Air conditioners

[gabby]

Whats the difference between vapor and prime. I have some Athearn BB here that I want to add them too but don't know which ones.

 

[UP2CSX]

Vapor air conditioners operate in the way a basic window or RV air conditioner operates. The refrigerant cycles from 100% vapor to 100% liquid as part of the cooling cycle. Freon of some type is the usual refrigerant. I'm not aware of a specific air conditioner type know as "prime" unless it's a brand name. My brother, who worked for Honeywell for 30 years in their heating and cooling division, has also never heard of the term, so I'll need some more information to understand your question.

 

[wheeler1963]

Jim, here's a "prime"

http://www.1stplacehobbies.com/cgi-bin/p_229-2308_n.asp

here's a "vapor"

http://www.1stplacehobbies.com/cgi-bin/p_229-2309_n.asp

 

[gabby]

Jim I'm afraid I can't give you any more info other than the links that Jerome has posted.

Jerome thank you for the links. Do you deal with tham at all????

 

[wheeler1963]

Bob, yes I've ordered through 1st Place Hobbies a lot. Very fast service and email updates if they are out of a product.

 

[UP2CSX]

From what I can tell, "Prime" is a South Korean company that produces this type of air conditioner. It's a hybrid type, that can function as an evaporative cooler or normal vapor type, depending on the humidity. It seems to be used mostly by western railroads, that typically operate in low humidity environments. Like the "vapor" models, it comes in several shapes and sizes, and I think the BMLA models are just basic representations of both types without trying to duplicate a specific model. The two types look very similar, so you'd really need to work from a prototype picture to get the right one.

 

[kenw]

Swamp coolers on the railroad? Those things are death to electronics.....

venturing ot here....

what I have seen (non-rr) are normal (in our case here, 'vapor') AC units that use a swamp cooler subsystem to add cooling capacity to the exterior (condenser) coils. The water vapor doesn't get to the interior of the cab (or house), it merely increases the efficiency of the condenser part of the system. The basic AC unit is the same, the swamp cooler is usually an add-on that pre-cools (in simple terms) the air that is drawn across the exterior condenser coils, increasing the heat transfer and efficiency. Dry air doesn't absorb heat too well.

If you have a typical air-sourced AC or heat pump in a very dry climate (SW USA), you would be wise to investigate, they can save a lot of $$$$.

 

[UP2CSX]

Ken, from what I can tell, the evaporative cooling pads are mounted on the exterior of the condenser coils to do exactly what you say, pre-cool the coils. None of the higher humidity air gets in the cab. It uses water from a reservoir mounted in the engine compartment or walkway. I've never seen one of these in operation so I only know what I read on the net. I know the BMLA products are really basic representations of both types, since neither much resembles most of the air conditioning units used on locomotives.

 

[wheeler1963]

Jim, Jim, Jim LOL You should know by now there is a prototype for everything. Here's one I took a picture of last year back home in Aurora Illinois. It's the same type as the BLMA a/c.

 

[Chris Roy]

Yeah, the DA a.c. units are now 'old-school' - the BLMA model is pretty accurate for the motor-home style units being installed as replacements / upgrades. Here's a shot of one installed on the equipment box of a MOW truck.

 

[UP2CSX]

Indeed, the Coleman/Dometic motor home type air conditioners seem to the most common used now on retrofits and replacements. It looks nothing like either of the DA models. I don't know if we'll start seeing these on new units from the factory, but they cost about $1000 each compared to about $5000 each for the more vibration resistant railroad only models. I suspect the railroads will figure it's better to spend the $1000, especially since crews I talk to say the A/C only works about half the time anyway.

 

[railBuilderDhd]

Jim, Jim, Jim LOL You should know by now there is a prototype for everything. Here's one I took a picture of last year back home in Aurora Illinois. It's the same type as the BLMA a/c.

Anyone know what that thing is on the front of the photo attached to the tracks?

Cool photo.
Dave

 

[wheeler1963]

it's a switch motor heater, keeps them from freezing in the winters.