A heater structure includes a heater body including a burner connected to a valve switch. A pilot fire assembly is covered by a protective cover that has ventilation holes. A switch unit includes an ignition switch, a shut-down switch, an ignition operator, and a shut-down operator. The ignition operator and the shut-down operator are structured to provide a swingable arrangement. The ignition operator may be operated to contact and press the fuel gas valve rod and the ignition switch to open the valve switch for supply fuel gas to the burner and to activate an ignition circuit to cause successive shootings of an ignition pin of the pilot fire assembly to set a flame on the burner. The shut-down operator is operated to contact and press the shut-down switch, so as to cut off a signal of the thermocouple and thus cut off the supply of the fuel gas.

Systems, tools, and methods are presented that enable a circuit to introduce a random time delay before actuating a relay to start or stop a supply of electrical power to a heating element of a heating, ventilating, and air conditioning (HVAC) system. In one instance, the circuit includes a time-delay switch electrically connected to the relay. The time-delay switch has a random time delay before entering a closed state or open state. The relay is operable to start and stop a supply of electrical power to the heating element in response to the switch entering, respectively, the closed state and the open state. Other systems, tools and methods are presented.

The present disclosure provides a method for controlling a fan heater, including: sampling an indoor temperature at a preset interval (S100); comparing the sampled indoor temperature with a preset temperature to obtain a temperature control signal (S200); and adjusting a power of a heater and a rotate speed of a fan according to the temperature control signal (S300). The present disclosure further provides a fan heater, a device for controlling a fan heater, and a storage medium.

An improved convection fan cover is provided. In one or more implementations, the improved convection fan cover has a shutter system. As the convection heating system operates, the shutter system opens and closes (or blocks and unblocks) vents in the convection fan cover, creating an oscillation effect that alters the flow of air throughout an oven cavity, contributing to a more even cooking profile.

A bedding climate control apparatus that delivers, in a quiet manner, forced airflow from a fan/blower within a housing to selectively deliver tempered (heated via a thermal element) forced airflow and non-tempered (room temperature) forced airflow through a flexible air conduit to bedding. The thermal element imparts heat to temper the forced airflow and the heat deliver may be adjusted to maintain a constant set temperature by adjusting imparted heating power depending on backpressure changes in the forced airflow and ambient temperature.

A room-air treatment system includes a basic module that has a first air-treatment unit and a control device for controlling the first air-treatment unit. The room-air treatment system includes at least one second air-treatment unit that can be coupled to the basic module, in particular the first air-treatment unit. The control device controls both the first air-treatment unit as well as the at least one second air-treatment unit.

A bedding climate control apparatus that delivers, in a quiet manner, forced airflow from a fan/blower within a housing to selectively deliver tempered (heated via a thermal element) forced airflow and non-tempered (room temperature) forced airflow through a flexible air conduit to bedding. A retention unit holds the flexible air conduit in position against movement and simultaneously retains the bedding in place.

A heater having a cover with an exhaust port and border a intake port allowing air to enter the heater. The heated air is then dissipated through an exhaust port on the cover of the heater. The border intake and cover of the heater have a perpendicular relationship whereas the exhaust port and cover have a parallel relationship.

An air supply device with air refreshing and insect repellent function include a housing, which comprises: an air duct unit supported inside the housing having a hollow body defining an air channel; a centrifugal fan received inside the air duct unit; two main air inlets arranged at two opposite sides of the housing; an air outlet arranged at a top portion of the housing and channeled through with the air channel inside the air duct unit at a front side of the housing perpendicular to each of the main air inlets; an auxiliary air inlet arranged at a rear side of the housing opposite to the air outlet; an auxiliary component, which is an aromatherapy component or a mosquito repellent component, connected to the housing at the auxiliary air inlet; and an optional heating component detachably connected to the housing at the main air inlet.

A heating unit for a heating, ventilation and/or air conditioning (HVAC) system may have a first airflow path through the heating unit, a second airflow path through the heating unit, and a heater assembly having a first heating coil positioned within the first airflow path, a second heating coil positioned within the second airflow path, and a coil divider separating the first heating coil and the second heating coil.