Active Cooling Solution for LED Heat Dissipation

In particular, as LED lighting continues to migrate to higher wattage and higher lumens, passive cooling solutions are no longer sufficient to conduct and emit heat out of the LED and into the surrounding environment in a fast and effective manner. This means that thermal management manufacturers need to develop smaller, lower cost designs, such as active cooling modules, to help cool higher power LED lamps and bulbs. Many new cooling designs are for LED downlights and spotlights, including A19 and MR16 bulbs. As an example, we will introduce Sunon and nuventix's series of LED active cooling modules.

Since LED lighting is not a market where manufacturers can effectively pursue cost, they must sell it by performance, explained John Fulmer, Suwon's Regional Sales Manager in the United States and the southern half of Latin America. This translates into the use of factors such as lumens, low power consumption and long service life to confirm the customer's return on investment (ROI) at a relatively high upfront cost.

Fulmer said that for large devices, sales performance, long life and overall value become more important. "When they enter these different applications, the scale of the thermal challenge becomes larger. It is no longer just a small bulb; it is a very large heat source." traditionally, electronic designers want to cool led systems through passive solutions if possible. In fact, most LED lights are cooled by some form of radiator or other passive cooling solution without fan, he said, adding that this is one of the reasons why Sunon and other heat suppliers have been playing with UAVs. They provide a variety of heat sinks in the cooling market.

"But what we found is that in order to realize the advantages of product technology, in some cases you really need active cooling," Fulmer said. He pointed out that even the perfect LED lamp that could theoretically last for many years could suddenly become a five-month bulb because it had exceeded the allowable thermal performance specifications.

Customers now tell thermal management suppliers that they can't cool some of their lighting fixtures well just by using radiators. In some cases, it's impossible because the radiators are too large and the cost is too high, Fulmer said.

The active cooler or cooling module uses both a radiator and a cooling fan. This is because radiators are a very good way to cool equipment, but they usually reduce their efficiency because they collect dust. However, according to Fulmer, there is an active cooler with a patented fan positive / negative steering design, which not only cools the radiator, but also cleans the water tank.

In addition, active coolers can generally be obtained with smaller size and lower cost. By selecting an active cooler, the size of the radiator is reduced, which saves more money than the cost of adding a fan. According to Fulmer, the combination of the two provides good performance at low cost and brings more benefits to the desktop.

Fulmer gave an example of a Philips product radiator solution with a diameter of 175mm, a thickness of 30mm and a weight of 570g. For the same LED light source, Sunon provides an active cooler with a much smaller water tank, with a diameter of 85mm, a thickness of 35mm and a smaller overall volume. It also weighs significantly less than the radiator, reducing the overall weight of the solution.

This can reduce the upfront cost of lighting fixtures. "When comparing the performance between the two, the active cooler performs better in cooling, so it is more likely to obtain a higher level of optical performance," Fulmer said. "It is also a low-cost solution because most of the cost is embedded in a large sink."

Sunon offers a variety of MR16 and A19 active coolers, including radiators and fans, including la001, la002, la003, la004, ta001, ta002, ta003 and ta004. They are available in a variety of sizes and shapes for spotlight applications (Figure 1). The minimum cooler diameter is 50 mm and the maximum cooler diameter is 85 mm. Radiators and fans can also be purchased separately.

Figure 1: Sunon provides various la00x and ta00x MR16 and A19 active cooling modules, which combine radiator and cooling fan to provide lower cost and smaller solution for hybrid LED spotlight manufacturers (picture provided by Sunon).

These active coolers are usually used for consumer LED products. Fulmer said that a variety of fan and radiator sizes are available to accommodate a variety of LED lighting provider products.

Nuventix also saves costs through its patented synjet technology cooler for industrial applications (see techzone article "industrial cooling using nuventix synjet technology and complementary led radiators"). The company offers a variety of coolers, including zflow 90 and synjet spotlight cooler 70 w for downlights and low ceiling lighting for industrial applications. The spotlight cooler adopts a small, lightweight and economical design, adopts forced cooling, consumes 70 W, and can achieve light of up to 10000 lumens in the overall dimensions of 118 to 134 mm.

Nuventix has also recently introduced the LED radiator r150-170 based on synjet Technology (Figure 2). The high shed led cooler is 33% smaller and 60% lighter than the passive cooling equivalent used in industrial applications. The modular solution can be used as a stand-alone heat sink or up to three synjets.

Figure 2: nuventix r150-170 high temperature box cooler for industrial applications reduces total cost of ownership by maintaining thermal performance and saving maintenance costs (provided by nuventix).

Due to heat pipe and synjet air transmission, the r150-170 led radiator can cool up to 20000 lumens in a circular design. The company said that lighting manufacturers can use smaller and cheaper LED arrays and still achieve high color quality and lumen output. This is because r150-170 has advanced thermal diffusion and heat transfer capabilities.

In conclusion, as LED lighting manufacturers move to higher power designs, passive cooling solutions are no longer sufficient to dissipate the heat generated by LED lamps. This means considering active cooling solutions for more efficient heat dissipation. In many cases, these solutions have a variety of advantages, including smaller package size and lower cost, which helps LED lighting designers maintain the specified performance level and LED life.