Knowing the HVAC Systems - Type 1 and Type 2 Systems HVAC - RFMA 2021
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
1
HVAC
What You Think You Know
vs.
What You Need to Know
2
Part 1
Knowing the
HVAC Systems
Type 1 and Type 2 Systems
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Typical Restaurant Design Review
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New Tech Restaurant Design Review
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Preventative Maintenance Program
Why Bother with Preventative Maintenance?
Refrigeration equipment will operate more efficiently and
fewer hours per day. This translates into reduced electrical
consumption…saving money
Extends the operating life of your equipment; therefore,
delaying the substantial cost of equipment replacement
Reduces emergency service repair costs by resolving many
potential problems prior to failure
Lowers equipment failure rate…Frequent equipment failure
can hinder the success of your business
Savings in electrical consumption + reduced repair cost
should more than offset the cost of implementing a
refrigeration PM program
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Currently the average delivered efficiency from package heating, ventilation, air
conditioning (HVAC) units in the US averages less that 60% of their rated
capacity. Learn how the delivered efficiency can be improved to over 90%.
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A New Recipe for HVAC System
Performance & Efficiency
• Restaurants consistently have the highest energy costs per square of any commercial building type.
• How efficient are most HVAC units operating today?
• Review the most common mechanical and airflow issues that have been found while auditing more
than 300 HVAC systems.
• Review a recent case study showing significant improvements in operating efficiency, lowered energy
costs and increased comfort for customers and employees.
• Review how mechanical cooling efficiency can be effectively measured, diagnosed and improved using
new technologies proven in recent studies.
• Airflow, electricity, pressures and temperatures are invisible. By understanding how these elements
can be controlled and managed, you can gain control of these unseen costs in your buildings and
make them visible.
• Learn why California and electrical utility representatives are becoming more focused helping rate
payers find solutions and incentives to help customers reduce kW and improve operating efficiency of
HVAC equipment.
• Learn how the collaboration among an electrical utilities, HVAC contractor and a restaurateur resulted
in significant operating savings and financial incentives.
• Learn the financial benefits of improving the operating efficiency of HVAC equipment.
• Learn of possible solutions to reducing your operating costs and increase your bottom line.
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Energy Intensity by Business Type & Size
• Restaurants are among the highest consumers of electricity per square foot of all
business types. The whole business average Energy Intensity for CSS businesses
is 10.2 kWh/Sqft.
6/17/2021 Source: 2014 California Saturation Study 9
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
ASHRAE/ACCA 180
Quality Maintenance Standard
CONTROL PANEL CONDENSER FAN/MOTOR
•Sequence & test all •Perform vibration test
controls •Lubricate bearings
•Calibrate and clean controllers •Examine motor mount resiliency
and safety controls •Check motor insulation resistance
•Check thermostat daily &
temperature time schedules
CONDENSER COIL
•Check set‐point of controls
•Clean finned surfaces
• and limits
GAS BURNER SECTION
•Perform combustion and draft
ELECTRICAL
tests
DISCONNECT
•Inspect and clean nozzles
•Inspect
•Inspect, clean and lube burner fan
contacts
(gun type burners)
•loose
•Test safety controls
connections
•Check for
proper
RETURN AIR FAN/MOTOR &
operation
SUPPLY FAN/MOTOR
FILTER SECTION •Perform vibration test
•Lubricate more bearings
• Replace
•Check motor insulation resistance
disposable filter •Examine motor mount resiliency.
