Posted by K. Jones on July 23, 2004, 7:25 pm
I've recently purchased a one acre lot that I intend to build a home on,
starting in about a year. I'm exploring the feasibility of building an
The lot is in Southern Ontario, Canada, sorta midway between Toronto and
Niagara falls. The lot is well sheltered, ringed with pine/cedar trees,
averaging about 20 feet in height. It's dead-calm in the middle of the lot,
even with the wind blowing hard enough to bend the tops of the trees over
significantly. My (evolving) idea so far is incorporating passive solar,
and active solar thermal, a wind generator for electricity, with a diesel
powered generator for backup/supplement.
I'm not new to solar PV, or solar thermal. I currently have a 6 panel
Norsun thermal system that I intend to take with me (they're not currently
"permanently" setup, and it's mostly dismantled in prep for moving to temp
quarters until the house is built). With the design&size of the house, I
expect the thermal panels to provide about 70% of my heating needs (I will
be likely be using a forced air system, hot water feeding a heat exchanger
in the air plenum, as I expect to have some sort of furnace
(oil/propane/whatever to be determined yet, though most likely oil, if using
diesel generator backup)).
What I have *zero* experience with is wind generators. I'd really like
to hear any comments / suggestions / criticism from current/past
owners/users of wind generators.
I currently have no idea of wind availability at the site, so I've purchased
an anemometer with very rudimentary data storage, which I'll be mounting on
a 60 foot pole. I'll be able to collect data for about 9 months before I
actually begin to build, so hopefully I'll have some idea of the feasibility
of potential wind generation. The wind+diesel generation is planned for the
first part of the construction, to, well, supply power for the construction
of the house.
This is out in "the country", where I can hear my neighbor 1/4 mile down
the road cough on a calm, still, night. What kind of noise levels would I
be looking at for a smaller, one household, type system? Am I out of my
mind thinking about a forced air heating system with wind generation? What
do you consider reliable (mechanically) turbine/generator manufacturers?
Reliable charge controllers, inverters etc? If you could build your wind
generation system all over again, what would you do different?
I'd also like to hear from anyone who uses *small* diesel generators.
Has anyone collected any *real* data for quantity of fuel used per kWh
produced? I've done some theoretical projections/models, however, "real
world" data/experience would kick the crap outta any guestimated
efficiencies I plug into my spreadsheet.
(btw anyone done this with a VW 4-cylinder pre "tdi" diesel engine??).
Any and all comments, positive and negative, (except for the "isn't
economically feasible/smart to do if you have grid power nearby" type) are
most welcome...........I'm well aware how to calculate payback schedules, et
al, but that has very little to do with the drive behind my reasons for
wanting to do this.....it's for the engineering
challenge/keep-me-entertained/perverse-satisfaction/hobby kinda thing.
Posted by Rex B on July 23, 2004, 9:00 pm
|| I'm not new to solar PV, or solar thermal. I currently have a 6 panel
||Norsun thermal system that I intend to take with me (they're not currently
||"permanently" setup, and it's mostly dismantled in prep for moving to temp
||quarters until the house is built). With the design&size of the house, I
||expect the thermal panels to provide about 70% of my heating needs (I will
||be likely be using a forced air system, hot water feeding a heat exchanger
||in the air plenum, as I expect to have some sort of furnace
||(oil/propane/whatever to be determined yet, though most likely oil, if using
||diesel generator backup)).
Have you looked at incorporating radiant heat tubing in the foundation?
Not familiar with the Norsun system.
Texas Parts Guy
Posted by K. Jones on July 24, 2004, 1:22 am
Hi Rex, thanks for your reply.
The Norsun is an older, evacuated flat-plate type of thermal panel. There
is a thin, "hollow", evacuated flat plate about 3-1/2 ft X 7-1/2ft under a
sheet of glass. The plate meets a header at the top, where the heat
exchange takes place. The idea is the refrigerant gas boils, travels up
towards the header, where it condenses on the header pipe carrying the
closed-loop fluid circulating between storage and the panel. Thus you only
have a small amount of glycol/water mix circulating through the system. One
"selling feature" touted was it as a "solar-diode", meaning that even if
your glycol pump ran all night, you wouldn't radiate your stored heat back
out the collector. I bought the system used, about 8 years ago, I don't
know how old this particular "technology" is.
The house is going to be 2 stories, with a full basement, "normal"
stick-framing. The floors are going to be a mix of carpets, wood, ceramics,
etc., so it really doesn't lend itself to an under-floor radiant heat type
system. I have been mulling over a zoned hydronic system, with individual
room thermostats. (many of the bedrooms will only be "occupied" a couple of
days a week). One of the reasons I like the forced air heat-exchanger
system, is (a) I already have all the equipment for such a set-up, and (b)
I've been fooling with my own absorption-type refrigeration for a few years,
and should I get a satisfactory working design, I'd like to incorporate it
into the house, but the forced air system isn't carved in stone.
Posted by N. Thornton on July 24, 2004, 11:06 am
What an opportunity. I know nothing about your climate, but if you
need cooling a very cost effective means is often to lay a pipe
underground and draw air in through it with fan. You'll need to look
elsewhere for figures, I've nothing to hand. If condensation in the
pipe is a problem you may want to use a heat exchanger on the indoor
Solarthermal panels can form some part of your roof covering, so
although they cost you lose a bit of cost of the usual roof covering.
Night time forced ventilation is a very cost effective way to reduce
day time temps.
Loft ventilation drops house temps in day.
Climbing plants on a wire frame near the house can reduce house temp
in day too by shading: deciduous plants dont lose you winter sun. The
separate frame means no problems with decorating, repairs, or plant
If theres one thing I'd want to do more than anything, it would be to
have a proper computerised heating and cooling system. There is so
much opportunity to improve temps by doing nothing more than opening
and closing ventilation at the right times, ditto fans. This could be
controlled with a rock stable computer, like an old BBC for example.
No way use a PC. You'd need sensors everywhere, and need to program
the machine. I've had at most 10C reduction in summer doing it by
hand, no computerisation, no proper monitoring, so doing it properly
would likely give you better. Also it extended the unheated time of
the year by adding 2-3C on to indoor temps.
Theres lots of stuff you could do there. Wind would not come high on
my list though, as in terms of result per input, its far behind the
Just for the hobby angle it would be nice to have a solar cooking ring
in the kitchen. I worked out how to do it.
BTW you can still use UFH to deliver a percentage of your heat if you
want. I've never had UFH but have heard glowing reports from folk who
fitted it. Your choice of floor coverings dont preclude it. One plus
with UFH is it takes much lower temp water, so can be run off solar
panels more of the year.
Posted by K. Jones on July 24, 2004, 4:57 pm
My biggest concern with "earth tubes" is mold, but your idea of a heat
exchanger would solve that problem.
They would help in both summer, and winter here.
I hope to use plants and trees to help with summer cooling, like you said,
deciduous plants won't interfere much with winter heating.
When I first envisioned the project, I imagined using an eprom with a basic
language interpreter as the driver for the controls, but
now, PLC's are dirt cheap, and their programming is pretty simple nowadays.
I'm looking a wind as a means to providing electrical power, provide noise
and mechanical reliability isn't too much of an issue
(and provided I can get the local building department to play ball).
A "solar cooking ring" in the kitchen? I'd like to hear more about that!
When I envision under floor heating, all that comes to mind is a grid of
pipework buried within a concrete slab. I'm having a hard time envisioning
system with a wooden joist type construction.