Heat recovery ventilation – Buyer Beware

A client was recently quoted for a heat recovery ventilation unit which has not been offered for some years. On investigation this unit has been superseded by units with much more efficient EC technology.
It appears a supplier has access to old stock of less efficient units. However, the potential buyer was not aware that he was buying old stock nor did the quotation reflect this. If this equipment had been installed the running costs for the next 20-25 years would be 30-40% higher than current EC units.
This client escaped but other house builders will be caught!