This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.
--
Jeff Gaines - Damerham Hampshire UK
Please reply to Newsgroup.

Jeff Gaines wrote:
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

The hose is to dump the waste hot air.
If you exhausted this into the room, well, that tends to defeat
the purpose.

Ideally, you should make up a close-fitting frame to fit inside the window,
with either polythene, or even acrylic or polystyrene sheet, with a hole
for the hose to go down.
This will significantly reduce air leaks.

In article , Jeff Gaines
writes
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.

IMM who posts here reckons that all you need is a thumping great fan in
your loft to cool your gaff!

No need for Aircon, so think of all the money you'll save))
--
Tony Sayer

Jeff Gaines wrote:

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

I installed a split unit in our home office last winter, and it's been
used extensively this summer. Very happy with it.

Rather than retype, here's the thread:
http://groups.google.com/groups?q=grunff+air+conditioning+millennium+air

--
Grunff

Ian Stirling wrote:

Ideally, you should make up a close-fitting frame to fit inside the window,
with either polythene, or even acrylic or polystyrene sheet, with a hole
for the hose to go down.
This will significantly reduce air leaks.

Or ideally, you should fit a split unit, which is really the only
sensible way to air condition a room ;-)

--
Grunff

In article ,
Ian Stirling writes:
Jeff Gaines wrote:
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

The hose is to dump the waste hot air.
If you exhausted this into the room, well, that tends to defeat
the purpose.

Ideally, you should make up a close-fitting frame to fit inside the window,
with either polythene, or even acrylic or polystyrene sheet, with a hole
for the hose to go down.
This will significantly reduce air leaks.

That doesn't work -- you'll end up with a vacuum in the room
or the room will implode, or your seals didn't work;-)

This is why the ones with a hose are not very good. I hacked one
which had a separate air intake for the evaporator and the condensor
such that it was effectively room sealed, and then it worked well.
Most don't have separate air intakes though, so you can't generally
do this.

--
Andrew Gabriel

Mike Harrison wrote:

Cheapest way to get a split is to find a company who will supply the hardware, let you bolt it down,
run pipes and wire up yourself,and then come and comission it (this is the only bit that needs
special tools & skills - brazing, vacuum pump, manifold gauge) - I saw a thread (maybe here ?) about
this, I think you'd be looking at about a grand all-in, but aircon engineers are a bit busy this
time of the year - you would get a better deal in winter...

You can get a wide range of pre-charged split units which you can
install with no specialist gear. Very easy install, and surprisingly low
prices.

--
Grunff

"Jeff Gaines" wrote in message
...
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

You can get portable units with an outside air handling unit too, although
they are more expensive. I use one in France when it gets too hot. There is
a self-sealing umbilical that will pass through a 50mm hole, although I
usually just stick it outside the ground-floor window, leaving a small gap.

Whatever you choose, the room unit will have a fan running constantly and
that may well be too noisy for a bedroom. I just chill the bedroom down as
much as I can, then turn it off overnight. Usually that works, even in a
Mediterranean summer. The next house will have a central unit, feeding
chilled air to each room though ducting.

Colin Bignell

"Jeff Gaines" wrote in message
...
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.
--
Jeff Gaines - Damerham Hampshire UK
Please reply to Newsgroup.

Some portable types as sold by DIY stores do have a thin rectangular outlet
to which a piece of foam fits over so that the window can be shut to some
extent and the foam fills the gap.
If you intend to sleep with it running, then a cheap portable is not a good
choice because they have noisy fans and compressor in a plastic case.
For a quiet unit, you would have to get a split system or have the cool air
ducted to your room.

Dave

On Thu, 05 Aug 2004 16:25:57 +0100, Jeff Gaines wrote:

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.

Portables are not great - noisy and not very efficient.
Most have an exhaust hose to blow the hot air out, problem is that if it's blowing air out of the
room, it is also drawing (warm) air in. Great if you're in the cool air blast, but not very good at
reducing the overall air temp in a room.
There are some that have an outdoor condenser unit on the end of refrigerant pipes, so the hot
intake and exhaust airflow is all outside the room.

