The Ballina-born forward went to school in Blackrock College before playing with Connacht at Under-19 and Under-20 level. He then went on to represent the Ireland Under-20s, playing against France in the 2011 U-20 Six Nations.
Heffernan, who plays his club rugby with Buccaneers, has featured predominantly for the Connacht Eagles this season. His first senior cap came last year when, at the age of 21, he was named to start against the Scarlets.
While the Mayo native started his rugby career as a back rower, he has this season moved to the hooker position. He started in the number 2 jersey for the Connacht Eagles against Ulster Ravens last week.
The province's assistant coach Dan McFarland said: "Halfway through this season, we started training with Dave at hooker. While it's early days, he has shown great progress and had a fantastic game against Ulster last week.
"He is an excellent athlete and a very physical player. I'm looking forward to working closely with him next season."
Daniel Qualter has been with the Connacht Academy for three years and now advances to a development contract with the province.
The Athlone-born lock has represented Ireland at Under-18, Schools and Under-19 level and has played 15 times for the Ireland Under-20s.
This season he made his debut for the Connacht senior team, coming off the bench against Edinburgh at home in the Sportsground.
His performance earned him a further two senior appearances in the Heineken Cup home and away games against French side Biarritz Olympique.
McFarland added: "Danny has shown huge potential at underage level. He is a very intelligent rugby player with excellent skills. He did very well for us when we needed him during the year and it's fantastic to have him as an option in the second row."
Connacht Rugby CEO Tom Sears commented: "We are delighted that Dave and Danny have graduated from the Academy through to the senior squad.
"It's testament to their ability and hard work but also that of our Academy coaches and staff who are doing an outstanding job producing home grown players of real quality.
"This epitomises what the Grassroots to Green Shirts campaign is all about and there are plenty more young players in our system who have the potential to follow the same pathway and go on to represent Connacht and Ireland in the future."