1. Rules & Standards
Dan Int-Hout
Chief Engineer,
Krueger

2. We don’t need no stinking rules!

3. Objectives Overview Thermal Comfort Acoustics
IAQ / Standard 62.1 Update

4. Source Control Dilution Filtration Environmental Acceptance Factors
Air Distribution
Environmental
Acceptance
Factors
Comfort
Acoustics
Filtration
Source Control
Dilution
IAQ
Acceptance
Successful interior design requires satisfying occupants’ space needs. This is a very complex task, requiring an understanding of a number of disciplines. Included in these are indoor air quality parameters, air distribution rules, acoustic considerations, and the thermal comfort requirements of the occupants.
If all four are acceptable, environmental conditions probably are, too. If one is not acceptable, however, occupants will complain, and often of the wrong problem. It is necessary to understand all four parameters to properly understand the true nature of complaints and to direct the proper resources to cure the problem.

5. LEED: LEED V4 went into effect in 20013.
ASHRAE Standard 62.1 (Ventilation)
VRP req’s must be fully met since V2.2 to get any points
Standard 55 (Comfort), is worth up to two points.
Ventilation points are gained by increased ventilation
There are no LEED products!
LEED is a design standard, and points are awarded for use of products in a design.
The mechanical systems in a building are exempt from the “% recycled components” calculation.

6. Thermal Comfort ASHRAE 55-2016: Latest Thermal Comfort Standard
ASHRAE Fundamentals 2017, Chapter 9
Predicted Mean Vote (PMV) - a single number rating.
Comfort envelope can be plotted using program listed in ASHRAE 55
Standard 55 mandates a maximum 5oF vertical temperature stratification.
Thermal comfort calculations are based on a heat balance solution, much like the heat balance for a building. Internal heat loads become metabolic rate, insulation becomes clothing, etc. Based on statistical human response data, allowable parameters have been developed for the controllable environmental variables in occupied spaces.
The ASHRAE and ISO standards use different methodology but require the same results. The ISO standard has the advantage of a single-number rating of combined parameters, making the analysis easier to understand and specify.
The ASHRAE Standard is under review and will be written in code language. It will most likely include the single-number rating when finalized. The present Standard, 55-91, does not include the single-number rating, but during preparation of the standard, a computer program was developed. This program, which would calculate PMV based on the most current understandings, was included in an ASHRAE paper. This program plotted the data on a psychometric chart, allowing easy analysis of the comfort envelope for a given set of conditions.

7. Typical “Executive Worker” Profile
Shown here is the comfort envelope for a typical male office worker wearing normal office clothing, but no jacket. Notice that 75°, 50% RH is not within the envelope.
The common complaint of this individual at 75/50 is not one of excessive warmth, however, but rather of “stuffiness.”

8. Typical “Clerical Worker” Profile
This is the comfort envelope for typical female attire (light blouse, short skirt) at a lower activity level (not moving around the office). Again, 75/50 is not in the comfort zone. The discomfort described here is also typically misdiagnosed, often expressed as “drafty.”

9. Plotting Both
It’s easy to see how the 75/50 system satisfies none of the people, any of the time! This expresses the need for occupant control (or flexible dress codes, or both).
Additionally, occupants will do whatever they can to make themselves comfortable. This often involves the dreaded 1500W heater under the desk!

10. Comfort Economics
Unlike in agricultural facilities, human productivity is hard to measure.
Buildings cost $2.00/ sq. Ft./Yr. to heat and cool.
Occupants get paid at least $ / sq. Ft./Yr. Some say $500/yr!
Moving thermostats cannot cost (or save) more than 5% energy.
While productivity is difficult to measure, some potentials can be related. Agricultural facilities can measure productivity, however, and recent studies showed that hogs allowed to control their temperatures actually increased productivity and reduced energy. (It’s true!)
Building HVAC system energy costs are typically much less than $2/sq. ft.
An occupant costing his employer $30,000/yr. occupies 150 sq. ft. of a building.
Moving the thermostat 5° either way from optimum can only reduce perimeter delta-t and return air heating/cooling loads by an amount equal to 5% of the total HVAC energy. While a big number in a large building, it is insignificant compared to salary costs. The ratio is 2000/1.
In the US, we only spend $10 to $15/sq. ft. for HVAC equipment in new construction . (In Europe, they spent $50/sq. ft.!)

