How tough was it to install a "sub-air" system under the greens at AGNC?

[David_Tepper]

Given the significant slopes & contours of the greens, I am curious how tough it likely was to install a "sub-air" system under the greens at AGNC from an engineering point of view.  Does the system use rigid pipes, flexible tubing or a combination of both? Is it important to keep the pipes/tubing a fairly constant depth below the surface of the green?

If rigid pipes are used, how is it done on greens with as much slope and contour as the ones at AGNC? It seems like it might require dozens and dozens of joints of various angles to connect the pipes on each green, so that the underground system can track the surface of the green reasonably well.

Does anyone know how this was done?         

[Don_Mahaffey]

David,
Sub-air is basically a vacuum attached to the green's drainage system.
There is a little more to it then that but in essence if a green has been built with the proper drainage system then sub-air can usually be added. Often the largest expense and biggest headache about installing a sub-air system is the power runs to each green. Because of this and the cost involved with having a permanent system at each green courses will often have a portable unit that can be towed out to greens that need drying out.

[David_Tepper]

Don -

Thanks for your response. I assumed the sub-air system was separate from the basic drainage system under the greens.

As it is not, I guess the question becomes how tough is it to install the piping/tubing of a drainage systems on greens with the slopes & contours of the ones at AGNC?

DT
 

[John Moore II]

David-Any difficulty involved in the installation of sub-air and drainage, etc., would be more than offset by the mountains of money that ANGC has. To install a sub-air system after a green is constructed might be difficult, but when installed as part of new construction, it would likely be easier. These things work really well though.

[Tim Nugent]

As Don pointed out - it's really just an air pump attached to the drainage piping.  In the vaccum mode it puts a negative pressure at the bottom of the greens profile, drawing air/water down and out the drainage.  It can also be reversed an force air up through the profile. This can help early in the season when the ground is cold or frozen and you wish to "warm it up". It works best when used in conjunction with a USGA style profile as the pea stone layer help diffuse/broaden the pressure differential.

[Mark Luckhardt]

A select few of our clients have reported some minor success hooking up the Sub Air to our internal greens drainage systems. As Tim states, the ability to use the peastone layer to broaden out the effect of the air movement is the most successful use of this technology.

As to the difficulty of installing our drainage system on Augusta's greens, my staff would relish the challenge as they often work on some of the more highly contoured greens in the country, recently several Walter Travis clubs with several original greens. Those were challenging.

[David_Tepper]

Guys -

Thanks for the info, but I have not gotten the answer I was looking for. Let me re-phrase the question - when installing the piping of a drainage system on a green with sizable and appreciable slopes/contours (such as the ones at AGNC), how do you deal with getting the pipes to move from one level to another? Are angled joints or flexible tubing used?

DT       

[Marty Bonnar]

Are angled joints or flexible tubing used?

DT       

David,
a combo!

We mostly use wavincoil which is a bendy pipe which comes in various diameters. Connections are made with moulded joints.
Check it out:
http://www.wavin.co.uk/

cheers (and see you soon!?)
FBD.

[Tim Nugent]

We would need some on-site info from the super or contractor but in general, pipes would be installed in a herring-bone or flag pattern.  HB utilize 45 degree Y's and flag's - T's.  The pipe itself may be either single walled or dual walled(single crushes easier but since we're talking existing putting greens, not much chance of that).  Single is very flexible while dual is rigid - but you force multiple, small, kink bends.  So, getting it to conform wouldn't be much a problem.  Also, remember that it isn't necessary for the underground gradient exactly match the surface contours.
I would think in old soil greens would yield a poorer result and may require more closely spaced pipes.

[Tim_Cronin]

David, try this link: http://subairsystems.com/SubAir/Works.htm

FYI, SubAir was invented by the former super at ANGC, and installed there first, beginning at the 12th green.

[Alan FitzGerald CGCS MG]

Guys -

Thanks for the info, but I have not gotten the answer I was looking for. Let me re-phrase the question - when installing the piping of a drainage system on a green with sizable and appreciable slopes/contours (such as the ones at AGNC), how do you deal with getting the pipes to move from one level to another? Are angled joints or flexible tubing used?

DT       

David the simple answer to your question is the slopes/contours don't matter to the drainage. The pipes have to drain, so are installed with a fall, they can't drain if they follow the contours up and down! The subair (as mentioned) blows through the drainage system and works best with a gravel layer to 'disperse' the air, so again the position of pipe doesn't really matter. Remember also that in a properly built USGA spec green the subsoil, gravel layer, choker layer (if it's included) and the final surface should all have the same contours to ensure it performs properly but the drainage pipe is installed underneath at whatever depth it needs to be to provide positive flow.

As for adding the system into an existing green, it all depends on the greens construction. If it's a properly built USGA spec green with internal drainage then you can hook it up to the existing drainage either with a portable unit or if you have the money by adding a permanent unit. As for an old push-up green I'm sure you would possibly get some benefit with a modified profile with XGD/TDI type drainage (but as Mark said, I can see its limitations as the tightness of the soil would restrict airflow) so ideally if you really wanted subair, in this senario the green would have to be rebuilt to USGA specs and have it added at that time.

[Bruce Wellmon]

THE best greens I've ever played on ALL seem to have SubAir systems.
My question is does the SA system keep the greens a constant temperature? Or is it moisture related only? I ask this because of the snow pics of Augusta National a few weeks ago. The SA greens had no snow and the others had snow. Other than temperature, could someone explain .   

[Tim Nugent]

Both, while it can aid in the evacutation of excess moisture, it also allows one to moderate the soil temperature (and canopy temperature).  When it snowed at AGNC, the ground was not frozen, so by pushing air up through the profile, it would naturally warm to something greater than freezing and melt the snow.  The same works in hot weather.  The warm air is pushed through cooler sub-surface soil and it cools, which in turn lowers the critical inch above the turf (the canopy zone) which can get to over 100 degrees.
Moisture carries latent heat (the reason an air conditioner works is it dehumidifies your house).