A better way to use a portable is to get a second hose (for the types that can do this), and have
the aircon in an adjacent room and blow the cold air into the room to be cooled. This works a lot
better, and also reduces noise substantially - most portable aircons are far too noisy to use in a
bedroom,

The best way by far is a properly installed split system. I have a Mitsubishi MSC12 system in my
office which has worked flawlessly for 5 years and both the indoor and outdoor units are very quiet
-easily acceptable in a bedroom. Talking to various people then and subsequently, Mistubishi is
about the best, but not the cheapest.

Cheapest way to get a split is to find a company who will supply the hardware, let you bolt it down,
run pipes and wire up yourself,and then come and comission it (this is the only bit that needs
special tools & skills - brazing, vacuum pump, manifold gauge) - I saw a thread (maybe here ?) about
this, I think you'd be looking at about a grand all-in, but aircon engineers are a bit busy this
time of the year - you would get a better deal in winter...
Most aircon installers will try to sell you a maintainance contract, but if you go for a decent
system in the first place, this shouldn't really be necessary as about the only thing that needs
doing is periodic air filter cleaning.

"Graham Wilson" wrote
| I use a 12,000 BTU portable unit that I purchased from B&Q.
| It was about £300.
| It is fantastic at chilling an office down, but it is noisy. ...
| I am thinking of getting a similar unit next year and then
| canabalising it (yes, I know it will screw the warranty).

Why don't you cannibalise the old one and keep the new one in the office,
until its warranty expires.

Then swap them round again, so the old one's in the office, so you can get a
new one on expenses.

Owain

On Thu, 05 Aug 2004 16:25:57 +0100, Jeff Gaines
wrote:

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

I use a 12,000 BTU portable unit that I purchased from B&Q. It was
about £300.

It is fantastic at chilling an office down, but it is noisy. I leave
it running on full power but turn the fan speed down using the remote
control if I have to make a telephone call.

The unit vents outside through the gap in a slightly open window.

They are too noisy for a bedroom.

I am thinking of getting a similar unit next year and then
canabalising it (yes, I know it will screw the warranty).

I was thinking of building a wooden box in the loft.

The current unit appears to have 2 intake grills on the side of the
airconditioning unit. One takes air in and passes it over the coolant
side of the system and this air is expelled as cold air. The other
intake passes air over the heat exchanger. This heat is then expelled
through the pipe as warm air.

There would be two very small grills in the bedroom ceiling. One
taking air to the unit and one returning air to the unit.



Graham

IMM who posts here reckons that all you need is a thumping great fan in
your loft to cool your gaff!

The only way that works is...
o 10,000cfm - which is about 48" across and over 1hp motor
o 10mph thro windows - sucks cool air in
o Absolutely HUGE roof vent - large chunk of a gable end as vent

They can be noisy, and poorly sealing in the winter, and really are for:
o Super-hot places like Arizona, SoCal, etc
o Where they are more about economy re reducing HVAC run-time
---- household HVAC is a few-Ton rating like a car
---- unlike a car house HVAC takes time = $s to drop temperatures
o Thus they are basically for low humidity climates

www.ebay.co.uk has NETT, Japan, split units
o 12,000BTU, wall-mount, split-unit - bids ~258, buy 498 IIRC
o Good for a picture of the type of thing to look for

Mitsubishi Electric are good for HVAC and dehumidifiers, although
for the latter they tend to be a bit pricey and the LCDs a bit fussy. The
key thing is compressor quality & external fan quality, cheap units tend
to cut corners on the bearings & motors (common on dehumidifiers).

If quoting, you need to know the HVAC hose run to the outside, there
are a) hose length limits and b) hose extensions cost quite a bit. Easy to
DIY, since it is self-sealing connections - just remember it's 40-70kg.

