Hello,
I just registered because I wasn’t sure where else to post my question.
I don’t own a house, but a condominium in a multi-family building from the 1930s (worker housing). For years, I had the original wooden frame windows, but in autumn 2015 I decided to have new PVC windows installed. These are double-glazed windows with a 5-chamber profile system and performance values of Ug=1.0 and Uf=1.3 (according to the contract).
Regarding noise insulation, the difference is really like night and day. However, I’m not entirely sure about the thermal insulation.
My apartment is heated by a gas boiler, which I can control via a panel in the bedroom that also measures the temperature. During the heating season, I’ve noticed the boiler keeps turning on repeatedly, like it did before. So the heat doesn’t seem to be retained effectively. Today, I carefully checked the heat loss: according to the panel, the temperature dropped by 1.5°C (2.7°F) between 9:30 a.m. and 12:00 p.m., after the heating period ended. My minimum temperature outside the heating season is 19°C (66°F), and during the heating season it’s 21°C (70°F). The outdoor temperature today is about 2°C (36°F). I feel the heat loss is rather high. I had also expected the boiler to stay off longer after heating up—after all, most energy should be lost through the windows, and I thought the new windows would insulate much better. Since I’m not very familiar with the technical details, I wanted to ask if there are simple ways to check the insulation performance of the windows (e.g., using a laser thermometer on the glass).
My apartment is located on the first floor and shares walls with neighboring units on all four sides, so only the front and courtyard sides are exterior walls. Of course, I don’t know how well the apartments above and below heat. The windows were installed according to RAL standards.
I would be very grateful for any tips...
I just registered because I wasn’t sure where else to post my question.
I don’t own a house, but a condominium in a multi-family building from the 1930s (worker housing). For years, I had the original wooden frame windows, but in autumn 2015 I decided to have new PVC windows installed. These are double-glazed windows with a 5-chamber profile system and performance values of Ug=1.0 and Uf=1.3 (according to the contract).
Regarding noise insulation, the difference is really like night and day. However, I’m not entirely sure about the thermal insulation.
My apartment is heated by a gas boiler, which I can control via a panel in the bedroom that also measures the temperature. During the heating season, I’ve noticed the boiler keeps turning on repeatedly, like it did before. So the heat doesn’t seem to be retained effectively. Today, I carefully checked the heat loss: according to the panel, the temperature dropped by 1.5°C (2.7°F) between 9:30 a.m. and 12:00 p.m., after the heating period ended. My minimum temperature outside the heating season is 19°C (66°F), and during the heating season it’s 21°C (70°F). The outdoor temperature today is about 2°C (36°F). I feel the heat loss is rather high. I had also expected the boiler to stay off longer after heating up—after all, most energy should be lost through the windows, and I thought the new windows would insulate much better. Since I’m not very familiar with the technical details, I wanted to ask if there are simple ways to check the insulation performance of the windows (e.g., using a laser thermometer on the glass).
My apartment is located on the first floor and shares walls with neighboring units on all four sides, so only the front and courtyard sides are exterior walls. Of course, I don’t know how well the apartments above and below heat. The windows were installed according to RAL standards.
I would be very grateful for any tips...
How large are the windows? If they are small, the effect will naturally be limited – in other words, is there more wall area or window area?
There can be many reasons why the heating cycles on and off the way it does. Is it controlled solely by a thermostat?
Do you have consumption figures? While your heuristic methods are understandable, it’s quite possible they may not be meaningful… especially since you don’t even know how long the temperature drop lasted with the old windows.
P.S. If the windows are truly airtight, hopefully the importance of ventilation has been explained – or even better, consideration has been given to a decentralized mechanical ventilation system with heat recovery!
There can be many reasons why the heating cycles on and off the way it does. Is it controlled solely by a thermostat?
Do you have consumption figures? While your heuristic methods are understandable, it’s quite possible they may not be meaningful… especially since you don’t even know how long the temperature drop lasted with the old windows.
