Two for One???

[Jae Williams]

Originally Posted by dandersen

Was that the side by side evap unit?

Yes, sometimes they were called that. "Duo-flex" was the registered trade name.

The coils were occasionally joined for custom usage--1 1/2 ton on one side, 2 1/2 ton on the other. Or various other mixes. The factory supplies, though, were generally matched by size.

[Charley L. Bottger]

Guys two condensing units one evaporator is common in light commercial HVAC and very common in commercial refrigeration but not in residential very unusual. But time has taught me to expect the uncommon in this HI business.

I would be very shocked to find two condensing units on one evap in a small residential unit unless the past owner was in the HVAC business and designed his own controls which would also require an oil separator to keep one condensing unit from robbing oil from the other unit which is a common occurrence with that type of set up.

I would have to think someone just left an abandoned unit. As Tony N. would say NEED PICTURES MORE THE BETTER.

[David P. Valley]

Guys,

Gary stated that both units are the same age.

[Charley L. Bottger]

Originally Posted by dvalley

Guys,

Gary stated that both units are the same age.

Ok I still need Pic's As you know David anything is possible

[Greg Veal]

Gary

I'm a little confused with your terminology, as you describe what you were seeing. I'm not critisizing, just trying to get a clear uderstanding of what's existing.

Attic installation - Minimal height and /or working space ?
Horiz. Nat.Gas Furnace (1) - ?
Horiz. designed Evap. Coil (1) - ?
Outdoor Cond. Units (Cooling only or Ht. Pump?) (2) - ?

Split or 2 staged or Circuited evap. coils were/are still used for a lot of light commercial construction today, according to a friend of mine in the business.
I use to design and spec them in the 70's and 80's, some even in residential situations, although those systems were usually reserved for higher end properties (local mansions ?).
I know Texas is hot, but 11/2 AND A 21/2 ton on 1100-1200 sq.ft.?? I hope you recommended to your Client, that further investigation was warrented by a Prof. HVAC Contr., for analysis and recommendations.

Good Luck

[sparksnmore]

Originally Posted by jwilliams4

Not necessarily. Many years age FEDDERS developed a dual coil that fit into a single furnace/air handler, but was operated by two condensing units. It was controlled by a thermostat with two mercury bulbs that would make connection 2 degrees apart. If the first system could not cool the house, the temperature would rise 2 more degrees and activate the second condenser.

Frequently the two line sets were joined in a common conduit and appeared to be a singe installation inside the house.

There was also an occasional attempt to use two small condensers in place of a larger unit (sometimes the cost difference was enough to do this) by joining the two lines into one larger line set. There were about 200 reasons why this didn't work, but you never know until you try.

I saw a lot of those old 2 stage Fedders units back in the 60's but they all had only one high side cabinet with two compressors, two condensers, two suction lines and two liquid lines.
Never saw one with two seperate high side units around here.