After market, under dash AC evaporator, on top of dash

[JerryP]

Looking for some opinions, or advice on my dash AC repair project I am considering.
I just ordered a new compressor for my Chieftain 23, Sanden 709 and am thinking of buying one of the Universal under dash evaporator units to put either on, or under the dash.
My questions, or quest for opinions has to do with,
1. Any reason it would not work?
2. Anyone else done this
3. Should I get one of the larger minibus size, or one of the smaller 13.4k ones.

Would love to tie two smaller ones together, one in front of the driver, and one in front of the passenger, but that is above my pay grade.

examples

http://www.ebay.com/itm/Universal-A-C-Bus-and-Van-Under-Dash-Evaporator-Assembly-12V-AC-AIR-CONDITIONER-/282006593484?hash=item41a8e71fcc:g:cvwAAOxy9DRR9qjW&vxp=mtr

http://www.ebay.com/itm/Universal-A-C-MiniBus-Under-Dash-Evaporator-Assembly-GREY/111909166734?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D36464%26meid%3Db932f46cbd3943fcabdc67d0cd3cb53d%26pid%3D100005%26rk%3D4%26rkt%3D6%26sd%3D261921206891

http://www.ebay.com/itm/UNIVERSAL-UNDERDASH-AC-EVAPORATOR-UNDER-DASH-A-C-AIR-CONDITIONER-12V-432-100A/262348137301?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D36464%26meid%3D2df5824feb4146148f9f3dc5cd0f05b4%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D282006593484

[Rickf1985]

Are you saying you want to use those instead of the factory heater controls? Why? You will not have defrost which is the most important part of the A?C system.
I guess they would work, it is a matter of whether they are matched up size wise with the compressor. If it is too small you will get liquid refrigerant back to the compressor which would not be good. You are also going to have to have lines made up and that could get real pricey. The stock stuff is already in there and engineered to fit, I would stay with that unless there is something I am missing.

[JerryP]

The controls do not work, so it solves a lot of problems

[JerryP]

I was originally going to use the original evap unit in a housing on the dash, however these units come complete, with box,  switch, fan, and motor.
In spite of installing my own HVAC units in my home, and, and doing all my own ac work on my car, I am not all that well versed on auto ac systems.


The plan is great on paper, but that tends to not always be the case in the real world.

[JerryP]

Rick,
I found several with a heater core in there also.
Thoughts?

[Rickf1985]

Again, seems like a lot of work when the original is there and all plumbed in including the ducting for the defrosters. My A/C is not working and I can tell you that on a rainy day the windshield will steam up and I don't care whether you have the defroster blower on high with the ceiling fans also on high, it does not clear the windshield. Especially if you were outside and got wet. You need that A/C to dry the air to clear the windshield. Let me ask you this, where does the condensate go from the stand alone unit? You must have to drill a hole in the floor?

[JerryP]

Again, seems like a lot of work when the original is there and all plumbed in including the ducting for the defrosters. My A/C is not working and I can tell you that on a rainy day the windshield will steam up and I don't care whether you have the defroster blower on high with the ceiling fans also on high, it does not clear the windshield. Especially if you were outside and got wet. You need that A/C to dry the air to clear the windshield. Let me ask you this, where does the condensate go from the stand alone unit? You must have to drill a hole in the floor?

The controls do not work, and I have no idea how to sort that mess out, as they are vacuum, and a mess
From what I can tell, only the defrost works, anyway
As far as drilling a hole, for the water to drain I have a way to route it, already.
There is a piece of the in dash ducting, floating around that has no home as far as I can tell.

Seems to me, it would be simpler to just delete the dash panel controls other than the heater core fan switch, and set the new eval, and possibly extra heater core up there, easily accessible.
I could be wrong though, probably am

[JerryP]

Just to add, I am trying to find the BTU rating for the OEM evaporator, and entire system, and the Sanden 709 compressor. So as to match up the equipment as much as possible.

[lemortede]

Defrost is the default for the switch if it's lacking vacuum....have you replaced all the vacuum lines under the dash?

[Rickf1985]

There are only two vacuum lines if I remember correctly, one from the vacuum reservoir to the dash control and the other from the control to the blower box. The heater controls should not be all that hard to find since they were used in cars and trucks of the same vintage. some were Dodge and some were GM but they are out there. Usually the biggest problem is the vacuum line coning into the control from the engine.

[JerryP]

Finally found some compressor capacities for my Sanden SD709 compressor.
Should i decide to go with one of the new under dash evap units.
I can get the bigger size with 22k BTU units