11. Comfort Economics
The ratio of productivity to energy savings is 2000/1.
A 10% reduction in productivity = rent cost!
Buildings’ HVAC first cost is $20-$35/sq. Ft.
The EBTR was proven (in 1981) to increase HVAC energy consumption by as much as 20%.
EBTR has been again imposed in federal buildings in California!
While productivity is difficult to measure, some potentials can be related. Agricultural facilities can measure productivity, however, and recent studies showed that hogs allowed to control their temperatures actually increased productivity and reduced energy. (It’s true!)
Building HVAC system energy costs are typically much less than $2/sq. ft.
An occupant costing his employer $30,000/yr. occupies 150 sq. ft. of a building.
Moving the thermostat 5° either way from optimum can only reduce perimeter delta-t and return air heating/cooling loads by an amount equal to 5% of the total HVAC energy. While a big number in a large building, it is insignificant compared to salary costs. The ratio is 2000/1.
In the US, we only spend $10 to $15/sq. ft. for HVAC equipment in new construction . (In Europe, they spent $50/sq. ft.!)

12. Comfort Summary
Thermal comfort is #1 reason for not renewing the lease (don’t fix the wrong thing).
Many IAQ and air distribution complaints can be cured with temperature changes.
Internal heat loads cost 2X power consumption.
Mandated designs and set points often waste energy. People will make themselves comfortable!
Vertical Stratification requirement is often ignored
Thermal comfort program available online!
The #1 reason for not renewing the lease is actually “Vertical Transportation” (elevators). But we are apparently working at taking over the top spot.
Temperature changes can overcome “stuffy” and “drafty” complaints.
Productivity far outweighs energy as a real cost in a building.
Heat generated in a building typically passes to the chiller for removal. You pay to generate the heat, then again to get rid of it.
People will do what they can!

13. Acoustics – Single Number Rating
Several single number rating schemes have been developed to deal with a spectrum of sound, which include:
NC, NR, & RC
dBA (A Scale, B Scale, & C Scale)
Sones & Bells
STC & NRC
This Slide is to show that there are different types of single number rating systems.
We will talk about NC and RC later. (Bold text is what we use in our section of the industry)
NC - Noise Criterion – Single number rating system.
NR – Noise Rating – European version of NC
RC – Room Criterion – Developed by Acousticians to show both a number rating and sound quality rating.
dBA (A Scale) – Weighted average. Not very good with high and low frequencies.
dBA (B Scale) – Rarely used – works between A Scale and C Scale.
dBA (C Scale) – Used for very high frequencies.
Sones – Rating system used for Exhaust Fans
Bells – Rating System used for industrial fans (very loud fans)
STC – Sound Transmission Class – Measurement of sound passage thru 2 ceiling tiles. Example : two sound proof rooms with ceiling with ceiling tile that is not sound proof. In one room, you make the noise and measure in the other room. The sound transmission goes thru the ceiling tile twice.
NRC – Noise Reduction Coefficient – Noise Source and measuring device is separated by a barrier (not a wall), turn noise on and measure the sound that bounces off the ceiling tile.

14. Acoustics – Evaluating Sound Data
A single number value cannot be used in an acoustical acceptability analysis
Octave band data is much more difficult to gather and use
Few products have octave band sound power data available
New test specifications will provide octave band data for a broad range of products
New test specifications will provide octave band data for a broad range of products (ARI – 260)
Only VAV boxes have certified octave band data.

15. Acoustics – RC Speech Privacy
The LETTER is determined on the chart by drawing a -5 dB slope per band through the numerical RC 1,000 Hz (also know as the SIL – Speech Interference Level line or the numeric RC Value).
H – Draw parallel line 3 dB above SIL line from 1000 Hz to 8000 Hz. If any plotted data for the 2000 Hz, 4000 Hz or 8000 Hz is above this +3 dB line, the you get an “H”
R – Draw parallel line 5 dB above SIL line from 16 Hz to 1000 Hz. If any plotted data for the 16 Hz, 31.5 Hz, 63 Hz, 125 Hz, 250 Hz or 500 Hz is above this +5 dB line, the you get an “R”
What you are looking for is values of point that are plotted above the two lines.
V – If the data points for the 16 Hz, 31.5 Hz and 63 Hz fall in Region A or B, then a “V” is assigned

16. Acoustics – Sound Paths2 3 4 5 6 1 C O
SOUND PRESSURE Lp
1 = Casing Radiated & Inlet
2 = Duct Breakout
3 = Distribution Duct Breakout
4 = Flex Duct Breakout
5 = Discharge
6 = Outlet Generated Sound

