Absorption heat transformers (AHTs) are advanced thermal systems designed to upgrade low-grade waste heat to higher, more useful temperature levels. By exploiting the thermodynamic properties of ...

With global warming becoming an urgent issue, heating our homes efficiently -- and sustainably -- has taken center stage. As winters become more unpredictable (and unexpectedly harsh), finding ...

All questions and answers are based on the 2011 NEC. Q. What are the grounding electrode requirements for a separately derived system, such as a transformer? [250.30(A)(4)] A. First of all, let’s ...