# HVAC refrigerant piping underground?



## earshavewalls (Mar 5, 2013)

I have never seen it, but a homeowner is asking about placing the refrigerant lines underground to be able to install an arcadia door at the master bedroom (at an existing window). I have not seen this done before and cannot find anything in the California Codes to allow or dis-allow the installation. What I have seen is many manufacturers of compressors/condensers have specified that none of the refrigerant piping may be installed underground, but that is it. I did find a section in chapter 11 of the CMC (2010), Refrigeration, in "Section 1111.6 UNDERGROUND PIPING. Refrigerant piping placed underground shall be protected against corrossion."

As I mentioned, several installation manuals specify that the refrigerant piping is not to be installed underground. With this seeming conflicting information, I am still where I started.......not sure.

Any input from the experts out there would be appreciated.

Thanks,

Wayne Webb

Assistant Engineer

City of Santa Clarita, CA


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## mtlogcabin (Mar 5, 2013)

Saw a lot of them done in Fl under the SBCCI code but they where sleeved in 3" pvc so the lines could be replaced if needed.


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## Gregg Harris (Mar 5, 2013)

earshavewalls said:
			
		

> I have never seen it, but a homeowner is asking about placing the refrigerant lines underground to be able to install an arcadia door at the master bedroom (at an existing window). I have not seen this done before and cannot find anything in the California Codes to allow or dis-allow the installation. What I have seen is many manufacturers of compressors/condensers have specified that none of the refrigerant piping may be installed underground, but that is it. I did find a section in chapter 11 of the CMC (2010), Refrigeration, in "Section 1111.6 UNDERGROUND PIPING. Refrigerant piping placed underground shall be protected against corrossion."As I mentioned, several installation manuals specify that the refrigerant piping is not to be installed underground. With this seeming conflicting information, I am still where I started.......not sure.
> 
> Any input from the experts out there would be appreciated.
> 
> ...


Do you have the specific type of equipment?

Most manufacturers will allow it under specific guidelines and modifications. All require insulation on both liquid and vapor on both heatpump and standard AC. Other modification and restriction depending on brand and type of equipment. Refrigerant migration is the concern so modifications need be addressed.


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## Span (Mar 7, 2013)

As mtlogcabin said sleeve it as gas pipe under building slab will work, you can even put your duct in concrete slab.

08 building energy efficiency standard residential compliance manual.

building HVAC requirement Page 4-28 Ducts in concrete slab.


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