Explosion Proof Air Conditioner FAQ

What is an explosion-proof air conditioner?

An explosion-proof air conditioner is a standard cooling unit that has been modified or purpose-built to operate safely in hazardous locations — environments where flammable gases, vapors, or combustible dusts may be present. The term “explosion-proof” refers to the electrical components and enclosures, which are engineered to prevent internal sparks or heat from igniting the surrounding atmosphere.

Vintage industrial voltmeter — understanding the electrical requirements

What’s the difference between Class 1 and Class 2 hazardous locations?

Class 1 locations contain flammable gases or vapors — think oil refineries, chemical plants, gas processing facilities, or any area where petroleum vapors, hydrogen, or solvent vapors may accumulate.

Class 2 locations contain combustible dust — grain elevators, flour mills, coal handling facilities, pharmaceutical manufacturing, and certain mining operations.

The distinction matters because the modification specs are different. Class 1 modifications focus on preventing ignition of gas/vapor. Class 2 modifications address the risk of dust accumulating on equipment and igniting.

What does Division 1 vs. Division 2 mean?

Division 1 means the hazardous condition exists under normal operating conditions — the flammable gas or dust is regularly present.

Division 2 means the hazardous condition only exists under abnormal conditions — equipment failure, accidental release, or unusual circumstances.

Division 1 requires more stringent (and more expensive) explosion-proof specifications than Division 2. The vast majority of industrial requests we receive are for Class 1, Division 2 — the most common classification at US refineries and petrochemical facilities.

What are Groups C and D?

Hazardous location Groups classify the specific flammable material present. The group determines which explosion-proof motors and components are required.

  • Group A — acetylene
  • Group B — hydrogen, some manufactured gases
  • Group C — ethyl ether, ethylene, cyclopropane
  • Group D — gasoline, benzene, butane, propane, alcohol, acetone, natural gas

Groups C and D cover the vast majority of petroleum refining and chemical plant environments. If you’re not sure which group applies to your facility, your safety officer or process engineer will have that information.

Can you modify any brand of air conditioner?

Yes. While Bard wall-mount units are our most frequently modified units, we can apply explosion-proof fabrication to virtually any brand — Trane, Carrier, Lennox, or a unit already on your site that needs to be brought up to spec. The modification work is the same regardless of the original manufacturer.

How much does an explosion-proof air conditioner cost?

Pricing depends on the classification (Division 1 vs. 2), the group (C, D, etc.), unit size, and whether you need the inside unit only or both inside and outside explosion-proofed.

As a general starting point:

  • Class 1, Div 2, Group C&D — inside unit only: $6,700–$7,600 for units up to 3 tons
  • Class 1, Div 2, Group C&D — inside + outside: $9,000–$10,000 for units up to 3 tons

Custom fabrication, stainless enclosures, special coatings, and Division 1 work are priced case by case. Call us for a quote — we typically turn them around in 24–48 hours.

How long does it take to get a quote?

We typically provide firm quotes within 24–48 hours of a phone call or email where we understand your classification, BTU requirements, and site conditions.

How do I know what classification I need?

If you’re not sure, the best starting point is your facility’s area classification drawing — also called a hazardous area classification document or HAC drawing. Your EHS (Environmental Health & Safety) team or process engineer will have this.

If you don’t have access to those documents, give us a call. We’ve worked with enough facilities to help you narrow it down quickly.

Do you ship internationally?

Yes, we have worked with international customers. International orders involve additional complexity around shipping, customs, and documentation. If you’re outside the US, give us a call and we’ll talk through what’s involved for your specific location.

What is Aqua-Aero coating and do I need it?

Aqua-Aero is a protective HVAC coating that shields coils and components from corrosion, salt air, and chemical exposure. We recommend it for:

  • Coastal or offshore installations
  • Chemical plant environments with corrosive vapors
  • High-humidity industrial settings

It significantly extends the service life of the unit in harsh environments. We’ll recommend it if your site conditions warrant it.

Can you do a redundant or N+1 system?

Yes. For mission-critical applications where downtime is not an option, we can configure redundant cooling systems — two units where one serves as automatic backup if the primary fails. We’ve built fully redundant N+1 10-ton systems and two-stage 20-ton units for space-constrained applications including conex box and tractor-trailer installations.

What is purge and pressurization, and when should I consider it?

Purge and pressurization under NFPA 496 lets you declassify the interior of a building by maintaining positive air pressure with clean, above-grade intake air. This means you can use standard (non-explosion-proof) equipment inside the building, with only the outdoor condenser requiring explosion-proof rating.

About 20–25% of our customers choose pressurization. Although the system itself costs $25,000–$50,000, it eliminates the need for explosion-proof rated equipment throughout the building interior — which often saves far more than the pressurization system costs. If a full XP buildout for a mid-size equipment shelter runs $150,000–$200,000, a $35,000–$50,000 pressurization system with standard equipment inside is a straightforward economic case.

Pressurization can be added to any existing unit or supplied as a standalone pressurization module. Learn more on our pressurization page.

Are explosion-proof window units still available?

Due to new refrigerant standards, we have been unable to source all of the explosion-proof rated components required for window unit modifications. We are not currently offering explosion-proof window units.

Explosion-proof mini splits are now the most affordable alternative — starting at $6,700 — if your application can accommodate an indoor evaporator head on a wall or ceiling. If no interior space is available, Bard wall-mount units are completely self-contained on the exterior of the building and require only supply and return air openings through the wall.

What’s the difference between a mini split and a Bard wall-mount?

A Bard wall-mount unit is completely self-contained on the exterior of the building — nothing inside except supply and return air openings through the wall. It’s ideal when interior space is at a premium or unavailable.

A mini split has an outdoor condenser and an indoor evaporator head that mounts on a wall or ceiling inside the space. Mini splits are typically more affordable, but they do require giving up some interior space for the indoor head.

If customers don’t mind giving up some interior space, mini splits are a great option. If they don’t have any space on the inside, we recommend a Bard wall-mount.

How do I get started?

Call us or fill out our quote request form. Tell us your classification (Class, Division, Group if known), the BTU or tonnage you need, whether you need inside-only or inside-and-outside explosion proofing, and your general site conditions. We’ll take it from there.

Call (844) 925-5668 — quotes in 24–48 hours.

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