Hi,

I have a room in my house that I use as an office that I have to keep the
door shut so the return air flow is very small. It has a 5/8" gap below the
2'6 door so I calculate this out to be around 18.75 sq.in. I have one air
vent in it and my *theory* is that I think is fed by a 6" flexible ductwork
of some type. This would be 28.27 sq.in. With my house set at 77 deg, this
room with the door open is usually around 81 deg. If I close the door which
is probably 12 hours per day, it rises to about 85 deg when the rest of the
house is 77 deg. I have a computer and a couple printers in it, so a few
things that generate heat.

The issue is that I am going to have to try and soundproof the room a little
better. I have a toddler that makes considerable noise and it can be
troublesome when I am working. I am going to get a solid core door and a
sweep for the bottom to cut off all the places where sound can enter
directly. This will however cut off the return air flow that I currently
have which doesn't seem to be doing the job.

My house currently has two return air vents both located in the hall way.
Each one is a 14x25, so 350 sq.in each or a total of 700 sq.in return air
flow. My HVAC system seems to be ductboard or some sort of flexble
ductwork. The ductwork that goes to all the supply vents is a round
insulated flexible stuff. The two existing return air vents look a bit
different in that they look like a constructed box tube. Silver foil on the
outside. I'm not sure if it is ductboard or something else.

Here are the things I have thought of doing, please recommend which is best:

1. Put in a vent that has nothing to do with the HVAC system, but is sort
of a room to room vent. I could pick another room that has decent enough
open space to one of the two main return air vents in the hallway. The
advantage here is that I wouldn't be doing anything on the HVAC system
myself. I am also providing a way for air to exit the room when supply air
wants to come in. I wonder however how well or not well this would work.
For some reason, it seems to me that even if I put in a large enough
vent/ductwork that it still wouldn't improve supply on my one supply vent.

2. Add a return air vent to my office. It looks like the smallest filter
that I can commonly find on the shelves at Lowe's is a 10x20. This would
add 200 sq.in. to my office for return air. Would this increase the airflow
I am getting through my single supply vent with the door shut? Would more
air being pulled out via the return vent push more cooler air in via the
supply? This would a nice feature if it worked out well. Are there any
downsides to this plan? I don't know if this is something I could do
myself, or partially do myself and then have the HVAC company that put the
system in come in and hook it up to the HVAC system.

3. Same as #2, but add a second supply vent in the office as well, doubling
it from 28.27 sq.in to 56.54 sq.in.

4. Are there any more issues with sound with either #1 or #2? I wonder if
#1 would be noisier because sound could come from the other room vent into
the office vent. I will probably be using the flexible ductwork like they
put in already so hopefully that doesn't transmit sound as well as something
metal might.

Thanks for any advice and help,

Alan

I would add a return air duct, tie into existing duct in hallway will make
it an easy/inexpensive thing to try. This will increase sound infiltration
though. If that doesn't work, and if its suficiently large enough of a
return, then consider adding another supply. I am in same boat - 3 PCs, 2
LCDs, 1 21" tube monitor, 3 printers, 2 fax machines, scanner, incandecent
lighting, halogen desk lamps, etc. All in 120sq ft room! Let me know how you
make out.

"SA Development" wrote in message
...
Hi,

I have a room in my house that I use as an office that I have to keep the
door shut so the return air flow is very small. It has a 5/8" gap below
the 2'6 door so I calculate this out to be around 18.75 sq.in. I have one
air vent in it and my *theory* is that I think is fed by a 6" flexible
ductwork of some type. This would be 28.27 sq.in. With my house set at
77 deg, this room with the door open is usually around 81 deg. If I close
the door which is probably 12 hours per day, it rises to about 85 deg when
the rest of the house is 77 deg. I have a computer and a couple printers
in it, so a few things that generate heat.

The issue is that I am going to have to try and soundproof the room a
little better. I have a toddler that makes considerable noise and it can
be troublesome when I am working. I am going to get a solid core door and
a sweep for the bottom to cut off all the places where sound can enter
directly. This will however cut off the return air flow that I currently
have which doesn't seem to be doing the job.

My house currently has two return air vents both located in the hall way.
Each one is a 14x25, so 350 sq.in each or a total of 700 sq.in return air
flow. My HVAC system seems to be ductboard or some sort of flexble
ductwork. The ductwork that goes to all the supply vents is a round
insulated flexible stuff. The two existing return air vents look a bit
different in that they look like a constructed box tube. Silver foil on
the outside. I'm not sure if it is ductboard or something else.

