which way to orient greenhouse
Karen Kolling
>I'm planning to build an 8x12 greenhouse and pouring of the slab will
>occur soon. Assuming the usual peaked roof along the longer axis, and
>aisle down the middle, is it better to orient the long axis north-south or
>east-west ? ? [It will be interesting to see how this vote goes i.e. to
>get n+1 opinions, ask n experts ]
North-South, I would say, then the plants get the most
sunlight. Drawing omitted for lack of sufficient initiative
to do it with |s and -s
Rick Gordon
Kolling) wrote:
I had thought the same thing, but have been doing a bit of research on the
subject lately and found some contrary information. Basically I think that
it has to do with latitude and what time of the year you intend to use it.
Considering that I'm in Seattle, and that I've just been reading the UBC
Guide to Gardening in British Columbia section on greenhouses, I think that
East/West orientation is best for up here.
The ideal greenhouse would be a 3/4 sphere facing south. In the summer
there is no problem with lack of light. In the winter however the low sun
angles and short day lengths greatly reduce the light levels, making
non-assisted growing impractical (here). So really the times we most need
one is spring and fall, and to keep the glazing surface as perpendicular to
the sun as possible during these periods, the optimium orientation is
East/West.
This may not be true in Mountain View, nor wherever llnl.gov is, but it's
worth considering the basis for such an orientation.
Hope this helps,
Rick
aka rgo...@adobe.com (Seattle office)
Don Pomplun
Rick Bogren
>From: kol...@adobe.com (Karen Kolling)
>Subject: Re: which way to orient greenhouse
>Date: Thu, 6 Oct 1994 23:50:32 GMT
Well, all the greenhouses at the University of Illinios College of
Agriculture are oriented east-to-west.
Rick
****************************************************************************
Rick Bogren e-mail: r-bo...@uiuc.edu
Media/Communications Specialist voice: (217)333-9439
College of Agriculture
University of Illinois at Urbana-Champaign
*****************************************************************************
Darren McLaughlin
: In article <pomplun-0610...@k2hug.llnl.gov> pom...@llnl.gov (Don Pom
plun) writes:
: >I'm planning to build an 8x12 greenhouse and pouring of the slab will
: North-South, I would say, then the plants get the most
: sunlight. Drawing omitted for lack of sufficient initiative
: to do it with |s and -s
I agree.. north south...
Eric J. Forbis
>In article <1994Oct6.2...@adobe.com> kol...@adobe.com (Karen
Kolling) writes:
>>In article <pomplun-0610...@k2hug.llnl.gov> pom...@llnl.gov (Don
Pomplun) writes
:>>>I'm planning to build an 8x12 greenhouse and pouring of the
slab will>>>occur soon. Assuming the usual peaked roof along the longer axis,
and>>>aisle down the middle, is it better to orient the long axis north-south
or>>>east-west ? ? [It will be interesting to see how this vote goes i.e. to
>>>get n+1 opinions, ask n experts ]
>Well, all the greenhouses at the University of Illinios College of
>Agriculture are oriented east-to-west.
The greenhouses on the St. Paul Campus of the University of Minnesota are also
oriented east-west.
Regards,
===================================================================
Eric J. Forbis forb...@gold.tc.umn.edu
-------------------------------------------------------------------
"Conscience, they tell us, is the creature of prejudice, but I know
from experience that conscience persists in following the order of
nature in spite of all the laws of man." _Emile_, Rousseau
===================================================================
Malcolm Bebb
forb...@gold.tc.umn.edu (Eric J. Forbis) wrote:
> In article <bogren.18...@cc-mail.agcomed.uiuc.edu> bog...@cc-mail.agcomed.uiuc.edu (Rick Bogren) writes:
> >In article <1994Oct6.2...@adobe.com> kol...@adobe.com (Karen
> Kolling) writes:
> >>In article <pomplun-0610...@k2hug.llnl.gov> pom...@llnl.gov (Don
> Pomplun) writes
> :>>>I'm planning to build an 8x12 greenhouse and pouring of the
> slab will>>>occur soon. Assuming the usual peaked roof along the longer axis,
> and>>>aisle down the middle, is it better to orient the long axis north-south
> or>>>east-west ? ? [It will be interesting to see how this vote goes i.e. to
> >>>get n+1 opinions, ask n experts ]
Sounds like a fun one.