That is a note re the "mobile" split units, they are still extremely heavy.
Lugging 130-140lbs+ plus storing off-summer isn't exactly easy. That
is also a recipe for dis-use which will see seals dry out = recharge cost.
--
DB.

"Mike Harrison" wrote in message
...
On Thu, 05 Aug 2004 16:25:57 +0100, Jeff Gaines
wrote:

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.

Portables are not great - noisy and not very efficient.
Most have an exhaust hose to blow the hot air out, problem is that if it's
blowing air out of the
room, it is also drawing (warm) air in. Great if you're in the cool air
blast, but not very good at
reducing the overall air temp in a room.
There are some that have an outdoor condenser unit on the end of
refrigerant pipes, so the hot
intake and exhaust airflow is all outside the room.

A better way to use a portable is to get a second hose (for the types that
can do this), and have
the aircon in an adjacent room and blow the cold air into the room to be
cooled. This works a lot
better, and also reduces noise substantially - most portable aircons are
far too noisy to use in a
bedroom,

The best way by far is a properly installed split system. I have a
Mitsubishi MSC12 system in my
office which has worked flawlessly for 5 years and both the indoor and
outdoor units are very quiet
-easily acceptable in a bedroom. Talking to various people then and
subsequently, Mistubishi is
about the best, but not the cheapest.

Cheapest way to get a split is to find a company who will supply the
hardware, let you bolt it down,
run pipes and wire up yourself,and then come and comission it (this is
the only bit that needs
special tools & skills - brazing, vacuum pump, manifold gauge) - I saw a
thread (maybe here ?) about
this, I think you'd be looking at about a grand all-in, but aircon
engineers are a bit busy this
time of the year - you would get a better deal in winter...
Most aircon installers will try to sell you a maintainance contract, but
if you go for a decent
system in the first place, this shouldn't really be necessary as about the
only thing that needs
doing is periodic air filter cleaning.

Recommendation of the Mitsubishi seconded. I have the MSC12RV/MUH12RV in our
conservatory and it has been running fine for several years now. Also works
in heat pump mode for winter heat - this is very effective, but probably
more useful for a conservatory than a bedroom. The cool-only models are a
little cheaper. They do a wide range of capacity units.

When we got ours it was around £1400 fitted. As Mike has pointed out there
is some special gear needed for commissioning. I think it would be possible
to install one of these by just uncoiling the supplied joining pipes and
connecting them to the outdoor unit, no brazing required. However you'd then
have to use the pipes exactly at the length supplied. In our case the
installer chap just chopped off the flexible pipes supplied and installed
brazed (I think) copper pipework which is now boxed in in an invisible way -
very neat. He alleged at the time that you get a better seal with "hard"
pipework. No idea if that was just waffle.

An older post on the subject ...

http://groups.google.com/groups?q=g:...et.com&rnum=48

Good luck.

Simon.

On Thu, 05 Aug 2004 16:25:57 +0100, Jeff Gaines
wrote:

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Hi,

Try leaving your bedroom window open with a fan elsewhere in the house
blowing out of another window, so it draws cool air into the bedroom.

If you start it running as it gets dark it will help to cool the room
by the time you go to bed.

It may or may not be good enough, but if it is it will be cheaper and
probably quieter to run.

Also leave the curtains or blind closed in the daytime to help keep
the room cool.

cheers,
Pete.

On Thu, 5 Aug 2004 20:23:10 +0100, "Owain"
wrote:

"Graham Wilson" wrote
| I use a 12,000 BTU portable unit that I purchased from B&Q.
| It was about £300.
| It is fantastic at chilling an office down, but it is noisy. ...
| I am thinking of getting a similar unit next year and then
| canabalising it (yes, I know it will screw the warranty).

Why don't you cannibalise the old one and keep the new one in the office,
until its warranty expires.

Then swap them round again, so the old one's in the office, so you can get a
new one on expenses.

