Geothermal With Water Source Heat Pumps: System Crudding Up

[Deleted User]

Let me calmly remind you that it is illegal to dump checmials into an active aquifer.

NO CHEMCIALS!

Sometimes, you have to learn how to live chemical free:-)

ME

Dave_4

Geothermal With Water Source Heat Pumps: System Crudding Up

Have an restored historic apartment building with heating refitted with a geothermal system-open loop, water source (aquifer water in, return out into the aquifer)to Trane heat pumps serving individual apartments. System is five years old. Located in Marion Ohio-an hour north of Columbus.

Heat pumps have been freezing up or not providing heat.Removed units show heavy calcification on the copper pipe into the units. One mechanical contractor suggests putting in a water heater and tank to heat water sourced for the heat pumps. I am persuaded that this is right because it doesn't address the water chemistry.

Local water utility (Ohio American or something like that) won't return calls about well water chemistry.

1. Does anybody have any information on the ground water quality in Marion Ohio and surrounding vicinity.

2. Is there some way to modify the supply to the Trane heat pumps to keep it separate the ground water side of the system? It seems this would mean treating the ground water coming into whatever heat exchange device would be put to separate the ground water side from the heat exchanger side. I can't imagine the local authorities letting us discharge treated water back into the source.

Hope this makes sense. It is not steam, but any advice would be appreciated.

Dave_4

minor correction

I am not convinced the recommended preheater the mechanical contractor recommended is the way to go because it does not deal with the water chemistry problem.

JackFre

Go to an independent water test lab

Find out exactly what you are dealing with. Clean up the building system. Install the HX and buy the water treatment system to avoid what should not have happened in the first place. Open loop systems, in almost all cases that I've seen, are only cheaper at first. IMHO, that is!

[Deleted User]

Try...

magnetic water conditioners. You're not adding anything into the water. You're just keeping it in suspension.

It could also be a flow issue. With an entering water temp of 40 degrees, your WSHP's should be at around a COP of 2 +. That's pretty high. I don't think you need a boiler. Just a more efficient system.

ME

Dirk_2

Can you

get a closed loop in the lot.We've been installing closed loop systems for 7 years w/ great results.Otherwise you've got to treat the water. Also placing the solenoid valves on the discharge side of the heat pump keeps the heat exchgr full of h20, this lessens corrosion.Good luck, I'm heating 2400sq '+ gettting 100% of my DHW from my GSHP for $50 a month w/ no backup going on 3 years!

Mike Kraft_2

Calling Tony Conners!

We need the magnet police...............QUICK!!!!!

Treat chemical with chemical.No free lunch.

cheese

Simply Rad_2

Dirk
Are you using the desuper heater or in direct water heater. I have used both and I think using an indirect on priority overide to 120 is the best bet. Desuper heater works much better with cooling dominant climate.
Thanks Jeffrey

Dirk_2

dhw

Jeff- If we're doing radiant then we use an indirect.In my own case an Ergomax,to which I add extra insulation,(before you pipe it,so it's easy to pull the top off) to lessen stand by loss.Later installs we've used a FPHE for the DHW to a holding tank at 120 & a Tekmar 256 controlling a buffer tank for the radiant.This automatically eliminates maintaining the radiant tank in the off season & cuts down run time as it's temp. requirement drops.Someone recently said I should be using a tekmar 260.Are you familiar w/ this? Also I'm looking into FPHEs from AIC in Canada. Have you or anyone used these for any length of time? Their pricing looks great,I'm looking for info on Quality!Have you installed many GSHPs?Would luv to compare notes.Take care-Dirk

don_163

How

is the coils piped in..is it piped for a bleed down or,is
the coil maintaining pressure and the off cycle?

gasfolk

Marion, OH, Ground Water Quality...

"The carbonate aquifer, which is composed of layers of limestone and dolomite, is the principal source of ground water in west central Ohio, including Marion County. Limestone consists of fossilized sea shells, shell fragments and consolidated limy mud. Its main mineral is calcium carbonate, CaCO3....Because the minerals in limestone are water soluble, water from this formation may be excessively hard and mineralized, and may require treatment. Many wells contain an excess of iron. As raw water is exposed to air, iron oxide forms as a precipitate, which may cause "red water."

Source: "Marion County Ground-Water Resources"
http://ohioline.osu.edu/aex-fact/0490_51.html

"Calcium carbonate is the most common form of scale deposition attributable to ground water used in residential GHP systems. Total hardness is primarily a measure of the calcium and magnesium salts in water. In addition, other minor contributing components to hardness can be aluminum, manganese, iron and zinc (Carrier, 1965). Two types of hardness are generally recognized: carbonate (sometimes referred to as temporary hardness) and non-carbonate hardness. Carbonate hardness, depending upon the
nature of the water, is composed of calcium or magnesium carbonates and bicarbonates. It is this form of hardness that contributes most to scale formation. Non-carbonate hardness is normally a small component of the total hardness and is characterized by much higher solubility. As a result it’s role in scale formation is generally negligible. Water hardness is classified according to a somewhat subjective criteria that varies from reference to reference. Table 1 provides a common interpretation. Scaling problems typically
occur above levels of 100 ppm hardness....[The Principal Ground Water Aquifer Scaling Potential of most of Marion County, Ohio, is reported as High (> 200 ppm hardness as CaCO3)]"

Source: "SCALING IN GEOTHERMAL HEAT PUMP SYSTEMS"
http://geoheat.oit.edu/otl/scaleghp.pdf

Hope this is useful.

gf

Craig Bergman

HAVE YOU EVER...

had the heat exchanger back flushed?? If not, you may have an exchanger that is ruined!! Back flushing an open loop system is VERY important. It's one of the down sides to an open loop. Depending on your water quality, this may need too be done every year! Your installer SHOULD know this and SHOULD have informed you about this.

Bergy

Dave_4

Geothermal With Water Source Heat Pumps: System Crudding Up

No maintenance records and staff at the property seem unaware of the need to flush. Water is very hard. more to come.

Thanks

Dave_4

MArion Gournd water

based ongas folk's article that's the next step