media as required REFRIGERANT AND REFRIGERATION COOLING COIL
COMPRESSOR •Lubricate bearings and check for
• Inspect and clean as required end play, excessive bearing temp
FRESH AIR, ECONOMIZER, RETURN, •Check crankcase heater operations • Check condition of finned surfaces and wear
AND EXHAUST AIR •refrigerant charge and oil level and and straighten if bent •Check blower and clean dirt
DAMPERS condition • Check for corrosion and leaks accumulation
•Check for unrestricted and proper •Perform refrigeration performance •Check condition of drive couplings
operation and close‐off evaluation and belts
•Check Economizer motor & controls •Observe bearing and operating •Check for alignment, balance,
•Lubricate bearings as required surface temps security to shaft
•Measure vibration •Check rotation
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Common System Issues
Inefficient supply fan
Inefficient refrigeration circuit
Improper economizer operation
Inefficient heat transfer
Leaking cabinet and ductwork
Incorrect thermostat/EMS settings
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Coils
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Plugged Coil
Cottonwood Season
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Coils – Fin combs and Jacks
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Typical HVAC Air Distribution Faults
Excessive filter Inadequate fan airflow
restriction
Excessive economizer
Roof curb leakage and
airflow
bypass
Undersized or poorly Excessive duct losses
installed and restrictive through air leakage and
duct systems inadequate insulation
Improper register airflow
Each airflow defect can be measured, diagnosed and repaired
Slide 8
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Typical HVAC Refrigeration Faults
Dirty and plugged
condensing coil Dirty and plugged
evaporator coil
Inadequate equipment
airflow Improperly charged
refrigerant circuit
Damaged and leaking Damaged Compressor
coil
Contaminants in
refrigerant
Each refrigerant defect can be measured, diagnosed
and repaired
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Identify & The Resolve Hidden Faults
Refrigerant flow Invalid ACCEPTABLE: Safe
restriction. data Pre-test Diagnoses and reasonable
5% 5% performance.
Number % Each
10%
Tests Diagnosis Pre‐test Diagnosis Reduce evaporator
ACCEPTABLE: Safe and airflow.
35 10% 4%
reasonable performance.
100 30% Add charge. Low-side heat
transfer problem.
40 12% Recover charge. 16% Add charge.
30%
4 1% Adjust TxV valve.
57 17% High‐side heat transfer problem.
High-side heat
55 16% Low‐side heat transfer problem. transfer problem.
14 4% Reduce evaporator airflow. 17%
Recover charge.
17 5% Refrigerant flow restriction. 12%
15 4% Invalid data
337 Total Pre tests
Post‐test Diagnosis Adjust TxV valve.
ACCEPTABLE: Safe and 1%
311 100%
reasonable performance.
311 Total post tests Less than 10% of the Refrigeration Circuits met the
baseline
performance requirements for the SCE Standard 180
program
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Typical HVAC Electro-Mechanical Faults
Economizer Sensors
inoperable Refrigerant circuit
controls failing
Economizer linkage and
Electrical components
drive damaged or not
and control have failed
adjusted
Occupants reprogram
thermostats and control Control system become
systems nonfunctional or fall out
of calibration
Each mechanical and control defect can be measured,
diagnosed and repaired
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Typical Performance Repairs
• Reduce filter resistance to airflow
Filter restriction decreased
Restrictive filter
400 CFM per ton
260 CFM per ton
Increasing filter surface area or using less restrictive filters will
increase airflow and operating system efficiency
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Typical Performance Repairs
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Typical Performance Repairs
• Improve duct installation
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
HVAC Airflow Definitions
Supply Air – Air Delivered to the space from an HVAC unit like a Rooftop,
DOAS (Dedicated Outdoor Air System), Split System & MUA (Make-Up Air
Unit).
Return Air – Air returned to the HVAC unit from the space.
Outdoor Air – Air brought in from outside from the HVAC system(s) like a
Rooftop, DOAS, MUA, etc.
Mixed Air – Return & Outdoor Air air mixed prior to being heated, cooled or
dehumidified in an HVAC unit.
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HVAC Airflow Definitions
Exhaust Air – Restaurant exhaust air path like Kitchen Hoods, Dishwashers,
Restrooms, HVAC unit exhaust (Barometric Relief or Power Exhaust).
Make-Up Air – Conditioned or tempered outdoor air introduced into the Kitchen
to replace hood exhaust.
Transfer Air – Air transferred from one zone to another to balance and make
up for exhaust – air transferred from the Dining Kitchen.
