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.
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 platform, we can apply explosion-proof modification to virtually any brand of air conditioner — Trane, Carrier, Lennox, Marvair, Mitsubishi, Daikin, Friedrich, York, or any other manufacturer. We’re an independent modifier, not a manufacturer, so we’re not pushing proprietary equipment. If your facility spec requires a particular brand, or you have an existing unit on site that needs hazardous location conversion, we can retrofit it to your exact classification.
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 Phenicon coating and when should I use it?
Phenicon HS is a Sherwin-Williams epoxy novolac phenolic coating that we apply to the entire air conditioning unit — evaporator coils, condenser coils, copper refrigerant lines, and cabinet inside and out. It was originally developed as an industrial tank liner for crude oil and brine service, and we are the only HVAC shop in the country using it.
We use Phenicon on units going to the most corrosive environments: offshore oil platforms, refineries with H₂S exposure, wastewater treatment plants, and chemical processing facilities. It is rated for full chemical immersion — far beyond what any standard HVAC coil coating provides.
What is Aqua-Aero coating and do I need it?
Aqua-Aero is a standard protective HVAC coil coating that shields coils from moderate corrosion, salt air, and chemical exposure. It’s appropriate for:
- Coastal installations (within 5 miles of salt water)
- Mildly corrosive industrial environments
- High-humidity settings
For severely corrosive environments — offshore, refinery H₂S, wastewater, chemical plants — we recommend Phenicon coating instead, which covers the entire unit and is rated for chemical immersion service.
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.
Do I need an explosion proof air conditioner for my facility?
If your facility has areas classified as hazardous locations under NEC Article 500 or 505 — where flammable gases, vapors, or combustible dusts may be present — any electrical equipment in those areas, including air conditioners, must be rated for the classification. Your facility’s hazardous area classification drawing (HAC drawing) will identify which areas require explosion-proof equipment and what Class, Division, and Group applies.
Not sure if your facility is classified? Call us — we can help you figure it out quickly based on what your facility does and what materials are present.
Can you use a regular air conditioner in a hazardous location?
No. Standard air conditioners contain motors, relays, contactors, and other components that produce sparks during normal operation. In a hazardous location with flammable gases or combustible dust, those sparks can cause an explosion. The National Electrical Code requires all electrical equipment in classified areas to be rated for the specific hazard present. Installing a standard air conditioner in a classified area is both a code violation and a serious safety risk.
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.
Related Pages
- What Is an Explosion Proof Air Conditioner? — complete guide with classifications, pricing, and real installations
- How Much Does It Cost? — full pricing breakdown across all unit types
- How to Choose — step-by-step buyer’s guide
- Explosion Proof Bard Air Conditioners — wall-mount units, our most common modification
- Explosion Proof Mini Splits — the most affordable option available today
- Explosion Proof Split Systems — for higher capacity installs
- Pressurization Systems — declassify your building interior
- Phenicon Coating — industrial-grade corrosion protection for the entire unit
- Custom Explosion Proof Air Conditioners — specialty builds, N+1, stainless steel
- About Us — who we are and why independence matters
- Get a Quote — most quotes in 24–48 hours