One of the most common myths about nodules is the diagnosis itself! Usually doctorâs donât have the necessary equipment (stroboscopy) to diagnose vocal problems. So all problems are called nodules. Every singer has a colleague who had ânodulesâ for this reason.
An RTU is a type of AHU. AHU stands for Air Handling Unit and the acronym RTU means Rooftop Unit. The Roof Top Unit is an outdoor AHU. As RTUs are mounted on the roof, there is no concern about creating extra space indoors for it as would be the case for the other types of AHU.
An air-to-air heat exchanger, or what is more commonly called today a Heat Recovery Ventilator (HRV), is a air change central ventilation system that exhausts stale air outdoors and brings in an equal quantity of fresh air to replace it while stealing the heat from the outgoing air to warm up the incoming air.