Editing Heat recovery ventilation (section)

=== Run-around ===
Run-around systems are hybrid heat recovery system that incorporates characteristics from other heat recovery technology to form a single device, capable of recovering heat from one air stream and delivering to another a significant distance away. The general case of run-around heat recovery, two fixed plate heat exchangers are located in two separate air streams and are linked by a closed loop containing a fluid that is continually pumped between the two heat exchangers. The fluid is heated and cooled constantly as it flows around the loop, providing heat recovery. The constant flow of the fluid through the loop requires pumps to move between the two heat exchangers. Though this is an additional energy demand, using pumps to circulate fluid is less energy intensive than fans to circulate air.<ref>{{Cite journal|last1=Vali|first1=Alireza|last2=Simonson|first2=Carey J.|last3=Besant|first3=Robert W.|last4=Mahmood|first4=Gazi|date=December 2009|title=Numerical model and effectiveness correlations for a run-around heat recovery system with combined counter and cross flow exchangers|journal=International Journal of Heat and Mass Transfer|volume=52|issue=25–26|pages=5827–5840|doi=10.1016/j.ijheatmasstransfer.2009.07.020|issn=0017-9310}}</ref>