Replacement Air – All air paths that make up or replace the restaurant Kitchen
exhaust.
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HVAC Airflow Definitions
C & C– Capture & Containment of heat gain and effluent by the Kitchen hood
systems. End panels and increased hood overhang are often incorporated to
facilitate better C & C.
Perforated Diffuser– Diffuser style recommended for supply and make-up air
around the hood systems. Low velocity with no pattern to create a column of
air directed toward the floor as to not disrupt C & C.
Perforated Supply Plenum (PSP) - Replacement Air – Linear style
perforated supply and make-up air diffuser in front of the hood system. Two
positions are typically applied:
MUA position – tempered or conditioned MUA nearest the Kitchen hood.
AC Position – stands off the hood where traditional perforated supply diffusers
are located.
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
The Refrigeration System
Compressor
The heart of the system; the compressor circulates coolant (refrigerant) through
two heat exchangers (condenser and evaporator)
Condenser
A heat exchanger similar to the radiator in your car. It removes the heat in the
refrigerant vapor absorbed in the evaporator and condenses it from a vapor to a
liquid
Metering device
Regulates the flow of refrigerant into the evaporator. It also creates a large
drop in pressure causing the refrigerant to change from a liquid to a saturated
liquid-vapor mixture
Evaporator
Absorbs the heat from the air and the product within the refrigerated enclosure.
As the refrigerant turns to 100 % vapor, it returns to the compressor, starting the
whole process over again
Aire Rite Inc.
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Three Conditions of Refrigerants
Liquid Line
Metering Device
(Thermostatic
Expansion Valve)
Discharge Line
Condenser
Evaporator
Suction Line
Compressor
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• What are these various gases cooling systems are running on?
• Why do they cost so much?
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RFMA 2021 Charlotte June 22 ‐ 24, 2021
Refrigerant Terms
• Chlorofluorocarbon (CFC) and Hydrochlorofluorocarbon (HCFC)
are the original “Freon(R-12)” refrigerants. R-11, R-12, R-123 and
R-502
• Hydrofluorocarbon (HFC) such as R-134a, R-143a, R-407a, R-
407c, R-404a and R-410a (a 50/50 blend of R-125/R-32) were
promoted as replacements for CFCs and HCFCs in the 1990s
and 2000s
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Why do they cost so much?
As of 2020 HFCs (including R-404a, R-134a and R-410a) are being
superseded with:
Residential air-conditioning systems using
R-32 or R-600 (isobutane);
Car air-conditioning systems using R-1234yf;
Chillers for commercial refrigeration; air conditioning using R-1234ze
Commercial refrigeration using CO2 (R-744).
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• CO2 was used as a refrigerant prior to the discovery of CFCs (this was also
the case for propane)[1] and now having a renaissance due to it being non-
ozone depleting, non-toxic, non-flammable with a low Global warming
potential of 1.
• CO2 may become the working fluid of choice to replace current HFCs in cars,
supermarkets, and heat pumps.
• Coca-Cola has fielded CO2-based beverage coolers and the U.S. Army is
considering CO2 refrigeration.
Note: Due to the need to operate at pressures of up to 130 bars (1,900 psi;
13,000 kPa), CO2 systems require highly resistant components, however these
have already been developed for mass production in many sectors.
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10RFMA 2021 Charlotte June 22 ‐ 24, 2021
Types of HVAC systems
Heat Pumps vs Splits vs Water Chilled vs Ductless Mini Splits
a) What are the differences?
b) The pros and cons of each
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Types of HVAC systems
Heat Pumps
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Split systems divide each system into its own unit, so your
heater and air conditioner are separate. Most QSR and Fast-
Food Restaurants have Split systems
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11RFMA 2021 Charlotte June 22 ‐ 24, 2021
Ductless Mini-splits are heating and cooling systems that
allow you to control the temperatures in individual rooms or
spaces. Mini-split systems have two main components -- an
outdoor compressor/condenser and an indoor air-handling unit(s)
(evaporator).
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The main advantages of mini splits are their small size and flexibility for
zoning or heating and cooling individual rooms.
