Brewery and Distillery HVAC and Ventilation Design

What You Need to Know

Breweries and distilleries present some of the most complex HVAC and ventilation challenges in commercial construction. The combination of extreme heat generation from brewing and distilling processes, high humidity, CO2 displacement from fermentation, and flammable ethanol vapour from distillation creates a design environment that demands specialist engineering input.

A typical craft brewery with a 10 to 30 hectolitre brewhouse generates 50 to 150 kW of process heat during a brew day. A distillery still house can generate 80 to 200 kW of radiant and convective heat from pot stills and column stills. Without proper ventilation, production areas become unbearable for workers and dangerous due to CO2 accumulation (breweries) or ethanol vapour buildup (distilleries).

The HVAC design must address five distinct challenges simultaneously: process heat removal, CO2 and ethanol vapour management, temperature and humidity control for fermentation and storage, comfort conditioning for taprooms and tasting rooms, and compliance with hazardous area classification requirements under AS/NZS 60079. Getting any one of these wrong can shut down production, endanger workers, or result in failed compliance inspections.

This guide covers the ventilation, cooling, and HVAC design requirements for both breweries and distilleries, from the production floor through to the public-facing spaces. The principles apply to craft operations (5 to 50 hL brewhouses) through to mid-scale production facilities (50 to 200 hL).

• AS 1668.2:2024, mechanical ventilation governs the minimum outdoor air ventilation rates for all occupied spaces. Brewery and distillery production areas are not specifically listed, so the engineer must calculate ventilation rates based on contaminant generation (CO2, ethanol vapour, heat) using the general principles in Section 4 of the standard. Taprooms, tasting rooms, and bar areas are classified as bars/lounges requiring 10 L/s per person outdoor air. (AS 1668.2:2024, Tables 4.1 and 4.2)
• Workplace exposure standards (WES) set the legal limits for airborne contaminants. CO2 has a time-weighted average (TWA) exposure limit of 5,000 ppm and a short-term exposure limit (STEL) of 30,000 ppm. Ethanol has a TWA of 1,000 ppm. The ventilation system must maintain concentrations below these limits during all operating conditions. (Safe Work Australia, Workplace Exposure Standards for Airborne Contaminants)
• AS/NZS 60079.10.1, hazardous area classification applies to distilleries and any brewery areas where flammable vapours or gases may be present. Ethanol vapour is classified as Group IIA, Temperature Class T2. The standard requires a formal hazardous area classification study that maps Zone 0 (continuous presence), Zone 1 (likely during normal operations), and Zone 2 (not likely but possible) throughout the facility. All electrical and mechanical equipment within classified zones must carry appropriate Ex ratings. (AS/NZS 60079.10.1:2022)
• NCC 2025, Part E1 and E2 govern fire safety and smoke management. Brewery and distillery buildings are typically classified as Class 7b (storage) or Class 8 (laboratory/production). If the facility includes a taproom or restaurant, that portion is classified as Class 6 (retail/food). Each classification has different requirements for fire resistance, egress, sprinkler protection, and smoke hazard management. (NCC 2025, Volume One)
• SafeWork NSW WHS Regulation 2017 (or equivalent in other states) requires employers to manage risks from hazardous chemicals, including CO2 and ethanol. This includes atmospheric monitoring, ventilation system maintenance, emergency procedures, and worker training. The regulation requires a risk assessment for any workplace where hazardous atmospheres may develop. (WHS Regulation 2017, Chapter 7)
• AS 2118.1, automatic fire sprinkler systems applies where the building area or Dangerous Goods classification triggers sprinkler protection. Barrel stores and spirit storage areas with ethanol above certain quantities may be classified as Dangerous Goods storage, requiring sprinkler protection designed to Ordinary Hazard Group 3 (OH3) or Extra High Hazard depending on the storage arrangement and volume. (AS 2118.1:2017)
• Dangerous Goods storage regulations apply to bulk ethanol storage. Ethanol is classified as Class 3 Flammable Liquid (UN 1170). Storage above 50 litres in a workplace (or 250 litres in a licensed premises) triggers requirements under the Dangerous Goods (Storage and Handling) Regulation, including bunding, ventilation, separation distances, and fire protection. The HVAC design must account for ventilation of any DG-classified storage areas. (Australian Dangerous Goods Code, Class 3)

Brewhouse and production area. The brewhouse is the hottest space in the facility. The mash tun, lauter tun, kettle, and whirlpool all generate significant heat, with the kettle boil being the peak load at 80 to 120 kW for a 20 hL system. Ventilation design must provide high-volume air exchange to remove heat and steam. A minimum of 15 to 25 air changes per hour is typical, with supply air introduced at high level and exhaust at both high level (for steam and heat) and low level (for CO2 during fermentation activities nearby). Local exhaust hoods above the kettle and whirlpool capture steam at the source, reducing the overall ventilation load. Hood capture velocity should be 0.5 to 0.75 m/s at the face of the hood.

