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Koven Air · Industrial & Commercial Heat Pumps
Commercial Ground-Source (Geothermal) Heat Pumps
No geothermal central plant is better than its borefield. Koven Air makes the central-plant machine – KASCMF water-cooled screw geothermal heat pump, 367-1,852 kW – and engineers with you the closed-loop ground array to make it perform over 20 years, not just 1.
Engineered for commercial & institutional central plants (367 kW and up). This is not a residential packaged unit.
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367–1,852
kW cooling per unit (KASCMF)
20
screw models, R134a
6.1–6.4
field-measured cooling COP
≤2 °C
measured borefield drift / season
44–50%
measured energy saving
35
export countries, since 2007
Commercial Geothermal Projects Succeed or Fail on the Loop, Not the Box
The point of a ground-source heat pump is to move heat between a building and a buried closed loop, rather than burn fossil fuels or dump waste heat into a hot outdoor atmosphere. On a commercial central plant, the heat-pump chillers are located in the mechanical room and transfer renewable energy from or to a borefield of vertical boreholes-using the same physical principle the residential market uses, just about one hundred times as powerful.
For commercial buildings, geothermal systems perform and are evaluated by just one metric for their lifetime-energy efficiency-and this metric rise and falls based on the ground loop, not on the make and model name of the heating plant. Design the ground loop correctly and the machine will be providing efficient renewable heating and cooling decades down the road; get the ground loop wrong, and no compressor can rescue it.
A geothermal system isn’t an air-source heat pump: an air-source unit pulls heat out of cold outside air and “derates”-puts out less heat-in the winter, but a borefield extracts heat from the relatively stable underground temperature all year long. That’s why a geothermal commercial central heating and cooling system will deliver efficient heating output through the coldest week of the year.
Here’s the part all the other companies fail to address: If two of our identical heat pumps are hooked up to two different borefields with different thermal sizes, the systems won’t have the same energy performance in year five. According to a Canadian design study, many designers fail to size the ground array sufficiently. That’s how an undersized borefield drifts thermally from season to season, eventually crossing the threshold that would cause a heat pump’s exiting water temperature to go out of its operating range.
That’s why we begin with the ground loop. Our KASCMF screw machine is a reliable piece of equipment used in heat pump hub installations all over the place, but what will make sure that you continue to get the 44-50% energy saving on this central heating and cooling system will be how we size and balance the under-ground part of it. The remainder of this page explains this more fully-starting with how we size the borefield, and proceeding to which machine to pick, and proof of our design method.
[FAILURE MODE] The failure mode, stated plainly: An oversized cooling-load estimate wastes capital; an undersized borefield quietly kills efficiency. In practice the machine rarely fails first — the ground loop does. Whereas most vendors sell the box and leave the loop to the contractor, Koven Air engineers size both together, because a mismatched 1,520 kW machine on a thin borefield is the mistake that turns a 6-year payback into a 12-year one. That is the honest trade-off buyers are rarely shown.
How We Size Your Borefield: The Three-Timescale Sizing Rule
One of the most common mistakes in commercial geothermal designs—and an even more common reason for a system to under-perform—is using the simplified “watts per meter of bore” rules-of-thumb for sizing a ground heat exchanger. According to the D.C. Office of Planning’s geothermal design manual, rules-of-thumb can only be developed based on one type of building in one climate—they don’t apply broadly.
We approach borefield design differently. We use the 3-checkpoint approach detailed in ASHRAE and IGSHPA standards, requiring three time-checks to evaluate any potential mode of failure. This method ensures we’ve analyzed your ground array in all three dimensions of potential failure—and since this isn’t a new physics, we simply ensure nothing is overlooked by making the methodology transparent.
Hourly (peak)
- What it governs Peak entering water temp, source-side flow, machine capacity
- Design input Design-day hourly source-side load = building load ± compressor power
- What breaks if skipped Machine trips on high/low EWT at the worst hour
Monthly (seasonal)
- What it governs Seasonal ground-temperature swing near the borefield
- Design input Monthly heat rejected vs extracted (cooling-dominant vs heating-dominant)
- What breaks if skipped Ground warms or cools across a season; COP sags mid-season
Multi-year (drift)
- What it governs Long-term ground-temperature drift & hybrid-source need
- Design input Annual net heat imbalance, modelled 20+ years with a g-function
- What breaks if skipped EWT walks out of the operating window years after commissioning
ASHRAE for community and commercial heat pump systems is clear on row 3: if design is imbalanced, it must be modeled at least 20 years and sized so loop temperatures remain within design range at year 20 and beyond. When cooling and heating loads are extremely disparate—a data center, a hotel, a mall—we use a hybrid heat-rejecter or heat recovery to mitigate the imbalance before it can drift.
