Window insulation

General windows comprise about one quarter of the surface area of exterior walls. Windows often help to identify the architectural style, design and give scale to a building. Just as windows define the character of a building, also the visual impact and appearance of new, replacement windows that do not match or replicate features can be dramatic. Problems in the window structure arise from a lack of maintenance, water and condensation damage, and ultra violet light degradation [48].

Casement replacement conserving the frame:

Replacement are needed not only to improve the appearance of the house, but also to take advantage of modern energy efficient windows that bring about an overall improvement of the ambiance of the house at low recurring cost of heating and cooling. If costumers want to replace just the casement, the frame need to be in a good condition. The replacement of the windows has to be realized by an expert, in fact it need a real know-how in order to avoid impermeable damage.

Casement replacement and new adaptive frame:

In this case (figure 35), the new replaced window is installed within the existing frame. This installation technique is simpler than a full-frame installation, but decreases the size of the window opening due to the nesting of the frames.

With this method the final frame is more massive and loose of translucency because the glazed surface is smaller. There also exist some risks to create thermal an acoustic bridges if the window frame is not perfectly adapted and if there is some interstice during the interlocking of the old and new window frame.

New Window casement (wood or other with double glazing) New window frame

Adaptation profile Compressed foam seal

Figure 35: Casement replacement and new adaptive frame. ADME 2014

EFFICIENT RENOVATORS

54

Complete window replacement:

It is the most powerful technique, and moreover it keep the pre-existing translucency.

Windows are designed for a variety of installation situations and techniques. In a full-frame installation, trim around the old window (interior and/or exterior) is removed and the old window frame is removed completely. The new window is secured to the studs surrounding the window opening, and the trim is replaced.

This operation is more major and expensive than the last one. This technique have to be use when the window frame is in bad condition, it bring a better thermal and acoustic insulation.

Addition of a second window:

In this technique users have to add a second window to the existing window (figure 36). In order to put in place this technique, there must be an adaptable architecture and room configuration. Also in order to have a good ventilation in the building, air inlet have to be created in both windows.

Installation of new triple-glazed windows:

Triple-glazed windows will achieve an excellent thermal insulation and high energy efficiency. Windows with triple shift aren’t suitable for building, which walls are not sufficiently insulated, since even a well-insulated window in the case of incorrect ventilation conduct to moisture damage or even to mold formation. Therefore house owners, especially in older buildings, make sure that the installation with the facade is combined insulation and in good conditions.

Existing window Added glass 12cm between

the glasses

Figure 36: Addition of a second window. ADME 2014

EFFICIENT RENOVATORS

55 About the construction of the Windows, it has to be know that since gas presents a better insulation than air, the spaces between the three discs are filled with gas argon or the more expensive krypton.

By the additional coating of the glass, once again isolated, it only allows a part of the solar energy to the inside so that unpleasant solar radiation is avoided, so that triple glazed windows provide a good indoor climate. In the following figure 37 it can be seen which the differences between single glazing, two panes insulation glass and triple-glazed are:

A triple-glazed window insulates six times more efficient than single glazing. The lower the U-Value break down, the better are the heat insulation properties of a window.

By good insulation values energy consumes decrease and therefore also the heating costs. In the following figure 38 there can be seen a general buildup of a triple-glazed window and the features it presents.

Figure 37: Comparison of different glazing systems. BMWI 2014

Figure 38: Triple-glazed buildup scheme. BMWI 2014

EFFICIENT RENOVATORS

56

Other ways to improving the insulating properties

: [49] There are many ways that windows can be insulated at night, or when a particular room is not being used in winter:

o Curtains: there are many ways that curtains can be made more effective. Users can use thicker material, or even a quilted material with an insulating filling. Adding a reflective covering to reflect heat back into the room, making sure that escaping down-draughts from between the window and the curtains are reduced by:

o Using a pelmet which fits well around the top of the curtain.

o Ensuring that the sides of the curtain connect as well as possible to the sides of the frame and to themselves in the middle.

o Providing a shelf or sill for the seam of the curtains to lie on.

o Ensuring that if a radiator does not go up behind the radiator does not go up behind the curtain (either tuck the curtain behind the radiator or fit a shelf).

o Blinds can be made to fit in slides at the side of windows, so they are easier to seal than curtains. The bottom of the blind can simply rest on the still and a simple flap can contain the top. Blinds, being more rigid than curtains, can more easily be treated with special coatings or incorporate a thin insulating film.

o Shutters: these can be designed to be both insulated and tight-fitting, and hinged so that they fold back and to the side when not in use. However these will almost certainly need to be specially made.

o Pop-in insulation panels, these are a cheap and effective solution.

A ridged sheet of insulation, preferably one that is a sandwich of aluminum foil and card (in order to protect the foil), is cut to size and fitted to exactly the inside of the frame and the side facing the room covered with fabric. The main disadvantage is the extra work required to place them each time you wish to insulate the

EFFICIENT RENOVATORS

57 window. One solution is to have them hinged at the top so they can swing up out of the way and be attached to the ceiling by hook.

o External security and insulation blinds. These are made first and foremost for security. However they have the advantage that they are placed on the outside of the house and so do not interfere with internal arrangements of rooms. They would be worth thinking about if costumers are having external insulation fitted, or a real security problem in the neighborhood, or the facade of the house has little aesthetic significance.

In document RENOVATION CENTER (Page 53-57)