A/C vs Air cooling

[07london55]

Can anyone explain the definitive difference between air cooling and air conditioning? I've always been under the impression that air con was the highly effective, gas guzzling system it is, whereas air cooling appears to have some confusion about it.

I've been looking at a few ex-GAL Geminis which appear to have the air cooling system fitted. Would the operator now (Go East Anglia) still be willing to use the air cooling systems fitted - or are they a complete pain and too costly for them to use/maintain like A/C?


Thanks

 

[The Lad]

Air Cooling simply cools the air, air conditioning controls temperature and humidity.

 

[Goldfish62]

Air Cooling simply cools the air, air conditioning controls temperature and humidity.

Perfectly put. Also, air cooling is useless in humid weather. As with aircon it's also useless if combined with opening windows.

I've been on brand new buses in London chucking out warm air through the air chill vents. More effective are white roofs and the air extraction fans at the rear of the bus which increase the flow of air through open windows.

 

[The Lad]

Well, it depends how the cooling is achieved, the simple way is to spray water into the air, as it evaporates it cools the air but at high ambient humidity there is little scope for further water to be held in the air and hence little cooling effect and as the air is more or less saturated with water your body can't lower temperature by sweating.
Slightly more complex is to use a compressor with evaporator and condenser which cools the air and removes some of the water vapour so the output air is cool and also more or less saturated but as it warms up it is able to hold more water and sweating is effective. It uses power for the compressor. Such systems are commonly in smaller shops and offices and have an external 'box' and an internal 'box' connected by small pipes and may be referred to colloquially as Air conditioning but they don't include the conditioning step

 

[Bletchleyite]

Slightly more complex is to use a compressor with evaporator and condenser which cools the air and removes some of the water vapour so the output air is cool and also more or less saturated but as it warms up it is able to hold more water and sweating is effective. It uses power for the compressor. Such systems are commonly in smaller shops and offices and have an external 'box' and an internal 'box' connected by small pipes and may be referred to colloquially as Air conditioning but they don't include the conditioning step

I suspect just about everyone calls that "air conditioning" even if it technically is not because the humidity isn't controlled, it's just reduced as a byproduct of the cooling. The former (using water) is called "evaporative cooling" and is reasonably effective but not if it's humid, but I don't think that system is used on transport vehicles, largely because it wouldn't work too well with water sloshing around the place.

 

[Goldfish62]

I suspect just about everyone calls that "air conditioning" even if it technically is not because the humidity isn't controlled, it's just reduced as a byproduct of the cooling. The former (using water) is called "evaporative cooling" and is reasonably effective but not if it's humid, but I don't think that system is used on transport vehicles, largely because it wouldn't work too well with water sloshing around the place.

It's used on some trains - the Class 165s retrofitted by GWR and Chiltern, rather than full aircon. I assume some of the large containers in the luggage racks are tanks to hold the water.

 

[Mikey C]

It's used on some trains - the Class 165s retrofitted by GWR and Chiltern, rather than full aircon. I assume some of the large containers in the luggage racks are tanks to hold the water.

I remember using a GWR 165 in the summer during a hot spell and it was like a freezer inside so the air cooling system was highly effective. Really noisy though, like being inside a factory!

 

[Bletchleyite]

It's used on some trains - the Class 165s retrofitted by GWR and Chiltern, rather than full aircon. I assume some of the large containers in the luggage racks are tanks to hold the water.

Are you absolutely sure it's evaporative cooling, and not just refrigerated cooling without humidity management?

It is very effective, I'll give you.

 

[Goldfish62]

Are you absolutely sure it's evaporative cooling, and not just refrigerated cooling without humidity management?

It is very effective, I'll give you.

TBH I couldn't be absolutely sure.