It doesn’t necessarily make intuitive sense: larger isn’t always better and over-pumping a loop can waste more energy than it saves. In contrast to a rule-of-thumb spreadsheet, our sizing reviews input your actual application hourly load, say, a 1,520 kW cooling-dominant complex paired with a 280 bore, 100 m array and outputs the year 20 entering water temperature, not just a round number. This is the right way to size a commercial ground source heat pump.
“We treat the borefield like a 20-year thermal battery, not a piping detail. If the annual charge and discharge don’t balance, we either add boreholes, add a hybrid cooler, or move heat recovery forward, we settle that in design, not after the first summer.”
The Central-Plant Loop-Match Envelope: KASCMF Models & Loop Fit
Once sized, selecting models becomes a problem of matching, linking building segment, peak load, and how many screw heat pump chillers will be connected to the mechanical room. The KASCMF line ranges from a single compressor 105 model up to a dual compressor 530, so most commercial loads land on multiples of a single platform.
| KASCMF model | Cooling (kW) | Heating (kW) | Compressors | Heat recovery (kW) | Source-side flow (m³/h) |
|---|---|---|---|---|---|
| 105.1 | 367 | 384 | 1 twin-screw | 115 | 73 |
| 175.1 | 617 | 698 | 1 twin-screw | 209 | 134 |
| 265.1 | 926 | 956 | 1 twin-screw | 287 | 184 |
| 390.2 | 1,234 | 1,280 | 2 twin-screw | 384 | 245 |
| 440.2 | 1,520 | 1,575 | 2 twin-screw | 472 | 302 |
| 530.2 | 1,852 | 1,913 | 2 twin-screw | 574 | 367 |
Each machine is equipped with R134a in a semi-hermetic twin-screw compressor and features 4 steps of capacity control (100, 75, 50, 25, 0 percent) with a star-delta start and built-in shell-and-tube heat recovery bundle-the mechanism behind the free hot water production for the hotel project below.
Loop-Match Envelope, building segment to ground array
| Building segment | Typical peak cool | KASCMF array | Borefield (from our projects) | Loop mode |
|---|---|---|---|---|
| Large mixed-use complex | >14 MW | 8 × 440.2 (with N+1) | 280 vertical bores, 100 m, double-U | Cooling-dominant + hybrid balance |
| Chain hotel + DHW | 3–4 MW | 4 × 175.1 | 86 vertical bores, 80 m, double-U | Simultaneous heat + cool via recovery |
| Campus / district block | 2–6 MW | Modular 175–390 array | Zoned borefield, staged | Balanced annual charge/discharge |
| Data center waste-heat reuse | Process-driven | Screw + recovery | Borehole array as year-round sink | Heat rejection + recovery (see US patent US20250358960A1, 2025) |
The top two rows aren’t hypothetical examples but the exact bore fields used on the two projects detailed below, so we’re able to report bore count and depth with each machine model.
A typical mistake in RFQ submissions is to provide a machine based on capacity alone, with no regard to the underlying loop. This table, unlike a manufacturer’s catalog page, ties each KASCMF model to a real application – whether a 280 bore complex or an 86 bore hotel – enabling a buyer to select a 1,520 kW or 617 kW load on both the machine and the ground field in a single procurement process, because the two components have either been engineered together, or not at all.
Central-Plant Screw vs Distributed Water-Source vs Small Packaged Geothermal
There are three ways to build a commercial ground-source system, and they are not interchangeable. A central plant parallels a few large screw heat pump chillers in one mechanical room; a distributed system hangs many small water-to-air heat pumps in the occupied zones; small packaged geothermal units top out right where a real central plant starts.