Since mini splits have no ducts, they avoid the energy losses associated
with ductwork of central forced air systems. Duct losses can account for
more than 30% of energy consumption for space conditioning
The primary disadvantage of mini splits is their cost. Some people may not like
the appearance of the indoor part of the system. While less obtrusive than a
window room air conditioner, they seldom have the built-in look of a central
system. There must also be a place to drain condensate water near the outdoor
unit.
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Water Chilled Systems
How loops work?
What to look for in leases for requirements.
(ex: water temp, strainers, maintenance schedule by Landlord, etc..)
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An open loop system
is one that uses groundwater from a conventional well as a
heat source in the winter and a heat sink in the summer. The
groundwater is pumped through your heat pump, and the
heat from the water is either extracted (in winter) or rejected
(in summer).
Geothermal systems are open loop systems
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A Closed-loop system
is designed to transfer heat through circulating water for air
conditioning, heating, or process applications. In many HVAC
applications, the closed-loop water is circulated through an air
handler coil, which either cools or heats the incoming air. This is
the most common water chiller system
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Know your building zones:
• Kitchen vs Customer areas
• Thermostat locations
• Open vs closed kitchens
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Typical Restaurant Design Review
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The importance of proper Air Balancing
• Positive overall, slightly negative in kitchen
• Seasonal issues
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Energy costs across the Country will
continue to rise!
Superior Energy Efficiency is a
Competitive Advantage
If you are not measuring…you are only guessing
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15RFMA 2021 Charlotte June 22 ‐ 24, 2021
When a Kitchen Exhaust System is Out of Balance…
By understanding how these elements can be controlled and managed, you
can gain control of these unseen costs in your buildings.
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The volume of airflow in a commercial kitchen exhaust system may be up
to 20 times greater that the airflow in a dining room. However, it is:
• Invisible
• Extremely expensive
• Usually out of control
• Often uncomfortable
• Affects the quality of food
• Determines employee production
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It is important to properly schedule the equipment with all features,
configurations and an air balance schedule
RESTAURANT
AIR PATHS EXFILTRATION
(POSITIVE
PRESSURE)
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16RFMA 2021 Charlotte June 22 ‐ 24, 2021
HVAC Schedule
It is important to properly schedule the equipment with all features, configurations,
acceptable manufacturers, complete model numbers, electrical and weight data with
contacts for technical support and pricing guidance
Consider the use of active dehumidification cycles (hot gas reheat), economizers
with reference enthalpy controls but no economizers in hot/humid ASHRAE Zone 1.
Properly apply evaporative coolers a moisture and maintenance perspective.
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Comfort & Energy
Guest and employee comfort is critical and a key aspect of
any good restaurant design. Temperature, humidity, dew
point and moisture management are on the minds of
restaurant designers. Non-conditioned make-up air and
other antiquated design philosophies can reduce comfort,
increase humidity and result in moisture damage and
bacterial growth. A properly designed system utilizing
conditioned air can increase comfort and save in overall
operating energy and decrease the total lifecycle cost or
total cost of ownership.
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Space Operating Conditions
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• Know your climate zones
• One suit does not fit all areas.
