Ammonia and Amine Ductless Fume Hood

What is the Ammonia and Amine Ductless Fume Hood?

An ammonia and amine ductless hood uses acid-impregnated carbon media to chemisorb alkaline vapours such as ammonia, trimethylamine and volatile amines. It is selected for small-scale work with ammonia solutions, buffers and amine chemistry where ducting is not available at the bench.

Overview

Air is drawn through the sash opening at 0.4–0.5 m/s by a fan and passes a prefilter before entering a bed of carbon impregnated with sulfuric or phosphoric acid. Ammonia and volatile amines are basic gases and are captured by acid-base chemisorption on the impregnated carbon, a mechanism different from the physical adsorption used for organic solvents. Media loading is 5–15 kg with a bed depth of 25–50 mm, and airflow is 300–700 m3/h. The body is polypropylene or epoxy-coated steel, since ammonia solutions corrode many metals. An electrochemical or colorimetric gas sensor at the outlet can indicate breakthrough, although amine odour is sometimes noticed first. Because the media is specific, the hood must not be used for organic solvents, which require plain carbon, or for acids, which require alkaline media.

How does it work?

A ductless fume hood uses a fan to pull room air through the sash opening at 0.4–0.5 m/s across the work area, then through one or more filter stages before discharge back into the room. A prefilter removes dust, and activated carbon beds adsorb organic vapours through physical adsorption. Chemically impregnated carbon or specialist media can capture acids, ammonia or formaldehyde. A HEPA stage can be added for particles. Sensors or timers indicate filter saturation, and airflow monitors ensure correct face velocity. Because filters have finite capacity, the hood is limited to known chemicals in limited quantities, and filter selection must match the vapour. The body is typically polypropylene or epoxy-coated steel, with lighting and a control panel.

What are the key features?

• Acid-impregnated carbon bed for alkaline gases
• Bed depth 25–50 mm, media mass 5–15 kg
• Airflow 300–700 m3/h at 0.4–0.5 m/s
• Polypropylene or epoxy steel construction
• Optional ammonia gas sensor at outlet
• Not compatible with solvent or acid vapours

What are the technical specifications?

A typical ammonia and amine ductless fume hood configuration offers filter media of Acid-impregnated activated carbon, media mass of 5–15 kg, bed depth of 25–50 mm, airflow of 300–700 m3/h, face velocity of 0.4–0.5 m/s and gases handled of NH3 and volatile amines (per media). Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Ammonia and Amine Ductless Fume Hood is used in ammonia buffer preparation, amine chemistry, water and wastewater testing and plating and photographic baths. Across the wider Ductless Fume Hoods class, laboratories also deploy it for teaching laboratories, quality control and pharmacies.

Which standards and certifications apply?

Relevant standards and methods include ASHRAE 110 (testing performance of laboratory fume hoods), AFNOR NF X 15-211 (ductless fume cupboards), ISO 14644-1, EN 14175-1 (fume cupboards, vocabulary), GB/T 34269 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Establish a chemical register before purchase and have the supplier confirm filter compatibility in writing. Change filters at the recommended interval or sooner if gas sensors or odour indicate breakthrough, because carbon saturation is sudden at the end of life. Test airflow and filter seals on installation and at least every 6–12 months, keeping records for audit. Place the hood away from doors and air currents, and with clearance to allow filter replacement. Dispose of used filters as hazardous waste. Train users to restrict quantities, keep sashes low and never use the hood for chemicals outside the compatibility list.

How do I select the right Ammonia and Amine Ductless Fume Hood?

Choose this media only for ammonia, amines and other basic gases in small quantities. Organic solvents need plain carbon and acids need alkaline media, so a mixed chemical list may require a different hood or a ducted system. RFQ: gas list, concentrations, daily quantities, sensor type and filter replacement interval.

How does it compare with other Ductless Fume Hoods variants?

Select by the chemicals used. Every application needs a chemical compatibility assessment from the supplier to match filter media, and the assessment should include quantities, frequency and breakthrough behaviour. Choose an activated carbon filter for organic solvents, impregnated carbon for acids or amines, and HEPA for particulates. Consider filter monitoring, such as gas sensors that signal breakthrough, rather than timers alone. Choose width, typically 600–1500 mm, noise level, and whether a base cabinet for storage is required. Ductless hoods are not suitable for unknown, high-volume or highly toxic chemicals, or for heated perchloric acid. Confirm local regulations on recirculating air, since some jurisdictions restrict their use.