Replies

1. 
   MikeHennessy | Jun 28, 2009 03:21pm | #1

   I've done this many times. I usually use rectangular ductwork the same dimension as the outlet register. Makes for fewer transitions and better air flow.

   In this one, the original floor register was under what is now a bookshelf cab on the right. I ran 4" X 10" duct under the cab base and cut registers under the window seat.

   View Image

   Mike Hennessy
   Pittsburgh, PA
   Everything fits, until you put glue on it.

1. 
   dlb | Jun 28, 2009 07:36pm | #6

   Thanks for the reply.

   Another question, if you don't mind. Does the toe kick register need to contain the same number of square inches as the one on the wall?

   Thanks,

   dlb

   .

    The undisciplined life is not worth examining.

1. 
   MikeHennessy | Jun 28, 2009 11:53pm | #7

   All you need to be sure of is that generally the opening should be equal to, or greater than, the cross sectional area of the duct delivering the conditioned air from the furnace. E.g., for a 6" round duct, you'd want a vent with at least 28 in sq. opening. So if you have 6" ducts, a 3" X 10" vent would be fine.Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.

1. 
   dlb | Jun 29, 2009 12:05am | #8

   so, the number of square inches is not dependent upon the opening size but the diameter of the duct work. I was not aware of that but it certainly will make things easier knowing that.

   Thanks,

   dlb

   .

    

   The undisciplined life is not worth examining.

   Edited 6/28/2009 8:22 pm ET by dlb

2. 
   Pondfish | Jun 28, 2009 04:07pm | #2

   try to maintain the same pipe dimensions from the wall to the toekick.  I also have had much better experience going to a HVAC supply house (than HD/Lowes) to get different sized boots and vent pipe.

   Avoid rectangular to round transitions, as this reduces airflow and can lead to a whistle or oher noise being created in the vent.

   Recommending the use of "Hide Signatures" option under "My Preferences" since 2005
3. 
   Jamie_Buxton | Jun 28, 2009 06:05pm | #3

   Why do you need a duct from the wall to the front of the toekick?   If you had no duct there, what's going to happen to the warm air?  It is still going to get delivered to the room. 

1. 
   MikeHennessy | Jun 28, 2009 07:12pm | #4

   "Why do you need a duct from the wall to the front of the toekick?"

   Cause hot furnace air, or cold A/C air, blowing through the underside of cabinetry tends to wreak havoc with the wood. Ducting is always best.

   Mike HennessyPittsburgh, PAEverything fits, until you put glue on it.

   Edited 6/28/2009 12:12 pm ET by MikeHennessy

2. 
   dlb | Jun 28, 2009 07:33pm | #5

   Thanks for the reply.

   I need duct work because I believe that using the space between the floor and cabinet bottom as a plenum would produce ill effects on the cabintry.

   dlb

   .

    The undisciplined life is not worth examining.

1. 
   Jamie_Buxton | Jun 29, 2009 01:05am | #9

   Well, this is your house, so your intuition rules.   But I don't think the heated air would have a big effect on plywood.   The air is somewhat warmer than the room air -- perhaps ten or fifteen degrees -- and somewhat lower relative humidity because it has been warmed.   That's just not a big difference.

1. 
   dlb | Jun 29, 2009 01:57am | #10

   Thanks for the reply. I have done some research on venting beneath cabinets and have not found anyone stating that it is O.K. to use the space below the cabinet as a plenum.  So, I must go w/ what I consider the most prevalent view.  And it is not my house so I would rather err on the side of caution.

   dlb

   .

    The undisciplined life is not worth examining.

1. 
   TerryBrogan | Jun 29, 2009 02:26am | #11

   Just put a piece of drywall on the bottom of the window seat. It won't absorb heat, it protects the underside of the wooden cabinet, and it deflects warm air into the room. Works fine.

2. 
   polarsea1 | Jun 29, 2009 05:48am | #12

   I just finished doing this in a bathroom I'm remodeling. I cut the wall vent down to floor level with a sawzall, removed the waste piece, then measured and had the local sheet metal shop make me an L shaped vent that would fit into the original hole (just a short spout on the turndown). To make it easier to install they made the part that came to the toekick so that it telescoped. Installed it, caulked it, taped it: no problems.

3. 
   dlb | Jun 29, 2009 03:30pm | #13

   Thanks for the reply. I checked into the same idea but upon review I designed the plenum too big so i am revisiting that issue. I do like your idea of making it telescoping - that would surely make the installation easier. Thanks for the idea!

   dlb

   .

    The undisciplined life is not worth examining.

3. 
   dane_j | Jul 01, 2009 03:52am | #21

   I believe that it is required by code. For any opening into the wall, the transition must be covered or protected by flame proof material. <!----><!----><!---->

   Code aside... it is just good workmanship!

