Sizing heat pumps: how to choose it

The perfect microclimate of a home depends on a number of fundamental factors: it is not enough to choose a heat pump, perhaps the most powerful, without evaluating the size, exposure, height of the rooms and the structure of the apartment.
Only after carefully examining the characteristics of the place where we live or where we work, will we be able to calculate the heat requirement and the right power of the heat pump system, both in the cooling and heating phase.

First of all… what are heat pumps?

Heat pumps are devices capable of transferring thermal energy from a colder environment to a warmer one: it is the reverse process to what happens in nature. To do this, heat pumps use electricity only to drive a compressor and other auxiliary devices. Heat pumps are used to heat or cool domestic environments: the air / water heat pump uses water as a vector medium and its exclusive temperature control system guarantees thermal stability and high energy efficiency. In short, a conscious green choice made in full respect of the environment!
And now let's deal with how to choose the power of a heat pump ...

The evaluation of the correct sizing of the heat pump: why it is important

An incorrect assessment of the heating needs would lead to a wrong purchase. There is no sizing of the heat pump that is 100% certain: however, there is an acceptable sizing at a statistical level, that is, the sizing that is closest to the real needs for heating or cooling. If we bought an efficient heat pump even in extreme and unlikely climatic conditions, we would have an oversized device for most of the time of its use.

How to size the heat pump according to the heat requirement

The minimum design temperature depends on a number of factors:

  • the climatic zone in which the house is located (north, north-east / north-west, south, south / east, south / west)
  • the exposure of the rooms and the entire building
  • the internal location of the rooms to be heated: lower floors, upper floors or central floors
  • the type of insulation of the premises: excellent insulation is a saving in terms of cooling or heating (evaluate the presence or absence of large windows)
  • the size of the rooms in square meters. In fact, the larger the house, the greater the capacity of the system must be. In this way it will be possible to determine the relationship between amplitude, KW and BTU
  • height and thickness of the ceilings: an apartment with a high and not very thick ceiling requires more heating in winter and more cooling in summer
  • the number of people who usually live in the apartment
  • the daily hours scheduled for switching on the heat pump


Here are some useful tips

Take into account the possible dispersions and evaluate the type of lighting and the quantity of appliances