I have a shop building with central hvac and I wanted to reduce the air flow
on one side of a divider wall (about 35% of the floor space) and add flow to
the other side. I figure on adding registers and maybe another run on the
"warm" side. On the "cold" side, would restriction of flow at the
registers be OK, or is it better to restrict the ductwork run near the
plenum?
Thanks
Bill

"bill a" wrote in message
news
I have a shop building with central hvac and I wanted to reduce the air
flow
on one side of a divider wall (about 35% of the floor space) and add flow
to
the other side. I figure on adding registers and maybe another run on
the
"warm" side. On the "cold" side, would restriction of flow at the
registers be OK, or is it better to restrict the ductwork run near the
plenum?
Thanks
Bill


Its called get a new manual D ran, and adjust accordingly. You dont just go
slapping in a new run, and registers.

And normally, (ok..its rare..not everyone goes out and buys the balometer)
someone that knows how to do the D will also be able to insure that the
airflow at the room is what it should be...

On Mon, 06 Dec 2004 15:31:32 GMT, "bill a"
wrote:

I have a shop building with central hvac and I wanted to reduce the air flow
on one side of a divider wall (about 35% of the floor space) and add flow to
the other side. I figure on adding registers and maybe another run on the
"warm" side. On the "cold" side, would restriction of flow at the
registers be OK, or is it better to restrict the ductwork run near the
plenum?
Thanks
Bill

You can do it yourself and you don't need a manual D.
You have the right idea, except you may want to just increase the size
of the duct to the side you want more air on. And after that you can
can fine tune with restricting the air on the side you want less air
in.



Pj

thanks
btw, what is a manual D, a sizing calculation method?
bill

"PJx" wrote in message
...
On Mon, 06 Dec 2004 15:31:32 GMT, "bill a"
wrote:

I have a shop building with central hvac and I wanted to reduce the air
flow
on one side of a divider wall (about 35% of the floor space) and add flow
to
the other side. I figure on adding registers and maybe another run on
the
"warm" side. On the "cold" side, would restriction of flow at the
registers be OK, or is it better to restrict the ductwork run near the
plenum?
Thanks
Bill

You can do it yourself and you don't need a manual D.
You have the right idea, except you may want to just increase the size
of the duct to the side you want more air on. And after that you can
can fine tune with restricting the air on the side you want less air
in.



Pj

bill a wrote:
thanks
btw, what is a manual D, a sizing calculation method?
bill

Yes a manual D is a calculation method of determining Duct size. It is
the right way of doing it to make sure everything will work properly and not
cause future problems. I suggest you find some to do the manual D.

"PJx" wrote in message
...
On Mon, 06 Dec 2004 15:31:32 GMT, "bill a"
wrote:

I have a shop building with central hvac and I wanted to reduce the
air flow
on one side of a divider wall (about 35% of the floor space) and
add flow to
the other side. I figure on adding registers and maybe another
run on the
"warm" side. On the "cold" side, would restriction of flow at the
registers be OK, or is it better to restrict the ductwork run near
the plenum?
Thanks
Bill

You can do it yourself and you don't need a manual D.
You have the right idea, except you may want to just increase the
size of the duct to the side you want more air on. And after that
you can can fine tune with restricting the air on the side you want
less air in.



Pj

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

I will get someone to look at it. The existing equipment needs to be
checked out anyway.
thanks
Bill

"Joseph Meehan" wrote in message
...
Yes a manual D is a calculation method of determining Duct size. It is
the right way of doing it to make sure everything will work properly and
not cause future problems. I suggest you find some to do the manual D.

On Mon, 06 Dec 2004 22:25:41 GMT, "bill a"
wrote:

I will get someone to look at it. The existing equipment needs to be
checked out anyway.
thanks
Bill

"Joseph Meehan" wrote in message
.. .
Yes a manual D is a calculation method of determining Duct size. It is
the right way of doing it to make sure everything will work properly and
not cause future problems. I suggest you find some to do the manual D.

No, you don't need a manual D. Take the money you would waste on a
manual D and spend it on a nice thermometer and you will be far better
served. You live in the house so you can 'adjust' the air flow to
get it just like you want it. Anyway, A manual D doesn't account for
many of the variables that change the temperatures of various rooms.
(Like my dog standing with his head stuck out the doggie door or my
daughter taking a 2 hour shower with scalding water)

Hey Bill,
Resriction of duct work anywhere is never ok! Static pressure drop is
the enemy of air flow and would only increase with any kind of
restriction. The duct work should simply be re-arrainged to dump more
air where you need it and less air where you dont.
Because or static pressure you can only put so much air so far thru a
certain size pipe, thats the physics of air flow. I guarentee your duct
system is not "oversized" , so, any increase in static pressure will
back up all the way to the coil and actually to the blower squirell cage
and decrease flow over the coil, which at 400 cfm per ton of refrigerant
will decrease the total efficiency of your hvac equipment.