The phrase "a minimum of one hour" is correct and usable in written English.
It can be used when specifying a required duration of time that cannot be less than one hour.
Example: "The meeting will last for a minimum of one hour, so please plan accordingly."
Alternatives: "at least one hour" or "no less than one hour".
Systems support provided on a per-hour basis, as available, with a minimum of one hour's work, billed in hourly increments.
Few schools comply with the requirement to offer religious education for a minimum of one hour a week.
Tip in the strawberries and leave to macerate in the fridge, covered with clingfilm, for a minimum of one hour, but no longer than three.
But they also found that the increased risk of death associated with sitting for eight hours a day was eliminated for people who did a minimum of one hour of physical activity a day.
PLEASE NOTE: All meetings and events are required to have a minimum of one hour of setup/training time prior to the listed start time for meetings and events and thirty minutes of breakdown time following the listed end time for meetings and events.
Samples were loaded in vials, flushed with helium, and dissolved in 99% phosphoric acid at 72°C for a minimum of one hour.
These charges range from a weekday daytime rate of £95 per hour at a minimum of one-hour call-out and 15 minute increments after this, to a 12am-7am rate of £200 per hour.
They were then recorded for a minimum of one additional hour.
Full darkness sends the birds to sleep, preventing them from eating and putting on weight, and so is kept to the minimum of one hour a night.
Studies were included if the intervention described was group-based education specific for people with type 2 diabetes and if the duration of education was a minimum of one session lasting for one hour.
Workers are guaranteed 11 consecutive hours' rest in any 24-hour period, a 20-minute rest break if the working day is longer than six hours, a minimum of one day off each week, a working week limited to on average 48 hours a week, and limits to night work of an average eight hours in any 24-hour period.
