The purpose of the present study is to accumulate knowledge on how a drain water heat recovery system
using a vertical inline heat exchanger and a heat pump performs under different drain water flow profile
scenarios. Investigating how the intermittent behavior of the drain water influences the performance for
this type of system is important because it gives insight on how the system will perform in a real life
situation. The scenarios investigated are two 24 h drain water flow rate schedules and one shorter schedule
representing a three minute shower.
The results from the present paper add to the knowledge on how this type of heat recovery system
performs in a setting similar to a multi-family building and how sizing influences the performance.
The investigation shows that a heat recovery system of this type has the possibility to recover a large
portion of the available heat if it has been sized to match the drain water profile. Sizing of the heat pump
is important for the system performance; sizing of the storage tank is also important but not as critical.