ASHRAE 62.2: What s New in 2016

Transcription

1 ASHRAE 62.2: What s New in 2016 Rick Karg 2018 Residential Energy Dynamics, LLC

2 What We Will Talk About Overview of mechanics of Logic behind the Standard. Sizing local ventilation (exhaust-only). Alternative Compliance Path. Sizing dwelling-unit ventilation. Alternative Compliance Path. Infiltration credit. Additional selected requirements. Changes to version. 2

3 Overview of 62.2 Standard 3

4 RED free web application 4

5 Free ASHRAE Residential Energy Dynamics 5

6 Logic Behind the Standard 6

7 Background and Logic Natural infiltration rates are variable. Dwellings have different contaminants. People react differently. Epidemiological effects are uncertain, especially at low contaminant levels. 7

8 Infiltration is variable! ResidentialEnergyDynamics.com Advanced Infiltration tool 8

9 Background and Logic Some studies show that increased ventilation can reduce DALYs lost: Assumes DALYs lost per 100,000 California homes, (assuming an occupancy of 4 people per home) Source: Logue et al., Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation, June 2011, LBNL-4945-E 9

10 Background and Logic Local bathroom ventilation reduces moisture and odors. Local kitchen ventilation reduces moisture, odors, and many harmful contaminates. 10

11 Background and Logic Dwelling-unit ventilation reduces general odors and contaminants. Some studies show that DALYs are lengthened with ventilation. 11

12 Cost to Operate Ventilation is Low Cost to operate motor every day, every hour 12

13 Philadelphia, PA 1400 CFM 50 Single-story dwelling, 1200 ft 2 Thermostat at 68 and 75 One year Increased heating and cooling loads per year in therms for ventilation 13

14 Sizing Local Ventilation (bathrooms and kitchen) Exhaust Only Fans 14

15 Local Ventilation Exhaust the worst air in the dwelling as quickly as possible. Bathrooms. Kitchens. 15

16 Local Ventilation Requirements Local exhaust fans must be installed in bathrooms and kitchen. Bathrooms (not half bathrooms) 50 CFM demand-controlled, or 20 CFM continuous. Kitchen 100 CFM demand-controlled*. * Vented range hood required if flow rate is less than 5 kitchen ACH. 16

17 Local Kitchen Ventilation This does not help the installer s reputation! 17

18 Alternative Compliance Supplement (Path) for Existing Dwellings ONLY Appendix A Existing Dwellings ONLY 18

19 Alternative Compliance Path For existing dwellings only. Provides alternative method of meeting local exhaust requirements in kitchens and bathrooms that do not have the existing LOCAL fan flow required by ASHRAE /2013/2016. Existing Dwellings ONLY 19

20 Alternative Compliance Path In each room where local ventilation should be, determine deficit relative to required demand-controlled rate: How much less than 50 CFM in bathrooms. How much less than 100 CFM in kitchens. For each room with a deficit, reduce room s deficit by 20 CFM if that room has an openable window.* *Deficit may not be below zero for any bathroom or kitchen. Existing Dwellings ONLY 20

21 Alternative Compliance Path Add up deficits and divide by 4. Add this result to the dwelling-unit ventilation requirement. This becomes the new dwelling-unit ventilation requirement. Existing Dwellings ONLY 21

22 Alternative Compliance Path For existing fans being used, sound and ducting requirements of 62.2 are not applicable, but must terminate outdoors. Existing Dwellings ONLY 22

23 Alternative Compliance Path Example #1: 3 Bedroom KIT -50 BR BR -100 BT Deficit = = 200 Add 200/4 = MBT BR No Windows in KITCHEN or BATHS Dwelling-unit vent. requirement = = 95 CFM Existing Dwellings ONLY Source: P. Francisco 23

24 Alternative Compliance Path Example #2: 3 Bedroom KIT -30 BR BR -80 BT Deficit = = 128 Add 128/4 = MBT BR 32 CFM Dwelling-unit vent. requirement = = 77 CFM Source: P. Francisco Existing Dwellings ONLY 24

