Having an outdoor heat pump with a lower BTU capacity than the combined BTU capacity of the indoor fan coil units can potentially lead to problems. In an ideal situation, the heat pump's BTU capacity should match or exceed the total BTU capacity of the indoor units.
The BTU (British Thermal Unit) is a unit of measurement used to indicate the amount of heat energy required to raise the temperature of one pound of water by one degree Fahrenheit. In the context of heating and cooling systems, BTU capacity refers to the amount of heat energy that can be produced or removed by the system within a given time.
When the combined BTU capacity of the indoor units exceeds the BTU capacity of the outdoor heat pump, it means that the heat pump may struggle to keep up with the demand for heating or cooling in extreme weather conditions. This can result in reduced efficiency, inadequate temperature control, and potential strain on the heat pump.
In such cases, the heat pump may run continuously or for longer cycles, leading to increased energy consumption, decreased system lifespan, and potential comfort issues. Additionally, the heat pump may not be able to achieve the desired temperature setpoints or maintain consistent temperatures throughout the indoor spaces.
To ensure optimal performance and efficiency, it is generally recommended to have a heat pump with a BTU capacity that matches or exceeds the combined BTU capacity of the indoor fan coil units. If the existing setup does not meet this criterion, you may want to consult with a professional HVAC technician or installer to assess the system and determine if any adjustments or upgrades are necessary.