Air Con Questions

[Naam]

I had the impression it was lower - perhaps you had mentioned wife liking it really cool or that 18 degree figure (which is definitely Arctic freezing for our blood).

you seem to be a bachelor Lopburi. if you were married you'd know that wives like it cold, warm, cool, hot, drafty or lukewarm without any priorities and in different sequences according to what they just "like to like".

Dear God, please don't let her read this!

[Naam]

I sure wouldn't argue cold air is not heavy than hot air, but as the cold air falls through the hot air or the hot air rises through the cold air the cold air ends up not being so cold anymore. Plus you just have the interaction between the lower layer cool air and upper layer warm air in the room...where basically that warm layer is making the cool air less cool. Maybe take it to an extreme...say you had a room with a 20 ft ceiling height compared to a 10 ft ceiling height...you've just doubled the volume of air in the room requiring cooling. But many calculators I've seen really don't consider ceiling height since I guess they consider then all around 9 ft give or take a little except in some houses where vaulted/high ceilings exist which increase the volume of air needing cooling; but the ones which do a more accurate calculation do include ceiling height.

after some valuable technical advice i received from you, you disappoint today Pib. cool air is indeed denser and therefore heavier than hot air (think of hot air balloons!). the ceiling height and volume of a room to be cooled is not a major factor to deal with, provided the indoor unit is not mounted in the ceiling or high up. a 20' ceiling double volume of a room same size but half height does not (repeat not) require double capacity or double energy.

the focus is on "leave the upper layer of air undisturbed". only a moronic contractor will install an inside unit all the way up in a room with a 20' ceiling except if the client demands a ceiling cassette unit because he wants to increase his carbon footprint. it goes without saying that volume has some effect on cooling but only in a range of 15-20%, in rooms with extremely high ceilings that negative effect can go even down close to zero.

summary:

the ones which do a more accurate calculation do include ceiling height

but if they use the total volume without adequate deductions in their calculations they are in my [not so] humble view... ignorants.

[Naam]

I am no expert and am unsure if ceiling height matters a lot? After all, cold air falls so I think the square meterage of the room matters more than ceiling height?

and the winner is... Doggie!

[Pib]

I sure wouldn't argue cold air is not heavy than hot air, but as the cold air falls through the hot air or the hot air rises through the cold air the cold air ends up not being so cold anymore. Plus you just have the interaction between the lower layer cool air and upper layer warm air in the room...where basically that warm layer is making the cool air less cool. Maybe take it to an extreme...say you had a room with a 20 ft ceiling height compared to a 10 ft ceiling height...you've just doubled the volume of air in the room requiring cooling. But many calculators I've seen really don't consider ceiling height since I guess they consider then all around 9 ft give or take a little except in some houses where vaulted/high ceilings exist which increase the volume of air needing cooling; but the ones which do a more accurate calculation do include ceiling height.

after some valuable technical advice i received from you, you disappoint today Pib. cool air is indeed denser and therefore heavier than hot air (think of hot air balloons!). the ceiling height and volume of a room to be cooled is not a major factor to deal with, provided the indoor unit is not mounted in the ceiling or high up. a 20' ceiling double volume of a room same size but half height does not (repeat not) require double capacity or double energy.

the focus is on "leave the upper layer of air undisturbed". only a moronic contractor will install an inside unit all the way up in a room with a 20' ceiling except if the client demands a ceiling cassette unit because he wants to increase his carbon footprint. it goes without saying that volume has some effect on cooling but only in a range of 15-20%, in rooms with extremely high ceilings that negative effect can go even down close to zero.

summary:

the ones which do a more accurate calculation do include ceiling height

but if they use the total volume without adequate deductions in their calculations they are in my [not so] humble view... ignorants.

Whoops, that "not" word in the first sentence (i.e., ....not heavy as hot air) shouldn't have been there......should have left out the "not" word and just said cold air is heavier than hot air. But the rest of the sentence implies/states cold air is heavier/denser. Fingers getting ahead of the brain. Bad proof reading on my part. Cheers.

[kyrre]

Normaly the unit is prefilled with freon. But you have 2 types, where one has the freon prefilled into the outdoor unit, and one where all parts are prefilled where you puncture the system when connecting together.

With the one that has prefilled outdoor unit it is importent to not have to long pip length without adding some more freon to the pipes. It normaly enough to flush freon gas in the pips and indor unit.

Also you should flush first with nitrogen and then vacum before you open the system og add gas to the pipes.

Air and moister is the enemy number one to air-com