17. Acoustics AHRI 885 acoustical application standard.
AHRI 880 air terminal test standard.
AHRI 260 ducted equipment except air terminals.
ASHRAE 70 air diffuser performance.
Note: ADC 1062 test code was obsoleted in 1984!
Acoustical quality suggests the use of RC (or newer measures) rather than NC.
ANSI requires 26NC in schools. (LEED V3 required 35NC/45 dBA)
LEED V4 for Schools requires 40dBA for the HVAC system as a prerequisite, and 885 can be used as validation

18. End Reflection

19. End Reflection
An end reflection happens when air travels from a main to a branch duct, and especially when it enters a flex duct connection.
Another happens when a duct terminates at the room, at the diffuser.
There is an end reflection when discharge sound enters the reverb room
AHRI 880 (and the MOT, ASHRAE 130) ignored this for 30+ years
AHRI 260 includes an end reflection correction
All manufacturers certifying sound through 880 had to correct their discharge sound data as of 2012.

20. End Reflection
This change only affects reported discharge sound power levels.
Manufacturers certifying sound through AHRI must use Appendix E of 885 when showing NC calculations.
AHRI 885 includes one 8” end reflection in Appendix E, as an application effect.
Actual unit Discharge sound is the same as before,. but will be reported a bit louder.
Engineers will need to update their discharge sound specifications.

21. Sound Specifications Should be based on clearly stated assumptions.
If duct lining is used – require”NC shall be determined in accordance with ARI 885, Appendix E”
A meaningful specification will specify octave band.
Do not over-silence!
Increases initial / operating costs, may hinder IAQ performance
Engineers have to review both specs and submittals to be sure they understand the changes in discharge sound ratings.
Utilize manufacturer’s air terminal selection software!

22. Designing for IAQ – 3 Strategies
Filtration
Source control
Dilution
Filtration
Source Control
Dilution
Three things are required for Mold growth:
Dirt
Dark
Damp

23. Indoor Air Quality Standing Standard Project Committee 62.1
Residential Committee is 62.2
Current Standard is ’16, and all addenda have been incorporated
Several more addenda have been added and more are in process.

24. IAQ Standard - Changes in place and coming
A listserv application can be made online!
Significant Modifications:
MERV 8 is required upstream of wetted surfaces (= 2” pleat?).
Plenum located equipment must be directly connected to the ventilation supply.
In some places, outside air particulate and ozone must be filtered.
Ventilation rate must be increased when in heating mode if ‘rules’ not followed.
Standard 62.1 is a prerequisite to LEED

25. IAQ Standard Standard 62.1 is on continuous maintenance.
Continuous and incremental changes are in progress.
It will attempt to be in coordination with building codes.
A Guideline document for designing systems above minimum requirements is being created.
Users Manual is available now.
The IMC has referenced 62.1 VRP in the newest release of the mechanical code.
There seems to be minimal public awareness of the dynamic nature of the Standard.

26. IAQ Standard Several ASHRAE Standards are on continuous maintenance.
Continuous and incremental changes are in progress.
Many standards are being incorporated into Building Codes
Failure to understand “the rules” can lead to both poor buildings and occupant dissatisfaction.

27. So you want to save money?
Things to consider:
First Cost
Energy cost
Occupant Salary costs
Life Cycle Costs

28. First Cost
Today’s typical first cost for HVAC is at or exceeding $35/Square Foot in a high end open office.
Costs are much higher for HealthCare facilities
Even strip malls and low end offices are costing over $20/sf

29. Energy Costs
A typical office building in the US costs about $2/square foot/year to heat and cool.
It is of course higher in places with high utility rates (like New York City!)
It is lower in places where economizer can be utilized a significant part of the time.

30. Occupant Salary Costs
On average, assuming about 150 sf/occupant, salary costs average at least $200/sf/y.
With higher occupancy, this can be as high as $600/sf/y.
Health Care is much higher.

31. Thermal Comfort Economics
ASHRAE Journal, June 2008
While productivity is difficult to measure, some potentials can be related. Agricultural facilities can measure productivity, however, and recent studies showed that hogs allowed to control their temperatures actually increased productivity and reduced energy. (It’s true!)
Building HVAC system energy costs are typically much less than $2/sq. ft.
An occupant costing his employer $30,000/yr. occupies 150 sq. ft. of a building.
Moving the thermostat 5° either way from optimum can only reduce perimeter delta-t and return air heating/cooling loads by an amount equal to 5% of the total HVAC energy. While a big number in a large building, it is insignificant compared to salary costs. The ratio is 2000/1.
In the US, we only spend $10 to $15/sq. ft. for HVAC equipment in new construction . (In Europe, they spent $50/sq. ft.!)

