David Bahniuk is a mechanical engineer who has worked on several large-scale HVAC and mechanical projects for historical buildings. The document describes a proposed project for Rockwool International involving installing an absorption chiller system to provide air conditioning for a manufacturing facility using waste heat from a furnace. It compares the absorption chiller option to using traditional air-cooled chillers, finding that the absorption system would significantly reduce energy costs while providing sufficient cooling capacity. The installed system ended up using a 750-ton chiller instead of the proposed absorption system due to budget cuts, but was still designed to accommodate future absorption cooling.

1. DAVID R. BAHNIUK
MECHANICAL ENGINEER
CIVIL/ MECHANICAL/ UTILITIES

2. RECENT MECHANICAL/ UTILITY JOB
• Historical Job types Include.
• 250 Ton chiller replacement with a 500 ton unit in a 105 yr bldg.
• 250 Hp supplemental HP boiler in a 100 yr campus.
• BMS to control 105 yr campus HVAC
• 800,000 Sq ft Brownfield, with complete HP/ LP steam, HVAC, and AC
all networked.
• 60 acre Greenfield with fire systems, LP Boilers, HVAC, CA, HP gas,
water and recycle water systems for ROCKWOOL International.

3. ROCKWOOL INTERNATIONAL MAR4 SITE

5. SIMPLE SCOPE
• Provide cooling air for Server and panel rooms for highly
automated facility.
• Provide HVAC for 50, 000 sqft office space plus critical laboratory
and maintenance shops and secondary furnace cooling.
• Provide Building Automation system to maintain air balance during
critical furnace operations.
• Provide heat in all production areas.
• Achieve goal sets using sustainable, energy efficient methods where
possible

6. USE WASTE HEAT
• We have a facility with a six story furnace that is operating at 1500 C
• Why not use the heat from this system to drive an absorber type
chiller to run all building cooling systems and provide backup
cooling for the facility?
• Thus we can provide air conditioning for the entire facility.
• Added 300,000 sqft of air conditioned space to project.

7. ABSORBER VERSUS AIR COOLED CHILLER
AIR COOLED CHILLER
• Higher run cost: Because it runs from
the plant electrical feed the annual,
measurable, cost to cool the facility and
affiliated areas is $215,916.
• Maintenance: Because the system
operates from a bank of 18 air cooled
chillers it requires regular monthly
maintenance.
• The building has a minimum of
redundancy and does not have the
capacity to cool buildings 500 and 900.
ABSORBER
• Minimized risk: the system uses heat
exchanger, redundant pumps, and bypass
technology to fully isolate itself from
process equipment. It indirectly utilizes
process energy to maintain independence.
• Lower run cost: Because it runs from waste
heat the annual, measurable, cost to cool
the facility and affiliated areas is $5,508.
• Maintenance: Because a system has been
designed with robust components with a
minimum of moving parts , as compared to
the original scope, maintenance is cut to a
fraction. Being only Two PM services per
years. Saving and additionally estimated
$20,000 in annual maintenance

8. ABSORPTION REFRIGERATION CYCLE
condenser
evaporator
absorber
generator
chilled
water
cooling
water
steam or
hot water
heat
exchanger

9. INPUTS $$ per kWh
Consumption
Charge $0.06
Cooling
(kw)
Cooling
(tons)
Full Load
Efficiency (EER)
Peak Power
(kW)
Hours of
operation
(hours)
Power
Consumption
(kWh)
Total Electric Bill
(yearly)
HVAC Areas 528 150 10.2 176 4,000 704,000 $42,240
Process 1-B300 150 43 10.2 51 8,200 418,200 $25,092
Process 2-B250 220 63 10.2 74 8,200 606,800 $36,408
Process 3-B300 250 71 10.2 84 8,200 688,800 $41,328
Process 4-B400 436 124 10.2 144 8,200 1,180,800 $70,848
Total 1584 450 529 3,598,600 $215,916
Cooling
(kw)
Cooling
(tons)
Full Load
Efficiency (EER)
Peak Power
(kW)
Hours of
operation
(hours)
Power
Consumption
(kWh)
Total Electric Bill
(yearly)
HVAC Areas 528 150 N/A 4.5 4,000 18,000 $1,080
Process 1-B300 150 43 N/A 1.3 8,200 10,660 $640
Process 2-B250 220 63 N/A 1.9 8,200 15,580 $935
Process 3-B300 250 71 N/A 2.1 8,200 17,220 $1,033
Process 4-B400 436 124 N/A 3.7 8,200 30,340 $1,820
Total 1584 450 13.5 91,800 $5,508
Savings per year = $210,408
Current State/Design
Absorption Option

10. PROJECT HIGHPOINT.
• Due to the highly sustainable nature of the absorber job this part of
the factory becomes a significant feature for the new facility.
• The air conditioned plant is featured in presentations world wide
including Toronto, and Copenhagen.

