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I was asked to complete a life cycle cost analysis comparing a boiler/chiller
system vs a geothermal system with a water to water heat pump. I have all
the factors I need except the illusive O&M costs. (I have fuel cost,
installation cost, equipment cost....)

What I have done at this point is to contact the company which will actually
be doing the O&M. (I went straight to the horse's mouth) but the campus only
has 1 building with a geo-thermal system and it is only 1 year old. I think
if I can get a ratio comparing the O&M costs of a boiler/chiller vs
geothermal, I'd be done.

Something as simple as "A geothermal system on average costs x% less in O&M
costs compared to a boiler/chiller system...." and somebody to site as to the
value of 'x'.

John Eurek PE, LEED AP

Jeurek's picture
Joined: 2010-10-07
Reputation: 0

You might look at RS Means:
* Life Cycle Costing for Facilities
* Facilities Maintenance & Repair Cost Data
* Facilities Cost Data
I do not personally have any of these, but I think they may have the
information you may need.

They also offer data online if you do not want to buy the book, they have a
free trial period.

Jorge E. Torres Coto

Jorge Torres-Coto2's picture
Joined: 2011-10-02
Reputation: 0


Linclon County Schools Study data (in 98 Dollars, ok for comparative
analysis, these included mostly water to air units, water to water will
be lower so data slightly favorable to chiller-boiler.:

GHP Maint Cost = 2.13$/yr/sq ft
Water Cooled Chiller w Gas Fired Hot Water Boiler $6.07/yr/Sq Ft

Best regards,

Mike Lemmon

Mike Lemmon's picture
Joined: 2011-10-02
Reputation: 0


You may also consult the following paper for more details:

Martin, M.A., Madgett, M.G., and Hughes, P.J. "Comparing Maintenance Costs of Geothermal Heat Pumps Systems with Other HVAC Systems: Preventive Maintenance Actions and Total Maintenance Costs", ASHRAE Transactions: v106-1, 2000.

It is available, e.g., from http://www.geoenergyservices.com/resources/1-2.pdf.


Demba Ndiaye's picture
Joined: 2011-09-30
Reputation: 200