32. What is the reality?
Energy costs are often much higher than predicted.
Occupant dissatisfaction with thermal environment is #1 reason for not renewing lease
Reported by BOMA (Building Owners and Managers Assn)
Renovation costs aren’t always considered when spaces are designed.

33. So what about energy cost predictions?
Loads are not what engineers think they are.
Energy use computer programs don’t have inputs for many emerging technologies.
Validation of energy models is seldom accomplished
Building operators have no clue how the system is supposed to operate to ensure both comfort and energy efficiency.

34. What is the result? Spaces are often too cold
Acoustics are poor (typically too quiet)
Energy bills are higher than predicted
Productivity suffers.
Tenants don’t renew the lease.

35. Spaces are often too cold.
In order to control humidity, and still meet minimum ventilation requirements, spaces are often sub cooled.
Reheat, while a solution to the comfort issue, is expensive.
Perimeter zones, in winter, are often severely stratified, with it being very cold near the floor and near exterior walls.
All too often, space heaters are found throughout the interior, increasing loads significantly.

36. Acoustics are poor.
In order to achieve a good acoustical environment, it is almost always necessary to add background sound masking.
Asking the HVAC system to provide that noise is very expensive.
Poor acoustical treatment of surfaces compound the issue.
Open ceilings, while often desired by architects and owners, often result in poor acoustical privacy.

37. Energy bills are higher than predicted.
Systems have difficulty controlling humidity at low loads
Poorly adjusted or selected air outlets don’t allow thermostats to sense room temperatures correctly
Operators don’t know how to run the system efficiently
Opportunities for free cooling or heat removal aren’t utilized.

38. Productivity suffers.
Occupants have high absenteeism from poor environmental controls
Lack of Acoustical Privacy reduces ability to concentrate
Inability of management to provide comfort reduces employee morale
Increasing ventilation is proven to improve productivity (and can gain a LEED point).
See my ASHRAE Journal article(July ‘13)!

39. Importance of Selection and Adjustment
The ASHRAE handbook suggests selecting diffuser to achieve an 80% ADPI at all air flow rates.
Most diffuser layouts have diffusers too close together, resulting in drafts at full flow
Some diffuser designs work better than others at low flows – a plaque-type is a good choice. Perforated and swirl diffusers not so much.

40. Minimum Ventilation Rates
At the Dallas ASHRAE meeting, an interpretation request discussed ventilation rates. It was stated that there are actually three rates:
Occupied Minimums are the sum, of occupant and floor area
Unoccupied (but available) is just based on floor area
Not Occupied means “off”.
So, we need to have three ventilation rates, not one.
When one zone changes, all the others need to adjust, suggesting the need for pressure independent, measurable ventilation rates for all zones.

41. RP1515
A recent research project was conducted at the Yahoo campus in California, RP 1515, by UC Berkeley, Taylor Engineering and Price Industries. Several interesting things were learned :
Interior loads are approaching the Minimum Ventilation Rate of Standard 62.1, at 55F. ( 55F is required for humidity control).
Occupant satisfaction was high at 0.22 CFM/SF, validating the Standard 55 maxim: “there is no minimum air speed for comfort”.
The Diffuser type and layout confirmed the Standard 55 User’s manual recommendation that ADPI be used to design diffuser layouts, and to demonstrate turn down limitations.

42. What can we do?
The “Rules” are becoming code, or at least the “Acceptable Standard of Care”.
Loads are dropping as Ventilation rates are increasing.
Perimeter loads are becoming less.
Ventilation rates are not constant.
The solution starts at the input of outside air.

43. There are “rules” that define how they operate
Summary
Diffusers are the devices that deliver conditioned air to the space: “the wheels on the car”
There are “rules” that define how they operate
Properly selected, installed, and adjusted, they can provide a comfortable environment
Improperly used, spaces can be drafty, uncomfortable, and sometimes uninhabitable

44. Net Zero Energy Building

45. Read my Air Distribution Blog on Krueger’s website!
Dan Int-Hout
Read my Air Distribution Blog on Krueger’s website! 45