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Many people wonder how these light-frame buildings function during the
summer heat, given that their insulation is so energy efficient during the winter.
Due to their massive nature, conventional buildings (brick, concrete)
warm up much slower than light-frame structures. This is, of
course, an advantage during the summer heat. But at the same
time, these massive buildings cool down slower, so they radiate
heat during the night.
In Table 1. illustrated the change of
inside temperature for the entire day
for conventional and light-frame buildings.
How can we gain protection
against the summer sun?
In both building formats, the doors and windows let in the most heat.
The most important task is to properly shade the windows. The architect
should take into account the plot’s properties, and can provide for
proper orientation of the building and use natural and constructed shading.
A The 2. Tables shows how we can protect our windows from the sun.
Planting deciduous trees on the southern and western
side of the building will shade the bottom floor windows during the summer,
but allow for sun in the winter.
Second storey windows should be protected with external, mobile shading units;
these can be shutters, louvers, or shades. Proper extension of the eaves
provides shade in the summer, but, does not affect sunshine during the winter,
thanks to the sun’s low angles.
Table 3. well illustrates,
that shading makes a small difference in the
inside temperature of light- and heavy-frame buildings.
With massive flooring
structure on the lower and upper levels, we can enhance the light-frame
buildings’ heat absorption properties.
For any building method,
air conditioning is a great way to counter the summer heat.
For light-frame buildings, the summer temperature depends on the
enclosure walls and the succession of layers in the roof structure / attic.
Usually enclosed and ventilated layers are to be used.
Walls with enclosed airspace are fitted with additional external insulation.
The façade and bevel siding are aerated, which reduces the wall’s tendency to
heat up during the summer. At the same time, this reduces the wall’s heat
transmission coefficient, which increases winter heating costs.
Light-frame attics can be quite
useful in this regard if the thick insulation, ventilation, and heat-resistant
foil are provided. Fiberglass or rock wool is installed just below a ventilated
layer of air, and between the rafters of appropriate height.
Certain methods of roofing allow
for more ventilation below the covering.
The installed ventilation layers
not only serve to dry-up any moisture, they also allow air to
move through and thus cool the hot surface.
The aluminum-coated thermal foil used in the roof structure
significantly reduces its heating.
To summarize: Good heat-insulation will
protect the house from heating up if the doors and windows are shaded.
The low heat-holding mass of wooden light-frame houses is, contrary
to popular belief, an advantage during the summer. In extreme heat,
you can quickly cool the building by opening windows during the night
or in the morning"
Valéria Polyák (Szép Házak - 2000.3.) |
