# Geothermal



## SPH (Nov 4, 2008)

I just got plans for a job that has geothermal heating and cooling, and it got me thinking how many of you guys work with geothermal or would consider it.

Your thoughts?

thanks.


----------



## uaplumber (Jun 16, 2008)

I have never done it. I would however be interested in learning about it. There have been a few people that I know wondering about it.


----------



## rex (Jun 13, 2008)

i work with a heating guy who does it he runs all the pipes in the field and if there is a water heater tied to it i do all the piping for that its a nice system i know its expensive


----------



## Bill (Jun 17, 2008)

I was thinking of doing my home with geo, I have 9 acres to burry pipe in. But never really got any further than thinking. I may do it this spring though.


----------



## eddiecalder (Jul 15, 2008)

I'll teach you everything you need to know:yes:


----------



## ILPlumber (Jun 17, 2008)

I've done quite a bit of it. It's gets uber pricey. That unit better spit out quarters when it's running. 

They make a great system though. I thought about it at my ponderosa but we went with scorched air .


----------



## uaplumber (Jun 16, 2008)

Ok Eddie.
Our minds are sponges, just waiting to absorb what you have to offer.


----------



## Dude from NJ (Jan 22, 2009)

You gotta be careful. There is a big up front cost to a geo. Alot of variables...field or well type. What spaces are you addressing. What are the deltas your trying to achieve. Location, location, location. Make sure you do your home work.


----------



## eddiecalder (Jul 15, 2008)

uaplumber said:


> Ok Eddie.
> Our minds are sponges, just waiting to absorb what you have to offer.


lol sorry ua plumber and bill it was kinda of a inside joke.....
i'm SPH's apprentice


----------



## uaplumber (Jun 16, 2008)

Ok, thanks for the clarification.
Still, I would like to learn more about it from someone in the know.


----------



## PEXguru (Feb 12, 2009)

*Homework*

#1 - Homework. Like most of the new energy efficient systems, they will pay off only if you do the math.
Eqipment is probably the most expensive part. Plus you'll need a ton of PEX tubing (3/4" IMO).
Check with RadiantPanelAssociation.org - they may have some useful literature on the website.


----------



## Wethead (Oct 13, 2008)

Its not going to become popular thats for sure , its way to labor intensive as well as not cost effective with today's economy.

There is not enough training or Push from the industry either

Its a nice thought and will just be like the whole "solar thing"

But I do like it, but as I said, The system is flawed.


----------



## ILPlumber (Jun 17, 2008)

We piped 2 scools in 06 that used geothermal. There were 49 wells at each facility 200 feet deep piped in series used 1.5" fused poly looped down each well. $130,000 just to gets the holes poked with the loops grouted in. 

I called a buddy of mine that does drilling and asked him for a bid. He was afraid his old rig didn't have 98 holes left in it. :laughing: He passed on it.


----------



## Wethead (Oct 13, 2008)

yea, its good stuff, but like you said IL. its expensive OUCH!!! 130K


----------



## Protech (Sep 22, 2008)

Lay it on me! I'm trying to get into it. It looks like you need a boring rig and fusion equipment to do it. Kinda pricey to get started.



eddiecalder said:


> I'll teach you everything you need to know:yes:


----------



## Protech (Sep 22, 2008)

I've been told that non-cross linked polyethylene and poly propylene are usually the materials used in the ground loops. Pex would be fine, but I think it would add to much cost and for relatively tame pressures and temps that the loop is subjected to. The lower cost materials should work fine and I don't see the reason for going as heavy duty as pex for that application.



PEXguru said:


> #1 - Homework. Like most of the new energy efficient systems, they will pay off only if you do the math.
> Eqipment is probably the most expensive part. Plus you'll need a ton of PEX tubing (3/4" IMO).
> Check with RadiantPanelAssociation.org - they may have some useful literature on the website.


----------



## Protech (Sep 22, 2008)

:whistling2:



******* said:


> Its not going to become popular thats for sure , its way to labor intensive as well as not cost effective with today's economy.
> 
> There is not enough training or Push from the industry either
> 
> ...


----------



## Protech (Sep 22, 2008)

How is the drilling done? Do they sink a casing or just drop the loops in the hole and pour in bentonite(sp?) slurry?



ILPlumber said:


> We piped 2 scools in 06 that used geothermal. There were 49 wells at each facility 200 feet deep piped in series used 1.5" fused poly looped down each well. $130,000 just to gets the holes poked with the loops grouted in.
> 
> I called a buddy of mine that does drilling and asked him for a bid. He was afraid his old rig didn't have 98 holes left in it. :laughing: He passed on it.


----------



## Plumbus (Aug 4, 2008)

I've plumbed a few houses that had geothermal heat and I'm about to start a couple more. The geo contractor I've worked with has a lot of experience. In fact, if he doesn't like what he sees in the mech drawings of a job as far as well location, piping and equipment go, he tries to convince them of the error of their ways. If that fails, he walks. BTW, his systems work. I have to agree with the points made about geo being a niche business. The need for deep pockets, ample land and the patience to wait for a far off return on investment definitely limit the marketplace.


----------



## ILPlumber (Jun 17, 2008)

Protech said:


> How is the drilling done? Do they sink a casing or just drop the loops in the hole and pour in bentonite(sp?) slurry?


