Negative Pressure Ambulances: A Buyer's Guide

Negative pressure ambulances became a mainstream purchase during COVID-19. Many health systems now keep a few in every region. This guide covers what matters when you specify one for export.

A negative pressure ambulance keeps the patient compartment at lower pressure than the cab and outside air, and pulls exhaust air through a high-efficiency filter. Leaks go inward; filtered air goes out.

How does the system work?

An exhaust fan draws air out of the sealed patient compartment through a filter. Because more air leaves than enters, pressure inside drops slightly below its surroundings, so air flows in through any gap rather than out. The cab is sealed from the compartment and has its own air supply.

What should I ask the converter?

• Which standard is the system designed and tested to?
• What pressure difference does it hold, and how is it shown to the crew?
• What filter class is used, and how is it changed safely?
• Can the system be switched off for normal use?
• Which surfaces and materials suit your disinfectants?

Which chassis should I choose?

The filtration unit and sealed partition use space, and crews in protective equipment need room. We usually build negative pressure on the 4x2 rear-wheel-drive long-wheelbase Transit with a high roof.

How do I keep it useful between outbreaks?

Specify a system that can be switched off, and equip the unit to ALS level. It then runs as a normal ambulance day to day and switches to isolation mode when needed.