How Heavy is an Air Handling Unit?
The weight of an air handling unit (AHU) typically ranges from 100 lbs (45 kg) for small residential units to over 10,000 lbs (4,500 kg) for large industrial systems. Here’s a breakdown:
Residential/small commercial AHUs: You’ll find these weighing between 100–500 lbs (45–227 kg), designed for spaces like homes or small offices.
Mid-sized commercial units: These range from 500–2,500 lbs (227–1,134 kg), handling airflow for medium buildings like schools or retail spaces.
Large industrial AHUs: Built for factories or hospitals, these can weigh 2,500–10,000+ lbs (1,134–4,536+ kg), depending on materials (steel vs. aluminum), added components (filters, coils), and customizations like modular sections.
Be sure to check out our page for commercial air handling unit services and repairers, and request a free quote for your project.
What is the Operating Weigh of the Air Handling Unit?
The operating weight of an air handling unit (AHU) typically ranges from 150 lbs (68 kg) for compact residential systems to over 12,000 lbs (5,443 kg) for heavy-duty industrial units. Here’s a detailed breakdown:
Residential/small AHUs: You’ll see operating weights between 150–600 lbs (68–272 kg), including components like fans, basic filters, and small coils.
Commercial AHUs: These range from 600–3,000 lbs (272–1,361 kg), factoring in larger coils, advanced filtration, and insulation.
Industrial AHUs: Operating weights span 3,000–12,000+ lbs (1,361–5,443+ kg), with added heft from heavy-duty motors, humidifiers, or modular sections.
How do you Calculate Air Handling Unit?
Here’s how you calculate an air handling unit (AHU) in 5 steps:
Determine airflow (CFM):
Calculate using: CFM = (Area × Height × Air Changes per Hour) / 60.
Example: A 1,000 sq ft room with 10 ft ceilings and 6 air changes/hour needs 1,000 CFM [(1,000×10×6)/60].
Calculate heating/cooling load:
Use Manual J or software for precise BTU/hr needs.
Factor in occupancy, insulation, windows, and climate (e.g., 20–30 BTU/hr per sq ft for cooling).
Estimate static pressure:
Add resistance from ducts, filters, coils, and grilles (e.g., 0.5–2.5 inches of water gauge).
Example: Filter (0.2 in) + Coil (0.3 in) + Ducts (0.5 in) = 1.0 in wg total.
Select fan power:
Use Fan Power (HP) = (CFM × Static Pressure) / (6,350 × Fan Efficiency).
Example: 1,000 CFM × 1.0 in wg / (6,350 × 0.6) ≈ 0.26 HP.
Verify with manufacturer data:
Match your CFM, static pressure, and load to AHU specs. Include a 10–20% safety margin for real-world conditions.
For accuracy, reference ASHRAE standards (e.g., 62.1 for ventilation rates) and use load-calculation tools.
What Factors Influence the Weight of an Air Handling Unit?
The factors that influence the weight of an air handling unit are size, material, construction, airflow, Capacity (CFM/Tonnage and other accessories.
Materials:
Steel-heavy units weigh 30–50% more than aluminum ones. Example: A 1,000 lb steel AHU could be 600–700 lbs in aluminum.
Components:
Filters, coils, and fans add weight. A standard coil adds 50–200 lbs (23–91 kg), while heavy-duty filters can add 10–50 lbs (4.5–23 kg) each.
Capacity (CFM/Tonnage):
Higher airflow (e.g., 50,000 CFM vs. 1,000 CFM) or cooling capacity (e.g., 20 tons vs. 2 tons) increases size and weight.
Insulation:
Thick insulation (e.g., 2–4 inches) adds 5–20% to total weight, depending on material (fiberglass vs. foam).
Customizations:
Modular sections, soundproofing, or reinforced frames can add hundreds of pounds. Example: Modular units may weigh 10–15% more than single-section designs.
Accessories:
Humidifiers, UV lights, or dampers add 5–50 lbs (2.3–23 kg) each.