standards, there are no cavity closures that I know of. If anything
there is a draught blowing behing the dot and dab.

I have wondered about the conservatory build up as this does get real
hot and as it is joined to the lounge you feel it in there too. but
having the doors open lets it all blow away.

David Hansen coughed up some electrons that declared:


It is probably simply the hot air rising over the day and you notice
it when you go upstairs to bed (presuming the bedrooms are
upstairs).

That is the conclusion I came to as well - my modern well insulated house is
horrid by evening upstairs in summer.


If it is then try opening some of the windows on the ground floor
and top floor slightly during the day. Opening them wide is not
necessary. This will produce a gentle current of air which will
limit temperature rises. In particular try opening the windows on
the shaded side of the ground floor and sunny side of the top floor.
Obviously leave the internal doors open. This may be difficult if
the house is unoccupied during the day, but opening them this way in
the evening may help and you can experiment at the weekends.



My trick was to open all the upstairs windows wide as soon as I come in
after work (or just after supper). By bedtime most of the stored heat has
dissipated and the air is fresh again.

Unfortunately, my wife's hayfever has kicked up again, so it's back to being
a steamed dumpling. I'll try your method next, David.

Cheers

Tim

"garym999" wrote in message
oups.com...
The rear of the house, with the conservatory faces NNW. Of the four
bedrooms one is to the rear, others to the front. The master bedroom
windows are open all year and the radiator is never on.

Upstairs by day is fine. Early evening is OK but by late evening the
difference is staggering. I know heat rises but I thought extra
insulation in the loft would help prevent the build up in there.

But that would trap the heat underneath, where you don't like it ...

On Mon, 09 Jul 2007 10:38:17 +0100 someone who may be Tim
Southerwood wrote this:-

It is probably simply the hot air rising over the day and you notice
it when you go upstairs to bed (presuming the bedrooms are
upstairs).

That is the conclusion I came to as well - my modern well insulated house is
horrid by evening upstairs in summer.

Insulation slows down heat coming in through the walls and ceiling
and so contributes to keeping buildings cooler in summer.

However, it does not stop radiation through the windows and if there
are large areas of unshaded southward facing glazing then the heat
this produces will be slowed from escaping through the upstairs
walls. The answer to this is to deal with the glazing, and/or limit
the solar temperature rise by ventilating.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Mon, 09 Jul 2007 10:20:08 +0100 someone who may be The Natural
Philosopher wrote this:-

The key to keeping houses cool in summer is to SHUT the windows by day -
and the curtains - and OPEN them at night.

If the windows don't allow much sunlight through. Otherwise the
sensible approach is to limit the solar temperature rise by
ventilation during the day. Cool air from the side of the building
away from the sun should be let in at low level to get the maximum
cooling.

Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.

At night the ground, warmed by the sun during the day, is giving off
relatively hot air and it makes little sense to draw this into the
building.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On Mon, 09 Jul 2007 10:20:08 +0100 someone who may be The Natural
Philosopher wrote this:-

The key to keeping houses cool in summer is to SHUT the windows by day -
and the curtains - and OPEN them at night.

If the windows don't allow much sunlight through.

Curtains are not noted for their inherent transparency.

Otherwise the
sensible approach is to limit the solar temperature rise by
ventilation during the day.

Not in this house,. With air temps up to 30C outside, and internals
nearer 25C, we don;t want any of that outside air coming in thank you!

Cool air from the side of the building
away from the sun should be let in at low level to get the maximum
cooling.

Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.

No, in the space between the curtains and the windows.. you DO have
insulating curtains I hope..

At night the ground, warmed by the sun during the day, is giving off
relatively hot air and it makes little sense to draw this into the
building.



Not at 3.a.m. it ain't.

On 9 Jul, 14:51, The Natural Philosopher wrote:
David Hansen wrote:
On Mon, 09 Jul 2007 10:20:08 +0100 someone who may be The Natural
Philosopher wrote this:-

The key to keeping houses cool in summer is to SHUT the windows by day -
and the curtains - and OPEN them at night.

If the windows don't allow much sunlight through.

