My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

In article ,
wrote:
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

Is some ways, yes. I'm assuming from the minimal description that this is
an evaporative cooler - while they do work they have serious disadvantages...

The cool the air buy blowing it over a damp surface - this causes the water to
evaporate which obviously has the side effect of raising the humidity of the
air...this isn't great.

Personally, I don't like the heat but I'd prefer hot and dry over cooler and
humid anyday.

Although the temp of the room may drop a bit the increase in humidity will
not always make the room feel any more pleasant - and possibly worse.

I wouldn't buy one myself. YMMV

Darren

wrote in message
...
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

Overall probably not worth it (IMHO) but it does dehumidify. Toddlers can
get hot and sweaty in weather as at present - if it helps him/her sleep
cooler/drier/better, you might think it's worth it! But probably only
effective for that with the window shut and the noise might keep him/her
awake. You can't, in the end, put energy into a closed room and not make it
hotter, even if you make it drier.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

wrote:
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

These coolers are best in hot dry climates where the extra
humidification might be desired. In this country where hot and wet is
the norm, they can actually make it harder to get cool.


--
Cheers,

John.

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

"Bob Mannix" wrote in message
...
wrote in message
...
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

Overall probably not worth it (IMHO) but it does dehumidify. Toddlers can
get hot and sweaty in weather as at present - if it helps him/her sleep
cooler/drier/better, you might think it's worth it! But probably only
effective for that with the window shut and the noise might keep him/her
awake. You can't, in the end, put energy into a closed room and not make
it hotter, even if you make it drier.


Ah, too late in the day - of course it makes the air wetter not drier,
that's how it cools it. Forget everything I said, waste of money!


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

used his keyboard to write :
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

The way they operate is as follows...

You fill a tank with water, the water is drawn up onto a material which
is in the air flow which causes the moisture to evaporate. The process
of evaporation needs energy, the energy being obtained from the air -
which is cooled as a result by 2 or 3 deg.

So far, so good - now the bad points...
The moisture ends up in the air, increasing the humidity. We always
notice hot days most, when it is humid because high humidity prevents
us from disposing of body heat by sweating.

So in a closed room using one of these you swap temperature for higher
humidity. You could get a quite similar cooling result by hanging wet
towels up and using an ordinary fan to blow air across them.


--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

wrote in message
...
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

A fan, maybe cieling fan, will be far more effective. Just put the cieling
fan high enough or get one with a guard around it. That unit looks like a
dehumidifier, which will use a lot of electricity.
A cieling fan would be far better.

On 12 May, 16:35, wrote:

Will it be any more effective than a fan?

They are excellent........

........in Arizona or in Foreign Legion forts in the Sahara.

However, in the UK they're a complete pile of poo.

Simply cooling the air makes the Rh higher. You can get something like
80% Rh indoors by simple cooling (no dehum) and this is
extraordinarily uncomfortable, clammy, close and muggy.

These things don't do simple cooling, though; they cool the air AND
they add moisture.
And Argos sell them. To people who can't read a psychrometric chart.

The legionnaires' disease should soon reduce the numbers of the
psychrometrically illiterate.

On Mon, 12 May 2008 08:35:32 -0700 (PDT), wrote:

Will it be any more effective than a fan?

The only way to effectively cool a room, ie bring the actual temperature
down, is to have some form of heat pump and dump the heat else where. An
evaporative cooler doesn't does this indeed the energy it consumes gets
dumped into the room as well so if anything it makes it hotter.

A large, slow, ceiling fan will be much more effective and quieter as the
very gentle flow of air enables the bodies own cooling system to work
properly. Rooms feel uncomfortable when the air isn't moving and your
sweat isn't evaporating as it should to cool you.

A normal fan blasts small amounts of air around quickly, a ceiling fan
makes the entire air in the room slowly circulate.

When I was back pack travelling through the Far East most rooms didn't
have air con just a ceiling fan. That on low was enough to make the 90deg
heat and 90% humidty perefectly acceptable turn it off and you "melted".
Just remember to keep your fluids up, in this case the fluids of the
toddler.

--
Cheers
Dave.

"Dave Liquorice" wrote in message
ll.net...
On Mon, 12 May 2008 08:35:32 -0700 (PDT), wrote:

Will it be any more effective than a fan?