The UK Consumer's Association looked at his a while ago, but I don't fully
remember the outcome. The bit I do remember, which was in the context of
lean-to greenhouses, was that getting the morning sun was important, more
so than getting evening sun.
Given that the middle of the day is typically hottest, having an east-west
orientation implies that the greenhouse will be slow to heat up in the
morning and will get very hot at midday, the extent depending on your
location.
Greenhouses can get too hot for some plants - ventilation is usually
essential - and an east-west orientation will maximize the temperature
_range_. In some areas that might be what you need. If there is
(relatively) plenty heat around at midday, why arrange your greenhouse to
maximize solar heat when there's plenty and minimize it when there's
relatively little (early a.m, late p.m)?
W.r.t to the university greenhouses mentioned, was their orientation
determined by specific considerations, or for the same reason that mine has
an east-west orientation - because it seemed a good idea at the time?
If I do it again, or need to reposition my greenhouse, I will reconsider
the orientation and think about a north-south orientation. However, if you
live in a built-up area, you should also take into account factors such as
shade from houses, fences and trees, which will have a much greater effect
when the sun is low.
Just my two penn'orth. Please post your final decision.
Malcolm be...@ferndown.ate.slb.com (Usual disclaimers apply)
Tech Pubs be...@embetech.demon.co.uk
Rick Bogren
>Given that the middle of the day is typically hottest, having an east-west
>orientation implies that the greenhouse will be slow to heat up in the
>morning and will get very hot at midday, the extent depending on your
>location.
>Greenhouses can get too hot for some plants - ventilation is usually
>essential - and an east-west orientation will maximize the temperature
>_range_. In some areas that might be what you need. If there is
>(relatively) plenty heat around at midday, why arrange your greenhouse to
>maximize solar heat when there's plenty and minimize it when there's
>relatively little (early a.m, late p.m)?
>W.r.t to the university greenhouses mentioned, was their orientation
>determined by specific considerations, or for the same reason that mine has
>an east-west orientation - because it seemed a good idea at the time?
I'm not an expert, but I believe the east-west orientation that gives a
long southern exposure is valuable the farther north you go in the northern
hemisphere, where the sun is low in the southern sky during the day. This
gives maximum exposure in the winter, when the greenhouse is most needed.
For hot summer days, a combination of ventilation and whitewash (to reflect
ths sun's heat) will keep temperatures from getting too high.
Karen Fletcher
: I'm planning to build an 8x12 greenhouse and pouring of the slab will
Long axis runs east-west. Not really a matter of opinion, just the way
it is ;-)
--
Karen Fletcher flet...@prairienet.org
=================The Garden Gate on Prairienet==========================
http://www.prairienet.org/ag/garden/homepage.htm
Steve Campbell
>Subject: Re: which way to orient greenhouse
>In article <1994Oct6.2...@adobe.com> kol...@adobe.com (Karen Kolling)
>writes:
>>From: kol...@adobe.com (Karen Kolling)
>>Subject: Re: which way to orient greenhouse
>>Date: Thu, 6 Oct 1994 23:50:32 GMT
>>In article <pomplun-0610...@k2hug.llnl.gov> pom...@llnl.gov (Don
>Pomplun) writes:
>>>I'm planning to build an 8x12 greenhouse and pouring of the slab will
>>>occur soon. Assuming the usual peaked roof along the longer axis, and
>>>aisle down the middle, is it better to orient the long axis north-south or
>>>east-west ? ? [It will be interesting to see how this vote goes i.e. to
>>>get n+1 opinions, ask n experts ]
>>North-South, I would say, then the plants get the most
>>sunlight. Drawing omitted for lack of sufficient initiative
>>to do it with |s and -s
>Well, all the greenhouses at the University of Illinios College of
>Agriculture are oriented east-to-west.
