ARCOAIRE EAA4X42L21A Evaporator A-Coil | 3.5 Tons
Arcoaire 3.5-ton uncased R-410A A-coil with a factory TXV, for a 21 in furnace or air handler.
Model numberEAA4X42L21A
514 316-2973 · sales@airgreen.ca
Quick facts
3.5 tons: the in-between size for 21 in furnaces
A well-sized air conditioning system is not chosen by guesswork. When a house’s load calculation falls between two common sizes, taking the larger or the smaller one has a cost: cycles too short and humidity poorly removed on one side, a house that struggles to cool down during heat waves on the other. The Arcoaire EAA4X42L21A A-coil offers a nominal 3.5-ton (42,000 BTU/h) size, on R-410A, for electric furnaces and air handlers 21 in wide. It is available while supplies last.
When the in-between size is the right choice
The size is decided during the estimate, based on the house’s dimensions, insulation, orientation and existing ductwork. If the result points to 3.5 tons, this coil matched with an outdoor unit of the same capacity gives a system fitted to actual needs. This is especially useful in Laval or on the North Shore, in two-storey houses enlarged over the years, where the old system was often chosen for a smaller house.
The EAA4X42L21A at a glance
According to Arcoaire’s nomenclature, this coil is designed for a 21 in cabinet: it matches furnaces and air handlers of the same width. It is uncased and fits in the plenum or in a suitable casing, not included. It installs vertically, in upflow or downflow. The R-410A thermostatic expansion valve (TXV) is factory-installed; the main tubes and fins are aluminum, with copper stubs. The coil weighs 40.0 lb (18 kg) for shipping.
With a heat pump, in winter too
Arcoaire’s brochure declares this coil compatible with a heat pump. Matched with an R-410A central heat pump, it distributes heat through the ductwork for much of the winter, and the electric furnace tops up in deep cold. Sold alone, however, it has no efficiency rating of its own and does not qualify for the LogisVert grant. Arcoaire does not publish a matching list for this model: we check the outdoor unit before ordering.
Installation and connection
AirGreen is a family business established in Montreal for more than fifteen years, holding RBQ licence 5645-9605-01 (ventilation, refrigeration and electrical). The on-site estimate is free and the quote is written. The coil connects with a 3/8 in liquid line and a 7/8 in suction line; we check the diameter and condition of the existing lines before reusing them. Then come brazing, the pressure test, the vacuum, the drain with its trap and commissioning. We serve Montreal, Longueuil and the South Shore, in addition to Laval and the North Shore.
Ask for your free estimate and a load calculation for your house. Financing is available.
The in-between size for 21 in furnaces
The EAA4X42L21A is set in the plenum of an electric furnace or air handler 21 in wide. It suits houses whose load calculation falls between two common sizes.
- Houses whose load calculation calls for 3.5 tons
- Central air conditioner or central heat pump on a 21 in electric furnace
- Replacing an R-410A A-coil of the same size
- Upflow or downflow installations
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Available while supplies last: Arcoaire’s website now features the next generation of coils.
- Sold alone: does not qualify for the LogisVert grant. The coil has no efficiency rating of its own; performance depends on the matched outdoor unit and air handler.
- Uncased: it fits in the plenum or in a suitable casing, not included.
- Designed for a 21 in wide cabinet, in the vertical position only.
- 3/8 in (liquid) and 7/8 in (suction) connections, R-410A: we check the diameter of the existing lines and the outdoor unit, since no matching list is published for this model.
Manufacturer documents
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Frequently asked questions
Why choose 3.5 tons rather than a round size?
The house’s load calculation dictates the size. When it falls between two common sizes, a 3.5-ton coil matched with an outdoor unit of the same capacity avoids oversizing or undersizing the system.
Are the existing refrigerant lines suitable?
The coil connects with a 3/8 in liquid line and a 7/8 in suction line. We check the diameter and condition of the existing lines, then adapt or replace them as needed.
Does it work with a heat pump?
Yes. Arcoaire’s brochure declares the series compatible with an air conditioner or a heat pump. The outdoor unit must run on R-410A.
Does the coil come with a cabinet?
No, it is uncased. It fits in the plenum or in a suitable casing, which we include in the quote if needed.
What warranty does Arcoaire offer?
A limited parts warranty of 10 years with registration within 90 days, or 5 years without registration, for owner-occupied residential use. Where the law prohibits requiring registration, the 10-year warranty applies automatically.
A 3.5-ton Arcoaire coil, installed by AirGreen
Tell us about your project: we check the sizing, confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 19, 2026.