D2—Lancaster Farming, Saturday, June 9,1984
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Swine producers:
Are heat exchangers for you?
Have you evern watched a
farrowing house fan in the middle
of winter and then gritted your
teeth because it’s pumping heat
right out the window?
“Your ventilation system, even
in well insulated swine buildings,
accounts for 75 to 80 percent of die
total heat lost,” says University of
Delaware extension livestock
specialist Dr. Ken Kephart.
The 1983-84 heating season may
be over, but he says now’s the time
for pork producers to think about
changes for next winter. What can
be done to reduce heat loss from
buildings?
One solution may be to install a
heat exchanger. This is a gadget
designed to recover some of the
heat from exhausted air before
it leaves a building. The unit works
by moving incoming cold air and
warm exhaust air very close
together so close that a sheet of
Most producers put a lot of
emphasis on underline quality
when selecting replacement gilts.
That makes sense. Without a
functional udder on the sow, her
baby pigs won't survive.
But believe it or not, it’s hard to
find solid evidence to prove this
theory. In the last 25 years, ex
periments from Missouri,
Nebraska, Minnesota and Europe
show little if any correlation
between the number of functional
teats and the number of pigs
weaned.
And now we have yet another
report, this time from Auburn
University. Researchers on that
project, S.B. Jungst and D.L.
Kuhlers, conclude: “gilt selection
programs that place selection
pressure on teat number and
against inverted and pin nipples
seem unwarranted” for improving
litter size or weight.
So, should we just ignore un
derline quality in the replacement
sow herd? Not in my book.
When you look at the Auburn
study, the number of functional
teats averaged 13.7 per sow.
Ninety-five percent of the sows had
between 11.7 and 15.6 functional
nipples. No wonder they couldn’t
find an effect. The worst sows in
the bunch had over 11 functional
teats. While an underline with 11
nipples isn’t great, it’s certainly
good enough to support nine pigs.
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metal or plastic is the only thing
separating the two air flows. The
result? Outgoing air is cooled off
and incoming air is warmed up.
“You can imagine the ad
vantages,” says Kephart. “Instead
of dumping zero-degree air into a
room, you may be able to bring in
30 or 40-degree air. Because
warmer air mixes more readily
than heavy, cold air, drafts are
often reduced. And reclaiming
heat saves money.”
Does this mean that anyone
adding supplemental heat to a
swine facility should buy a heat
exchanger? Not at all, says the
specialist. Before making that
decision there are lots of things to
consider, such as ventilation rate,
air distribution, and the com
patibility of a heat exchanger with
your present ventilation system.
The heat exchanger should
provide the minimum ventilation
fork Prose
Kenneth B. Kephart
Extension Livestock Spec.
University of Del.
And in the other studies (where
the data are shown) nearly all of
the sows used had good underlines.
There just weren’t enough poor
ones in the group to back up what
we’ve been practicing all these
years.
The folks at Auburn looked at a
lot of other underline traits besides
total number of teats. They also
examined number of teats in front
of the navel, number of inverted
nipples, number of pin nipples,
underline length and total body
length. The only trait that had any
effect on litter survival of litter
weight, was underline length.
And as strange as it seems, their
data shows that when underline
length decreases by five inches,
litter size is improved by one pig
and litter weight is increased found
pounds at six weeks. I’d like to see
that study repeated.
Am I saying all these ex
periments are useless? Not at all.
They make an important point, but
they miss one, too.
If all the gilts in your herd have
at least 12 functional teats, there’s
probably little justification in
selecting for underline quality. But
if you’ve got some that have only 7
or 8 good nipples, they sure aren’t
going to raise 9 or 10 pigs and you
should select against those gilts.
That’s the point these studies
missed.
rate for the facility. For example,
the minimum airflow requirement
for a sow and litter is about 20
cubic feet per minute. If there are
20 sows in one room, the heat ex
changer should deliver about 400
cfm or slightly more.
It also ought to have two fans
one to blow air into the unit and one
for exhaust. Manufacturers often
design the exhaust fan slightly
larger than the intake fan. That
creates a slight vacuum inside the
building, and under most con
ditions, that’s preferred. “Keep in
mind that the exhaust fan deter
mines your ventilation rate. So it
should be sized to your needs,”
Kephart says.
Cleaning can be a real chore with
some units. The volume of dust and
dirt that has to travel through the
narrow channels and tubes in these
units can get them dirty in a hurry.
And as dirt accumulates, air flow
and efficiency decrease. So a
system that’s easy and quick to
clean is a must.
Air inlets are another con
sideration. Most heat exchangers
have a single discharge point. This
can be a problem in large rooms.
