Dunbavin has linked up with former Stanley managers Paul Cook and Leam Richardson at League Two high-flyers Chesterfield in a temporary deal until the start of February.
The 33-year-old has made 169 appearances for Stanley, but has fallen out of favour under current boss James Beattie.
He started the Reds’ first five games of the season on his return from long-term injury, but Stanley made a poor start to the campaign and the keeper was then ruled out with a knee problem.
Marcus Bettinelli became Stanley’s regular stopper after arriving on loan from Fulham, and Dunbavin did not even make the bench in many games after his return from injury – with Beattie opting to go without a substitute goalkeeper.
Even after Bettinelli’s shock recall by Fulham on Christmas Day, Beattie opted to start with 19-year-old keeper Andrew Dawber and still there was no place on the bench for Dunbavin.
Dawber impressed in goal and Beattie is still hoping to bring Bettinelli back on loan for the rest of the season.
The 21-year-old has been on the bench for Fulham in their last three Premier League games but regular stopper Maarten Stekelenburg, the Netherlands international, could soon return from injury.
Dunbavin is expected to be second choice to Tommy Lee at Chesterfield.
Cook said: “I know Ian and he’s very much a larger than life character who energises the place.
“We’ve lacked senior cover on the bench.”