• (Particularly in California where 30 miles
near the coast can make a large difference
on settings and layout )
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Economizers
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FUN FACT
CHICAGO REGULATIONS ON ECONOMIZERS AND
RESTAURANTRS ODOR CONTROL
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Findings Summary From Peter Jacobson’s Study for the
California Energy Commission of 215 Commercial RTUs
under 120,000 BTUs (10 tons)
Economizers
Refrigerant charge
Low air flow
Cycling fans during
occupied period
Fans run during
unoccupied period
Ducts outside
conditioned space
Simultaneous heating
and cooling
No outside air intake at
unit
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Problem Frequency
Note: Source “Small HVAC System Design Guide,” California Energy Commission, October 2003
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19RFMA 2021 Charlotte June 22 ‐ 24, 2021
Performance Upgrades
• Economizer Upgrades & Retro Commissioning
Test, measure and verify
economizer performance
Upgrade to the new generation of
Advanced Digital Economizer
Controls
Measure and adjust minimum and
maximum airflow
Commission economizer
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Example of a recent advanced
Economizer Control Upgrade
KW Usage and Cooling Operation of a 20 Ton Roof Top Package Unit
% of Compressor
Item KW Used
Stage 2 KW
Economizer – Main Fan Only 3.0kW 14%
Economizer – Main and Exhaust Boost
4.5kW 20%
Fan
Compressor Stage 1 14kW 64%
Compressor Stage 2 22kW 100%
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Kitchen Exhaust – Overview
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The Grease Exhaust System
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How a Kitchen Exhaust System Works
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Hood Filter Maintenance
Incorrect filter fit
• The hood and filters should be maintained on a
regular basis. This should be evident no matter how
long it has been since a professional service has
cleaned the entire system.
Filter must fit vertically to
allow grease to drain
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Hood Filter Maintenance
Incorrect filter fit
Filter must fit vertically to
allow grease to drain
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Hood Filters waiting for KEC
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Hood Filters Cleaned in Place
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Hood Filters Cleaned in Place
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Hood Filters Cleaned in Place
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23RFMA 2021 Charlotte June 22 ‐ 24, 2021
Hidden Hood and Duct issues
Grease in the light globes
are a sure sign of grease
leakage above the hood
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Hidden Hood and Duct Issues
Grease in the light globes
are a sure sign of grease
leakage above the hood
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Hidden Hood and Duct issues
This access panel is neither grease tight nor a Listed assembly. This does not
comply with NFPA 96, Section 7.4.3.3.
Grease in the light globes
are a sure sign of grease
leakage above the hood
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24RFMA 2021 Charlotte June 22 ‐ 24, 2021
Hidden Hood and Duct Issues
EXAMPLES OF DUCTMATE F1 and F2 ACCESS: DO NOT USE THESE STYLE
ACCESS PLATES ON GREASE DUCTS, THE GASKETS ON THESE DO NOT KEEP
THE GREASE FROM LEAKING-USE THE UL LISTED DUCTMATE ULTIMATE
PLATE ONLY
Grease in the light globes
are a sure sign of grease
leakage above the hood
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Hidden Hood and Duct Issues
Grease in the light globes
are a sure sign of grease
leakage above the hood
F2 door leaking already vs Ultimate door with zero grease leakage at 3
months in same concept with same sales figures.
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Hidden Hood and Duct Issues
Grease in the light globes
are a sure sign of grease
leakage above the hood
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25RFMA 2021 Charlotte June 22 ‐ 24, 2021
Hidden Hood and Duct Issues
Ductmate Ultimate
Access plate. UL listed
for grease duct.
Grease in the light globes
are a sure sign of grease
leakage above the hood
Flamegard
Access Plates.
UL listed for
grease duct.
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Hidden Hood and Duct Issues
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Inside of Access Plate Latch Issue
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26RFMA 2021 Charlotte June 22 ‐ 24, 2021
Hidden Hood and Duct Issues
You can see where the
cleanings stop up the
stack here 3 months after
opening
Same concept after 15
years of the same neglect,
they were getting cleaned
quarterly!
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Fans
• Types of fans
• The differences between HVAC fans and exhaust fans
• Cleanliness of fan blades
• Proper rotation
• Belted sets
• Direct drive – Open vs Sealed motors, VFD’s etc.
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Upblast Fan
Grease in the light globes
are a sure sign of grease
leakage above the hood
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Just When You Think You Have Seen Everything
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Inside an Exhaust Fan
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Inside an Exhaust Fan
• Broken Vibration
Isolators
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Inside an Exhaust Fan
Motor air cooling intake
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Inside an Exhaust Fan
Motor air
cooling
INTAKE SIDE Discharge side(back
intakeOF FAN of fan blades)
BLADES
Behind the fan blades are one of the most important areas of concern.
Note: Intake side is clean, but the discharge side is not.
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