F Standard & Right-Sizing HVAC Systems:

Transcription

1 F Standard & Right-Sizing HVAC Systems: Prepared by: Rob Pope Ecolighten Energy Solutions Ltd. Prepared for: City of New Westminster Spring 2017 Builder & Designer Breakfast Using analysis developed for: Natural Resources Canada Local Energy Efficiency Partnerships (LEEP)

2 AGENDA 1. Overview of F Standard 2. Standards for Practice 3. NRCan Study using F Key Takeaways

3 OVERVIEW OF THE F STANDARD

4 KEY CHANGES TO F STANDARD Key changes from the 1990 version include: o Now recognizes the heat recovery provided by heat and energy recovery ventilators. o Now includes advancements in window and wall technologies o Updated air tightness metric.

5 F & BC BUILDING CODE The F standard is referenced in the BC Building Code and other building industry publications including: o BCBC Section Capacity of Heating Appliances: The required capacity of heating appliances located in a dwelling unit and serving only that dwelling unit, shall be determined in accordance with CSA F280 o Homeowner Protection Office (now BC Housing) states in Energy Efficiency Requirements for Houses in British Columbia: HVAC systems and ducts are required to be sized in accordance with good practice, such as described in the Thermal Environmental Comfort Association (TECA) reference material, CSA F280, and Section 9.32 and 9.33.

6 CURRENT STANDARDS OF PRACTICE

7 EXISTING LANDSCAPE Variety of load calculation tools for Residential Part 9 homes with varying levels of sophistication and market adoption. Rule-Of-Thumb TECA Quality First HOT2000 Wrightsoft Elite LoopCad Pro Builders assume mechanical contractors are performing BCBC compliant load calculations to support the sizing and design of HVAC systems. Load calculations requirements vary by jurisdiction for permits/inspections.

8 STANDARDS OF PRACTICE Most common practice from mechanical contractors point-ofview is the use of TECA Quality First. Less common practice is HOT2000 modeling (completed by Energy Advisor) and mechanical contractors referring to these calculations for sizing HVAC. Too common practice is mechanical contractors using of rule-ofthumb. Least common practice is homes built using more sophisticated design and building practices that utilize load calculation tools (e.g. Wrightsoft and Elite) from design professionals.

9 STANDARDS OF PRACTICE Get it done right! The importance of proper load calculations is underscored by the multiple benefits enjoyed by all stakeholders involved new home construction projects. CONSUMERS Improved comfort with a better performing home. BUILDERS Reduced call backs, improved relationship with trades and better finished product. SUPPLIERS & MANUFACTURERS Equipment should operate closer to design intent with increased longevity. ARCHITECTS Confidence that home aesthetics and functionality are better integrated HVAC CONTRACTOR Improved confidence that HVAC equipment meets load requirements for home.

10 SENSITIVITY ANALYSIS USING F280-12

11 But first.. Let s play guess the heat load!

12 GUESS THE HEAT LOAD HOUSE #1 HOUSE #2 HOUSE #3 Whistler 5,487 sf U % of wall area Walls at eff. R24 (average) 2.5 of 3 Levels above grade Flat R34.1 eff. 3.5 ach/50 Nanaimo 1,986 sf U % of wall area Walls at eff. R of 3 level above grade 3.5 ach/50 R39 eff. Roof over attic West Vancouver 8,940 sf U % of wall area Walls at eff. R f 3 level above grade 3.5 ach/50 Flat R26.5

13 GUESS THE HEAT LOAD HOUSE #1 HOUSE #2 HOUSE #3 F ,405 BTU/h F ,523 BTU/h F ,722 BTU/h

14 DETACHED HOME EXAMPLE Harrison Highlands 3,786 ft 2 single

15 DESIGN CONDITION CONTEXT and the factors that tend to most affect equipment sizing Design Heat Loss (DHL) Cold Winter Night Design Heat Gain (DHG) Hot Summer Day F280-12: must meet 100% of DHL, or more F280-12: must meet 80% of DHG, or more

16 DESIGN LOADS Before considering any upgrades Space Heating Design Loads Using CSA F with specs that meet BCBC 2012: Applying a rule of thumb CSA F Space Cooling Design Loads Using CSA F with specs that meet BCBC 2012: Applying a rule of thumb CSA F *Reduction from 4 tons to 3 tons

17 SO WHAT HAVE WE FOUND Smaller heating equipment Smaller A/C equipment Smaller duct work Smaller and fewer bulkheads

18 IMPORTANCE OF CONSIDERING UPGRADES that can impact size of a mechanical systems New home sensitivity analysis considered different options for: window selection wall selection air tightness ventilation duct leakage impacts All analysis was carried out on this home: Highlights are shown on the following slides

19 UPGRADE PACKAGES CONSIDERED BASE CASE UPGRADE 1 UPGRADE 2 OPAQUE ASSEMBLIES Below Grade Walls BCBC 2012 R12 ENERGY STAR (Vancouver) R21.8 R2000 (Vancouver) R33.7 Above Grade Walls R15.7 R21.8 R38.5 2lb S.F. Exposed Floor R12 R12 R30 XPS Roof - Attic R39 R50 R60 Double Pane, Argon Double Pane, Argon Double Pane, Argon WINDOWS HRV U-0.32 U-0.28 U-0.28 SHGC SHGC SHGC ACH/ ACH/ ACH/50 70% eff. 75% eff. 75% eff.

20 INTERESTING UPGRADE PACKAGES Space Heating Design Loads Upgrade 2 (R2000) Upgrade 1 (Energy Star ) Rule of Thumb Base Case OPAQUE ASSEMBLIES Below Grade Walls Above Grade Walls Exposed Floor Roof - Attic WINDOWS HRV UPGRADE 1 ENERGY STAR (Vancouver) R21.8 R21.8 R12 R50 Double Pane, Argon U-0.28 SHGC ACH/50 75% eff. Space Cooling Design Loads Upgrade 2 (R2000) Upgrade 1 (Energy Star ) Rule of Thumb OPAQUE ASSEMBLIES Below Grade Walls Above Grade Walls R38.5 Exposed Floor R30 Roof - Attic R60 WINDOWS HRV UPGRADE 2 R2000 (Vancouver) R33.7 2lb S.F. XPS Double Pane, Argon U-0.28 SHGC ACH/50 75% eff. Base Case

21 CONCLUSIONS 1. Improve confidence. Carrying out CSA F heat loss/gain analysis will right size heating and cooling systems, improve comfort, and can reduce cost. 2. Ensure F compliance. Make sure your heat loss/gain is completed using a solution that conforms with CSA F Don t guess. Reinforce the importance of taking ownership of the load calculations being completed on the home. 4. Good process leads to good results. Getting load calculations completed to F standard will help homeowners and Builders avoid the issues with HVAC equipment oversizing.

22 Questions? Thank you. Rob Pope Ecolighten Energy Solutions (O) (C) (E)