Objective
The aim of the project is to demonstrate the energy savings that can be achieved by utilising a movable window insulation blind. Total energy savings are expected to be 15 TOE/yr; payback 4 - 5 yrs.
The results obtained indicate that a substantial overall saving in energy is possible in the range of 13% to 20%. The savings due to reduced air infiltration were an average 27% greater than that due to lower building envelope losses and would be even greater in the case of houses which had warped or ill-fitting windows.
Having measured the energy inputs in each of the three houses during the two heating seasons and having adjusted the total energy inputs in the second heating season to correspond with a similar degree day heating season as had occured during the first heating season a comparison of the results obtained indicated the following savings due to the window insulation.
House nr 1: 2,043 kWh
House nr 2: 5,150 kWh
House nr 3: 4,540 kWh
Savings per m2 of window covering were:
House nr 1: 65 kWh
House nr 2: 120 kWh
House nr 3: 94 kWh
Detailed analysis using known U values for the different elements of the houses and also the thermal resistance of 0.402 m2 deg. C./W which had been measured for the window covering by means of a guarded hot box yielded the following breakdown of the savings between fabric savings and ventilation savings.
TOTAL SAVING kWh FABRIC SAVING kWh VENTILATION SAVING kWh
House nr 1 2,043 880 1,163
House nr 2 5,150 2,320 2,830
House nr 3 4,540 1,995 2,545
Expected cost of the insulation is now from 50-75 UKL
House nr 1
---------- : is a typical modern dwelling house. It is insulated to the standard set down in the current Irish Building Regulations having the following U values :
0.4 W/M2/deg.C. for roofs
0.6 W/M2/deg.C. for external walls and floors
It has 40 m2 of external double glazing in metal frames which have a U value of 3.3 W/M2/deg.C.
House nr 2
---------- : is a nine bedroomed guest house. It also has been insulated to current Irish Building standards except for the absence of floor insulation. It has 60 m2 of external single glazing in wooden frames which have a U value of 4.7 W/m2/deg.C.
House nr 3
---------- : is a purpose built solar house. It is insulated to the following standards :
0.44 W/M2/deg.C. for walls.
0.4 W/M2/deg.C. for roof.
0.6 W/M2/deg.C. for floors.
The external windows in this house are also double glazed and have wooden frames. The southern wall is a mass wall 350 mm in thickness. It has been painted Tile Red externally. It is not permanently insulated but it is fronted by a single glazed conservatory along its entire length. The conservatory is insulated on its internal side by the use of the window insulation during the night. The window insulation consists of a 6 mm layer of fiberfill on each side of a layer of reflective plastic which acts as a vapour barrier and two outer layers of cloth. All five layers are ultrasonically welded together into a quilted pattern. The shade itself provides an R value of about 0.7. The sides of the shade are bonded around a 6 mm cord which runs down side tracks making a very effective seal. The lower edge of the quilt contains lead weights and a compression foam strip to provide a good seal on the bottom edge. The top of the quilt has an extra roller behind the main one to keep the shade firmly against the window head casing. It is expected that the U value of the windows will be reduced to 2.3 in the case of house nr 1, 3.6 in the case of house nr 2 and the average reduction in the case ofhouse nr 3 should be 2.4 W/M2/deg.C.
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
CO. Galway
Ireland