My units are gas filled?

All units are gas filled air is a mixture of mainly Nitrogen and Oxygen, some sealed units have Argon or Krypton gas installed, these heavier gases help with the unit’s thermal performance

However, as the seal has failed the heavier gases have long escaped and been replaced with moist air, you could consider replacing the unit with another heavy gas filled unit that will fail again in another 5 - 10 years.

Any money you might save by the slightly better thermal performance of heavy gas filled units will never pay for new units every few years.