SNIP

A large, slow, ceiling fan will be much more effective and quieter as the
very gentle flow of air enables the bodies own cooling system to work
properly. Rooms feel uncomfortable when the air isn't moving and your
sweat isn't evaporating as it should to cool you.

Interesting. We have them in every room apart from kitchen & bathroom and
they do work very well. Now I understand why.

Cool!


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On May 12, 4:35*pm, wrote:
My wife wants to buy thishttp://www.argos.co.uk/static/Product/partNumber/4250313/Trail/search...AIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

Useless. A complete waste of money. Doesn't give any benefit in even
mildly warm weather. Get a proper air conditioner.
You can air con a small room a unit for £300 off ebay. I fitted a
double unit last
year. One outdoor unit two indoor units for two rooms. £600 it's great
cool in summer hot in
winter.

On 12 May, 23:43, "Dave Liquorice"
wrote:

The only way to effectively cool a room, ie bring the actual temperature
down, is to have some form of heat pump and dump the heat else where. An
evaporative cooler doesn't does this indeed the energy it consumes gets
dumped into the room as well so if anything it makes it hotter.


At the risk of sounding pedantic, they do cool the air.

The moisture absorbs the latent heat of evaporation that it needs to
change from a liquid to a vapour from the air, so the air temperature
does go down. The amount of latent energy involved in getting moisture
into, or out of, the air is large and it can be a larger load than the
sensible heat gains (sunshine, lights, computers, etc.). An
evaporative cooler should produce 2 or 3 degC (at a guess, I've never
used one) of cooling. Relative humidity goes up, which is the huge,
unanticipated catch.

An arrangement I once saw advertised, for commercial air handling
units, divided the supply air into multiple narrow ducts and the
evaporative cooling pads were on the outside of these, with the
extract air stream blowing over them. It should have worked in theory,
but I never saw any in use so I'd assume there were other
unanticipated catches involved (insignificant cooling, lime scale,
corrosion, etc.).

On Tue, 13 May 2008 05:44:19 -0700 (PDT), Onetap wrote:

The only way to effectively cool a room, ie bring the actual
temperature down, is to have some form of heat pump and dump the heat
else where. An evaporative cooler doesn't does this indeed the energy
it consumes gets dumped into the room as well so if anything it makes
it hotter.

At the risk of sounding pedantic, they do cool the air.

But only some of the air leaving the unit, the air cooling the motor will
be hotter. you are pumping in several hundred watts of electrical energy
most of which will end up as heat. Yes the latent heat of evaporation will
takes some of it, until the water condenses else where...

As I said the only real way to cool a room is to have a heat pump and
shift the heat from the room to somewhere else.

An arrangement I once saw advertised, for commercial air handling
units, divided the supply air into multiple narrow ducts and the
evaporative cooling pads were on the outside of these, with the
extract air stream blowing over them. It should have worked in theory,
but I never saw any in use so I'd assume there were other
unanticipated catches involved (insignificant cooling, lime scale,
corrosion, etc.).

Yes that should have worked but there is an important difference between
that and an in room evaporative cooler. The heat is being dumped outside
via the extract air flow...

--
Cheers
Dave.

On Mon, 12 May 2008 23:43:33 +0100 (BST), "Dave Liquorice"
wrote:

On Mon, 12 May 2008 08:35:32 -0700 (PDT), wrote:

Will it be any more effective than a fan?

The only way to effectively cool a room, ie bring the actual temperature
down, is to have some form of heat pump and dump the heat else where.
[snip]

Not always. In fact, in the UK, it's rarely the case.

Specifically in the case of the OP (cooling a UK bedroom at night), no
heat pump is needed to dump the heat out of the room. Just ventilating
with outside air will give all the temperature drop you need on all
but the very hottest of UK nights.

I'd start by opening a window. If there isn't enough wind to make that
work, come up with some cunning arrangement to make a fan pull in
outside air.

If you go down the fan route, you could even put a thermostat on it...

Cheers,

Colin.

On 13 May, 14:57, "Dave Liquorice"
wrote:

At the risk of sounding pedantic, they do cool the air.

But only some of the air leaving the unit, the air cooling the motor will
be hotter. you are pumping in several hundred watts of electrical energy
most of which will end up as heat. Yes the latent heat of evaporation will
takes some of it, until the water condenses else where...


