Question:
I am wondering if there are any reliable – and reasonably bright – LED light bulbs available yet to replace CFL’s?
Chris Burns’s Answer:
There are no screw-in LED’s that we can recommend at this point but the industry is moving very fast, so we hope to see some high quality screw-in products within a year or two. The problems have been with light output, color temperature and especially durability. LED’s are not inexpensive so it is very disappointing when they fail prematurely, which has been a problem. http://www.efficiencyvermont.com/pages/Business/HVAC/Lighting/LED/ gives a good overview about LED technology and http://www.efficiencyvermont.com/stella/filelib/LED_EligibleProductsList_Residential_052909.pdf provides a list of LED products currently eligible for rebates from BED and Efficiency Vermont.
Question:
I live in a condo, and my slider doors are metal framed, face south, and look like the original ones. I place foam padding on the floor and draw the vertical blinds at night to cut down on the winter draftiness. During winter days, I open up the blinds to let the sun pour in and then need not turn on my heater until 9 p.m. some days. In addition to being leaky, my current sliders have glass that is slightly “stained” between panes. I’m thinking of doing some replacement. The condo board has decided to only allow one make of replacement slider. It is part plastic (even the bottom molding) white in color, and the frame covers more surface area (less glass exposed). Since there are about three inches of frame at the top of the slider, part of my view of the sky would be blocked with the specified doors. While I understand that less glass surface can be a good thing for keeping heat in, am I not also losing on solar energy reaching my interior? If I were to simply replace the glass in my existing sliding doors, would that be an opportunity to “seal” the doors better within the existing metal frame?
Chris Burns’s answer:
A friend, who had a similar two-bedroom condo whose slider faced east, asked a similar question. He replaced the door and likes it, but he took my advice and added more attic insulation, and weather-stripped and latched the attic hatch, which was uninsulated and very leaky. He reports his place is warmer in the winter and cooler in the summer. He relies totally on the Rinnai heater and has found the condo recovers more quickly from the temperature set-back when he comes home from work. BED’s John Lincoln would be happy to take a look at your place for similar opportunities. John and I do not think the glass replacement idea would be worth it as it would only address heat loss through the glass, not what is coming through the moving parts of the door and at the points where the slider is attached to the rough opening on the wall. As important, it would not address the thermal bridging issue, which good sliders do. My sense is that you would be better off with an Energy Star-rated slider. I would not expect huge savings from full replacement as the slider is a relatively small percentage of the overall heat loss of the building. The attic, exterior walls and an uninsulated slab are much higher contributors. You may get a 4-to-8 percent savings on your heating costs with a good slider. You may be eligible for a tax credit. Check out www.energystar.com for some useful information.
