Fresh air into joists

Ingenjörsfirman Wahlberg & Co HB

Heavy compressed paper pulp HCPP in joist to obtain air distribution and reduce impact sound in multiple-unit dwellings. – An offer about development cooperation.


The multiple-unit dwellings of today are small, in respect of both the living  area and number of rooms. The low-energy houses have less need of warming energy and a greater need of cooling energy as well as air exchange in order to compensate for higher amount of CO2, which is a consequence of more people  per m2.Therefore the need of a larger volume of fresh air increases. Low temperature airborne energy is more competitive, than waterborne ones to radiators. The cooling energy too may well be used as airborne.  As a consequence of  what is written above, there is a growning interest in and development of  compact flat-situated FTX-units with a high thermal efficiency.
According to Swedish Building Regulations of today, there is a claim of minimum 0,35l/s and m2, that the air devices of today amost settle.

At higher air exchange there is a demand for:
 -Better homogenisation of supplied fresh air in rooms ………………   (diffircult with todays air devices)           
 -Draught-free rooms irrespective of location.
 -No disturbing noise from air devices.
 -Possibility to head the supplied air against  a cold or varm surface. (Impossile with air devices of today)   

The multiple-unit dwellings of today are often made of wood ,whose joist and raised floors demand reduction of impact sound.


The heavy compressed and fire-retardant paper pulp carries the floating floor  and found pro room/flat a large diffusor, that distribute the centric supplied air uniformly against the periferi under heavy fall of pressure almost independent of amount and distribution of pressure.
See sketch of principle below.

english luft

Air under very low pressure passes a slot between a shirting along the floor periphery and walls. The air stream ascends walls and large wall panes and blends with the air mass of the room to escape along the periphery of the ceiling and further  back to the FTX-aggregat of the flat.
The heat content of the air stream is spread over the entire surface of the floor under which it passes. It comes from an air intake duct between joists passes subfloor and hit a cone under the floor to facilitate uniform spread of the air through the diffusor. If the issue is cooling , the air stream change direction and pass from ceiling to floor in the room to reach a good air blanding effect of the air mass of the room as when the warm air stream pass from floor against the ceiling.

HCPP, that supports the floating  floor has also the advantage when rightly glued to the floating floor to reduce impact sound in the flat below. This property contributes to the building  economy by reducing the height of the joist arrangement incl. Floors.


Experiences och tests

The delivery of air, heat and chilliness  to the low-energy house, that was designed and built of MSc Helge Wahlberg 2006 has performed very well. The house was certificated as a silver building by the Swedish Miljöbyggnad ( Environmental Building). Do also look at in Swedish) The height of the joists turn out to be too high to be used i multiple-unit dwellings. Therefore the following  experiments and tests were carried out:
- Examination work for Master Degree: Floor ventilation combined with floor heating  TMPE01 at Linköping Institute of Technology  20160311, that verified the advantage of described air current through HCPP.
- At RISE, Research Institutes of Sweden the following tests regarding HCPP has been carried out:
- a1/2016-05-14, Ref. 6P04481rev. 160519  Determination of the reduction of transmitted impact noise…   
- a2/2016-05-17 Simmons acoustics and development ab : Comments to a1 – Reduction of Impact noise is considerable…..
- b/Load test of floor construction 1 x 1,2 m with treated HCPP: 27 kN/m2 as long –duration test. The vertical lasting deformation was negligible.

The continuous development work in co-operation:

In order to utilize the air stream advantages experienced from our work with HCPP. It must be built together with floor and subfloor to  modular plywood units to be installed on joists.

WHB, Engineering Firm Wahlberg & Co HB is looking for a partner, primary for development of production and  a full scale test of a 20 -25 m2 double floor in a newly erected building structure. There is already a company, specialized in FTX aggregates, who is willing to participate in said test. WHB desires  to cooperate until evaluated  test installation etc..Thereinafter release the right to the product to the partner of WHB against a reasonable compensation. Swedish design protection for HCPP has been granted by the Swedish Patent and Registration Office.

Helge Wahlberg

590 49 Vikingstad