Replies

1. 
   popawheelie | Mar 01, 2008 05:50pm | #1

   There are a couple of things I thought of off hand that you should check before building. Radon could be introduced into the house through them. Drainage or slope in the tubes so there is a low humidity in them.

   We had a house down the street from us that had a pipe buried underground for air intake. The grill at the end was just off the street. The neighbor three houses up the street had a cesspool that had failed and he just ran his sewage into the ivy in the front yard. It would overflow most of the time and run down the street right in front of the grill. They blocked off the intake after they figured out what the neighbor was doing.

   the intake for the air was in the wrong place and the guy with the sewage... well what can i say?

1. 
   MikeSmith | Mar 01, 2008 06:05pm | #2

   i've got one... runs under the drive..... under the garage.... and into the basement

   30" aluminum culvert pipe.... about 60'

   me and  my nephews have crawled thru it a couple times about  '87 or so

   never did hook a blower up to it

   finally stuck a wall in front of it when we listed the house..... the real estate agent got tired of trying to explaing what it was all about

   Mike Smith Rhode Island : Design / Build / Repair / Restore

   Edited 3/1/2008 10:06 am ET by MikeSmith

2. 
   Bish | Mar 02, 2008 03:36am | #6

   Seem's as though radon wouldn't be a problem as long as all joints were sealed underground. I envisioned something like 4" sch 20 {sewer pipe} backfilled with sand down about 3-4' with the ends terminating above ground with protective enclosure and screening/filter, pitched for drainage, with blower in basement? I'm on 40 acres, next closest neighbor 1/4 mile away, surrounded by wooded ravines so no problem as far as sewers. I wouldn't be near my own septic either. Good thoughts though, thanks.

1. 
   popawheelie | Mar 02, 2008 04:47am | #9

   It seems pretty obvious but I just thought I'd bring it up. If the intake air is water laden it might condense on the walls of the pipe. It depends on you climate when you are using them. If you pitch the pipe to some location where the water can be dealt with it should be fine.

   Just an idea. I'm going to plant a couple a fragrant rose bushes by a window that we will open for ventilation. You could do the same with your intake terminations. there are some really nice plants you can use like lilacs or whatever suits your fancy. The house should smell real nice and your wife (if you have one) will be duly impressed.

   I plan to surround this window with the roses and maybe put an awning over it to channel in the rose scent. The roses are due here any day. I can't wait.

2. 
   Riversong | Mar 02, 2008 05:05am | #10

   The ones I've known of are much larger diameter pipes (plastic culvert would work well).  Think of the intakes as windows.  A 4" diameter window won't deliver much air without major power assist.

   The beauty of earth tubes is they can be part of a solar powered ventilation system - using the sun to cool your house!

   Ideally, a high glazed cupola or clerestory windows with operable vents would act as a solar chimney and create an updraft that would draw the cooled air in at ground level through the earth tubes.

   The two primary problems are moisture/mold and critters.

   A good overview is available here:

   http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12460

    

    

   Riversong HouseWright

   Design *  * Build *  * Renovate *  * ConsultSolar & Super-Insulated Healthy Homes

   Edited 3/1/2008 9:14 pm ET by Riversong

2. 
   jimblodgett | Mar 01, 2008 06:50pm | #3

   Have you read the book "Passive Annual Heat Storage" by John Hait?  Quite a bit of it is dedicated to earh tubes. 

   I'll eat your peaches, mam.  I LOVE peaches!

1. 
   Bish | Mar 02, 2008 03:37am | #7

   Thanks,
   I'll try and check it out.

1. 
   McPlumb | Mar 02, 2008 04:43am | #8

   I would like to suggest that you look around for a working system that is in use and the owners are happy with.

   There are some design issue's that should be researched.

   The smaller the pipe, the more resrtiction there will be.

   Larger pipe will allow more volume, with less friction from the side wall of the pipe.

   I have wanted to try this type of setup too.

   I just haven't done the homework to see what gives the best bang for the buck.

3. 
   craigf | Mar 01, 2008 10:20pm | #4

   A local radio station uses them to help cool their transmitter. Three or four large dia. PVC pipes sticking up out of the ground with some sort of homemade caps on them. I don't know what sort of fan, filter etc. is on the inside.

   Fairly arid climate here.

4. 
   craigf | Mar 01, 2008 10:28pm | #5

   The school in town was built in the 20's. Every room has a hollow chase to it which leads to the attic. On the roof is a large round vent.

   The chase is all closed off now and A/C installed.

   I've been told that they would open the vents into the chase and crack the windows at night. Convection would then pull the cool night air thru the building.

   Oldtimers said they can't remember being uncomfortably hot.

5. 
   IdahoDon | Mar 02, 2008 05:50am | #11

   Under the category of "fun projects for your own house" I came across an interesting idea that makes perfect sense for homes with radiant heat.  For each heating zone, an additional loop would be made under the frost line to the exterior of the building, say encased in a few inches of concrete alongside the footer.

   In the winter the external loops are shut off with valving and do not circulate water.  In the summer the external loops are opened up and the connection to the boiler is shut down. 

   This wouldn't solve the cooling problem completely and it would create a strange temperature differential (just as radiant heating in the ceiling does in the winter), but it was nonetheless interesting. 

   I have absolutely no idea how effective it would be or a rule of thumb for how long the tubes need to be on the exterior to make a difference.

    

    

   Beer was created so carpenters wouldn't rule the world.

1. 
   MikeSmith | Mar 02, 2008 06:02am | #12

   don.. i don't think it would be very effective... it might even cost more electricity to run the pumps than to run a few small window sized A/C's

   heat moves from hot to cold..so to chill the air it would have to give up it's heat to the floor, then the floor to the slab, the slab to the water and the water back to the earth

   very small delta-T's in each caseMike Smith Rhode Island : Design / Build / Repair / Restore

1. 
   IdahoDon | Mar 02, 2008 06:07am | #13

   You're probably right.  A big step up are the hydronic heating/cooling systems that I've only heard about in commercial applications, but there must be downsized versions.  It essentially runs chilled water through the pex for more heat transfer.  If the concrete has enough mass it would take care of itself in most situations. 

   Beer was created so carpenters wouldn't rule the world.

1. 
   BillHartmann | Mar 02, 2008 06:34am | #14

   One common system was an open loop radiant and during the summeer domestic water would be run through the slab before being used.The problem is that that to get much cooling the slab ahs to be cool enough that you often get condensation on the floor..
   .
   A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

2. 
   cargin | Dec 19, 2008 07:05am | #15

   Mike

   Bump.

   Rich