>Rick
In the southern hemisphere, I would orient a traditional peaked glasshouse
north-south so that the the maximum glass area is exposed to the sun. If you
place the glasshouse east-west, all that expensive glass on the south (your
north) will never get the sun on it!
_________________
| |
| | ^North (Your South)
| | Assuming peak runs on the long axis then
|_______________| < no sun on glass here.
I will be building a solar design, and it is oriented with all the glass
facing north (your south), and the south side thermal mass and insulation.
Then again, we don't have the extremes of temperature that some of the
American northern areas get. Summer max here 36C and Winter min -10C (on rare
occasions) with only occasional snow, never really settling on the ground.
Hope this helps!!
Steve
--
_______________________________________________________________________
Steve Campbell University of New England
Project Manager Armidale NSW 2350
CONCEPT Project Australia
Phone; 067 73 3463 E-mail:scam...@metz.une.edu.au
FAX; 067 73 3743 Note: This ^ is the figure one.
_______________________________________________________________________
Mike Carter
>Don Pomplun (pom...@llnl.gov) wrote:
>: I'm planning to build an 8x12 greenhouse and pouring of the slab will
>: occur soon. Assuming the usual peaked roof along the longer axis, and
>: aisle down the middle, is it better to orient the long axis north-south or
>: east-west ? ? [It will be interesting to see how this vote goes i.e. to
>: get n+1 opinions, ask n experts ]
Common sense applies.
First, determine which would fit into your landscape the best. Your question
may be answered at this point.
Second, if the greenhouse will be used only in the late spring, summer and
early to late autumn, the sun will be high enough in the sky that orientation
will not be a significant factor. The plants will get direct and/or reflected
light from all sides. The shading of some plants by others is minimized.
Third, if the greenhouse will be used in the winter months, the sun will be
very low all day. In this case orient it east west. This will help prevent the
plants closest to the sun from shading the ones in back (the sun will shine up
the aisles) (This, of course, assumes the aisles will be oriented along the
center ridge.)
I do not remember where you live, but in Canada (or any northern country), a
home hobbyist growing plants all winter should really consider insulating the
west and north walls and sometimes even one quarter to one half the roof, to
prevent heat loss. Paint those walls white to maximize light reflectance. The
extra cost is minimal, and will pay for itself in one or two winters. In this
scenario, the axis of the roof line would be east-west.
Everyone has their view, but in my mind, there are two main factors:
1. the shading of the "back" plants must be avoided and
2. maximize light dispersion while preventing overheating.
Your design should incorporate features designed to accomplish these points.
It may not be a traditional house-like structure with a roof peaked in the
middle. Half the fun is designing your own to fit in to your landscape.
Have Plants.........Will Grow
MFC
David DeGroote
>In article <1994Oct6.2...@adobe.com> kol...@adobe.com (Karen Kolling) writes:
>>From: kol...@adobe.com (Karen Kolling)
>>Subject: Re: which way to orient greenhouse
>>Date: Thu, 6 Oct 1994 23:50:32 GMT
>
>>In article <pomplun-0610...@k2hug.llnl.gov> pom...@llnl.gov (Don Pomplun) writes:
>>>I'm planning to build an 8x12 greenhouse and pouring of the slab will
>>>occur soon. Assuming the usual peaked roof along the longer axis, and
>>>aisle down the middle, is it better to orient the long axis north-south or
>>>east-west ? ? [It will be interesting to see how this vote goes i.e. to
>>>get n+1 opinions, ask n experts ]
>
>>North-South, I would say, then the plants get the most
>>sunlight. Drawing omitted for lack of sufficient initiative
>>to do it with |s and -s
>
>Well, all the greenhouses at the University of Illinios College of
>Agriculture are oriented east-to-west.
>
>Rick
>
The current "wisdom" is to have the long axis run east and west. At higher
latitudes-ie. lower winter sun angles the structure will self-shade the
north interior when the long axis is north-south. We are very happy with the
orientation.
David