Transparent WHRB recovers maximum possible heat from the gases. It gives atleast 7 to 10% extra output compared to other make. This needs a much bigger economizer & high manufacturing cost for Transparent but gives benefit to user in terms of more savings.

In other makes , eventhough economizer is provided, heat is recovered upto a temperature level where the manufacturing cost is less. This results in cost savings for WHRB supplier but recurring loss to the user.