Heat exchanger effect

When air is drawn by suction into the building interior through the layer of heat-insulating material at a very low rate of flow, an exchange of heat takes place.

Calculations performed at the Royal Institute of Technology in Stockholm indicate that the increase in temperature of the incoming air can be compared with a corresponding increase in a heat exchanger for recovery by an efficiency rate of 15 percent.

Please compare with a big heat exchanger which change energy between outward passing exhaust air and inward passing outdoor air.

This can give a maximum temperature efficiency of ca 45 %, but it is expensive and must be cleaned once a year. Our arrangement gives us 15% without extra costs.

    • Nature always strive for temperature balance.

      As cold outdoor air passes through the insulation on its way into the building in the cold period of the year, it cools down the thermal-energy carrying insulation fibres, wherewith the outdoor air is heated and the heat returned back into the building.

      Even a thin thermal insulation layer will provide a highly effective heat-insulating effect.

      The pressure equalising layer provides an evenly distributed air stream through the roof insulation.

    • The roof functions as a preheater for the incoming air in two ways: partly by the solar heating developed under the roofing material outside the insulation and partly by the heating of the incoming air during its passage through the insulation.

    • The dynamic air intake procedure lead to a normal insulation thickness gives en insulation capacity corresponding to more than double the thickness.

      Considerably thinner insulation layers can be used to preserve against coldness, than what is common in other systems.

    • But a summer´s day there is very hot in the attic.
      The fact is the roof insulation is dimensioned to keep out the heat at summertime.

      At summer time we don´t want the heat to penetrate inside.
      That is why we use cool outdoor air from a northen side at summer.

As a result of the low rate of flow, the thermal insulating layer will also engender an effective filtering effect, such that the through-passing air will be practically particle-free.

    • Investigations at Dept. of Building Physics. Lund University shows that practically no particles from outside or from the insulation joins the outdoor air into the house.

      Please look at the report "Optimät - a concept for energy efficient and healthy single family houses based on dynamic insulation technique, Arne Elmroth, Bertil Fredlund and others, Lund University, Box 118, S-22100 LUND"
      (The house in the report was furnished with loose wool of glass fibres)

    • Because the air is sucked in through a large thermal insulation area, loading of the thermal insulation with particles separated from the air sucked through the insulation will be negligible in light of the practical life span of the building.

    • The term of life of the "Filter" has been calculated to at least 200 years.

More about Dynamic fresh air intake, please look at the reference to "the solution for several of serious building problems of today", below.


Information about the RESARO system for small houses

Short information about the
"Dynamic fresh air intake"