[net.general] Energy Efficient Window Design Conte

courtney (01/09/83)

#R:dvlcn:-9300:hp-pcd:5000008:000:2292
hp-pcd!courtney    Jan  8 17:55:00 1983

In response to the initial premise of Dave's posting
"As you ALL know...", a couple of comments:

 *** "Energy efficient houses" do not have a chimney. ***
   If they have the facility to burn wood, they do so
   with a wood-burning stove which uses a flue and gets
   its combustion air from outside (though a small duct).

 *** Even in very well-built houses (ie., built with
     energy efficiency in mind), up to half of all heat
     energy loss is due to infiltration (air leakage
     through walls, around doors and windows, etc.).  ***

   In less well-built or older homes, the energy loss
   due to infiltration can exceed 70% of the energy
   budget of the house.  Consideration of this reality
   leads to construction ideas such as the following:

      -build the home with a plastic lining between the
       insulation and the interior siding of all walls,
       ceilings, and floors (the vapor barrier must be
       on the INTERIOR SIDE of the insulation to avoid
       moisture problems, in agreement with the fact
       that moisture is flowing from the inside of the
       building to the outside).       

      -to the greatest degree possible, locate all
       plumbing and wiring (including sockets and
       switches) in interior partitions, rather than
       walls which share a side with the great outdoors.
       This minimizes interference with the insulation
       and vapor barrier which reside in these exterior
       walls.

      -now that a building has been created which is
       completely unlivable due to domestic pollutants
       and the lack of fresh air (if there is any of that
       outside), one or more (passive) air-to-air heat
       exchangers are installed at appropriate locations
       in the building to provide ventilation while
       recovering upwards of 70% of the thermal energy
       in the exhausted air!

      (By the way, an "adequate" ventilation rate for a
       room with people smoking is about 10 times that
       which is considered adequate for rooms without
       people smoking...)

   *** As to doing better with radiant energy lost from
       windows, I have not seen a system which does not
       have any of the drawbacks that Dave listed.      ***

                          Courtney Loomis