The $1.16 million federally-funded, state-of-the-art unit replaced a worn-out bus that was cramped inside and unable to fit the latest equipment.

The bus was with the blood service for 28 years, and travelled hundreds of thousands of kilometres between Newcastle and Lake Macquarie.

However, in the past year, it had broken down several times and became unreliable.

This left the bus's southern-most clients at Swansea without a mobile blood unit.

The new unit is the Hunter's third and it has been assigned to the Newcastle and Lake Macquarie region and will service Swansea.

It will also stop at Belmont, Warners Bay, Valentine, Mayfield, Broadmeadow and Cardiff.

The unit is fully airconditioned and has reclining chairs and a reception area.

It is expected to contribute about 170 donations to the blood service's weekly target of 900 for the Hunter - 20 more than the old bus mobile unit.

The blood service estimates it will collect more than 4500 litres of blood in the next 12 months.

Regular donor Dean Richardson, who works for a conveying company at Mayfield's Steel River Industrial Estate, contributed 500 millilitres.

A donor for five years, he visited the new unit at Mayfield CSIRO last Wednesday.

It was the new unit's second public appearance after its debut at Valentine the previous week.

Mr Richardson said the new unit was "fantastic" compared to the bus it replaced, which could be intimidating to first-time donors because it was small and cramped.

The old bus will be revamped and sold at auction in the coming weeks.