Counter intuitively the temperature with air cooling stabilised at a higher temperature of 72 °C in testing using the lower powered Hepatochem lamp. The air surrounding the smaller Hepatochem lamp is able to vent more readily than around the larger Kessil lamp, so we did not find a solution to using the air flow to lower the temperature further (figure ). The difference in operating temperature of the two types of lamps could be due to a more efficient heat sink incorporated into the 32 W Kessil lamp.