Here are the things I have thought of doing, please recommend which is
best:

1. Put in a vent that has nothing to do with the HVAC system, but is sort
of a room to room vent. I could pick another room that has decent enough
open space to one of the two main return air vents in the hallway. The
advantage here is that I wouldn't be doing anything on the HVAC system
myself. I am also providing a way for air to exit the room when supply
air wants to come in. I wonder however how well or not well this would
work. For some reason, it seems to me that even if I put in a large enough
vent/ductwork that it still wouldn't improve supply on my one supply vent.

2. Add a return air vent to my office. It looks like the smallest filter
that I can commonly find on the shelves at Lowe's is a 10x20. This would
add 200 sq.in. to my office for return air. Would this increase the
airflow I am getting through my single supply vent with the door shut?
Would more air being pulled out via the return vent push more cooler air
in via the supply? This would a nice feature if it worked out well. Are
there any downsides to this plan? I don't know if this is something I
could do myself, or partially do myself and then have the HVAC company
that put the system in come in and hook it up to the HVAC system.

3. Same as #2, but add a second supply vent in the office as well,
doubling it from 28.27 sq.in to 56.54 sq.in.

4. Are there any more issues with sound with either #1 or #2? I wonder
if #1 would be noisier because sound could come from the other room vent
into the office vent. I will probably be using the flexible ductwork like
they put in already so hopefully that doesn't transmit sound as well as
something metal might.

Thanks for any advice and help,

Alan

Before all the other stuff, could you tell us the fundamental stuff?
Whether you're trying to heat or cool at the time of the problem. And
your local climate.

TTFN,
J

Hi,

Before all the other stuff, could you tell us the fundamental stuff?
Whether you're trying to heat or cool at the time of the problem. And
your local climate.

Sure, I am in Oklahoma, and the biggest issue is cooling during the summer.
I usually shut the vent down to about 50% in the winter and it seems to run
more closely to the house temp during those months.

Thanks for the help, I appreciate it!

Alan

Hi,

I would add a return air duct, tie into existing duct in hallway will make
it an easy/inexpensive thing to try. This will increase sound infiltration
though.

Yes, the place I would add the office return air duct is only about 5 feet
from the hallway return air duct, but that is a prime noise area, so I was
thinking of running it from the office a little further down and join it up
to the return ductwork where it isn't so close to the hallway return air
vent.

If that doesn't work, and if its suficiently large enough of a return, then
consider adding another supply. I am in same boat - 3 PCs, 2 LCDs, 1 21"
tube monitor, 3 printers, 2 fax machines, scanner, incandecent lighting,
halogen desk lamps, etc. All in 120sq ft room! Let me know how you make
out.

I know what you mean, too much heat producing equipment! I had 180W in
ceiling fan bulbs that I've replaced with some floroescents for now. I
prefer the incandescent light, but these do product much less heat. Once I
get the air vent put in I'll probably go back to the incandescent ones
though.

I'll post how this all turns out when I get it done... We are still having
100 deg days here and there so hopefully I can get it done before it gets
colder to see what the effect is.

Thanks,

Alan

"SA Development" wrote:

Hi,

Before all the other stuff, could you tell us the fundamental stuff?
Whether you're trying to heat or cool at the time of the problem. And
your local climate.

Sure, I am in Oklahoma, and the biggest issue is cooling during the summer.

Then you want the return vents up high to return warm air to the air
conditioner, assuming that you have central air.

You should be able to get a grill that fits between two studs 16" and
use the air space between them for the vent, on an interior wall.

That is what I did, replace a single double stud wide grill with two
half wide, one low and one high.

SA Development wrote:
Hi,

I have a room in my house that I use as an office that I have to keep the
door shut so the return air flow is very small. It has a 5/8" gap below the
2'6 door so I calculate this out to be around 18.75 sq.in. I have one air
vent in it and my *theory* is that I think is fed by a 6" flexible ductwork
of some type. This would be 28.27 sq.in. With my house set at 77 deg, this
room with the door open is usually around 81 deg. If I close the door which
is probably 12 hours per day, it rises to about 85 deg when the rest of the
house is 77 deg. I have a computer and a couple printers in it, so a few
things that generate heat.