To ensure proper air distribution,
some engineers recommend
connecting a discharge duct to the
unit when the room measures
more than 20 feet in either
dimension.
And then there’s the matter of
compatibility. “You already have
one ventilation system and it must
work smoothly with the heat ex
changer you buy,” points out
Kepluut. For example, when
temperatures get too high in the
building, another fan should come
on. And when it does, an additional
inlet must open to allow air into the
room. When the fan shuts off, the
inlet should automatically close to
prevent backdrafting.
Anything in a hog facility is
subject to rot, rust or total
destruction, so durability is also
important. Be sure to buy a heat
exchanger that will last long
enough to pay for itself.
The efficiency of a heat ex
changer is measured in terms of
heat recovered, as a percentage of
total ventilation heat loss. Ac
cording to the specialist, this is
determined by the design of the
unit and environmental conditions
(primarily temperature and
humidity) inside and outside the
building.
“Most manufacturers advertise
an efficiency rating,” he says. “A
realistic expectation is 40 to 60
percent. When a sales rep men
tions the efficiency of his unit, find
out the exact conditions under
which the measurement was
taken. Then discuss the
specifications with an extension
engineer in order to compare units
made by various companies.”
Heat exchangers work better
when it’s very cold outside and
quite warm inside. So they’re
generally well suited to nurseries
where temperatures often are
maintained at 80 degrees or more.
“They certainly won’t pay in a
finishing unit,” Kephart says.
H.WW
Studies have shown heat exchangers to be particularly
effective in nurseries where high temperatures are main
tained.
“And many people question
whether putting one in a farrowing
house is justified, since tem
peratures there are usually in the
65- to 70-degree range.”
Will a heat exchanger pay for
itself? It might. Or it could cost you
even more money.
“Suppose you keep the fans
turned down to save on heating
costs,” the specialist explains.
“You’ll save fuel, but vou’re also
Rutgers offers beekeeping course
NEW BRUNSWICK, NJ -
Rutgers University will again be
offering its ever popular three day
beekeeping short course. Probably
one of the oldest continuously
offered beekeeping short courses
in the country, this course has
attracted people from all walks of
life, people of all ages, and people
from all over the United States and
from many foreign countries.
Adams County
Poultry Assoc.
scholarships
GETTYSBURG - The Adams
County Poultry Association this
year is sponsoring scholarships at
Penn State. These scholarships
will be awarded to Adams County
students who have been accepted,
or are attending Penn State
University. Students must be
Adams County residents majoring
in a curriculum offered by the
College of Agriculture or Human
Development.
Preference will be given to
students interested in Poultry,
Food Science, Community
Nutrition or Foods and Nutrition.
Selection of recipients will be
made by the Adams County
Poultry Association Board of
Directors based on scholastic
ability, financial need, activities
and interest in poultry or related
fields.
Further information regarding
the scholarship program is
available from William W. Murray
111, County Agriculture Agent, 1135
Chambersburg Rd., Gettysburg,
Pa. 17325.
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under-ventilating. So if you install
a heat exchanger, you’ll be moving
more air than you were when the
fans were turned back. In this
case, even though the unit is
recovering heat, your fuel bill
could actually go up.”
So consider all the details before
deciding to,go whole hog into heat
exchangers, Kephart concludes.
They aren’t meant for everybody.
The beekeeping background of
those attending has ranged from
rank novices just contemplating
getting into beekeeping to com
mercial beekeepers.
This year with Dr. Rad Roberts,
Rutgers’ Beekeeping Specialist
being away, the course will be
under the direction of Mr. Jack
Mathenius, the New Jersey
Supervisor of Beeculture and Dr.
Bob Berthold, Delaware Valley
College, Pennsylvania’s
Beekeeping expert. Emphasis will
be mainly on the practical aspects
of beekeeping with discussions and
demonstrations in the classroom
and laboratory and hands on ex
perience in the field.
The dates for the course are
Wednesday, Thursday, and
Friday, June 27,.28 and 29, 1984.
Additional information and an
application can be obtained by
writing or calling Mr. Ned Lipman,
P.O. Box 231, New Brunswick, NJ
08903 or by calling 201-932-9271 or
932-8996.
Union County
Fair schedules
livestock sale
LAURELTON A Junior
Livestock Sale will be held in
conjunction with the Union County
Fair on August 8, at 8:00 p.m.
Staged at the Union County West
End Fairgrounds along Route 45 in
Laurelton, the sale will feature 4-H
and FFA livestock, and will be
followed by a sale of Holstein
steers.
Proceeds from the steer sale will
be donated to a fund set aside by
the fair association to erect a new
dairy show barn.
Celebrating its 59th year, the
Union County Fair has hosted the
Livestock Sale for the past five
years.