Owain


Many thanks for all the responses :-))
I will follow them all up.
I quite like the idea of a 'thumping great fan' - if I could get
one of those with an attractive 35 year old blond on the other
end I guess sweltering in this humidity wouldn't be such a
problem!

--
Jeff Gaines - Damerham Hampshire UK
Please reply to Newsgroup.

I bought a 1hp window unit from Sears when I was in the USA a couple of
months ago and carried it home as checked luggage. It cost $80, or about
£45. I then bought a site transformer on Ebay for about £30 to plug it into
and now have a semi portable unit I rest on the sill of my bedroom or lounge
window. A couple of bits of MDF blank the gaps at the side (the supplied
plastic curtain was too small) and the unit works perfectly. Proper
refrigerated cold air for £75, I wonder why we are ripped off so much in the
UK.

http://www.sears.com/sr/javasr/produ...PPL&pid=04 27
4054000

Colin

"tony sayer" wrote in message
...
In article , Jeff Gaines
writes
This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep. It's not a big room, 4m x 3.1m but on the south facing
corner of a bungalow.

Any recommendations whether to go for a portable unit (they all
seem to need a hose hanging out the window which seems to defeat
the object) or a 'built in' solution with outside/inside units?

Any manufacturers better/worse from your experience?

Many thanks.

IMM who posts here reckons that all you need is a thumping great fan in
your loft to cool your gaff!

No need for Aircon, so think of all the money you'll save))

Too true.

"Jeff Gaines" wrote in message
...

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep.

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the room
cool. It works.

"Colin M" wrote in message
...
I bought a 1hp window unit from Sears when I was in the USA a couple of
months ago and carried it home as checked luggage. It cost $80, or about
£45. I then bought a site transformer on Ebay for about £30 to plug it
into
and now have a semi portable unit I rest on the sill of my bedroom or
lounge
window. A couple of bits of MDF blank the gaps at the side (the supplied
plastic curtain was too small) and the unit works perfectly. Proper
refrigerated cold air for £75, I wonder why we are ripped off so much in
the
UK.


http://www.sears.com/sr/javasr/produ...PPL&pid=04 27
4054000

Colin



The unit you bought is not very powerful (though it is good value). Homebase
do one about twice the power for £150 this summer. I bought a slightly more
powerful unit again for £250 and other than it sounding like a bus engine,
I'm happy. Aircon in the US is very much cheaper than in the UK - yes we are
ripped off but it is coming down in price. My unit is pretty powerful
(12000btu) and cools the room to about 16 degrees which is lovely and cool.
It does tend to suffer from the internal drip tray filling up sometimes.
For a bedroom I'd recommend a split unit - I'm considering one now I have
the portable as I love the cool air, but the noise is a bit annoying (though
less annoying than unbearable heat!). I'd almost certainly try to fit the
unit myself though as the air con fitters charge a lot of money on top of
the already inflated prices of the units!

On Fri, 6 Aug 2004 01:42:21 +0100, "IMM" wrote:


"Jeff Gaines" wrote in message
.. .

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep.

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the room
cool. It works.


Put it in the rooms as well, so that you don't have to go in them. A
win-win situation.


..andy

To email, substitute .nospam with .gl

In article , IMM abuse-
writes

"Jeff Gaines" wrote in message
.. .

This heat/humidity is getting to me!

I have been thinking about putting some form of Air conditioning
just in the bedroom so at least I can have somewhere cool to
sleep.

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the room
cool. It works.




Yes in laa-laa land it does, in our gaff it seems to be due to rising
air and heat from the rest of the house. Theres three layers of fibre
glass quilt up there already now!, dunno how much more I could get in
there.

In between the joists, across that at right angles, and then another
layer at right angles again!.......
--
Tony Sayer

IMM wrote:

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the room
cool. It works.

Heh...up until 2 weeks ago I would have been prepared to accept this
argument. Up until then, we had no insulation in the loft - just
plasterboard, air then slates.