Curtains are not noted for their inherent transparency.

Otherwise the

sensible approach is to limit the solar temperature rise by
ventilation during the day.

Not in this house,. With air temps up to 30C outside, and internals
nearer 25C, we don;t want any of that outside air coming in thank you!

Cool air from the side of the building away from the sun should be let in at low level to get the maximum
cooling.

Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.

No, in the space between the curtains and the windows.. you DO have
insulating curtains I hope..

At night the ground, warmed by the sun during the day, is giving off
relatively hot air and it makes little sense to draw this into the
building.

Not at 3.a.m. it ain't.


The philosopher is right on this one. And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops, (not the air temp, which is a different beast) and this reduces
the daytime temp rise, as the brickwork starts off colder.

This can also be done effectively during the evening if (and only if)
you use proper control system. Waving your hand out the window and
saying which is warmer leads to a totally ineffective result.

A differential thermostat plus fan can thus be used to knock a few
degrees off the house temp most of the time. Worked very well at last
place.

Windows that lock in the open half an inch position can be useful for
this.

Resulting hay fever can be dealt with by wet filtering the incoming
air - but dont let the cloth dry out or the dust is released. Put it
in the wm while wet..


NT

On 9 Jul, 07:37, garym999 wrote:

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Interesting.

I'd think it's sunshine/solar radiation falling on the outer surface
of the wall. Depending on the materials and construction, this can
make the outer face ludicrously hot. This heat takes some time to wend
it's way through the structure, usually several hours. I'd suggest
looking up tables for incident solar radiation in the CIBSE guides; I
think there was also a factor called summat like suntime, used to
estimate the time delay before the solar radiation incident on the
outer wall surface made its appearance in the occupied space.

Depending on the affected wall area, you could slap up some foil-faced
insulation to assess whether that is the cause. If not, I'd be looking
at nuisance heat emissions from the heating systems.

On Mon, 09 Jul 2007 14:51:42 +0100 someone who may be The Natural
Philosopher wrote this:-

If the windows don't allow much sunlight through.

Curtains are not noted for their inherent transparency.

They are however generally on the inside of the house. Sun hitting
them will cause a temperature rise within the house.

Otherwise the
sensible approach is to limit the solar temperature rise by
ventilation during the day.

Not in this house,. With air temps up to 30C outside, and internals
nearer 25C, we don;t want any of that outside air coming in thank you!

You have the same external air temperature on all sides of the
house? Fascinating, but unlikely this far away from the equator.

Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.

No, in the space between the curtains and the windows

The air in that space is generally connected to the air in the rest
of the room, whether the curtains are insulated or not. Do you have
some particular arrangement of curtains where this is not the case?
If so, what is it?



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Mon, 09 Jul 2007 08:41:51 -0700 someone who may be
wrote this:-

The philosopher is right on this one.

Incorrect.

And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops,

It goes down because there is not a solar gain at night. The flow of
heat in the fabric reverses. Ventilation will reduce the temperature
of the fabric to some extent, but the extent of this depends on the
conditions (including how much heat is being given off by the
ground).

Of course what happens depends to a large extent on the particular
sort of building one is considering.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Jul 9, 7:37 am, garym999 wrote:
Our house is about 7 years old. Outer red brick walls, cavity
insulation, aero type blocks for inner wall, dot and dab plasterboard
finish.

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Anyone know why this is and how we might stop it?

We have added an extra layer of insulation in the loft but this has
not helped much.

During late afternoon and evening when the interior gets warmer than
outside, any convection through open windows will be from the lower
floor up to the upper floor.

So when there is no breeze, especially at night, the upper floor rooms
will feel stuffy as air is heated on it's way up, and then flows _out_
of the upper floor bedroom windows when it's at it's warmest.

If you have a spare room/study try and have a large fan blowing air
out of that window in the evening and at night. This will help to draw
cool night air _in_ though the upper floor bedroom windows when it
will be at it's coolest.

If this works out OK then try moving your bed under the window for
summer.

cheers,
Pete.

