yeah good afternoon youtube it was about six or seven years ago i put together this in window
solar air heater and what it is it's a double wall polycarbonate panel and it's got a fan here
in the bottom corner and then there's one up in the upper corner the intake is up here and then
basically the air comes down around through this labyrinth and then it's blown out through
this 120 millimeter pc fan over there so when i built this i made a series of videos
i don't think i did a very good job explaining how this works because i've got a quite a number of
comments and questions over the years and i wanted to do this update video to explain a little better
so number one this has been installed and operating every day since i built it
so i'm still using it it's running today there's warm air coming out of there so
i put a picture in of the heater that was shown on the this whole house show
that kind of was the inspiration for this although mine is quite different
so that heater that was shown on this old house was a stand-alone unit it was basically
a hot air panel with a little solar panel and a fan on it that sat in the middle of a room
and you would have sunlight shine on the panel it would heat the air and then the fan would blow it
out like this one does now that particular device is basically worthless it doesn't do anything
that's the common question that i get is that the heat that's come through that window to heat
the air has already come into the room and that's the case even with my heater so this
device here this thing in the window doesn't really capture any additional heat it doesn't
make heat i mean the heat that's come in here and is blowing out that fan is already in the room
if i took this thing out the same number of watts of heat would be coming in the difference is
heat flows two directions and at night this heater is a very good insulator like i said
it's double wall polycarbonate panel and then it's got an air gap in the double wall panel
and then there's two air gaps one before the metal mesh and then one on the other side of the metal
mesh then there's a single pane glass window so this is an older house it was built in the mid 50s
and you can see it's just single pane glass with aluminum frames so that by definition is r1
insulating value is a single pane of glass well this double wall polycarbonate panel
is about r2 and then the the air gaps in there between the metal mesh i think it's about a half
inch on each side that's probably another r1 or so so if you add up all the insulating value of this
heater it's about an r4 for heat going out now for heat coming in because i'm blowing air through
there it's like r1 coming in the heat comes easily through the window it gets captured and then it
gets blown out into the room here so the way to really describe this it's like a thermal diode
the heat comes in relatively easily there's r1 for heat coming in and it's r4 for heat going
out and in the winter most of the time it's cold and dark outside so having something that limits
the heat going out is better than having a an open window checked here real early in
the morning it wasn't particularly cold last night only got into the middle 40s i think
here's the window sill so i wanted to check the temperature so we've got about 62 and if i go
over here to the plain glass part i get about 56 57 and you can definitely feel just a cold
down draft on my hand right there where over here no feeling of cold at all so i think that
help keep the heat in at night and keep the cold air out now of course i could have some thermal
curtains there i could lower the curtains at night raise them when the sun is shining but that's
a lot of work you got to remember to open the curtains on the sunny days and close the curtains
as the sun sets this thing runs automatically it triggers off of a solar panel here that's on the
outside if there's enough light on that panel to run the fan it runs the fan the other thing
is because this is a very good insulator i leave it in place in the summer because in the summer
we get the afternoon sun comes right in this window and makes it really hot and
uncomfortable in here but this reflects most of the heat out and then the the other minor
point is on the other side of this window about six feet away is my neighbor's bedroom window
again i could use the the shades that i have i could lower these that's what i used to do was
lower them at night raise them during the day with this i can just leave it in there all the time and
the fact that i can't see into my neighbor's window is a big benefit i've just left this in
place like i said this is single pane aluminum frame windows the common question is well why
don't you just put in double pane triple pane windows i probably will one day to do new windows
it makes sense to do all the windows in the house it doesn't make sense just to do one window i
might as well do all the windows and that's a fair chunk of money to do all the windows in the
house like i say i'll probably do it at some point like if the uh gas company came out with a rebate
i don't get 25 back i would jump on it right away there's no rebates right now and this
costs a lot less than a new window and i could do it right now and i could just do this one window
and it's been working quite well so yeah just to summarize so this in window heater doesn't capture
any additional heat that wouldn't have come through the window already if i took this thing
out there would be no change in the amount of heat coming into this room but if i take this out
there's four times as much heat being lost to the outside as there is if i leave this in place
and again this is automatic i don't have to raise and lower curtains or do anything i just leave it
like this the other thing i've done is put some bubble wrap on the window just so that in the
older months i lose less heat to the outside again i don't really care because i'm just
looking into the neighbor's kid's bedroom window this thing it blocks the view it gets the heat in
it limits heat loss and i've just left this in place for six or seven years now i would only take
this thing out if i were to replace these windows and get some double pane windows i heat the house
on solar heat my main solar panels kind of cut off in the late afternoon but this thing keeps
going until the sun drops over the house next door as always thanks for watching