What is the difference between Type 1 and Type 2 ductwork?

Author: Mr. Carey Doyle Jr.  |  Last update: Sunday, June 28, 2026

Type 1 hoods are called grease hoods or ducts. They are designed to remove heat smoke and grease build-up from your kitchen. These vent hoods work in a commercial kitchen to remove grease and prevent fire. The type 2 hoods are designed to remove condensation from the kitchen atmosphere.

What is type 2 ductwork?

Steam Removal: Type 2 hoods are specifically designed to capture and remove steam and heat generated by cooking equipment. They employ a combination of exhaust fans and ductwork to effectively ventilate the kitchen.

Should I get a Type 1 or type 2 vent hood?

Vent Hood Duct: Size, Gauges, Material, and Make-Up Air
  • Type 1 hoods are to be used with appliances that produce grease and smoke. Such as fryers, griddles and ovens.
  • Type 2 hoods are to be used with appliances that produce only heat and steam and no grease or smoke.

What is Type 1 venting?

Type I hoods (commonly referred to as “grease hoods”) capture the air above cooktops, deep fryers, griddles, grills, woks, charbroilers, (tilting skillets, braising & frying pans, infrared broilers, stoves, ranges, barbecue equipment, salaman- ders) and open-flame stoves.

Do type 2 hoods need fire suppression?

Type 2 hoods are by definition handling smoke exhaust with grease laden vapors from cooking equipment. The fuel source defines that they be protected with K class wet chem agent.

What Is The Difference Between Type I Type II Hoods?

Where are Type 1 hoods required?

A Type I hood is required where smoke is produced as part of the cooking process. The intent is not to require a Type I hood where there is a possibility of food being burned and producing smoke. For example, smoke that is produced when toast is burned does not mean that a Type I hood is required over a toaster.

Is Type 2 hood cheaper?

Type II hoods are easier to install because you can use them without ductwork or vents. For this reason, they're often less expensive than a Type I hood with an exhaust system; however, local codes may significantly reduce their usability.

What is Type 1 ductwork?

Type 1 hoods are called grease hoods or ducts. They are designed to remove heat smoke and grease build-up from your kitchen. These vent hoods work in a commercial kitchen to remove grease and prevent fire.

What is the difference between Class 1 and Class 2 ductwork?

There are four classifications of industrial duct systems: Class 1—includes non-abrasive applications: make-up air, general ventilation, gaseous emissions control. Class 2—includes applications with moderately abrasive particulate in light concentrations; i.e., buffing and polishing, woodworking, grain dust, etc.

What are the requirements for a Type 2 exhaust hood?

Type II hoods shall be constructed of steel having a minimum thickness of 0.0296 inch (0.7534 mm) (No. 22 gage) or stainless steel not less than 0.0220 inch (0.5550 mm) (No. 24 gage) in thickness, copper sheets weighing not less than 24 ounces per square foot (7.3 kg/m2) or of other approved material and gage.

What is a good CFM for vent hood?

Most range hoods for residential kitchens are 200 to 600 CFM. The best way to determine how much airflow you need is to use the formulas we shared above for calculating CFM based on the size of your kitchen and/or BTU of your gas cooktop range.

What can you cook with a type 2 hood?

A Type II hood is used when performing holding, reheating, baking, or using an enclosed deck type pizza oven that produces only heat and steam.

Do ovens require Type 1 hood?

Type I hoods are required for equipment that produce smoke or grease-laden fumes. This includes equipment such as fryers, ranges, griddles, convection ovens, tilt skillets and broilers. Type II hoods are used where grease isn't present to remove steam, vapor and odors.

What is the difference between Type 1 and Type 2 vents?

While Type 1 hoods tackle grease and smoke, Type 2 hood systems focus on a different battlefield: heat and moisture. These hoods cater to kitchen equipment like dishwashers, ovens, and pasta cookers, which generate heat and steam during operation.

What is Class 2 ducting?

Class 2 power ducting is for low voltage applications (230v/11kV & 20kV with 450kN compression performance at operating temperatures of 50°C). It meets ENATS 12-24 and BS EN 61386 specifications.

What is Type 2 HVAC?

If new HVAC techs will service high-pressure air conditioning and/or heating units, they need to be certified with this designation. The test for Type II certification covers additional issues related to high- and very-high-pressure appliances, including leak detection, leak repair requirements and refrigeration.

What is the best type of HVAC ductwork?

Galvanized steel is a great duct material because it is durable and non-porous. These qualities can help keep your HVAC system healthy and mold-free. Rigid ducts can also be made of aluminum, which has similar benefits but is more lightweight.

What is class 1 duct used for?

UL Listed Class 1 Air Ducts and Class 1 Air Connectors are intended for use in heating and cooling system designed for comfort air movement. Exhaust ducts for domestic and commercial clothes dryers must be constructed of metal and have a smooth interior finish.

What is Type 1 HVAC?

Type I certification is for technicians to service, maintain, and repair small appliances that contain CFCs, HCFCs, or HFCs. Technicians can have either Type I or Universal certification which includes Type I to service appliances covered under Section 608. Type I appliances must be: Hermetically sealed.

What is class 2 ductwork?

Ducts conveying nonabrasives, such as smoke, spray, mists, fogs, noncorrosive fumes and gases, light fine dusts, or powders. Class 2. - Ducts conveying moderately abrasive particulate in light concentrations, such as sawdust and grain dust, and buffing and polishing dust.

What are the three types of ducting?

There are three main types of ducting used within domestic ventilation systems: rigid ducting, semi-rigid ducting and flexible ducting.

Is 400 CFM range hood good?

Is 400 CFM enough for range hood? For most home kitchens, a 400 CFM range hood suffices. But if your cooking involves high heat or your stove has a high BTU output, consider a higher CFM.

What are the requirements for a Type 2 hood duct?

Type II hoods constructed of steel shall be not less than 0.024 of an inch (0.61 mm) (No. 24 gauge). Hoods constructed of copper shall be of copper sheets weighing not less than 0.17 ounces per square inch (oz/in2) (7.47 kg/m2). Joints and seams shall be substantially tight.

What requires a Type 1 hood?

Type I hoods shall be installed where cooking appliances produce grease or smoke as a result of the cooking process. Type I hoods shall be installed over medium-duty, heavy-duty and extra-heavy-duty cooking appliances.

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