We have relatively new high efficiency gas furnaces that feed into 100
year old ductwork.

In particular, our 2 third floor bedrooms are fed off the same 9" riser
that feed the 2nd floor bedrooms underneath it. As a result, there is
much less heat reaching the third floor than the 2nd floor. 

Even adjusting the dampers at the takeoffs to the bedrooms has only
limited effect, since the airflow is just not powerful enough 3 floors
up.

So, I am wondering whether someone makes a booster blower that would sit
just below the 3rd floor vent grill and would not require ripping up the
walls, ceilings, or floors to install.

Note I know they make inline fans that it into the duct itself, but that
would seem to require breaking into the wall to access the duct. I want
something that would sit right underneath the vent grill.

On Jan 22, 9:24=A0am, blueman  wrote:
> We have relatively new high efficiency gas furnaces that feed into 100
> year old ductwork.
>
> In particular, our 2 third floor bedrooms are fed off the same 9" riser
> that feed the 2nd floor bedrooms underneath it. As a result, there is
> much less heat reaching the third floor than the 2nd floor.
>
> Even adjusting the dampers at the takeoffs to the bedrooms has only
> limited effect, since the airflow is just not powerful enough 3 floors
> up.
>
> So, I am wondering whether someone makes a booster blower that would sit
> just below the 3rd floor vent grill and would not require ripping up the
> walls, ceilings, or floors to install.
>
> Note I know they make inline fans that it into the duct itself, but that
> would seem to require breaking into the wall to access the duct. I want
> something that would sit right underneath the vent grill.

is the vent into the third floor in the floow or on the sidewall.  You
could mount a fan in either location if you have a way to get
electricity to the fan.

On Jan 22, 9:24=A0am, blueman  wrote:
> We have relatively new high efficiency gas furnaces that feed into 100
> year old ductwork.
>
> In particular, our 2 third floor bedrooms are fed off the same 9" riser
> that feed the 2nd floor bedrooms underneath it. As a result, there is
> much less heat reaching the third floor than the 2nd floor.
>
> Even adjusting the dampers at the takeoffs to the bedrooms has only
> limited effect, since the airflow is just not powerful enough 3 floors
> up.
>
> So, I am wondering whether someone makes a booster blower that would sit
> just below the 3rd floor vent grill and would not require ripping up the
> walls, ceilings, or floors to install.
>
> Note I know they make inline fans that it into the duct itself, but that
> would seem to require breaking into the wall to access the duct. I want
> something that would sit right underneath the vent grill.

We always think first about boosting input, but flow requires that
input to get back to the furnace. Any chance that too many closed
doors might be part of the problem? Or blocked/inadequate returns?

Joe

blueman wrote:
> We have relatively new high efficiency gas furnaces that feed into 100
> year old ductwork.
>
> In particular, our 2 third floor bedrooms are fed off the same 9"
> riser that feed the 2nd floor bedrooms underneath it. As a result,
> there is much less heat reaching the third floor than the 2nd floor.
>
> Even adjusting the dampers at the takeoffs to the bedrooms has only
> limited effect, since the airflow is just not powerful enough 3 floors
> up.
>
> So, I am wondering whether someone makes a booster blower that would
> sit just below the 3rd floor vent grill and would not require ripping
> up the walls, ceilings, or floors to install.
>
> Note I know they make inline fans that it into the duct itself, but
> that would seem to require breaking into the wall to access the duct.
> I want something that would sit right underneath the vent grill.

Google heat vent booster.

"blueman" <N...@nospam.com> wrote in message 
news:m...@consult.pretender...
> We have relatively new high efficiency gas furnaces that feed into 100
> year old ductwork.
>
> In particular, our 2 third floor bedrooms are fed off the same 9" riser
> that feed the 2nd floor bedrooms underneath it. As a result, there is
> much less heat reaching the third floor than the 2nd floor.
>
> Even adjusting the dampers at the takeoffs to the bedrooms has only
> limited effect, since the airflow is just not powerful enough 3 floors
> up.
>
> So, I am wondering whether someone makes a booster blower that would sit
> just below the 3rd floor vent grill and would not require ripping up the
> walls, ceilings, or floors to install.
>
> Note I know they make inline fans that it into the duct itself, but that
> would seem to require breaking into the wall to access the duct. I want
> something that would sit right underneath the vent grill.

I haven't seen you around for a while.  Nice to know you are still here.

What size is the boot or grill area?  I imagine some field engineering can 
be done.

One of those hassock type fans sat over a floor register or a cheap box fan 
in front of a wall register might let you test the concept at minimal 
expense.

Colbyt 

On Jan 22, 9:24=A0am, blueman  wrote:
> We have relatively new high efficiency gas furnaces that feed into 100
> year old ductwork.
>
> In particular, our 2 third floor bedrooms are fed off the same 9" riser
> that feed the 2nd floor bedrooms underneath it. As a result, there is
> much less heat reaching the third floor than the 2nd floor.
>
> Even adjusting the dampers at the takeoffs to the bedrooms has only
> limited effect, since the airflow is just not powerful enough 3 floors
> up.
>
> So, I am wondering whether someone makes a booster blower that would sit
> just below the 3rd floor vent grill and would not require ripping up the
> walls, ceilings, or floors to install.
>
> Note I know they make inline fans that it into the duct itself, but that
> would seem to require breaking into the wall to access the duct. I want
> something that would sit right underneath the vent grill.

