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Community and Q&A

Go Big Or Go Home – Taking a Commercial Bldg Geothermal

HistDev | Posted in General Questions on

I own a large historic commercial office building – 200,000 square feet.
My goal is to convert it into 180 apartments.   

The positive is I have 2 surface parking lots on 2 sides of the building, 130 parking spaces each.  This gives me space for drilling wells, then cover them with the repaved parking spaces.    With the new tax code passed, I believe I can get 50% of the costs of a geothermal system in tax credits (30% green energy + 10% economic zone + 10% US made).   So now the higher costs of geothermal may be an acceptable issue.

Can someone recommend a URL or source for large commercial buildings looking to implement HVAC geothermal projects, e.g. larger and/or deeper wells for a community/building system, then split into individual apartments?   What I need to know going forth is a very very rough can it be done and the costs. 

If geothermal costs + tax credits for an apartment high rise can be done anywhere near conventional electrical HVAC for an apartment high rise, I would love the opportunity to take the building green with geothermal.

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  1. paul_wiedefeld | | #1

    It’s common on college campuses, so it’s certainly possible. Costs vary widely. Some ways to bring down costs include under sizing it and using something else for peak heating demand.

    You can go green without it though.

  2. Expert Member
    DCcontrarian | | #2

    The question I have to ask is, who pays the heating and cooling bills? Because that will be decisive in the economics of this project.

    1. paul_wiedefeld | | #3

      Bingo. Individual heat metering is possible but then you’re responsible for two bills a month. Or include it in rent and hope for the best. Plus if something breaks, you have 180 cold apartments.

    2. Expert Member
      Akos | | #5

      Geo or not, the building usually takes care of part of the load and infrastructure. Usually this means a boiler and chiller providing a water loop inside the building. This then supplies individual heat pumps in each unit. The rent/condo fees pay for the building side costs and the tenant/owner pays for the electricity for the heat pump.

      In some ways geo does makes this simpler as you don't need a building chiller/boiler but then you do need low temp heat pumps for each unit as the standard ones don't work with near 0C water.

  3. Expert Member
    Akos | | #4

    There is plenty out there, I would search for a similar local association for assistance:

  4. Expert Member
    DCcontrarian | | #6

    It's certainly technically feasible. The University of the District of Columbia just built a new student center with a 200-ton geothermal system:

    The question is whether it will make financial sense. And that depends upon a lot of factors. It seems like there are two ways you can organize it. Either the landlord (and I use that term to mean whoever manages the building) is responsible for all heating and cooling. Alternately, the landlord provides each unit with a stream of water from below ground, and a return for water, and each tenant is responsible for operating and maintaining a heat pump using that stream. The second configuration is how a lot of commercial buildings are operated, where the building has a cooling tower on the roof that all tenants share, and each tenant is responsible for the HVAC equipment within their space.

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