19i sizing

[Traffic]

House presently has a 4 ton AC installed and that is sized right.

We are planning on replacing that with a 4 ton 19i Trane. All bids came in with that same size.
On reading info here and from Trane, I know the Trane 19i 4 ton has 2 compressors, a 1 1/2 ton and a 2 1/2 ton and that they cannot run at the same time. So the largest I will have is a 2 1/2 ton unit.

Am I replacing a 4 ton with a 2 1/2 ton ???? Will I be undersized ????

This is not making sense to me...............................

[mark beiser]

You misread something, or someone posted incorrect info. The 1st stage compressor is a 2 ton compressor, the 2nd stage is a 4 ton compressor.

[Traffic]

From the Trane fact sheet.....................for the 4 ton

The #1 compressor is a 1 1/2 ton
#2 compressor is a 2 1/2 ton

[mark beiser]

What "fact sheet" are you referring to?

The compressor sizes you are talking about are for the 2.5 ton XL19i.

[Gunnery Sergeant Hartman]

From the Trane fact sheet.....................for the 4 ton

The #1 compressor is a 1 1/2 ton
#2 compressor is a 2 1/2 ton

Please post your fact sheet...

[skippedover]

I agree with the reply from Mark Beiser. Trane builds their 2-stage units with one full size compressor, in this case 4-tons, and one 1/2 size compressor, again in this case, 2-tons. Either one or the other compressor runs but NOT BOTH simultaneously. When the T-stat calls for 2nd stage, the first stage compressor shuts off, the condenser fan speeds up and after about 20-seconds the 2nd stage compressor comes on. Please also know that as with any manufacturer, the 19-i unit in 4-tons probably does NOT give 19-SEER performance. If you check ARI website for equipment specs, you'll see that any combination of equipment in the 4 & 5-ton capacities usually doesn't meet the highest SEER claims. One must think of the manufacturer's nameplate as a name only, such as a Ford Taurus or Toyota Camry. The mileage of each different sub-model within the major category may vary according to installed equipment and weight of the vehicle. So it is with the high efficiency claims of manufacturers.

[aircooled53]

Ultra Efficiency with the TRANE XL19i


1. Weatherguard II™ Top
Made of a durable polycarbonate material, it’s attractive, functional and built to last. The top shields the unit from leaves, ice and other debris, and directs noise and hot air up and away from plants.

2. Variable Speed Outdoor Fan Motor
Operates quietly and saves energy.

3. Quick Access To Electrical And Refrigerant Controls
All electrical and refrigeration components are easily accessed for fast installation and service.

4. Refrigerant Filter Drier
Prolongs unit life and system reliability by keeping refrigerant clean and dry.

5. Dual Climatuff® Compressors 2.0 ton/4.0 ton
Allow for two-stage comfort. Each compressor is tested for quality assurance. Backed by a 10-year warranty.

6. Compressor Sound Insulators
Wrap the compressors in insulation to reduce operating noise and provide for quieter operation.

7. Integrated Fan Orifice
Trane’s unique mounting of the shaft down fan motor and integrated fan orifice improves airflow and enhances performance. This innovative design also provides quieter operation.

8. All-Aluminum Woven Spine Fin™ Coil
Internally grooved, continuous tubes in each circuit help prevent refrigerant leaks while providing low airflow resistance and efficient heat transfer. So corrosion resistant, we back it with a 10-year limited warranty.

9. Galvanized Steel Louvers
Designed for maximum coil protection and long-lasting durability.

10. Powder Paint Finish
Blends well with any architectural style. Baked-on, porcelain-like powder paint covers all louvered panels uniformly, increasing protection from rust and corrosion.

11. DuraTuff™ Basepan
DuraTuff™ basepan is designed with a unique construction technique for extra support. Made with a durable composite material, it will not crack, warp, corrode or rust.

12. Electronic Demand Defrost
Solid-state control eliminated unnecessary defrost cycles for energy savings and longer compressor life.

[pstu]

I do have a copy of Trane technical manual titled "Split System Cooling Product and Performance Data", publication # 22-1746-01-0103. It is from a couple years ago but as far as I know there have been few if any changes.

For your 4-ton 19i, if you use the TWE04913 air handler which is apparently the best SEER, you get 49,000 btuh total capacity at ARI test conditions. If you run at 95F outdoors and 63F wet bulb indoors (say 75F dry bulb), Stage 2 capacity is 45,600 btuh and Stage 1 is 25,300. This should be authoritative info unless I misread something.

One ton is equal to 12,000 btuh, so the ARI capacity with this match is actually 4.1 tons, at 95F is 3.8 tons on Stage 2 and 2.1 tons on Stage 1.

Hope this helps -- Pstu