Should I
exhaust my central vacuum outside?
Let's use some common
sense...
Let's take a moment to fill you in on
our own professional thoughts, and what seems to be the latest trend for
central vacuums. Venting central vacuums started back in the 70's and lasted
through the 90's. People would either vent them up into their attics, crawl space, or
outside away from the home. It sounds good in theory, but there are some
major problems with doing either, which we will get into more detail
throughout this page. One big reason is that venting your central vacuum in
the attic or outside can lead to potential motor and heat problems, which
have been known to cause house fires.
Nutone®
AirVac®
Drainvac®
Purvac®
Vacuflo®
Royal®
Rule #1
Hoover®
Duovac®
Beam®
Eureka®
Honeywell®
Electrolux®
Protect your motor from dirt, heat and water...
The three leading causes for premature motor failure.
* Builders today are putting more
emphasis on insulating homes to be an
AIR-TIGHT environment, conserving more energy and
increasing efficiency. Better insulation can save you a lot of
money.
Going Green Helps
Not Only the Environment, but Allergy Sufferers As Well.
In
2002, the Division of Allergy and Immunology at the University
of California, Davis, conducted a clinical study that proved a
link between central vacuum systems and allergy relief. The
study found that patients experienced a 40% to 61% improvement
in their symptoms when they switch from using a portable vacuum
to a built-in central vacuum system to clean their homes.
One
important note
of caution,
if your primary concern is removing dirt, dust, pet hair, allergens,
etc.. then venting the
central vacuum outdoors is an option, but certainly not the
best idea for environmental reasons because it will suck out a lot of conditioned air from
inside your home which will increase your utility bills.
It's highly recommended in the central vacuum industry to use a
vacuum that has a true finer filtration system such as the
ActiVac II
(seen below) that does not require the exhaust to be vented
outside. It's more eco-friendly to have an airtight insulated
home.
- National
Association of Homebuilders, Green Building Standards
Thanks to
UC Davis, Builders Magazine and the American
Lung Association for supplying this information.
About Motors: Central vacuum motors are
engineered for suction only, not to be used as a blower. They are designed
to have an intake valve, which is where the suction comes from, and an
exhaust valve, where old air can be vented out to keep the motor cool. Good
central vacuum units have a built-in filter. All the motor is designed to do
is suck in air. The dirt and dust being sucked up gets trapped in a filter,
bag, or cartridge. This keeps any unwanted particles from going into the
motor. A good example would be a swimming pool filter. The water goes
through the filter to clean it out and the filter retains any dirt and
debris, leaving only clean water and protecting your pump from any debris.
Back in the day, central vacuums were very loud while the motor was working.
These days you can simply put a muffler on the exhaust to reduce the noise
by up to 6 decibels. Older central vacuums before the 1990's did not have
the greatest filter system so particles were often caught in the motor.
About 8-10% of what was picked up just gets exhausted right through the
motor, decreasing suction power and motor life, making venting even more important. This didn't paint a clean picture of hygienic dust removal back in the day.
* The majority of
better central vacuum companies no longer require mandatory venting for
their vacuums. It's listed as optional. The exception to this would
be "true-cyclonic" central vacuums, which absolutely MUST be vented outside
due to the nature of how they work. With a better understanding from this
page on how and why to vent central vacuums, we leave it up to the customer
to decide which way is better for them.
Venting in your Attic: Venting
in the attic is done for two reasons, mainly for noise reduction.
It was quieter to just vent into the attic. Also, since warm air rises,
people figured that the attic would be a suitable place to vent to. However,
there are some major problems with doing it this way. Since older motors
gave off more heat than they do today, it possessed a serious
fire hazard. The heat coming from the ventilation pipe was often very hot, and could easily melt things such as PVC pipes being used through the house. If a spark from a bad motor should fly up into your attic, it could easily ignite your insulation on fire. Also, since all the dirt and dust and germs that were vacuumed up are being vented right above you in the attic, those particles would just settle to the floor and absorb into the insulation. The vent was basically just an open pipe, so any object blocking or partially blocking the opening could melt or ignite whatever was blocking it. Even worse, smaller objects could just fall right into the open tube down into the vacuum, potentially ruining the motor and causing a fire. Back then, there were very few regulations for venting central vacuums unlike today. There were no building codes that were enforced and some house fires were started this way until building regulations kicked in and started enforcing safety laws. Today's motors are engineered with airflow in mind, keeping them cool and prolonging the life of the motor/unit.
Venting Outside: When you exhaust a central
vacuum system outside, there are numerous problems you can encounter. Could
it be a fire hazard? It's possible. Here's some thoughts from some companies
that don't approve of the idea. After all the many years of venting outside,
researchers are no longer recommending this practice as it will suck
much conditioned air from inside your home and exhaust it outside,
increasing your
utility bills. Your heating bill goes up in the winter, sometimes
caused from your central vacuum as well as your air conditioning cooling
bill in the summertime. That is just wasting your hard earned money. You
might as well put the air conditioning on and open the windows and front
door and leave.
