ahri standard 1330 discussion · ahri standard 1330 discussion scope definitions influencing...
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AHRI Standard 1330 Discussion
Scope
Definitions
Influencing Factors
What A Higher Radiant Efficiency Means
Increased Comfort
Fuel & Electrical Savings
Optimum Building Performance
INTRODUCTION
INFRARED FACTOR (IF):
The rating of units based on the radiant coefficient, or the percentage of radiant output listed as Infrared Factor (IF) from 7 to 15.
CAN/ANSI/AHRI Standard 1330-2015 Performance rating standard for radiant output of gas-fired infrared heaters
PURPOSE: The purpose of this standard is to establish for infrared heaters:
definitions; test requirements; rating requirements; nomenclature;
minimum data requirements for published ratings
SCOPE: This standard applies to infrared heaters that are gas-fired
high-intensity infrared heaters and gas-fired low-intensity
infrared heaters with inputs up to and including 400,000 BTU/h
per burner intended for installation in and heating of indoor or
outdoor spaces.
COMBUSTION EFFICIENCYIMPORTANT DEFINTIONS
Radiant Efficiency: A colloquial term that is used to describe the radiant performance of an appliance. This term is created by considering the Gross Radiant Coefficient as a percentage
INFRARED FACTOR (IF): A published rating based upon Gross Radiant Coefficient. The Infrared Factor, or “IF”, categorizes radiant coefficient into increments of 0.05 in a range of IF-7 through IF-15. A ratio of 0.35 and below corresponds to the minimum rating, an IF-7. Any coefficient breaching 0.7 is recognized as an IF-15. This factor allows for a quick comparison of multiple appliances and provides a neutral footing for all gas-fired radiant units.
Gross Radiant Coefficient: Heat emitted by the infrared appliance through the appliance’s radiation plane divided by the gross heat input of the test gas. This can be interpreted as the useable heat radiated by the system divided by the input to determine a ratio
CAN: The Standards Council of Canada
AHRI: The Air-Conditioning, Heating and Refrigeration Institute
Radiant Efficiency Infrared Factor (IF)
≤ 35% 7
> 35% ≤ 40% 8
> 40% ≤ 45% 9
> 45% ≤ 50% 10
> 50% ≤ 55% 11
> 55% ≤ 60% 12
> 60% ≤ 65% 13
> 65% ≤ 70% 14
> 70% 15
Infrared FACTOR
Determining the INFRARED FACTOR
(RADIANT EFFICIENCY)
REQUIRED EQUIPMENT – Measuring Radiant Efficiency
Radiometer
Gas meter
Data Acquisition
Controller (DAQ) /
Computer with
specialized software
Thermometer /
Barometer
Measuring Grid
Radiation Reference Plane
INFLUENCING FACTORS
Radiant Efficiency
Heat Exchanger Material
Reflector Material
Reflector Design
Convective Losses
Orientation
Thermal Efficiency
Combustion Efficiency
Does NOT explain how well energy
turns into comfort heating
COMBUSTION EfficiencyConvert fuel to ENERGY
THERMAL EfficiencyEnergy NOT LOST to exhaust
Does NOT explain how well energy
turns into radiant heat
CONVECTIVE LOSSESEnergy LOST to exhaust or poor appliance design
Plays a significant role in determining radiant
efficiency
EMISSIVITY
MATERIAL EMISSIVITYAluminized Steel (Heat Treated) 0.79Hot Rolled Steel 0.80Porcelainized Steel 0.92 to 0.96Cast Iron 0.35 to .70Stainless Steel (Type 304) 0.36 to 0.73Schedule 40 Black Steel Pipe 0.95
REFLECTIVITY
MATERIAL REFLECTIVITYAluminum (Mill Finish) 0.91Aluminum (Polished) 0.91Stainless Steel (Type 304) 0.27 to 0.64
OVERALL DESIGNCombining high quality materials and innovation
ROBERTS GORDON® considered all factors to
increase radiant output
• Converting energy input into useable radiant heat
• AHRI 1330 measurement methodology
ROBERTS GORDON® Infrared Heaters
deliver more radiant heat to the floor than
any other infrared heater in the industry
BENEFITS OF A
HIGHER RADIANT EFFICIENCY
“Recognizing the reduced fuel requirement for these applications, …. it is desirable for manufacturers of radiant heaters to recommend installation of equipment with a rated output that is 80 to 85% of the heat loss calculated by methods described in Chapters 17 and 18 of the 2013 ASHRAE Handbook – Fundamentals.”
