Condensing and Non-Condensing Heating Concept / Hybrid Systems

In response to new advancement in condensing boiler design and size, many applications utilize multiple condensing boilers in addition to the non-condensing boilers. That triggered Heat-Timer’s patent design of the Mini-MOD-CNC . It is intended to manage the two groups of boilers to maximize system efficiency at the lowest operating cost while maintaining the desired comfort. The Mini-MOD-CNC operates each group based on the target temperature switching set point.

Depending on the actual Target Temperature, the Mini-MOD-CNC will determine which group of boilers will be the lead and which group will be the lag. The Condensing group of boilers will be the Lead group when the Target temperature is below the Switching Set Point. However, when the Target temperature rises above the Switching Set Point, the Non-Condensing boiler group will be the lead group and the Condensing Group will be the lag group.

Basically, the Mini-MOD-CNC will allow the condensing group of boilers to operate as along as the Target Temperature is below the Switching Set Point. During that period, if additional output boilers are needed, the Mini-MOD-CNC will energize the Non-Condensing boilers to meet the load. When less output is required the Mini-MOD-CNC will de-energize the Non-Condensing boilers prior to de-energizing the Condensing boilers.

To eliminate any short-cycling due to rapid changes in the outdoor temperature while using outdoor reset, an adjustable Switching Delay is used. It can be adjusted to satisfy different heating system installations.