They do cool the air.

There is one here, for example; http://www.tombling.com/cooling/port...air-cooler.htm

The electrical power input is 690 W.

The rate of evaporation is 53 litres in 10 hours = 0.001472 kg/s.

The latent heat of vaporization at (let's say) 21 degC is 2451 kJ/kg.

The cooling effect due to evaporation is (0.001472 x 2451) kJ/s = 3.61
kW.

The net cooling effect is (3610 – 690) W = 2918 W approximately.

Got that?

They cool the air, as anyone could show with a thermometer, so you
couldn't demand your money back because it doesn't cool.
Not many people would have a hygrometer handy.

We are agreed that they're a waste of money.

"Onetap" wrote in message
...
On 13 May, 14:57, "Dave Liquorice"
wrote:

At the risk of sounding pedantic, they do cool the air.

But only some of the air leaving the unit, the air cooling the motor will
be hotter. you are pumping in several hundred watts of electrical energy
most of which will end up as heat. Yes the latent heat of evaporation
will
takes some of it, until the water condenses else where...


They do cool the air.

There is one here, for example;
http://www.tombling.com/cooling/port...air-cooler.htm

The electrical power input is 690 W.

The rate of evaporation is 53 litres in 10 hours = 0.001472 kg/s.

I would like to see it evaporate anything when the Rh is 100%, which it is
for a fair portion of the time.

In article ,
Onetap writes:
On 12 May, 23:43, "Dave Liquorice"
wrote:

The only way to effectively cool a room, ie bring the actual temperature
down, is to have some form of heat pump and dump the heat else where. An
evaporative cooler doesn't does this indeed the energy it consumes gets
dumped into the room as well so if anything it makes it hotter.


At the risk of sounding pedantic, they do cool the air.

Yes.

Trouble is that humans really don't care much about the
actual temperature, but do care about the wet bulb temperature,
as we're actually all damp when we're too hot. Cooling by
raising the humidity doesn't reduce the wet bulb temperature,
so although a (dry bulb) thermometer will show a temperature
reduction, you won't feel it, and you won't be able to cool
yourself any better (often quite the opposite).

Evaporative and swamp coolers work really well in hot dry
climates. They don't work in the UK climate.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Tue, 13 May 2008 21:10:33 +0100, dennis@home wrote:

I would like to see it evaporate anything when the Rh is 100%, which it
is for a fair portion of the time.

Not indoors... In the winter with the CH on the indoor RH is around 30%.
In summer with the CH off it is aroond 50%. But then we don't have an
evoporative air "cooler" chucking out 1.1 gallons of water an hour...

We have a 25' long 2' thick and 20' high lump of stone through the middle
of the house, keeps the place cool in summer and warm in winter.

--
Cheers
Dave.

Onetap wrote:

We are agreed that they're a waste of money.

I think they're OK for spot cooling in a limited range where there's a
good throughflow of air.

Would be best for cooling face and body of one person if up on a
nearby table/shelf.

cheers,
Pete.

"dmc" wrote in message ...
In article
,
wrote:
My wife wants to buy this
http://www.argos.co.uk/static/Product/partNumber/4250313/Trail/searchtextAIR.htm
to cool our toddlers room.It's a relatively small double room about 12
feet by ten feet.

Will it be any more effective than a fan?

Well I'm not sure, but I have brought one of these :-

http://www.maplin.co.uk/module.aspx?...&doy=14m5#spec

Maplin L35AK


And I certainly felt cooler while it was blowing air using just the water.
I'd assume the air would be further cooled by the addition of the ice packs.

In fact my one was in use in the store where the staff were using it behind
the till
point so I guessed it must work, and I got a used discount too
..
So ended up paying £35, so I considered it a worth while buy.


Is some ways, yes. I'm assuming from the minimal description that this is
an evaporative cooler - while they do work they have serious
disadvantages...

The cool the air buy blowing it over a damp surface - this causes the
water to
evaporate which obviously has the side effect of raising the humidity of
the
air...this isn't great.

I'm not sure what the Maplin one is but it does seem to work.
I assume that blowing warm air over cold water that the this warms
the water and cools the air, which is what I want.


I wouldn't buy one myself. YMMV.

I'd like to give it a good test on a hot day and measure humidity and temp.