- “Infrared Radiant Heating.” 2016 ASHRAE Handbook HVAC
Systems and Equipment. Atlanta, GA: ASHRAE,
2016. 16.1. Print.
ADJUSTMENT FACTOR FOR INFRARED EQUIPMENT SIZING
ADJUSTMENT FACTOR FOR AIR EQUIPMENT SIZING
ADJUSTMENT FACTOR FOR INFRARED EQUIPMENT SIZING
ADJUSTMENT FACTOR FOR INFRARED EQUIPMENT SIZING
ADJUSTMENT FACTOR FOR FUEL SAVINGS!
ADJUSTMENT FACTOR FOR EVEN MORE FUEL SAVINGS!
LOWER YOUR THERMOSTAT
AND ACHIEVE THE SAME
COMFORT LEVELS
Mean Radiant Temperature (MRT)“The net amount of Infrared Energy
available from surfaces to provide comfort”
OPERATIVE TEMPERATURE (To)
Calculations with STANDARD REFLECTOR
MRT + T To = AIR
2Formula:
Operative Temperature can be
defined as the average of the mean
radiant and ambient air temperature
Air Heating
MRT = 65°F TAIR = 75°F
=65 °F+ 75°F
= 70°F2
To =75 °F+ 65°F
= 70°F2
To
Infrared Heating
With Standard Reflectors
MRT = 75°F TAIR = 65°F
TURNING THE THERMOSTAT DOWN
For every degree that you lower the thermostat setting, you save approximately 3-4% in fuel usage
REMEMBER:
“Equivalent perceived comfort at lower air temperatures”
Infrared Heating
To =75°F + 65°F
= 70°F2
Calculations with STANDARD REFLECTOR
INCREASING THE MRT
WITH A HIGHER RADIANT EFFICIENCY
Floor Temperature – Standard Reflector
Ave temp 95.4Max temp 117.4
Floor Temperature – High Efficiency Reflector
Ave temp 99.7Max temp 122
End Wall Temperature – Standard Reflector
Ave temp 93.4Max temp 104.2
End Wall Temperature – High Efficiency Reflector
Ave temp 97.4Max temp 108.6
Side Wall Temperature – Standard Reflector
Ave temp 92Max temp 97
Side Wall Temperature – High Efficiency Reflector
Ave temp 95.9Max temp 100.8
MRT increase (Deg F)
Std High Eff
Floor 95.4 99.7 4.3
End Wall 93.4 97.4 4.0
Side Wall 92.0 95.9 3.9
Average MRT increase: 4.1 Deg F
MRT - is simply the weighted mean
temperature of all the objects
surrounding the body
MRT also has a strong influence on thermophysiological comfort indexes such
as predicted mean vote (PMV). (ASHRAE 55)
OPERATIVE TEMPERATURE (To)
Calculations with HIGH EFFICIENCY REFLECTOR
MRT + T To = AIR
2Formula:
Operative Temperature can be
defined as the average of the mean
radiant and ambient air temperature
Air Heating
MRT = 65°F TAIR = 75°F
=65 °F+ 75°F
= 70°F2
To =79 °F+ 61°F
= 70°F2
To
Infrared Heating
With High Efficiency
Reflectors
MRT = 79°F TAIR = 61°F
TURNING THE THERMOSTAT DOWN
For every degree that you lower the thermostat setting, you save approximately 3-4% in fuel usage
REMEMBER:
“Equivalent perceived comfort at lower air temperatures”
Infrared Heating
To =79°F + 61°F
= 70°F2
Calculations with HIGH EFFICIENCY REFLECTORS
Q & A