"Too many lives have been lost within our community, in many cases because nobody knew what to do," said Mr Allen - writes herald.ie.
"If a person suffers cardiac arrest, it's vital that the defibrillator is used as soon as possible."
A defibrillator shocks the heart and helps to restore normal rhythm, meaning a trained volunteer can keep a person alive until paramedics arrive.
For the Ballyfermot Lifesaving Project, 34 local businesses and organisations made donations to buy the defibrillators and staff and owners took St John Ambulance CPR courses to learn how to use them.
Mr Allen, a project manager at the charity's national headquarters, will now help to replicate Ballyfermot's success in other Irish communities.
Mr Cardiff, who is in charge of the charity's local division, is a full-time paramedic with the National Ambulance Service.
The defibrillators can be found at Centra, Londis, Chasers, Lloyds Pharmacy, the Civic Centre, Ballyfermot College and Ballyfermot Sports and Fitness Centre.
In the new year, the two men will begin the final stage of the project, which will see more defibrillators installed in up to 15 schools and colleges in Ballyfermot, Chapelizod and Inchicore.
"We set out to raise the money in July. The cost of a defibrillator has come down to about €1,300, which is what some people spend on a TV or a phone," said Mr Allen.
"We approached local businesses for contributions and invited their staff to take part in free training sessions.
"We had an overwhelming response and held several training courses," he said.
"The results have been amazing. The defibrillators are now out in the community and it is guaranteed that one day they will give a person a second chance at life.
"Ballyfermot will be the model project and will be the safest community in Ireland following the success of this project."
Mr Allen recalled an incident in 2008 when he and his brother saved the life of a man who suffered a cardiac arrest while attending the Simon Fun Run in Dublin's Phoenix Park.
"We arrived within seconds, saw he wasn't breathing and CPR was performed and the pads placed on his chest.
"A shock was delivered to his heart and he started breathing again. He was in his 50s, and got a second chance at life."
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