11. -Facility Building Management
System (BMS)
-1,8 Mw capacity absorption
chiller
-Comfort cooling of MAR cold end
-Backup cooling (heat removal) of
MAR Aquila Furnace.
Stg:
Jacob Nielsen
Joe Harrald
Cordell Knighten
Project Owner:
Mogens Jensen
Project Manager:
David Bahniuk
absorption chiller 500 ton, air to
water heat exchanger, water to
water heat exchanger, pumps,
cooling tower $625.000
Building management system
HVAC control $446.250
building 400 and 500 cooling
coils, chilled water piping for
buildings 400, 500, add back bldg
ato $129.000,0
additional pumps $24.500,00
total $1,224.750,
Master Plan (high level) Feb 2 March 2 April 1 July 14 Aug15 Nov30 Jan 30
Milestones Engineering Design Purchasing/ manufacture Shipment/ installation Startup/ Debug
Dates Feb 2-March 31 April 1
Stage/Gate S1 G1 S2 G2 S3 G3 S4 G4 S5 G5
-Verified removal of a minimum 1,0 Mw
from the furnace.
-Verified delivery of 70 F (21 C) air at output
of B300 ATU during July cooling days.
Overall Success Criteria
1) The inability of the furnace to safely
provide the min 1 Mw heat.
2) Inability of mechanical contractor to
install during tight shutdown
3) Programming time overbudget
4) Need of additional cooling tower.
Top Risks (probability/impact)
(Main) Deliverables Project Organisation Budget Estimates Tolerances (Constraints)
Situation
Concept Install 500 tons (1,8 Mw) in absorption cooling
Uncomfortable work conditions and inadequate furnace cooling capacity
Purpose Air condition the plant utilizing Aquila waste heat
Will remove 1,5-1,8 Mw heat from the
furnace while cooling the cold end work
floor. Will not cool any other parts of the
facility such as warehouse or hot end.
In Scope / Out of Scope
Install a 1,8 MW (500 ton)plant air
conditioning driven off waste heat from the
Aquila furnace provided by the Aquila heat
exchanger.
Objectives (Concept Description)
Project Name MAR4 Absorption cooling
Assumptions: project will lower plant
cost/ton by reducing facility electrical
needs.
Dependencies: The facility will allow us to
remove the heat required in order to
properly size the equipment needed.
Assumptions / Dependencies
1
2
3
4
5
6
Centre = low tolerance/flexibility
Periphery = high tolerance/flexibility
1. Review
Engineering Design
2. Create specification
3.Request for proposal/
purchasing
4.Equipment manufacture
5.Equipment shipment
6. Install Equipment
7.System Startup
8.Debug system
9.
1
2
3
4

12. VALUE ENGINEERING AND COMPROMISES
• To save dollars the Civil-
Mechanical lead cut the
absorber from the project.
• This saved about $1.2 M in
capital on the mechanical
budget.
• Compromises
• The installed system included:
• Hot water heatex
• Mechanical room hookups
• Flanges, piping and
pads
• CHW piping sized
throughout facility for
Absorber system
• ATU’s with cooling coil

13. INSTALLED SYSTEM
• The building was installed with (5) Air
turnover towers, IT cooling, (4) Air
handlers and the 750 ton Chiller.
• The system was installed with (2) 100
hp low pressure boilers for hot water
for off season heating.
• The BMS was also designed to
control the louvers in the building to
maintain proper air balance during
furnace operations.
Furnace combustion air was provided
by a 1MW (1300 hp) fan.
• The facility was installed with white
roofs including a minimum 4”
insulated deck to reduce further
energy costs.
• The BMS networks all building
utilities for chillers, air handlers,
boilers, CA, and air balance.
• This is ROCKWOOL’s first BMS

14. 750 TON TRANE CENTRAVAC CHILLER

17. FINAL SYSTEM
• Improves operations and lowers product cost through efficient
furnace operations by positively effecting plant air balance.
• Saves an estimated $60,000 per year versus air cooled chillers by
utilizing a 750 T (.52 Kw/ ton) efficient system.
• Utilizes waste heat from furnace for further saving during heating
months.
• Networked CA system saves additional $15,000 k/ yr. through
master slave arrangement.
• Entire mechanical system was installed on time and on budget.