nbeckman34
01-06-2010, 09:30 PM
I am looking at specifying Aaon VAV D/X RTUs on a 10,000 SF doctors office and would like to know everyone's thoughts on this system. The system would be (2) Aaon RN013 VAV, RTU's and (1) Aaon RN08 DOAS. DOAS are a must in South Florida and with the DOAS in place the turn down of the VAV system is not dictated by ventilation rates of low airflow interior zones. The ventilation airflow is connected to the low pressure ductwork downstream of the VAV boxes.
What type of life expanctancy has everyone experienced with the Aaon RN model rooftop units?
The doctor is looking for a life cycle cost difference between the VAV system and a system with Trane CV RTU's with the Aaon DOAS. I have specified the Aaon 100% DOAS for 3-4 years and have not had a problem with them as of yet.
I expect the intial price of the Aaon VAV system to be about 70-100% higher than the inital cost of the (6) trane RTUs. I am expecting the price of the Aaon system to be about aound $170,000.
I am afraid if we cannot see a life expectancy in the 20 year range, they will not be able to recover the intial cost with associated energy savings, if there is any energy savings over the Trane RTUs. I have not done an energy analysis as of yet on the VAV system but I have a hard time believing there will be a significant energy savings with this system due to the higher system pressure and the need for reheat at some loading conditions. This is especially true if the fans on the CV units are cycled with the compressors.
What type of life expanctancy has everyone experienced with the Aaon RN model rooftop units?
The doctor is looking for a life cycle cost difference between the VAV system and a system with Trane CV RTU's with the Aaon DOAS. I have specified the Aaon 100% DOAS for 3-4 years and have not had a problem with them as of yet.
I expect the intial price of the Aaon VAV system to be about 70-100% higher than the inital cost of the (6) trane RTUs. I am expecting the price of the Aaon system to be about aound $170,000.
I am afraid if we cannot see a life expectancy in the 20 year range, they will not be able to recover the intial cost with associated energy savings, if there is any energy savings over the Trane RTUs. I have not done an energy analysis as of yet on the VAV system but I have a hard time believing there will be a significant energy savings with this system due to the higher system pressure and the need for reheat at some loading conditions. This is especially true if the fans on the CV units are cycled with the compressors.