On 9 Jul, 18:00, Aidan wrote:
On 9 Jul, 07:37, garym999 wrote:

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

I
think there was also a factor called summat like suntime,

I think it was sol-air, but that doesn't include any time delay
functions. The relevant books are in my loft, I think.
http://en.wikipedia.org/wiki/Sol-air_temperature

Googling for Solair produced, amongst other things, a link to the
Solair "family oriented nudist resort and campground, owned and
operated by its members. ..."
I don't think that was it.

The gist of it is that the walls and floor slabs act as storage
heaters, soaking up heat in the sunshine and re-emitting it from both
wall faces, some time later.
This sounds a bit extreme for that to fully explain it. Have you
ensured the heating is OFF, isolated with working valves. Is it UFH?

wrote:
On 9 Jul, 14:51, The Natural Philosopher wrote:
David Hansen wrote:
On Mon, 09 Jul 2007 10:20:08 +0100 someone who may be The Natural
Philosopher wrote this:-
The key to keeping houses cool in summer is to SHUT the windows by day -
and the curtains - and OPEN them at night.
If the windows don't allow much sunlight through.
Curtains are not noted for their inherent transparency.

Otherwise the

sensible approach is to limit the solar temperature rise by
ventilation during the day.
Not in this house,. With air temps up to 30C outside, and internals
nearer 25C, we don;t want any of that outside air coming in thank you!

Cool air from the side of the building away from the sun should be let in at low level to get the maximum
cooling.
Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.
No, in the space between the curtains and the windows.. you DO have
insulating curtains I hope..

At night the ground, warmed by the sun during the day, is giving off
relatively hot air and it makes little sense to draw this into the
building.
Not at 3.a.m. it ain't.


The philosopher is right on this one. And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops, (not the air temp, which is a different beast) and this reduces
the daytime temp rise, as the brickwork starts off colder.

This can also be done effectively during the evening if (and only if)
you use proper control system. Waving your hand out the window and
saying which is warmer leads to a totally ineffective result.

A differential thermostat plus fan can thus be used to knock a few
degrees off the house temp most of the time. Worked very well at last
place.

Windows that lock in the open half an inch position can be useful for
this.

Resulting hay fever can be dealt with by wet filtering the incoming
air - but dont let the cloth dry out or the dust is released. Put it
in the wm while wet..


Thats a good trick..

NT

David Hansen wrote:
On Mon, 09 Jul 2007 14:51:42 +0100 someone who may be The Natural
Philosopher wrote this:-

If the windows don't allow much sunlight through.
Curtains are not noted for their inherent transparency.

They are however generally on the inside of the house. Sun hitting
them will cause a temperature rise within the house.

Otherwise the
sensible approach is to limit the solar temperature rise by
ventilation during the day.
Not in this house,. With air temps up to 30C outside, and internals
nearer 25C, we don;t want any of that outside air coming in thank you!

You have the same external air temperature on all sides of the
house? Fascinating, but unlikely this far away from the equator.

Remember that sunlight falling on (internal) curtains will cause a
temperature rise within the room.

No, in the space between the curtains and the windows

The air in that space is generally connected to the air in the rest
of the room, whether the curtains are insulated or not. Do you have
some particular arrangement of curtains where this is not the case?
If so, what is it?


Single glazed windows, and floor length interlined (3 layer) curtains:
There is almost no air movement between the trapped space and the room.

The curtains/sg windows are in fact more effective than triple glazing.

David Hansen wrote:
On Mon, 09 Jul 2007 08:41:51 -0700 someone who may be
wrote this:-

The philosopher is right on this one.

Incorrect.

And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops,

It goes down because there is not a solar gain at night. The flow of
heat in the fabric reverses. Ventilation will reduce the temperature
of the fabric to some extent, but the extent of this depends on the
conditions (including how much heat is being given off by the
ground).

That radiates straight out. The ground surface is typically the coldest
place at night - hence ground frost/mists etc.

Openimng low level windows is very effectice in intridiceing cold air
and if teh upper windos are open too, a chimeny effect develops.



Of course what happens depends to a large extent on the particular
sort of building one is considering.

