Terms of service
Plain terms for using this website. Plenumair is a demonstration brand, not a trading ventilation company.
What this site is
Plenumair is a concept build produced by Lumith to demonstrate web design and engineering for the ventilation trade. It does not represent a real installer, and no ventilation work can be contracted through it.
Company names, project locations and testimonials shown here are illustrative.
Prices and figures
All prices are illustrative and exclude VAT. They do not constitute an offer or a quotation.
The airflow calculator gives an indicative figure based on Approved Document F (2021) for continuous mechanical ventilation. It is a guide, not a design. A real design accounts for floor areas, terminal positions, duct pressure loss and the equipment selected, and must be produced by a competent person.
Liability
The site is provided as it is. Nothing here is professional advice, and no reliance should be placed on it when specifying or installing a ventilation system.
Intellectual property
The design, code and illustrations on this site belong to Lumith. Get in touch if you would like to license or purchase them.
Last updated August 2026. Back to the site