To the right is a typical
outside central vacuum exhaust vent. The flaps (or louvers) open when the
force of the air being exhausted from the central vacuum push them open, and
close when it's not being used. Now, what would happen if you live in a
place where it snows regularly? All of the snow and ice would freeze over
and cover the flaps, keeping them shut and suffocating the motor. That would
lead to it overheating and possibly failing or igniting. Again, the
idea of a motor is to suck in air and exhaust air out.
Even up to 10 years ago, outside venting was required. Times have changed! Venting is no longer mandatory because today's motors run much cooler and have fans to help control temperature as well as better advanced filtration, making your house a greener, energy efficient, and healthier environment for you and your family.
* As an example, if someone were to block your mouth from breathing, it'd be the same type of scenario. Just like you need to have fresh air in your lungs and exhale the old air out, motors operate the same way.
What would happen should
your motor start suffocating? Within 30-60 seconds, it would rev up to a
screaming decibel level, and a lot of back pressure would build up. You'd
also start to smell the electronics burning from the heat. The PVC pipes
connected to it would start to melt from the extreme temperature, which
could cause a fire hazard. It would start violently vibrating and quite
possibly fall right off the wall, and if it landed on anything flammable
like cardboard or paper...well, you'd have a problem on your hands. It's a
catastrophic failure and most likely will destroy your whole central vacuum
unit. The motor is considered the "brain" of the unit, and just like humans
if the brain is not getting enough air it will die. It's a fire safety
nightmare.
First, to make the initial venting opening, you have to drill a 2 1/4" hole
from the inside of your house to the outside. Another big problem with
outside venting is flooding. Since you're drilling a hole that goes inside
your home from the outside, any rain and water that falls can leak through
and flood your basement or garage.
A lot of people also were
complaining to their servicemen that their
house was infested with all kinds of rodents and bugs. Little bugs and
varmints like ants, bees and roaches, even mice and rats, are able to crawl right
down the exhaust tube, or even travel between the pipe and housing material
into your home where they continue to breed and cause infestations.
On extremely hot days,
direct sunlight could melt or warp the plastic flaps on the exhaust vent
shut, preventing it from venting.
On very windy days, you
wouldn't want the dust and everything else that was exhausted to be whisked
back inside your home through a window, car port, or open door.
Like the illustration to
the left shows, sometimes the length of the exhaust pipe which includes the 'elbows'
causes the motor to strain. It's like blowing too much air through a drinking straw, it causes back pressure, which in turn causes the motor to work harder. Again, motors were made to suck in air, not blow it
out. When venting, the longer length of the pipe means it has to work harder
to move the air out and can cause a back pressure that harms the central
vacuum unit.
The two largest motor manufacturers (Ametek and Domel) don't really have an official opinion on how to vent their motors, the main focus is to have them run as cool as possible without any dirt, sand, or exhaust back pressure occurring. From an engineering standpoint, central vacuum motors require a balance of air flow. The delicate balance means the air that gets sucked into the motor must be allowed to be released somewhere equally. If the balance is thrown off, problems will occur and in turn will cause a loss in suction and shorten the life of the motor.
We also believe it's an
inconvenience to have to install the central vacuum unit very close to where
you're going to exhaust it. It limits the placement options of where you can
place the unit, and it could cause you to have to rearrange where you have
things placed just to make room for the vacuum. If you must exhaust, you could
use one short straight piece of tube directly outside. In conclusion , we are not opposed to venting outside, we just
believe that the outside elements should stay outside and that there is a
better way to vent your central vacuum.
The
New ActiVac II "all-in-one" (seen above)
now takes the place of all these older methods.
Self-venting HEPA-type/
Charcoal Exhaust Filter
A
micro-exhaust HEPA-type bag can also help in
capturing microscopic particles and motor carbon dust from the exhaust air
of the vacuum cleaner. A very good alternative to venting outside. Some
micro-bags even have active charcoal incorporated into the fabric of the bag
to help eliminate any foul odors that usually occur within cyclonic or bagless (dump out) type vacuum units.
Carbon Dust
Exhaust Filtration
This type of filtration is on a lot of
newer, more
modern types of central vacuums. This19ilter
snaps into place directly onto the vacuums
exhaust to eliminate the need for venting
outside as well as in the attic. Filters out microscopic dust particles as well as carbon
dust.
Intake Sound
Reducing Muffler
Known in the industry as a
top hat muffler, it helps cool and quiet the intake motor when it's sucking
in air. It lowers the irritating noise level. Typically found on Hayden® and
older NuTone® central vacuums, usually on the top of the central vacuum unit.
Also acts as a filter by preventing any dust from entering the motor, and
prevents motor burn-out and vibrations.
Sound Reducing Muffler/Exhaust Vent
(Left) This type of muffler system, when attached to the exhaust of a central vacuum unit, helps lower the decibel (sound) level without compromising performance. It contains an acoustic sound-suppressing foam. This muffler is compatible with any model or make central vacuum ever made, so there's no worries wondering if it'll fit. Also helps reduce motor vibrating and exhaust noise.
