I am planning a family room in my basement. I want to provide heat/air
conditioning to this new room by tapping into the existing forced air
central system. Maybe I'm missing something but the work does not appear to
be difficult nor requiring great skill.
Does anyone know of a book which an absolute beginner can use to do some
simple ducting work? The book should contain details of tools needed and air
flow balancing, etc.
thats the problem, the balancing of the air//// most homes that were
built had an a/c heat system designed for that house.. it was done with
calculations by the a/c heat guy who went to school for this,, now you
come along and plan the mess with the even flow of the air to the
house... and are looking for a BOOK on doing it???? even with a book,
you still have to realize that the ducting was not figured into the
original, so you have to take off the added air to make sure the
original is correct before you mess up the original air flow.........
Jim is correct but you should be able to work this out if your heating and
AC system has any excess capacity left.
If your furnace is in the basement, the best bet would be to come directly
off the plenum (the chamber where the air comes out of the unit, where all
the other vents are tied in). This way you won't be upsetting the balance of
the existing ducts.. The output from the existing vents will be slightly
deminished but you could control this by putting a damper in the new duct so
you could turn it off if your need all the heat upstairs.
Last but not least, you need to provide for air return to the air handler..
This is normally from one central return air register in the main part of
the house.. If you fail to provide a return from the basement you will be
pumping air into the basement and all of it will have to find a way upstairs
to reach the return duct. This would carry damp or dusty air from the
basement into the main house.. Also, if you ever closed the basement door to
the upstairs, the basement would be come pressurized and that would cause
the excess warm air to escape through cracks or up the chimney, via the
furnace fire box.
If you can't find a book on doing vent ducting, check at HD and see if they
have a class scheduled..
It's not obvious to me that sucking musty air from the basement into the
heating system and distributing it evenly throughout the house is particularly
better than driving it out under the cellar door. If that's likely to be a
I'd invest in better than average filters for that branch.
Yea, but it may not work well. The heating and cooling system for you
home is just that, a complete system custom designed for your home. Messing
with it can result in some unpleasant results.
You need to get a good professional in, who can do the proper
measurements and calculations for total heat load, cooling load and
distribution and see if your system might have the excess capacity to handle
it. If not they can suggest the best alternative for your specific
I don't have suggested reading. But, I know my neighbor quickly found
that cooling his newly finished basement required more cooling tonnage
than his existing A/C provided. The heating was adequate. Lots of
factors to consider. It might be cheaper to add stand alone heating
and/or cooling to the newly finished space. Consider professional
evaluation or two--many times they will give one free in hopes for a
I concur 100%. I have an HVAC guy whose anal retentiveness would make
Felix Unger look like a garbage picker, and there's far more involved in
a lot of HVAC issues than simply slapping up some duct work after
reading a book as the person who started this thread wants to do. In
fact, he was just here yesterday explaining to my in-laws how something
within the AC system installed in their newly-purchased used home could
produce some corrosion problems down the line because of acid-laden
moisture produced by a system that really wasn't the best deal the
owners could/should have installed in the first place.
It's probably just me, but IMO if shit like HVAC, structural
engineering, fine carpentry, golf, and understanding what women really
want were obtainable by simply reading a book, everyone and his brother
would be out doing it.
They are understandable if you have a good book and know how
to study. You are confusing understanding with finger
dexterity, art, and experience. If people read the damn
manuals, they wouldn't have to hire some one to teach them
how to use a word processor and they wouldn't suddenly be
surprised after 2 years call a repairman when they didn't
realize that they had to push on the brake pedal to move the
For a simple one story system, not much knowledge is needed
and very little thought is put into the design of the
distribution system. You just run ducts (all the same size)
to every room to an outside wall and usually under a
window. If the room is fairly big you run two ducts to the
room. Many smaller houses have a single or a two ducts for
the return. If you design it yourself the only decision is
the size of the distribution tubes (only about 3 size
available) which you will make based mostly on economics and
do some math to figure out the size of the return(s). We
aren't talking about an office building.
Much interesting stuff in this thread. In the interests of keeping my
original post to a reasonable length I had to omit some things. My basement
is fully heated and cooled in the original design. There are four registers
set into the plenum. By dividing off part of the basement with a wall and
then directing say, two of the register outputs into that walled off space
(plus returns) I shall not be disturbing overall air flow to the basement or
to any other part of the house.
In the past I have found I provide much better heating/cooling to previous
houses by deliberately adjusting the registers for winter and summer. In the
winter I close off most of the upstairs registers while in the summer I open
the upstairs registers and close off most of those downstairs. This may not
be good practice but it has worked for me for 30+ years.
As to book learning. I hail from another country where regulations and
standards are different (not inferior). In the US I had an extension built
on one of my houses. After reading some books I did most of the framing, the
electrics, the plumbing, the drywalling, the taping and the painting. I did
NOT do the ceilings in drywall nor did I do the mud skim on the drywall.
These two items were far too difficult for me requiring skill and experience
which I did not possess. At the appropriate stages during the project local
building inspectors came to check out my project. There were very few
My whole life has been dependant on reading good books rather than going to
schools. Even when you go to schools the instructors will usually tell you
to read books or instruct from books. Carefully reading books, manuals and
regulations is 90% of the learning process. The remainder is common sense.
However, I must observe that must compilations of Regulations (Building
Codes) represent the worst English I have ever seen.
And I really would like a recommendation for a good book on ducting.
I designed the heating and cooling system for my house and started out
thinking that would be easy. I found it to be one of the most time
consuming efforts I've undertaken. Properly addressing the variations
caused by solar heating changes throughout the year, wind driven
cooling, humidity changes, air infiltration and zoning interactions plus
specifying the needed insulation took a long time. I'm happy I spent
the time because we have no drafts and uniform heating and cooling
throughout while our neighbors constantly complain. The added benefit
is that I heat the house and all hot water in a 6,000 sq ft house for
less than 900 gallons of oil per year.
If you know how to do this the benefits are tremendous. If you don't it
may be daunting. When I started mine (early 90s) I bought a text
published by Prentice-Hall (don't recall the author but he was a
licensed Professional Engineer) It had so many significant errors in it
that I discarded it and started from scratch, so be wary of books that
purport to tell you how to do it. Make sure the author knows what he's
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