P.S. If the windows are truly airtight, hopefully the importance of ventilation has been explained – or even better, consideration has been given to a decentralized mechanical ventilation system with heat recovery!
I never really gave much thought to the old windows because I didn’t expect much from them anyway. That’s different now—I’m paying much more attention. I want to find out if my doubts are justified or unfounded.
The windows are characteristically large for an older building, but there’s definitely more wall than window. Except in the bedroom, where a two-leaf, fully glazed balcony door leads to the balcony. The dimensions there are 1120 x 2410 cm (1120 x 2410 cm (440 x 95 inches)) plus 520 x 1410 cm (520 x 1410 cm (205 x 56 inches)) (window next to the balcony door). In the living room, the dimensions are 1650 x 1470 cm (1650 x 1470 cm (650 x 58 inches)) plus 600 x 1470 cm (600 x 1470 cm (236 x 58 inches)) (three-leaf window). Both rooms are about 12–14 m² (130–150 ft²) each, and the entire apartment is about 44 m² (470 ft²).
I ventilate once or twice a day for about 5 minutes each time—I was told this should prevent mold, etc. What do you mean by controlled residential ventilation?
The windows are characteristically large for an older building, but there’s definitely more wall than window. Except in the bedroom, where a two-leaf, fully glazed balcony door leads to the balcony. The dimensions there are 1120 x 2410 cm (1120 x 2410 cm (440 x 95 inches)) plus 520 x 1410 cm (520 x 1410 cm (205 x 56 inches)) (window next to the balcony door). In the living room, the dimensions are 1650 x 1470 cm (1650 x 1470 cm (650 x 58 inches)) plus 600 x 1470 cm (600 x 1470 cm (236 x 58 inches)) (three-leaf window). Both rooms are about 12–14 m² (130–150 ft²) each, and the entire apartment is about 44 m² (470 ft²).
I ventilate once or twice a day for about 5 minutes each time—I was told this should prevent mold, etc. What do you mean by controlled residential ventilation?
Yes, exactly that... depending on the wall construction, this might be insufficient—although the risk is probably lower with a complete sandwich panel setup.
So, 12 sqm (130 sq ft) of windows – temperature difference from outside 2°C (36°F) to inside 19°C (66°F). If your U-value improves from 2.5 W/m²K to 1.2 W/m²K, you save 1.3 W/m²K * 19 K * 12 m² = 296 W, or over 4 months 296 W * 120 * 24 h = 850 kWh of heat energy, which equals about 85 cubic meters (3,000 cubic feet) of gas * $0.70 = $60 per year in heating costs.
All very approximate assumptions, but roughly correct. If you save $40, that’s still plausible. If your annual costs are higher than before, then not.
Just a rough estimate for your assessment.
So, 12 sqm (130 sq ft) of windows – temperature difference from outside 2°C (36°F) to inside 19°C (66°F). If your U-value improves from 2.5 W/m²K to 1.2 W/m²K, you save 1.3 W/m²K * 19 K * 12 m² = 296 W, or over 4 months 296 W * 120 * 24 h = 850 kWh of heat energy, which equals about 85 cubic meters (3,000 cubic feet) of gas * $0.70 = $60 per year in heating costs.
All very approximate assumptions, but roughly correct. If you save $40, that’s still plausible. If your annual costs are higher than before, then not.
Just a rough estimate for your assessment.
Exactly – energy-efficient upgrades often just barely pay off, which is probably how the prices are calculated (I assume quite boldly).
€60 (about $65) in annual energy savings – but of course, there are additional benefits like increased comfort, higher property value, and properly functioning windows.
Feel free to review the calculation critically again, but it shouldn’t be entirely wrong.
€60 (about $65) in annual energy savings – but of course, there are additional benefits like increased comfort, higher property value, and properly functioning windows.
Feel free to review the calculation critically again, but it shouldn’t be entirely wrong.
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