We then laid 150mm of insulation. Since doing so, the upstairs has been
significantly hotter - about 3-4 C increase.

--
Grunff

In article ,
IMM wrote:

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the room
cool. It works.

It doesn't in my house. Nor I suspect for other people who live in places
where heat rises (I accept that this may not be the case on your planet).

heat from the house rises and collects up stairs. Heat is not lost through
the ceiling as the insulation stops it. I left the loft hatch open for a
while the other day and although it was unbearable in the loft the room
with the hatch felt noticably cooler...

Of course, keeping doors closed could help but that seems to be incompatible
with small children.

Darren

In article ,
tony sayer wrote:

IMM who posts here reckons that all you need is a thumping great fan in
your loft to cool your gaff!

So he's moved on from the daft "plant gernaiums to lower temperature by 15
degrees and rh by 40%", then?

Grunff wrote:

Heh...up until 2 weeks ago I would have been prepared to accept this
argument. Up until then, we had no insulation in the loft - just
plasterboard, air then slates.

We then laid 150mm of insulation. Since doing so, the upstairs has been
significantly hotter - about 3-4 C increase.

Well to be fair it does work the way it was inteneded then ;-)
(i.e. keeping all that nice heat in)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Does IMM also believe in fairies ( childish type)?

LOL

Capitol

(dmc) wrote in message ...

Of course, keeping doors closed could help but that seems to be incompatible
with small children.

Darren

So now is the time to wander over to Screwfix or Toolstation and buy internal
door closers (just the small cylindrical ones) for internal doors which you
can set to "bias" the door into the closed position.
These have proved invaluable in the winter in that my blood pressure has
reduced since I don't have to rant so often.

I've also purchased and fitted the beefier door closers (the ones with
pistons in them I think) to our external doors and these too have been
invaluable.

Mungo

"IMM" wrote in message
...
snip

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the
room
cool. It works.


IMM, re-writing the laws of physics again I see..

IMM, you really are one sure ****.

On Sun, 8 Aug 2004 16:43:37 +0100, ":::Jerry::::" wrote:


"IMM" wrote in message
...
snip

Forget expensive a.c. Put extra insulation in the loft. In bedrooms heat
comes down from the hot loft, the insulation prevents this keeping the
room
cool. It works.


IMM, re-writing the laws of physics again I see..

IMM, you really are one sure ****.


Maybe there would be a way to constructively use the heat that builds up in the loft though - surely
if you had an openable vent in the roof and ceiling, then the hot air in the loft would rise out of
the vent, drawing cooler air in through the room.

Mike Harrison wrote:

Maybe there would be a way to constructively use the heat that builds up in the loft though - surely
if you had an openable vent in the roof and ceiling, then the hot air in the loft would rise out of
the vent, drawing cooler air in through the room.

The fundamental difficulty you come up against is there are times when
there is no cooler (or more to the point, cool and dry enough) air to be
drawn in! If it is too hot and muggy outside, the best you get from
sucking it is is too hot and muggy inside.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Mike Harrison" wrote in message
...
On Sun, 8 Aug 2004 16:43:37 +0100, ":::Jerry::::" wrote:


"IMM" wrote in message
...
snip

Forget expensive a.c. Put extra insulation in the loft. In bedrooms
heat
comes down from the hot loft, the insulation prevents this keeping the
room
cool. It works.

IMM, re-writing the laws of physics again I see..

You are a fool

IMM, you really are one sure ****.

Still a fool.

Maybe there would be a way to constructively
use the heat that builds up in the loft though - surely
if you had an openable vent in the roof and ceiling,
then the hot air in the loft would rise out of
the vent, drawing cooler air in through the room.

Now for something sensible...Yep that could happen. But you need sealed
dampers and controls to ensure that it operates at the right time.

"IMM" wrote in message ...

snip
Still a fool.


You said it, I'm glad that you are finally being truthful about yourself.