25 Alternative Compliance Path Example #3-80 KIT -0 BT Add dwelling-unit fan here >20 CFM - so no deficit for this bathroom BR BR Deficit = = 98 Add 98/ MBT BR 32 CFM Dwelling-unit vent. requirement = = 70 CFM Source: P. Francisco Existing Dwellings ONLY 25

26 Sizing Dwelling-Unit Ventilation Exhaust, Supply, or Balanced 26

27 ASHRAE 62.2 Requirements Dwelling-unit ventilation: A mechanical exhaust system, supply system, or combination thereof shall be installed for each dwelling unit to provide dwelling-unit ventilation... 27

28 Dwelling-Unit Ventilation Assumes two occupants in master bedroom and one in the other bedrooms. Over this density, increase ventilation by 7.5 CFM/person. Ventilation air must come directly from the outdoors. Infiltration credit is allowed for envelope air leakage 28

29 ASHRAE Q tot = 0.03A floor + 7.5(N bedroom + 1) Basic dwelling-unit ventilation equation 29

30 Dwelling-Unit Ventilation The dwelling-unit ventilation requirements of the Standard may be satisfied by intermittent operation Example: HRV rated at 150 CFM capacity. Dwelling-unit requirement is 50 CFM. Operate HRV on a timer for 20 minutes out of every hour to get 50 CFM average. At least once every 3 hours 30

31 Infiltration Credit for Existing and New Dwellings 31

32 Dwelling-Unit Ventilation New Dwellings Q tot = 0.03A floor + 7.5(N bedroom + 1) Total Required Ventilation Rate, Q tot - Infiltration Credit, Q inf * - Required Mechanical Ventilation Rate, Q fan * Maximum of 2/3 of Q tot 32

33 Dwelling-Unit Ventilation Existing Dwellings Q tot = 0.03A floor + 7.5(N bedroom + 1) Total Required Ventilation Rate, Q tot + Alternative Compliance Supplement - Infiltration Credit, Q inf * Required Mechanical Ventilation Rate, Q fan * Full amount Existing Dwellings ONLY 33

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36 Additional Selected Requirements of Standard

37 Attached Garages Must prevent migration of contaminates to the adjoining occupiable space. All joints, seams, penetrations, and openings must be sealed or gasketed. Any ducts in the garage must leak less than 6% of total heating/cooling system air flow. 90 CFM of leakage for a 1500 CFM system. 37

38 Instructions and Labeling Provide to owner or occupant of dwelling unit: Information on ventilation systems installed; Instructions on proper operation; and Instructions on proper maintenance. Controls shall be labeled as to their function. 38

39 Ventilation Operation Manual Customer education is very important. Make up an operation manual for occupants. Have extra copies available. Purpose of ventilation. Proper operation of ventilation system, dwelling unit and local. Maintenance suggestions. 39

40 Provide Owner s Manual 40

41 Sound Ratings for Fans The sound ratings of installed ventilation equipment shall meet the requirements of the Standard. 1 sone maximum for continuously operating fans. 3 sone maximum occupantcontrolled fans. Already-installed fans in existing homes exempt. 41

42 Ventilation Ducting If outside thermal envelope, insulate. Rigid ductwork preferred. Flexible duct specifications. Support properly. 42

43 Not good! 43

44 Selected New Features of

45 Overview ASHRAE Standard 62.2 is a continuous maintenance standard New changes are always being discussed New full editions every 3 years Next edition in 2019 This session is a preview of what appears in the 2016 edition. 45

46 Square footage Clarifies that square feet is defined as the square footage of finished areas. All Dwellings 46

47 Square Footage All enclosed above- and below-grade finished areas suitable for yearround use. Include basements, or parts thereof, only if they are finished in a manner similar to the rest of the dwelling. All Dwellings 47

48 Implication: Square footage Many have asked whether to include the square footage of a basement. This addendum clarifies that the standard includes finished areas but not unfinished areas. All Dwellings 48

