Wintertime AC

[lectric80]

Sure, the added efficiency comes from the extra surface area - more gas is touching metal at all times - and parallel paths (hotter gas is spread out over more area), but it's not proportionately that much more area directly exposed to the air flow. I've never found any real numbers except the 30% efficiency figure. None of those statements said anything about saving space or making the unit smaller. AC Delco talks about saving weight with their "replacement" unit, but never mention improving performance. What is the definition of condenser efficiency, if it's not amount of heat removed at a certain refrigerant and air flow?

It only makes sense that the replacement units would be parallel flow, as that's what the factories will be set up for. They save on extra tooling and save on material.

I have never seen any concrete numbers, and in fact the only experience I have is just using what is already there. I plan to replace the condensor in my Blazer when I get through the rebuilding, and of course will be using a parralel flow type unit, but that is only because those who do refrigerant have recommended it.

I do know that even with a slightly smaller unit, there is still a lot more surface area in the piping to help remove the heat. But, I don't know how much more efficient that makes the unit versus using a slightly larger tube and fin condensor. Even the AC Delco unit doesn't seem to make much sense because there really isn't that much weight in a condensor.

 

[lectric80]

Never seen or heard yet, of a vehicle explosion from leaking freon from front end collisions anyways, even just had a friend of mine smash the crap out of his S-10 a few weeks back, and we had just topped off his r-12 system about 2 weeks before this crash, his truck didn't blow up.

I keep hearing about flammability issues with different freons, I have yet to see flames from them under the typical every day use we put them through.

I know freeer warehouses use ammonia for reefer units, obviously a nasty chemical, but does real good at refrigeration.

And 34 degree vent temps,? I dunno, maybe these are old temps that people are used to from older 70's equipment, but so far, every newer vehicle I have been in, usually has a single digit temp coming out of the vents.

I have never seen single digit temps from any system, the temperature at the vents is going to vary based on the temperature of the air being fed into it. No matter how efficient the system is, the air only makes contact with the evaporator for a short amount of time so can only be cooled so much. My Caddy, which is an original R134 system has vent temps of around 33* when it is in recirculate mode and usually around 34* with 90-95* outside temperatures. Typically there is only a 14-22* drop in temperature between the inlet and outlet side of the evaporator, but that is where mine usually reads.

If you can find a system that is blowing out single digit temps I would be surprised since the components of the HVAC system will not withstand that. Plastic ducting and other components would be damaged with air that cold. You do know we are talking farenheit not celsius, right? 32* farenheit is freezing temp, and much colder than that would actually be harmful to the occupants of the vehicle.

 

[4xcrazy]

Mine must be broken then, I have also checked the vent temps with a mercury type thermometer as well, guess I'll try a few others to see what their readings are.

I did worked on a friends Ford F-150 a few weeks ago because he was complaining about the ac not getting as cold as his Chevy van, which I also worked on to get it in single digits as well. He gets the Ford here and it's in the 30* range, pressures were alittle low, added a can of freon, got the temps down in the low teens, but that's all it would do. Apparently not enough air flow over the condensor on that model of truck according to some research we did.

I'll take video of this if need be.. These systems do get very cold, even when it's above 100* outside in Phoenix, we usually end up having to turn down the fan speed or move the vents away from blowing directly onus, they do get cold.

Also this is on the MAX recirculate setting as well, so it continues to pull inside cabin air and recool it as well.