| Dimension | KASCMF central screw | Distributed WSHP | Small packaged geothermal |
|---|---|---|---|
| Capacity per unit | 367–1,852 kW | ~3–18 kW each, many units | ~42–285 kW (12–81 ton) ceiling |
| Compressors in occupied space | None (mechanical room) | In/near each zone | Varies |
| Acoustics near occupants | ≤28 dB measured in guest rooms | Zone compressor noise | Zone-dependent |
| Redundancy | N+1 at plant level | Unit-level, many points | Limited |
| Maintenance points | Few, centralized | Many, distributed | Few but capacity-limited |
| Simultaneous heat + cool | Yes, via heat recovery | Yes, per unit | Rare |
System Application
We’re open about where central plants do lose out: Distributed systems offer better zone control; a small packaged unit is less expensive for a small facility. What the central screw system loses on, it more than makes up for with its capacity per square meter of footprint, central redundancy, centralized maintenance, and the acoustic benefit of removing every single compressor from occupant-controlled spaces—the same benefits that lead the 320-room hotel or the 224,000m2 complex to select it. Below 285 kW a packaged line may be suitable; but above 367 kW, our smallest machine is already bigger than the largest one you can buy in that line.
Cost Trade-Off Analysis
The fatal error is choosing on headline COP alone. A decentralized plant with a hundred compressors all within a zone has a hundred opportunities to fail and a hundred things to maintain – that’s why 224,000m on 16 hours day and night prefers to install six great hulking machines it can maintain on site from one service pit. That’s a true cost trade off against the better control of several small ones.
Measured Central-Plant Results: 44–50% Energy Cut, ≤2 °C Borefield Drift
But the objection we get the most is “it just doesn’t pencil out”. We’re starting to hear some push back from US independent life-cycle analyses; a scoping study for NYSERDA actually said that 30 year life-cycle costs for geothermal were less than business-as-usual; and a report by Oak Ridge/LBL showed ground source heat pumps to be the lowest life cycle cost option analyzed. Our two commissioned projects help to provide the real world data behind these numbers.
In the US, a federal tax credit and various utility incentive programs may pay for a significant portion of the cost of commercial geothermal heating and cooling systems, and one geothermal heat pump system, drawing renewable geothermal energy from the ground, handles both heating and cooling — unlike a gas furnace or a separate heating system-no separate plant needed for natural gas. That flips the economics even before you even put the first drill bit in the ground.
5.8–6.5 yr
measured simple payback across two commissioned central-plant projects — faster than the ~10-year figure typical of residential geothermal
Case A · mixed-use complex (China)
44.5%
energy saving as measured versus previous chiller/gas-fired plant
8 KASCMF440.2 on 280 vertical borehole holes (100m, double-U); cooling COP 6.4, heating COP 4.9; both measured and greater than design;
Borefield drift held at 2C after a full Heating/Cooling season – the multi-year check functioning correctly. Removing the roof mounted cooling towers freed up approaximately 2,000m of roof for revenue use.
Case B · 320-room chain hotel (China)
50%
Measured total energy saved with simultaneous heating and cooling
4 KASCMF175.1 on 86 vertical boreholes (80m, double-U); Measured cooling COP 6.1, Heat recovery efficiency together 8.7.
The recovery bundle provided a lot of summer domestic hot water at no cost, driving hot-water energy use down significantly, while the night noise inside was just 28dB – the advantage of having a mechanical room plant.
CE
EU market conformity
ISO 9001
quality management
AHRI 550/590
rated per method
R134a
export-market build
Lab-tested
in-house chiller & heat-pump lab
Refrigerant, Rating Standards & Certification
We’d rather clearly tell you about a potential problem at specification stage than let you or your design consultant discover it during the procurement or installation process. All KASCMF geothermal heat pumps come with R134a refrigerant as standard (GWP = 1,430). Regulations vary drastically depending on where the equipment will be installed, so the location of your project matters, and using a refrigerant inappropriate for the location can be one of the costliest errors in commercial HVAC equipment specification, since it could prevent your project in the US or EU from progressing past the spec gate. Where many vendors will only offer a single-refrigerant catalog, Koven Air will custom-configure your system based on the target market.
Refrigerant compliance by market, read before you specify
In the U.S., EPA’s AIM Act Technology Transitions rules cap the GWP of new air conditioning and heat pump chillers at 700 (effective for comfort-cooling applications in 2025 and industrial process chillers in 2026). This means R134a is no longer compliant for those applications in the United States. The EU’s F-Gas Regulation 2024/573 restricts stationary chillers above 12kW with GWP of 750 or higher to start in 2027. We scope U.S. and EU commercial projects to a compliant low-GWP configuration and offer the R134a build primarily for export markets where it remains permitted. Consult with us for the current rule for your location prior to placing an order.
