Air-In® supply air valves increase the comfort of living and save energy.
Air-In® supply air valves offer superior noise reduction values and the draught-free air quantities.


The different preferences of inhabitants often cause problems for the ventilation of flat buildings. Even the most carefully adjusted ventilation does not work correctly if some inhabitants block valves. This problem can be solved by means of frequency converter operated constant pressure regulators that can be used to enhance the standard of living and keep the ventilation in balance.

Constant pressure regulators allow constant air volumes in flats even when other inhabitants block valves in other flats. The amount of air stays stable and does not grow as in an unregulated situation.

Save energy and increase the operating life of equipment

Even a slight decrease of rotation speed of pump and fan drives results in significant savings of energy. Energy can be saved effectively and equipment wear can be decreased by adjusting the rotation speed by means of a frequency converter. This also saves money.

Other benefits of frequency converters include steady start-ups and stops. Starting up a drive can use even 7 times the power when started up to full speed. Using a frequency converter, this power can be controlled both as a financial expense and mechanical wear. All mechanical parts last noticeably longer when unnecessary twitch and impact loads to the system are avoided.

All Mitsubishi Electric frequency converters are easy to use and reliable. All frequency converters can be programmed and meet international requirements.


  • Better standard of living (more even flow of air/water)
  • Saves cost, energy and nature
  • Decreases maintenance costs


  • Air conditioning machines supply/exhaust (roof exhaust fans, door fans)
  • Pumps (constant pressure, pressure shock, circulating water)
  • Heating/cooling (fan compressors, control of condenser fan)

Other benefits:

  • Pay-off period of a couple of years to a couple of months
  • Maintenance-free and durable
  • Adjusted according to the application
  • Low cost of investment
  • Easy to install
  • PID regulation prevents unnecessary operation (such as constant pressure pumps)
  • Possibility to transfer alerts if a belt breaks, for example
  • Allows increasing the power of existing equipment, such as air conditioning machines

Sample calculation of the savings generated

Savings from using a frequency converter with an air conditioner
- assumed pay-off time of the investment as electricity used by the drive

Calculation model from a Beijer Electronics site. The result is achieved using the Beijer Electronics formula with the following values:

Nominal output of the drive 15 kW
Operating time per year 3600 h
Price of electricity 0,12 cent / kWh
RPM requirement / year 60%
Investment cost € 3,277

Pay-off time

0.87 years

Annual savings

€ 3,785


Savings generated from the preheating of air-conditioning as district heat or electricity

Comparison between a 2-speed air conditioning and use of frequency converter