Ventilation Ducts in Hospitals - HDPE or PP?

Whoever placed the order for the ducts must also specify the required materials. If they expect you to provide the specs, make sure that your specs are accepted and signed. Otherwise you might get into endless trouble later.

Ask the contrator that cleans the ductworks about materials and physical limitations of equipment. Unless you are the engineer of record on the job, you can specify nothing. If the engineer asked you then place him in touch with a few contractors that maintain ductwork. Allways, the most durable/repairable is the best choice.

Please get hold of a suitably qualified engineer to assist you with interpreting the drawings and specifications for the project. Ventilation ducting design is laced with all manner of quirks that without the CORRECT training and EXPERIENCE will become a nightmare. Hospitals have their own set of rules/laws to comply with, or you could spread all manner of disease by airborne bacteria and viruses.

As for HDPE or PP, the previous posts are correct, check the contract specs. Just of interest, most plastic/wire reinforced flex ducting is lined with polyester as it has a very low level of sustaining microbial growth, and is strong.

Another good practice is always contract a second professional engineer to verify the designs of the ducting before you go to manufacture and installation. If he disagrees with the design discuss it with the specifier. Believe me, if the system does not work well, you will be pulling it out at your expense, maybe not financially but your reputation will be in tatters.....that's also financial!

For specialty HVAC, it's always a good idea to request a specification from a MEP Engineer with experience designing medical HVAC systems. Ductwork must be cleanable and have proper filtration, balancing etc. This will protect your liability, and give the HVAC contractor a road map, and yes a pier review by a third party is always wise for projects concerning health care. They run the risk of becoming very litigious.