Loads of trains of thought to follow. House is heated by conventional
radiators but of course this time of the year are not needed. The
front of the house with three of the bedrooms faces SE and the rear
with one bedroom, ensuite and bathroom faces NW with a nice big red
brick wall facing SW. So do I assume that it is this wall that is
collecting all the heat? If this is the case I also guess there is
very little I can do about it as I do not want to paint it White.

Another train of thought was heat travel via the loftspace. It is of
conventional construction with the cavities open at the top where the
roof is resting. Could the heat be rising out of the cavity at night
in to the loft space and then building up?

On 9 Jul, 20:13, garym999 wrote:


brick wall facing SW. So do I assume that it is this wall that is
collecting all the heat?

Could be. So is it most pronounced after a day of sunshine? We haven't
had much of that recently, where is it? Barbados?
I'd have thought the wall insulation should reduce it, most similar
houses don't suffer from this, so I'd suspect there's something else
going on, defective cavity insulation or something. Any neighbours
similarly afflicted?

Another train of thought was heat travel via the loftspace. It is of
conventional construction with the cavities open at the top where the
roof is resting. Could the heat be rising out of the cavity at night
in to the loft space and then building up?

Possible, then the loft would be even hotter than the rooms. A
thermometer with a remote sensor element would allow you measure
what's going on up there.
Is the cavity ventilated with airbricks at the bottom? Hot air won't
convect out the top unless there's cold air going in at the bottom.

If so, shouldn't these be ducted through to ventilate the floor
cavity? Builder chaps please advise.

Barbados AKA Oxfordshire. The house is one of two and we face the sun
and sheild the neighbours. The cavity has weep vents all aound and two
air bricks to the lounge for the fireplace. These are lined with a
sleeve but not sealed did wonder about sealing these with expanding
foam.

"Mary Fisher" wrote in message
. net...

"garym999" wrote in message
oups.com...
The rear of the house, with the conservatory faces NNW. Of the four
bedrooms one is to the rear, others to the front. The master bedroom
windows are open all year and the radiator is never on.

Upstairs by day is fine. Early evening is OK but by late evening the
difference is staggering. I know heat rises but I thought extra
insulation in the loft would help prevent the build up in there.

But that would trap the heat underneath, where you don't like it ...

It keeps the heat radiating from the hot loft.

garym999 wrote:
Our house is about 7 years old. Outer red brick walls, cavity
insulation, aero type blocks for inner wall, dot and dab plasterboard
finish.

By day the house is reasonably comfortable, save the conservatory. But
as night comes the house starts to warm, especially upstairs making
the smaller rooms really stuffy.

Anyone know why this is and how we might stop it?

leave open the loft hatch at night - hot air will all zoom upwards

On 9 Jul, 18:14, David Hansen wrote:
On Mon, 09 Jul 2007 08:41:51 -0700 someone who may be
wrote this:-

And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops,

It goes down because there is not a solar gain at night.

I'm sure you understood what was said really.


Ventilation will reduce the temperature
of the fabric to some extent

bingo

Of course what happens depends to a large extent on the particular
sort of building one is considering.

yes, but most of us live in brick or block. Anyone living in a wooden
shed is out of luck.


NT

On 9 Jul, 20:08, The Natural Philosopher wrote:
wrote:

The philosopher is right on this one. And it goes further too. If you
vent the house all night long, the temp of the fabric of the building
drops, (not the air temp, which is a different beast) and this reduces
the daytime temp rise, as the brickwork starts off colder.

This can also be done effectively during the evening if (and only if)
you use proper control system. Waving your hand out the window and
saying which is warmer leads to a totally ineffective result.

A differential thermostat plus fan can thus be used to knock a few
degrees off the house temp most of the time. Worked very well at last
place.

Windows that lock in the open half an inch position can be useful for
this.

Resulting hay fever can be dealt with by wet filtering the incoming
air - but dont let the cloth dry out or the dust is released. Put it
in the wm while wet..

Thats a good trick..

NT

....one thing i didnt mention before is it needs a lot of airflow for
many hours, but given that it works nicely.


NT