Cooling effect of trees
 

I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had to
have them removed, and I thought that my house would be much hotter at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat during
the day, and gave it off at night which made my house hotter at night.
Would this make sense?

Thanks

Tom

Cooling effect of trees
 

On 7/9/2007 6:32 PM, wrote:
I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had to
have them removed, and I thought that my house would be much hotter at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat during
the day, and gave it off at night which made my house hotter at night.
Would this make sense?

I'm a docent at a showcase garden. When I conduct a tour, I always ask
the guests to grasp a leaf on one of the trees near the entrance (white
mulberry or liquidambar). The leaves are cooler than the air around
them. Trees are natural air conditioners. In the garden, shade from
the trees is cooler than shade from the picnic umbrellas or in the
Japanese pagoda.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/

Cooling effect of trees
 

wrote in message
oups.com...
I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had to
have them removed, and I thought that my house would be much hotter at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat during
the day, and gave it off at night which made my house hotter at night.
Would this make sense?

Thanks

Tom


The breeze blockage theory makes some sense.
However, you never indicated if those trees provided any substantial shade
for the house itself. So, the shade theory is lacking for evidence.

Having lived in a house without air conditioning while growing up, and a few
houses like that in my early 20s, I understand how the sun and the house
work in producing heat inside the house. The worst of the heat is just
before sunset dragging out to many hours into the night. It may be
substantially warmer in the house at night. Some call it "the house giving
up its heat". Bet you at least got a swamp cooler.
Dave

Cooling effect of trees
 

"tomba wrote:
I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had to
have them removed, and I thought that my house would be much hotter at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat during
the day, and gave it off at night which made my house hotter at night.
Would this make sense?

Too many details missing but in general the same trees that shade a
house during the day increase humidity inside a house, which make it
feel warmer at night. Tree limbs should never be permited to hang
over a roof, the constant shade causes moisture accumulation in
roofing materials, which can cause severe damage to roofing materials
and roof sheathing. Also the heat that builds inside an attic during
daytime radiates into the house by inversion as soon as the outside
air cools at night. Have you logged indoor temperature and humidity
levels? Trees cannot take the place of good insulation, light
blocking window blinds, and air conditioning. Attic ventilation and
radiant barriers can help somewhat but they do not eliminate radiant
heat inversion. Trees however do offer substantial cooling, if you're
a bird.

http://www.ornl.gov/sci/roofs+walls/radiant/index.html

Cooling effect of trees
 

wrote in message
oups.com...
I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had
to
have them removed, and I thought that my house would be much hotter
at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat
during
the day, and gave it off at night which made my house hotter at
night.
Would this make sense?


The first guess makes some sense. Then second doesn't. The Trees could
be reflecting heat back to the house that otherwise would dissappear
into space. Sort of like the air cools more at night on a clear night
then it does on a cloudy night. Or, the trees could just be increasing
the humidity near them.

Bob

Cooling effect of trees
 

When there are no leaves on Cornus florida you can touch the stems and tell
which stems maintain a symplast. The ones that maintain a symplast are cold
compared to symplastless stems.


Sincerely,
John A. Keslick, Jr.
Arborist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.

"David E. Ross" wrote in message
.. .
On 7/9/2007 6:32 PM, wrote:
I am not sure this is the best place to ask this question. There were
two large trees in my backyard which provided a lot of shade. I had to
have them removed, and I thought that my house would be much hotter at
night. I do not use AC. With the trees removed it seems as if the
house is cooler. The only two reasons I can come up with is that the
trees blocked evening breezes, or that the trees absorbed heat during
the day, and gave it off at night which made my house hotter at night.
Would this make sense?

I'm a docent at a showcase garden. When I conduct a tour, I always ask
the guests to grasp a leaf on one of the trees near the entrance (white
mulberry or liquidambar). The leaves are cooler than the air around
them. Trees are natural air conditioners. In the garden, shade from
the trees is cooler than shade from the picnic umbrellas or in the
Japanese pagoda.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/