Replies

1. 
   Brian_Smith | Feb 25, 2002 07:23am | #1

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   put the HEED program to use. found out that there will be an $800 annual return on investment if i replace the single glazed windows on a client's house with dual glazed.

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   FredL | Feb 26, 2002 03:11am | #2

   *Dear Brian,Thanks for the link. I have greatly benefited from the use of energy modeling software. But it's important to understand their limits. They are most valuable for comparing the relative merits of competing thermal protection measures. I think you've found an interesting example. Typically, window rehabs will only knock 5-10% off the space heating load of a single family house. In the cases where an $800 savings is really possible with new glazing, cost of heat is way too high. The owners should get off electric resistant heat or address combustion efficiency issues first.Be very careful about promising ROI from any thermal renovation. There are lots of reasons for this, not the least of which is occupant behavior. We can talk about those more if you like.Cordially, Fred

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   Brian_Smith | Feb 26, 2002 07:13am | #3

   *true enough fred, on all counts.surely more valuable (and only intended) as a relative guage. but it is ucla school of architecture and the data comes from the client's own utility co; hence, no better projection possible.i believe it was so significant because:-2001 rates were at their highest in So Cal (database used).-client at home 24/7 (retired, elderly).-tstat @ 80 during winter and 65-70 during summer.-the location is "high desert". nightime winter temps @ 10s-20s typical (no cloud cover) and summer day temps above 95 typical.-tiered pricing raises rates by %100 at their peak (tier 4). this client was reaching tier 3 pricing.-half of the house's windows, the patio doors, and an unused fireplace are all located around the LR/DR that have 11' high cathedral ceilings and no ceiling fan to redistribute warm air mass. wall insulation is standard r-14. ceiling r-value unknown (assumed standard). gas (not energy star) heater with LR/DR registers located furthest from heat source. i believe the ducting to be same diameter to all registers. -i only varied nature of window glazing (from 1-glaze to 2-glaze, low e)i would have included a screenshot but, alas, don't have my favorite graphics programs (2020 or gimp) on this computer |:-(>|user behavior. laughable (already given tstat settings).the elderly gentleman (more temp sensitive) sets the tstat at extremeshis daughter and her fianceehis teenage granddaughter (actually the sensible albeit selfish one - tries to keep tstat "normal" but reopens her register wide open after i adjust it) 7 year old grandson - in&out, doors left open,...chimney unused (found baffle wide open - been that way all winter).southern exposure windows and french doors have shades closed 24/7 during winter. as you can see, the windows and some free advise is going to make some difference.the reason that the LR blinds are closed is that the window glare interferes with the client's television viewing enjoyment. i've wondered if a low e film would be better than manufacturer's coating in this regard. are they tinted? would that make a difference anyways? opinions?brian

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   Brian_Smith | Feb 26, 2002 07:29am | #4

   *fredl,if you give the heed program a test run, let me know how this program compares to others that you use.i came across these ucla programs while looking for actual design programs for hvac systems and baseboard heating. best of this bunch appears to be HVAC-Calc ($389 or $39/home). chief architect fails. any recommendations appreciated.brian

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   FredL | Feb 26, 2002 08:22am | #5

   *Dear Brian,Thanks for putting up the data. I was hesitant to ask, just showing up on the doorstep and all. Maybe we can have some fun with this.Best, Fred

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   Cloud_Hidden | Feb 26, 2002 11:54pm | #6

   *Brian,My energy guru says, "thanks man thats totaly cool, im doing a solar bid now."Jim

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   Brian_Smith | Feb 27, 2002 07:47am | #7

   *jim,let me know what he thinks after he tinkers with it.okay?brian