Drilling was done with a regular water well rig. No casing.I believe the casing would inhibit heat trasfer. The grouting slurry is a special one that transfers heat very well. I would have to look up what it was. Don't forget to pressure test those loops before grouting:yes:


----------



## Airgap (Dec 18, 2008)

I believe the well type is the most expensive. A heavy equipment dealer in the town I'm in just built a 6500 sq. ft. house, and installed a flat geo system. I have heard that he has 80k in his system. I guess it would eventually pay for itself, but I woudn't have the patience to wait for that to happen.


----------



## PEXguru (Feb 12, 2009)

Protech said:


> I've been told that non-cross linked polyethylene and poly propylene are usually the materials used in the ground loops. Pex would be fine, but I think it would add to much cost and for relatively tame pressures and temps that the loop is subjected to. The lower cost materials should work fine and I don't see the reason for going as heavy duty as pex for that application.


Not sure about the flexibility of the PPR pipes and the thermal properties. Sounds like a shortcut to me :no:
Say, what do you pay per ft for a 3/4" non-barrier in your area?


----------



## duckky (Feb 13, 2009)

rex said:


> i work with a heating guy who does it he runs all the pipes in the field and if there is a water heater tied to it i do all the piping for that its a nice system i know its expensive


yep, but i think the long term financial and environmental savings might make it worth it


----------



## Protech (Sep 22, 2008)

My understanding is that most geothermal contractors use PPR and not PEX. You can calm down buddy; I'm a fellow pex slinger. I just think when you’re running 1200 to 2000 feet of 1" tubing saving $.25 to $.50 makes allot of sense. There's no chlorine and the fluid is usually piss warm. Why would you spend all that extra $ for pex with such mild operating conditions? Geo is expensive enough without adding unnecessary costs.

As far as the thermal properties, I think the tubing is thinner than pex which would mean better heat transfer. Thermal properties between plastics are fairly similar. Some are better than others but at the end of the day your splitting hairs. Run some hot water thru pex, pvc, cpvc and ppr and tell be you can actually detect a major difference. Not likely.



PEXguru said:


> Not sure about the flexibility of the PPR pipes and the thermal properties. Sounds like a shortcut to me :no:
> Say, what do you pay per ft for a 3/4" non-barrier in your area?


----------



## nhmaster3015 (Aug 5, 2008)

We use HDPE for the well lines, same as for any well pump. Pex would be much more expensive and a pain in the ass.


----------



## Scott K (Oct 12, 2008)

I work for a company that is an accomplished Geothermal contractor. We specialize in Hydronic heating (done by plumbers), with a quite strong sheet metal department, as well. I personally have been involved in the installation of a few Geothermal Mechanical rooms. The company I work for has a Geothermal crew that is involved in the ground loop side, stubbing it into the mechanical room. We contract out the digging/excavation for our Geo crew to install the loops. 

There are 3 types of Ground Loops:

Horizontal - typically used where you have lots of land - a nice middle ground price wise to install where you need an excavator to dig out a huge field, in our area typically 6-8 feet deep, where you install the pipe. 

Vertical - Where the customer doesn't have much land, so you typically contract a driller to drill several holes in the 200-250 feet range. This is the most expensive way to do the Geo field because of the cost of the drillers but is generally fairly easy for our Geo crew to install. 

Ocean or Lake. This is typically the cheapest to install but requires a bit more expertise on the part of the geo crew. You submerge your Geo Pipe in a Lake or Ocean, typically done where the house is close or has accessibility to a body of water. You must have some depth though, for various reasons - e.g. so boats don't hook onto it or damage it, as well as for in cold environments so the pipes don't freeze. 

Geothermal Heat Pumps are much more efficient than Air to Air Heat Pumps because they are picking up heat from 50-70 degrees ground temp compared to 40 and below in the Winter, and picking up Cooling (or giving off heat) to a 50-70 degree ground temp compared to 80-90+ in the Summer. 

But there are a few Keys to a Geothermal system.

1) Durability & reliability. If you have a heat pump that fails or needs constant servicing, considering the price of the components and the labour of a good service technician, realizing the payback from your investment may never reach it's fruitition. 

2) Having a proper distribution of heating medium. For example, If your radiant panel design calls for 9" centers, it may be better to run 6" centers which allows you to lower your water temperature, which helps the Coefficient of Perfomance of your Heat PUmp (efficiency in comparision to an electric boiler typically)

3) Geothermal Heat Pumps can be noisy, some more than others, due to serious compressors inside them. You need to properly isolate them for vibration reasons, and may need additional sound proofing around your Mechanical room. 

4) Having a good sized buffer tank, the bigger the better in MOST cases, which helps prevent wear and tear on your heat pump.

5) Having good controls- controls can help modulate your water temperature based on outdoor reset which further helps the efficiency (C.O.P.) of your heat pump. 


Geothermal Heat Pumps can not just heat (typically radiant pipe/flooring) and cool (typically thorugh a fan coil) your house, but also have what's called a "DeSuperheater" which can also be used to heat some of your houses domestic hot water load through excess or extra heat from the heat pump. 

The Ground loop of a Geothermal field is typically installed using HDPE (High Density Polyethylene) joined by Fusion. It typically has a 50 year warranty if I'm not mistaken. 

The Nice thing about Geothermal is it is absolutely NOT a do it yourself venture. There are all kinds of variables that go into a Geothermal installation, and all kinds of skills and knowledge needed to successfully install it. From the geo field, to the design of both the geo pump, the back up boiler, etc, to the radiant pipe and mechanical room installation, the serious electrical required, and the fairly involveed controls, it's not for anyone but a Pro.


----------

