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How’s this for solar gain!

DCcontrarian | Posted in General Questions on

It’s 4:19 on December 23. My outdoor thermometer says 21.0F. I’m in Washington, DC, where the 99% heating design temperature is 21F. Inside my house it’s 71.7F on the first floor, 72.5F on the second floor and 73.6F on the third floor. All of my thermostats are set for 70F. According to my logs the heat has not run in any of the zones since this morning! I have to assume that solar gain (plus occupant activity) are able to keep the house warm on the design day!

Today was clear — but it’s also the second shortest day of the year.

I don’t have a question — I just feel like telling anyone who will listen!

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  1. DennisWood | | #1

    I get it :-) Sounds like a very efficient setup. I also would consider 22 F pretty warm ha. We're seeing -13 F right now.

    Now my guess with all that glass is the heat story is a bit different at night?

  2. Expert Member
    DCcontrarian | | #2

    I'll tell you tomorrow. This is my first winter in this house. It's supposed to get into the single digits tonight. Before today the coldest I had ever seen was 26F.

  3. Expert Member
    BILL WICHERS | | #3

    Not bad! How do things fare in your steamy hot summers though? I know my friends in Baltimore tell me their air conditioner is running maybe 9-10 months out of the year...

    I totally understand sharing your building science accomplishments with like minded people too :-) I was, just this morning, looking at my daughter's little gingerbread house and thinking It looks to be primarily constructed from medium density gingerboard (MDGB :-), but the frosting looks like it would do a pretty decent job of air sealing. The dormer window would complicate attic venting somewhat, and I'm sure glad I don't have to work on such a steeply pitched roof!" :-D


    1. Expert Member
      DCcontrarian | | #4

      I've gone to pre-fab modular construction for all of my holiday treats. I find it saves assembly time and the consistency and quality are much higher.

      Does your friend in Baltimore work in a meat locker? Average high temp in May is 76F and October is 68F, we get about four months of cooling season from June to September. I have a 4' overhang on the southern side of my house and a row of mature poplars that provide shade during the growing season, I only really get direct sunshine in the summer after about 5pm. There will be days when it will be nice all day and then around 5:30 in the afternoon the AC kicks on.

      1. Expert Member
        BILL WICHERS | | #5

        He's in a row house in the Federal Hill area, maybe half a mile from the bay if that. Probably mostly South facing, but things are kinda angled down there and I've never really paid a lot of attention. Maybe the neighbor on the other side of the shared wall heats too much -- that would artificially extend the cooling season if so.

        All this thinking of that area is making me miss crab soup. I haven't been out there in several years. Maybe it's time to pay the expensive overnight shipping and call G and M...


  4. [email protected] | | #6

    Overheating already, lol.

    1. Expert Member
      DCcontrarian | | #8

      73.6 F is overheating?

  5. mikeolder | | #7

    You'd be ok in the east then.. Ive read there's rolling blackouts in North Carolina and Tennessee and people are breaking out fossil fueled generators and stoking wood burning fireplaces!

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