Daniel Reich in his gallery on 23rd Street in Chelsea. He previously held exhibitions in his tiny studio apartment.

Mr. Reich was among a group of young dealers who brought new energy into contemporary art in New York in the early 2000s, tacking against the trend toward a more button-down, sleek, big-money business.

He first showed emerging artists and collectives in his 200-square-foot ground-floor studio apartment on West 21st Street, where visitors had to ring the bell for No. 2A to see the shows. Mr. Reich stowed his inflatable air mattress in the tub during business hours.

“His bathroom ended up being the art storage, and there was some incident when the shower got turned on and damaged something,” said the artist Scott Reeder, whose work was in Mr. Reich’s first exhibition in the apartment, a free-form group show called “Miss World 1972,” in December 2001.

That show included many young artists who were then little known but who went on to have significant careers. Among them were Roe Ethridge, Virgil Marti, Mr. Reeder and his brother Tyson, and Eli Sudbrack, known as Assume Vivid Astro Focus. Holland Cotter of The New York Times praised the show, saying that Mr. Reich had “figured out a way to be in Chelsea without necessarily being of Chelsea.”

The gallery moved to a modest commercial space on West 23rd Street in late 2003 and made its name with shows emphasizing small-scale works that projected an intimate, sometimes melancholic, hand-wrought quality. Newcomers like Christian Holstad and Hernan Bas, along with established artists like Jack Pierson, often explored gay sexuality and gender in unexpected ways.

Mr. Reich also focused on painters, like Paul P. and Henry Taylor, who in a 2005 exhibition included a portrait of Mr. Reich “in all his bemused, bespectacled, bright-eyed intensity,” as Roberta Smith described it in The Times.

Alfred Daniel Reich was born on Dec. 8, 1973, in New York City and raised in Brooklyn Heights and Larchmont. In addition to his sister, he is survived by his parents, James and Barbara Reich.

Mr. Reich studied art history at Hampshire College in Amherst, Mass. After graduating in 1996, he went to work for Pat Hearn, a pioneering gallery owner in the East Village and later Chelsea; she made Mr. Reich her director.

When Ms. Hearn died at 45 in 2000, Mr. Reich struck out on his own, with so little money that his mother had to help him pay the rent on his apartment. “The bottom line,” he said in an interview, “was that I really wanted to have a gallery, and sometimes you just have to start doing something with whatever you have at your disposal.”

Despite critical success, he struggled to make the gallery work as a business, and in 2011 he closed his commercial space. In a posting on his Web site announcing the closing, he sounded more hopeful than dejected.

“In the original spirit of the gallery, which began out of my apartment in the winter after 9/11, I feel that this moment has a specificity ripe for change,” he wrote. “One of my favorite things about my gallery is that it exists close to the earth and is a gallery of its time.”