Nuventix has raised $8 million more to develop new markets and improve the efficiency of its system to cool light-emitting diodes (LEDs) and servers with blasts of air.

The new funding includes $3 million from Braemar Energy Ventures, $1 million from Korean firm Uniquest and a $4 million line of credit from Silicon Valley Bank, the Austin, Texas-based startup announced Monday.

The new funding closes out the company's series C round at $18 million, and brings the company's total investment to $32.5 million since its 2005 funding, it said.

Nuventix raised $14 million in July from investors including Advanced Technology Ventures and Braemer Energy Ventures (see Wakonda, Nuventix Raise Millions).

Nuventix's SynJet technology allows LED makers to place more lights more closely together than would be possible with traditional passive cooling methods, meaning more light per unit of space, the company said.

LEDs are mainly used in outdoor traffic signals and roadside signs, though several companies are developing them for the indoor lighting market (see DOE Says LEDs Can Shine in 12 Markets).

LEDs are seen as a far more energy efficient replacement for traditional incandescent light bulbs, and they don't have compact fluorescent lights' problems of poorer light quality and use of toxic chemicals.

The main barrier to adoption remains their high price. But venture capitalists and mainstream lighting companies alike are spending millions to invest in or acquire promising LED startups (see Lighting the Way to Efficiency).

Beyond cooling LEDs, Nuventix is seeking to expand its business of supplying SynJet cooling for high-performance servers, it said.