MECHANICAL HVAC CONSULTING ENGINEERING.                                           DESIGN, INSPECTION: Water, Heating, Cooling, Piping, Heating, Ventilation, Air Conditioning, Controls.                                               Slide Rule Engineering Design IWA 1633 & 1638                                                                                                     Decimal Point Slide Rule Calculator 

 Phone Control AB

 PeriProx Control Solutions.




WERN Inter AB started 1963 in Sweden as the HVAC consulting engineering company Wern

Inter VVS AB. It was founded by Carl R. Wern, a Registered Professional Mechanical Engineer in

the state of Michigan, USA, Carl´s brother George joined in 1964 the company. Its present name 

was registered 1984.

The company has been engaged in various engineering design projects such as 

- Apartment, Hotel, Shopping, Office and Recreational buildings etc

- Swedish Embassy buildings in Europe, Africa, Asia and North America

- Slide rule design awarded with gold medal to the Wern brothers

- Slide rule calculator design and production for various clients

- Touch control for lighting installations patented in 1972

- Patent licence sold 1976 to Ericsson for picture telephony on an ordinary subscriber line.

P-Phone Control AB (PPC) was founded 1992 by Carl together with his brother George in a

joint venture agreement with their brother Lars who is a registered European Patent Attorney.

PPC is specialized in proximity sensing R&D where a sensor device was patented 1972 by

the Wern brothers in a digital version following analog versions inspired by Nikola Tesla. 

A first patent of interests to mention was registered 1928 in the USA by the Soviet inventor 

Léon Theremin. He developed an electronic musical instrument controlled without physical contact.

The Wern brothers proximity sensor was first used in lighting installations for touch control and

thereafter in art museums as invisible shields preventing exhibited objects from being touched.   

Today called PeriProx, the technology has been shown applicable for providing enhanced security 

in 2000 to a Saab car and in 2009 to a Scania truck.

Slide Rule Reference 

Oughtred Society, Roseville, California. USA.                      www.oughtred.org

International Slide Rule Musum, Denver Colorado, USA.    www.sliderulemuseum.com

National Museum of American History. http://americanhistory.si.edu/collections/object-groups/slide-rules

Wikipedia.                                              https://en.wikipedia.org/wiki/Slide_rule


System Wern Slide Rule IWA 1633 & 1638.  Gold medal award at the International Exhibition in Brussels 1966.

IWA 1633

Manual 1            Manual 2

IWA 1638


Design layout made by WERN INTER AB for some of our Clients.

IWA07133.  Air Duct Calculator       SI75.   Conversion Factors                kv81.   Valve Factor 

1972. Metric System. 170x240 mm              1975. Technical system. 90x120 mm              1981.Water, Steam & Air. 90 x 120 mm

Manufactured by IWA, W. Germany.             Manufactured by INPLASTOR,  Sweden.       Manufactured by INPLASTOR, Sweden.   

Manufactured by Inplastor AB, Sweden.

Draftsman triangle   SI-GUIDE   NavigationRuler   EO70.EconomicOrderSize

HVAC Mechanical Prototype Calculators

Water - Heating - Ventilation.  Prototypes to be shown later.

              Mechanical Design Projects                   Åhléns City    MechanicalProjects to be shown later/World wide

Conversion factors IWA1638

CRW Background

 1946. Hermods Correspondence Institute, Malmö. Mathematics, Building Construction, etc

1949. Swedish HVAC Engineering Degree, Stockholm Technical Institute, Sweden.

1960. Registered Professional Engineer in Michigan, USA     

1960. ASHRAE Life Membership  

1983. Registered Professional Engineer in Minnesota, USA

1994. Swedish Institute for Technical Approval in Construction - Function Control/Ventilation

Stockholm, Sweden

Copyright Carl R. Wern