Earth temperature nowadays is gradually increasing due to the greenhouse effect, and how to efficiently use energy becomes a big issue that everyone should pay attention to. Therefore, heat pump system is a future-oriented trend. It can not only absorb heat energy in the air but also heat up water for domestic usage through thermal energy conversion and finally exhaust cold air. However, there are two common issues often discussed over heater control panels. First, the user interface design of control panel is neither simple nor distinct. People cannot locate and recognize the correct function button at the first sight while operating. Second, most modeling design for existing control panels are likely designed to industrial style. Attaching the industrial design control panel on the wall in normal domestic house is too abrupt. Therefore, this thesis comes up with two design guidelines by discussing above two problems. Two design guidelines are principles for control panel appearance design and principles for human interface design.