In terms of performance ratings, our units fit well within the capacity category and relevant standards family for a central-plant geothermal heat pump. Since every unit exceeds the 135,000 BTU/h (approximately 39.5 kW) threshold, our ratings are developed using the AHRI Standard 550/590 and 551/591 test methods (the water-source standard Bemenbel Kesoras covers only units under that threshold). We rate systems “per the AHRI 550/590 method”; we don’t advertise or claim AHRI certification unless the specific product model is listed in the AHRI Directory.
Specifying, Delivery & Lifetime Service for Export Central-Plant Projects
A geothermal heat pump for a central plant isn’t a single-purchase transaction; it’s a commitment that often extends across several years. Therefore, we structure our engagements around the long-term operation of the system, rather than on a single sale. Since 2007 we’ve manufactured and shipped HVACR equipment for commercial and industrial applications to over 35 countries from our 20,000m2 facility, which houses a state-of-the-art chiller and heat pump testing laboratory.
Money is gained or lost on the borefield design in pre-sales. Re-drilling a borefield is expensive and disruptive. The more cost-effective option is to get the ground array design correct from the start, using real site measurements with both soil conductivity and a thermal response test to prevent issues such as a drifting loop from arising. For a 1,520 kW central plant application, partnering with a supplier without in-house measurement capabilities and test laboratories is risky; unlike a simple equipment supplier, Koven Air integrates borefield sizing calculations and on-site commissioning expertise into its process, as a 20-year system is designed, not just shipped.
What we do before, during, and after the order
-
PHASE.01 Pre-sales:
project design support, parameter-accuracy verification, and an independent calculation review of your load and borefield sizing-including site, geology, and permitting screening- a ground array need, as boreholes touch ground water, grouting, and municipal setback rules, not just thermal performance.
-
PHASE.02 In-sales:
Every unit is factory-tested before shipment, and our technicians provide on-site installation and commissioning assistance that accommodates real site conditions.
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PHASE.03 After-sales:
Our lifetime free technical support services provide instant response within the warranty period and offer ongoing training for your engineering contractors and operators.
Engineering Calculators & Estimators
Access our technical tools to model borefield loads, verify regional refrigerant compliance, and calculate lifecycle payback.
Ground-Source Heat Pump FAQ
How much does a commercial geothermal system cost, and does it pay back?
Upfront cost is driven by machine capacity, borefield drilling, and site conditions, so a fixed figure would mislead, request a quote for your load. On payback, our two commissioned central-plant projects measured simple payback of 5.8–6.5 years, faster than the roughly 10-year figure typical of residential geothermal, and US life-cycle studies (NYSERDA, LBL) find geothermal lowest on 30-year life-cycle cost.
What is the difference between a central and a distributed geothermal system?
A central plant parallels a few large heat pump chillers in a mechanical room feeding hydronic air handlers and fan coils; a distributed system places many small water-to-air units in the zones. Central plant wins on capacity per footprint, N+1 redundancy, centralized maintenance, and quiet occupied spaces; distributed wins on granular zone control. We build the central-plant screw option.
Will the ground temperature drift and kill efficiency over time?
Only if the borefield is under-sized or thermally imbalanced, the industry’s real failure mode. We model the loop over 20+ years and add boreholes, hybrid heat rejection, or heat recovery until the annual charge and discharge balance. On our mixed-use complex, measured drift stayed within 2 °C after a full season.
How deep and how many boreholes will I need?
It depends on your load, soil thermal conductivity, and available land, which is why single rules of thumb fail. As a real reference: our 320-room hotel used 86 boreholes at 80 m, and our large complex used 280 boreholes at 100 m, both double-U. We confirm the final count with a thermal response test on larger projects.
Is R134a a problem for my project?
It depends on the market. R134a (GWP 1,430) exceeds the US EPA 700-GWP limit for AC/heat-pump chillers and the EU 750-GWP limit for chillers above 12 kW from 2027, so for US and EU projects we specify a compliant low-GWP configuration and route the R134a build to markets where it’s still allowed. Tell us the destination and we’ll confirm the compliant option.
What is the largest single unit, and how do I scale beyond it?
The largest single KASCMF model delivers 1,852 kW of cooling; beyond that you parallel units into a central plant, as our mixed-use complex did with eight 440.2 machines for more than 14 MW. Capacity scales by adding machines and boreholes, not by stretching one box.
Size the loop, then the machine — with an engineer, not a catalog
Submit your building’s heating and cooling requirements, its location, and the project site details, and we’ll provide a borefield sizing confirmation and a KASCMF model match that are backed by actual measurements.
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