(Right) The Exhaust Vent is a white PVC cover with three louvers designed to terminate the central vacuum’s exhaust air. When the central vacuum system is running, the louvers automatically open to pass the exhaust air to the outside. The exhaust vent cap mounts to the wall with four screws and connects to the system’s steel or PVC exhaust tubing/pipe.
* Be aware of exhaust vents
made from metal!
Metal is susceptible to rusting in outdoor environments.
*
Be aware of shady characters on the internet selling two of these
mufflers connected, often with duct tape or a homemade
jerry-rig
clamp of some sort, and trying to fool the public into thinking that
it will offer double the quietness. All that does is create more
weight and will often just fall off the vacuum.
Customer Warning
Cyclonic, or
"true-cyclonic" systems have to be
vented outside,
but the average customer wouldn't figure
that out until after they've actually bought the vacuum and read the
instructions. If you asked a typical pushy salesman "why
do I have to vent outside?" they will try to dodge the question
because that is a very big downside to cyclonic vacuums. That should send a
RED-FLAG to any customer.
Not only is it a filthier system to clean out and maintain, but a small
percentage (3-9%)
of the lighter dust such as carpet fibers, pet hair, and regular dust
typically get sucked up into the motor entering the fan blades, bearings,
armature, and the electric components.
4% of that actually PASSES through
the motor, and that is EXACTLY the reason why you MUST
vent outside - the dirt would otherwise be vented into your home
where it came from. Dirt and dust that don't pass through it get
caught in the motor easily, causing it to heat rapidly and can lead to premature motor failure. This is why cyclonic vacuums typically have lower
life expectancy. Think of it like a clothes dryer, after a while the lint
starts to pile up and blocks most of the airflow. Like the header to this
page says, let's use some common sense here. Without any ventilation, it
could overheat and cause a fire. 98% of the top central vacuum manufacturers
do not
believe in a gimmicky theory like "true-cyclonic". Some of the claims you would hear coming from a company who pushes cyclonic vacuums would be
"never loses power", "no filters to clean", "no loss of suction", and so on.
Be careful of these shady marketing tactics.
Read our blog about venting
and proper care of your central vacuum system.
* We've also
heard some mistruths on the internet about people claiming their own
private-labeled cyclonic central vacuums are like the world-famous Dyson
vacuums which are heavily advertised on TV, which is also cyclonic and needs
no bags. But the real truth is, it's completely the opposite. Dyson's
have a HEPA filter built into it, knowing that there are particles that
still get through the system, and their patented technology is considered
"true" cyclonic. Trust us, we sell them in our retail store. The
private-labeled cyclonic systems try to affiliate themselves with the Dyson
name by listing similarities between their vacuums, just because Dyson's are
well known throughout the world.
A very cheesy marketing strategy. ...To be continued...
In
2002, the Division of Allergy and Immunology at the University
of California, Davis, conducted a clinical study that proved a
link between central vacuum systems and allergy relief. The
study found that patients experienced a 40% to 61% improvement
in their symptoms when they switch from using a portable vacuum
to a built-in central vacuum system to clean their homes. 
When you exhaust a central
vacuum system outside, there are numerous problems you can encounter. Could
it be a fire hazard? It's possible. Here's some thoughts from some companies
that don't approve of the idea. After all the many years of venting outside,
researchers are no longer recommending this practice as it will suck
much conditioned air from inside your home and exhaust it outside,
increasing your
utility bills. Your heating bill goes up in the winter, sometimes
caused from your central vacuum as well as your air conditioning cooling
bill in the summertime. That is just wasting your hard earned money. You
might as well put the air conditioning on and open the windows and front
door and leave.
First, to make the initial venting opening, you have to drill a 2 1/4" hole
from the inside of your house to the outside. Another big problem with
outside venting is flooding. Since you're drilling a hole that goes inside
your home from the outside, any rain and water that falls can leak through
and flood your basement or garage.
A
micro-exhaust HEPA-type bag can also help in
capturing microscopic particles and motor carbon dust from the exhaust air
of the vacuum cleaner. A very good alternative to venting outside. Some
micro-bags even have active charcoal incorporated into the fabric of the bag
to help eliminate any foul odors that usually occur within cyclonic or bagless (dump out) type vacuum units.
(Left) This type of muffler system, when attached to the exhaust of a central vacuum unit, helps lower the decibel (sound) level without compromising performance. It contains an acoustic sound-suppressing foam. This muffler is compatible with any model or make central vacuum ever made, so there's no worries wondering if it'll fit. Also helps reduce motor vibrating and exhaust noise.
Cyclonic, or
"true-cyclonic" systems have to be
vented outside,
but the average customer wouldn't figure
that out until after they've actually bought the vacuum and read the
instructions. If you asked a typical pushy salesman "why
do I have to vent outside?" they will try to dodge the question
because that is a very big downside to cyclonic vacuums. That should send a