4. 
   oldusty | Jun 29, 2009 09:54pm | #14

     You can also use one of the simple little scoop fixtures readily available , it will direct the air flow to the front of the opening or ducting.

             I have had some folks make them out of sheet metal and hook them up to a register .

      Anymore I try and slot the top of the toe kick under the floor of the cabinet to closely equal the volume of the floor vent.This way they are out of sight .

      The   Better and Best plans have the registers and vents in less high profile locations where they won't detract from the beauty. It's many of these small details that take fore thought and planning skills , that make the difference .

                 regards   dusty

5. 
   GaryW | Jun 29, 2009 10:15pm | #15

   I've been using the space within the toekick as a "plenum" for years, just getting the HVAC guy to vent up through the floor, and then cutting in a register in the face of the kick.

   Gary W

   gwwoodworking.com

1. 
   DonaldCBrown | Jun 30, 2009 02:50am | #16

   Gary-Using the space under the cabinet as a plenum is probably fine for heating. It might not be the thing to do for cooling, though.When I built my present house, the HVAC contractor did as you describe: ran the duct through the floor and told me to cut an outlet in the toe kick when I installed the cabinets.There is a crawl space beneath my house, and I live in an area of very high summer humidity. The conditioned air pooling beneath the cabinet could bring the temperature of the the subfloor in that area well below the dew point of the unconditioned air in the crawl space.The net result was that water collected on the underside of the supfloor and wicked to a broader area than just the cabinet spot. When I began to feel soft spots in the kitchen area, I removed some tile and discovered large areas of rot. Water had also been trapped between the subfloor and joists.I ended up replacing most of the kitchen subfloor and six joists.The HVAC contractor says he no longer uses the plenum scheme; he runs insulated duct all the way to an outlet in the toekick.Don

1. 
   GaryW | Jun 30, 2009 03:03am | #18

   Donald,

   That makes good sense, but I wonder we could lay sheet foam insulation on top of the sub-floor within the toe-kick "plenum," and maybe one under that floor, within the crawl space. 

   Insulated duct makes good sense, and labor and material might be less than that to lay in insulation.Gary W

   gwwoodworking.com

2. 
   oldusty | Jun 30, 2009 05:15pm | #19

   Donald ,

           Thats interesting so much damage was from the conditioned air pooling under the cabinet space . Why was the air not being moved through the vent , how does it get to pool ?

         Was any liability taken by the hvac guys ?

        This has been a standard way for years and yours seems an isolated and extreme case of condensation and humidity and such .

      regards    dusty

1. 
   DonaldCBrown | Jun 30, 2009 05:55pm | #20

   dusty-I found it pretty interesting, also. Some details:- The incoming air was from a duct terminated at the floor and pointing upwards. Thus there was a turbulent flow toward the outlet, allowing ample time for cooling of the floor.- Air temperature at the duct outlet was about 50 degrees F, according to the HVAC guy.- The damage wasn't noticed for a long time. The condensation on the subfloor may have been going on for six summers.- The underside of the floor was insulated with fiberglass batts, thus hiding from casual view the water pooling on the underside of the subfloor. I had worked in the crawlspace a number of times over the years without suspecting anything. When I did investigate the softening of the floor and pulled out the insulation, there was a film of moisture over a wide area and drops of water forming. The fiberglass had absorbed the drops without showing obvious wetness.I concluded before I contacted the HVAC contractor that my goal was to get the problem fixed. I had no desire to get into a fight about liability, so I assured him at the start that I simply wanted to report information that might be useful to him in his business. He was kind of defensive, but when he told me that water couldn't condense on the subfloor because it wasn't metal I figured we didn't have much of offer each other. He did say that they had stopped doing kitchen outlets that way several years before; he didn't say why.I agree with you that the plenum method has been standard practice for a long time. Most houses in this area are built on slabs, but crawl spaces are not that unusual.

2. 
   oldhand | Jun 30, 2009 03:02am | #17

   That's what the HVAC guys have always told me to do. Never have had any bad feed back about it..

3. 
   cowtown | Jul 01, 2009 05:31am | #22

   Gary was sayin.....

    

   I've been using the space within the toekick as a "plenum" for years

   ******************************************

   Hey, so yer the guy that all them duct cleaners are lookin for....

   And all the pest control folks too....All that extra space, heated too, is an excellent place for mouse nests and dust to accumulate.

   Of course buying a 3x10 corner and a couple of feet of 3x10 duct is just a huge expense due to all the time it takes, certainly not for the cost of materials. And I realize that a pair of tin snips ain't in every cabinetmakers tool box.

   Last job, the HVAC guy offered me a job (joking) and then said he was impressed. At least he didn't call me lazy  eh?

   And somewhere, methinks the fire code folks would object to heat ducts to be dumped into blind spaces, but I'm just guessin there.

   Eric in Calgary