The issue is that I am going to have to try and soundproof the room a little
better. I have a toddler that makes considerable noise and it can be
troublesome when I am working. I am going to get a solid core door and a
sweep for the bottom to cut off all the places where sound can enter
directly. This will however cut off the return air flow that I currently
have which doesn't seem to be doing the job.

My house currently has two return air vents both located in the hall way.
Each one is a 14x25, so 350 sq.in each or a total of 700 sq.in return air
flow. My HVAC system seems to be ductboard or some sort of flexble
ductwork. The ductwork that goes to all the supply vents is a round
insulated flexible stuff. The two existing return air vents look a bit
different in that they look like a constructed box tube. Silver foil on the
outside. I'm not sure if it is ductboard or something else.

Here are the things I have thought of doing, please recommend which is best:

1. Put in a vent that has nothing to do with the HVAC system, but is sort
of a room to room vent. I could pick another room that has decent enough
open space to one of the two main return air vents in the hallway. The
advantage here is that I wouldn't be doing anything on the HVAC system
myself. I am also providing a way for air to exit the room when supply air
wants to come in. I wonder however how well or not well this would work.
For some reason, it seems to me that even if I put in a large enough
vent/ductwork that it still wouldn't improve supply on my one supply vent.

2. Add a return air vent to my office. It looks like the smallest filter
that I can commonly find on the shelves at Lowe's is a 10x20. This would
add 200 sq.in. to my office for return air. Would this increase the airflow
I am getting through my single supply vent with the door shut? Would more
air being pulled out via the return vent push more cooler air in via the
supply? This would a nice feature if it worked out well. Are there any
downsides to this plan? I don't know if this is something I could do
myself, or partially do myself and then have the HVAC company that put the
system in come in and hook it up to the HVAC system.

3. Same as #2, but add a second supply vent in the office as well, doubling
it from 28.27 sq.in to 56.54 sq.in.

4. Are there any more issues with sound with either #1 or #2? I wonder if
#1 would be noisier because sound could come from the other room vent into
the office vent. I will probably be using the flexible ductwork like they
put in already so hopefully that doesn't transmit sound as well as something
metal might.

Thanks for any advice and help,

Alan



I have the same situation, but I do have a return. Basically since this
room is small and has essentially 2 space heaters + laser printer, it
gets toasty. Keeping the door open helps a bit. I have a window
exhaust fan that I can use and it helps a bit. But all in all I think I
will need a booster fan. Plus a new computer desk that can vent the
heat out the back instead of the front into me.

--
Respectfully,


CL Gilbert

You also may wish to consider why the extra heat. Maybe you can cut
down on the heat if a lot of it is coming from windows or
underinsulated outside wall or whatever. I doubt the computers are
warming it up 12 degrees. I agree the return vent is probably
necessary, but there also may be air infiltration problems identified
that may mean hot air is coming in from outside and into the wall
cavities or from the floor (crawlspace or basement) or the temp of the
outside wall and windows on the inside is way high.

Just a thought. No sense adding a return air duct if the drywall
surface on the outside wall is 98 degrees, if you know what I mean...
blowing foam or cellulose into the uninsulated cavity or sealing it
from underneath if that's the problem will help tremendously.

One simple way to find out if heat is coming up through the floor and
into the wall cavities and heating up the drywall, which heats up the
room is to go into the crawlspace with incense stick or cigar or
something smoke producing and run it along the sill plate or rim joist
or whatever you want to call where the wall sits on the foundation, and
if it's hot down there and smoke is sucked up or blown away from the
plate, that's a problem easily addressed. If it's sucking in, it's
better than blowing out. If it's sucking in, it's sucking in the air
temperature in the crawlspace. If it's blowing out, you are sucking air
from the attic. HOT!

Simply sealing off the bottom of the cavity stops the "chimney effect"
so you don't have to seal off the attic side of the cavity.

Just a thought...

abi

I assume you've verified that all the ducts are connected correctly, ie
that none has fallen half apart from tape drying out, etc. Also make
sure any balance controls on the ducts going to the warm room are fully
open.

In addition to adding a return, which should help, there are several
other alternatives. There are booster blowers available that can be
inserted into a supply duct going to the area that is too hot. There
are also booster fans that can be placed over the vents. This type
senses when the air flow starts and turns itself on. I've tried the
first type and it definitely helped, though it's not fully effective.
Finally, you might want to consider adding a window unit to the room.
Of all the solutions, that one is guaranteed to work.