Fermentation and conditioning rooms. These spaces require precise temperature control. Ale fermentation operates at 15 to 22 degrees Celsius. Lager fermentation requires 8 to 14 degrees Celsius. Cold conditioning (lagering) operates at 0 to 4 degrees Celsius. Temperature stability within plus or minus 1 degree Celsius is critical for product consistency. The primary cooling method is glycol circulated through jacketed fermentation vessels, not room air conditioning. However, the room itself needs ambient temperature control to prevent condensation on vessels, walls, and ceilings. Maintain room temperature at 14 to 18 degrees Celsius for ale fermentation rooms and 4 to 8 degrees Celsius for cold stores. Humidity should be controlled to 60% to 70% RH to minimise condensation risk.

CO2 management. Fermentation produces approximately 0.5 to 1.0 kg of CO2 per kilogram of sugar fermented. A 20 hL batch fermenting 12 degrees Plato wort generates roughly 100 to 120 kg of CO2 over 5 to 7 days. CO2 is 1.5 times heavier than air, so it sinks and accumulates at floor level. This is the primary life safety risk in a brewery. Low-level exhaust extraction at 300 mm above finished floor level is essential in any room containing open or vented fermenters. CO2 monitoring with alarms at 5,000 ppm (TWA limit) and 15,000 ppm (evacuation trigger) should be installed at breathing height (1.5 m) and at low level (300 mm).

Distillery still house. The still house requires ventilation designed for contaminant control of ethanol vapour. During distillation, ethanol vapour can escape from still joints, condensers, spirit safes, and collection vessels. The lower explosive limit (LEL) for ethanol is 3.3% by volume (33,000 ppm). Ventilation must maintain concentrations well below 10% of the LEL (3,300 ppm) at all times, which is also below the workplace exposure standard of 1,000 ppm TWA. Typical still house ventilation rates are 20 to 30 air changes per hour. All fans serving the still house must be rated for the hazardous area zone classification, typically Zone 2 for the general area and Zone 1 within 1 metre of the still, condenser, and spirit collection point.

Barrel store and spirit storage. Barrel stores (rickhouses) holding whisky or other spirits in oak barrels experience continuous low-level ethanol evaporation known as the "angel's share," typically 2% to 4% of barrel volume per year. This creates a chronic low-concentration ethanol vapour environment. Ventilation must prevent accumulation above the workplace exposure standard. Natural ventilation with high and low openings is common for large, open barrel stores. Mechanical ventilation at 6 to 10 air changes per hour is required for enclosed barrel rooms. The space is typically classified as Zone 2 under AS/NZS 60079.10.1.

Taproom and tasting room. These are the public-facing spaces and require standard comfort air conditioning. Design conditions are 22 to 24 degrees Celsius in cooling mode and 20 to 22 degrees Celsius in heating mode. Outdoor air rates per AS 1668.2:2024 are 10 L/s per person for bar areas. The main HVAC challenge is managing the heat load from a high occupant density (taprooms often have 1.0 to 1.5 m2 per person at peak), kitchen or food service heat gains, and solar loads through large windows or roller doors that many brewery taprooms feature. A split system or VRF system is the most practical choice for taprooms in the 100 to 300 m2 range.

Glycol cooling systems. The glycol chiller is the backbone of any brewery's process cooling. It provides chilled glycol (typically minus 5 to minus 2 degrees Celsius) to fermentation vessel jackets, bright beer tanks, cold conditioning tanks, and the heat exchanger for wort cooling. Glycol system sizing is based on the total connected cooling load across all vessels, the number of vessels operating simultaneously, and the peak demand during wort knockout (crash cooling from 95 degrees Celsius to 20 degrees Celsius in 30 to 60 minutes). A 20 hL brewery typically requires 30 to 60 kW of glycol chiller capacity. The glycol chiller rejects heat through an air-cooled condenser, which must be located where it has adequate airflow and does not create noise issues for neighbours or the taproom.