49 15 CFM Threshold (de minimis) For existing buildings, if Q fan is less than or equal to 15 CFM, dwellingunit ventilation is not required. DOE WAP Memorandum 007, 9/17/2014 Existing Dwellings ONLY 49

50 de minimis Homes using Appendix A do not require dwelling-unit ventilation if the fan flow requirement is 15 CFM or less. Implication: fewer fans need to be installed Existing Dwellings ONLY 50

51 Kitchen Local Exhaust Ventilation Demand-controlled, enclosed kitchen Range hood 100 CFM min. Other, including downdraft 300 CFM min. or 5 ACH (kitchen volume) Demand-controlled, non-enclosed kitchen Range hood 100 CFM min. Other, including downdraft 300 CFM min Demand-controlled bathroom 50 CFM [no change] All Dwellings 51

52 Kitchen Local Exhaust Ventilation Continuous operation May be part of balanced mechanical system Self-operating with accessible override Enclosed kitchen 5 ACH (kitchen volume) Bathroom 20 CFM [no change] All Dwellings 52

53 Makeup air systems Prohibits the use of gravimetric or barometric dampers in non-powered makeup air systems (Section 6.4). Mainly an issue for homes with large kitchen exhaust. Would need either a motorized damper OR a powered makeup air system (e.g. fan). All Dwellings 53

54 Multifamily Compartmentalization Changes the metric for multifamily compartmentalization from 0.2 CFM 50 /square foot of enclosure (6- sides) area, to 0.3 CFM 50 /square foot of enclosure area (Section ) Existing Multifamily 54

55 Rationale ASHRAE 62.2: What s New in 2016 Multifamily Compartmentalization 0.3 seemed more achievable. 0.3 still appeared to provide good protection from neighbors. Implication Nominally would require air sealing between units Not a bad idea, not going to save energy There is a recognition that this is not achievable in many retrofit projects, still being worked on. Existing Multifamily 55

56 Multifamily Scope Change Brings all multifamily dwelling units into the purview of 62.2 regardless of building height Leaves common spaces/mechanical rooms/elevators/etc. in the hands of 62.1 All Multifamily 56

57 Multifamily Scope Change Implication: Provides clear direction of what standard to point to for larger multifamily buildings and ventilation. Previously neither 62.1 nor 62.2 covered these buildings in the retrofit context. All Multifamily 57

58 Multifamily Scope Change Implication: Title now: Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. All Multifamily 58

59 Multifamily Infiltration Credit Allows for an infiltration credit to be taken for horizontally-attached multifamily homes, which includes common walls, subject to a reduction factors. All Multifamily 59

60 Implication: ASHRAE 62.2: What s New in 2016 Multifamily Infiltration Credit For the first time SOME multifamily units can get an infiltration credit. How it is calculated: Do a blower door test of the unit. Calculate the fraction of enclosure area (6-sides) that is NOT attached to other units or garages. Multiply infiltration estimate from blower door test by this fraction. Q fan = Q tot (Q inf * A ext ) A ext = exterior surface total envelope surface All Multifamily 60

61 Residential Energy Dynamics (RED) ASHRAE Tool. All new 2016 features are part of the tool. Yellow highlights are new sections for the horizontallyattached multifamily dwelling units. 61

62 Ventilation Controls Dwelling-unit ventilation Readily accessible manual On-Off control (i.e., fan switch or dedicated branch-circuit overcurrent devices). Controls shall include text or an icon indicating the systems function. Exception: For multifamily dwelling units, On-Off not required to be readily accessible. All Dwellings 62

63 Ventilation Name Change Whole-building (whole-house) ventilation changed to dwelling unit. Implications: Accommodates single-family AND multifamily buildings. All Dwellings 63

64 Unvented Space Heater Scope Change Brings unvented space heaters into the scope of the standard. Allows 62.2 to set requirements related to these devices. All Dwellings 64