Usually this problem is the result of incompetent installers who didn't
run enough duct or return capacity to the farthest areas. And as
you've figured out, completely fixing it later isn't easy.

I agree with the below a small window unit(thermostat controlled)
sufficient to cool room with supply closed will keep room at a steady
temperature and can be chosen for being quiet.
A steady sound such as the ac fades into the background and also masks
sounds from other areas. Cost and time would probably be less than
installing return and possibly additional supply. Small efficfient
acs don't pull much current so that is not likely to be a problen
Stan



On 19 Aug 2005 16:00:12 -0700, wrote:

I assume you've verified that all the ducts are connected correctly, ie
that none has fallen half apart from tape drying out, etc. Also make
sure any balance controls on the ducts going to the warm room are fully
open.

In addition to adding a return, which should help, there are several
other alternatives. There are booster blowers available that can be
inserted into a supply duct going to the area that is too hot. There
are also booster fans that can be placed over the vents. This type
senses when the air flow starts and turns itself on. I've tried the
first type and it definitely helped, though it's not fully effective.
Finally, you might want to consider adding a window unit to the room.
Of all the solutions, that one is guaranteed to work.

Usually this problem is the result of incompetent installers who didn't
run enough duct or return capacity to the farthest areas. And as
you've figured out, completely fixing it later isn't easy.

Hi,

Thanks for all the good advice. A small window unit wouldn't be my first
choice as the room faces the front of the house and wouldn't look the best,
but thanks for the idea.

Thanks,

Alan

----------------------------------------------------------------------------------



www.sadevelopment.com - Home of the best disk utilities that you can't live

without. Try them for free; They require no operating system to work!

abi wrote:
You also may wish to consider why the extra heat. Maybe you can cut
down on the heat if a lot of it is coming from windows or
underinsulated outside wall or whatever. I doubt the computers are
warming it up 12 degrees. I agree the return vent is probably
necessary, but there also may be air infiltration problems identified
that may mean hot air is coming in from outside and into the wall
cavities or from the floor (crawlspace or basement) or the temp of the
outside wall and windows on the inside is way high.


Just one computer heats up my room. its toasty when I enter, but when I
turn on my gaming rig, 10 minutes its much warmer. Like I said,
equivalent to small space heater.


Just a thought. No sense adding a return air duct if the drywall
surface on the outside wall is 98 degrees, if you know what I mean...
blowing foam or cellulose into the uninsulated cavity or sealing it
from underneath if that's the problem will help tremendously.

One simple way to find out if heat is coming up through the floor and
into the wall cavities and heating up the drywall, which heats up the
room is to go into the crawlspace with incense stick or cigar or
something smoke producing and run it along the sill plate or rim joist
or whatever you want to call where the wall sits on the foundation, and
if it's hot down there and smoke is sucked up or blown away from the
plate, that's a problem easily addressed. If it's sucking in, it's
better than blowing out. If it's sucking in, it's sucking in the air
temperature in the crawlspace. If it's blowing out, you are sucking air
from the attic. HOT!

Simply sealing off the bottom of the cavity stops the "chimney effect"
so you don't have to seal off the attic side of the cavity.

Just a thought...

abi



--
Respectfully,


CL Gilbert

"Verily, verily, I say unto you, He that entereth not by the door() into
the sheepfold{}, but climbeth up some other *way, the same is a thief
and a robber."

GnuPG Key Fingerprint:
82A6 8893 C2A1 F64E A9AD 19AE 55B2 4CD7 80D2 0A2D

For a free Java interface to Freechess.org see
http://www.rigidsoftware.com/Chess/chess.html

Hi,

Just one computer heats up my room. its toasty when I enter, but when I
turn on my gaming rig, 10 minutes its much warmer. Like I said,
equivalent to small space heater.

It doesn't take much with the heat that processors generate these days...
I'm going to add a small return air vent to the room and see what happens,
hopefully it will improve things.

Thanks to everyone for the help,

Alan

----------------------------------------------------------------------------------

www.sadevelopment.com - Home of the best disk utilities that you can't live
without. Try them for free; They require no operating system to work!

Hi everyone,

I added a return air to my office bedroom last night and it is working great
so far. My office that had been running 85+ deg with the door shut is now
between 79 deg with the door shut. I have the thermostat set at 76 so it is
only 3 deg above the rest of the house instead of 9 deg above the rest of
the house.

Thanks for all the advice,

Alan