Ive seen ones that plug into 120v and come on with airflow that fit on
top a register like you mention but I dont know if they do anything,
before just closing off registers you need to know and monitor the
temp of the exchanger, reducing airflow can run it hotter than the
design temp, overheat it and kill its life. You just drill a hole
above the exchanger and insert a probe Meat-cooking type of
thermometer. Booster Fans can easily be installed in the basement
ductwork

"hr(bob) h...@att.net" <hrh...@att.net> writes:
> On Jan 22, 9:24 am, blueman  wrote:
>> We have relatively new high efficiency gas furnaces that feed into 100
>> year old ductwork.
>>
>> In particular, our 2 third floor bedrooms are fed off the same 9" riser
>> that feed the 2nd floor bedrooms underneath it. As a result, there is
>> much less heat reaching the third floor than the 2nd floor.
>>
>> Even adjusting the dampers at the takeoffs to the bedrooms has only
>> limited effect, since the airflow is just not powerful enough 3 floors
>> up.
>>
>> So, I am wondering whether someone makes a booster blower that would sit
>> just below the 3rd floor vent grill and would not require ripping up the
>> walls, ceilings, or floors to install.
>>
>> Note I know they make inline fans that it into the duct itself, but that
>> would seem to require breaking into the wall to access the duct. I want
>> something that would sit right underneath the vent grill.
>
> is the vent into the third floor in the floow or on the sidewall.  You
> could mount a fan in either location if you have a way to get
> electricity to the fan.

Vent is in the floor approx 4x12"

I have power in the wall nearby but was hoping ideally for a low voltage
solution so that I could run wiring under the carpeting and into the
vent without safety/code issues.

Joe <j...@aol.com> writes:
> On Jan 22, 9:24 am, blueman  wrote:
>> We have relatively new high efficiency gas furnaces that feed into 100
>> year old ductwork.
>>
>> In particular, our 2 third floor bedrooms are fed off the same 9" riser
>> that feed the 2nd floor bedrooms underneath it. As a result, there is
>> much less heat reaching the third floor than the 2nd floor.
>>
>> Even adjusting the dampers at the takeoffs to the bedrooms has only
>> limited effect, since the airflow is just not powerful enough 3 floors
>> up.
>>
>> So, I am wondering whether someone makes a booster blower that would sit
>> just below the 3rd floor vent grill and would not require ripping up the
>> walls, ceilings, or floors to install.
>>
>> Note I know they make inline fans that it into the duct itself, but that
>> would seem to require breaking into the wall to access the duct. I want
>> something that would sit right underneath the vent grill.
>
> We always think first about boosting input, but flow requires that
> input to get back to the furnace. Any chance that too many closed
> doors might be part of the problem? Or blocked/inadequate returns?

Poor returns are undoubtedly contributing since the only returns are in
the open first floor hall (which is open to the 2nd floor though the
stairway to the third floor is enclosed).

In the future when we renovate, we will need to add returns on the 2nd
and 3rd floor (particularly since we want to add AC) but in the short
term there is no easy way to fix that situation since there are no
obvious open chases, stacked closets etc. going up to the 3rd floor.

So that together with the fact that the supply duct is shared with the
2nd floor makes me think that the best near-term solution would be to
boost flow from the terminal end. But obviously I am open to other
suggestions if they are easier/simpler...

ransley <M...@Yahoo.com> writes:

> On Jan 22, 9:24 am, blueman  wrote:
>> We have relatively new high efficiency gas furnaces that feed into 100
>> year old ductwork.
>>
>> In particular, our 2 third floor bedrooms are fed off the same 9" riser
>> that feed the 2nd floor bedrooms underneath it. As a result, there is
>> much less heat reaching the third floor than the 2nd floor.
>>
>> Even adjusting the dampers at the takeoffs to the bedrooms has only
>> limited effect, since the airflow is just not powerful enough 3 floors
>> up.
>>
>> So, I am wondering whether someone makes a booster blower that would sit
>> just below the 3rd floor vent grill and would not require ripping up the
>> walls, ceilings, or floors to install.
>>
>> Note I know they make inline fans that it into the duct itself, but that
>> would seem to require breaking into the wall to access the duct. I want
>> something that would sit right underneath the vent grill.
>
> Ive seen ones that plug into 120v and come on with airflow that fit on
> top a register like you mention.
I was hoping for something that would sit inside the register since the
register is on the floor. Also, low voltage would be preferable since I
wouldn't need to worry about properly routing line voltage but instead
could use a low voltage wire running under the carpet.

> before just closing off registers you need to know and monitor the
> temp of the exchanger, reducing airflow can run it hotter than the
> design temp, overheat it and kill its life. You just drill a hole
> above the exchanger and insert a probe Meat-cooking type of
> thermometer. Booster Fans can easily be installed in the basement
> ductwork

My concern over adding the booster fan in the basement is that the
ductwork for each side of the 3rd floor is shared with the same side of
the 2nd floor. So, a push solution would probably end up boosting flow
more to the 2nd floor (since the ducts feeding the 2nd floor rooms are
not only closer but also much larger).

Again, the root of the problem is of course a system design issue but
until we renovate, I am looking for an interim solution.

"Bob F" <b...@gmail.com> writes:
> blueman wrote:
>> We have relatively new high efficiency gas furnaces that feed into 100
>> year old ductwork.
>>
>> In particular, our 2 third floor bedrooms are fed off the same 9"
>> riser that feed the 2nd floor bedrooms underneath it. As a result,
>> there is much less heat reaching the third floor than the 2nd floor.
>>
>> Even adjusting the dampers at the takeoffs to the bedrooms has only
>> limited effect, since the airflow is just not powerful enough 3 floors
>> up.
>>
>> So, I am wondering whether someone makes a booster blower that would
>> sit just below the 3rd floor vent grill and would not require ripping
>> up the walls, ceilings, or floors to install.
>>
>> Note I know they make inline fans that it into the duct itself, but
>> that would seem to require breaking into the wall to access the duct.
>> I want something that would sit right underneath the vent grill.
>
> Google heat vent booster.

Thanks very helpful - I tried googling before but did not know what to
call it.