A pool heat pump transfers the heat absorbed from the ambient air to the pool water. For a residential pool heater, a large amount of fresh air is needed for the proper heat transfer. The refrigerant in the system becomes warmer with the heat from the air through this process. And the heat will be delivered to the pool water by the INVERBOOST pool heat pump. Usually, the outlet air from the system is around 10 degrees cooler than the air which enters the system. If you stand in front of a running pool heat pump (except for some pool heaters without a fan grid in the front panel), you could feel the chill wind.
It might happen that in some applications, installers realize the pool heat pump needs fresh air. To solve this problem, the installer connected pipes to the pool heater to remove the cold air emitted by the unit so the pool heat pump gets fresh warm air. Nevertheless, the design of the propeller fan which is used to move air through the pool heat pump does not combat any significant airflow resistance, which is exactly what the piping system presents. There will be a loss of performance, and also the potential failure of components because of the resistance of free flow through the system. Therefore, using pipes to get air in and out of the indoor INVERBOOST pool heat pump is not recommended.
So indoor installation is not suggested. If there is no other solution and you insist to install the pool heater indoor, make sure there is enough fresh air for the environment.