04_DesignPH_Exposures

Nov. 11, 2017

DesignPH – 04: Surface Exposures, Modeling Webinar. June 30, 2020

bldgtyp

Ed May | Partner, Building-Type, LLC (architect, passive house consultant, teacher)

2 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

1

Nov. 11, 2017

NYPH 2020 Technical Workshops

May 19th June 2nd

June 16th June 30th July 21st TBD…

bldgtyp

3 / 55

Agenda [1 hour]

•

DesignPH Review

•

Surface Exposure and Heat Loss

•

Surface Modeling for DesignPH 2.0

•

Surface Exposure in DesignPH 2.0

•

Shading Surfaces in DesignPH 2.0

4 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

2

Nov. 11, 2017

DesignPH Review

Requirements

What you’ll need: • A copy of the DesignPH 2.0 plugin • Sketchup 3-D modeling software • A copy of the PHPP v.8 or 9 (and Excel)

6 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

3

Nov. 11, 2017

https://foursevenfive.com/designph-2-0/

bldgtyp

7 / 55

Sketchup

8 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

4

Nov. 11, 2017

Sketchup Extensions Manager

bldgtyp

9 / 55

Start DesignPH Plugin [Each time you run Sketchup]

10 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

5

Nov. 11, 2017

DesignPH Workflow 1) Model Geometry

2) Tag Model Geometry w/ Data

3) Analyze

4) Export

bldgtyp

11 / 55

DesignPH Workflow 5) Import

12 / 55

NYPH: DesignPH Technical Workshop

6) Complete the PHPP

bldgtyp

6

Nov. 11, 2017

Surface Exposure and Heat Loss

How do you calculate the heat loss of a surface?

Heat Losssurface = Areasurface × U-Valuesurface × ∆T ( But / hr ) In 1.

2.

3.

( ft2 )

( But / ft2-hr-F )

(F)

order to calculate the transmission heat loss for each surface of a building, we need to: Determine the surface area (ft2) Determine the surface’s U-Value Determine the difference in temperature between inside and outside

14 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

7

Nov. 11, 2017

Example: 4” of XPS Insulation (R-20) QT-surface = Areasurface × U-Valuesurface × ∆T

68 F 10’-0”

28 F

Areasurface = 10’ × 30’ = 300 ft2 U-Valuesurface = 0.050 Btu/hr-ft2-F ∆T = 68 F – 28 F = 40 F

30’-0”

QT-surface = 300 ft2 × 0.050 Btu/hr-ft2-F × 40 F QT-surface = 600 Btu/hr

bldgtyp

15 / 55

How do you calculate the heat loss of a surface?

How do we know this value?

Heat Losssurface = Areasurface × U-Valuesurface × ∆T ( But / hr ) In 1.

2.

3.

( ft2 )

( But / ft2-hr-F )

(F)

order to calculate the transmission heat loss for each surface of a building, we need to: Determine the surface area (ft2) Determine the surface’s U-Value Determine the difference in temperature between inside and outside

16 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

8

Nov. 11, 2017

Historical Weather Data • https://www.ladybug.tools/epwmap/ • https://energyplus.net/weather

bldgtyp

17 / 55

ASHRAE 99.6% Case

18 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

9

Nov. 11, 2017

PHI ’Peak Load’ Case: 24 Hour Avg. Temp

The ‘Peak’ Temp= The lowest

24 Hour Average Temp Hourly Temp

bldgtyp

19 / 55

PHI ’Peak Load’ Case(s): 24 Hour Avg. Temp

Why are there two peak loads in the PHPP?

CASE 1:

CASE 2:

Low= -1.3 F

20 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

10

Nov. 11, 2017

So Which one do I use?

Depends on who you are doing the modeling for?

• For ASHRAE / Manual-J, etc..

Use the ASHRAE value • For PHI Certification, use the PHI values.

Its not about ‘right’ vs. ‘wrong’. Its that different protocols and different softwares are set up to take different types of inputs. Just be sure to use the type that your software is expecting.

bldgtyp

21 / 55

Wherever it comes from, this value describes the air temp.

But not every surface on our building is exposed to the outdoor air. Some will be exposed to zones which are warmer than the outdoor air.

68F 7.9F

?

?

22 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

11

Nov. 11, 2017

Temperature Correction Factor Notice the delta-T varies. The PHPP applies a correction factor to the exposure temp. for certain surfaces

bldgtyp

23 / 55

Example 1: Correction Factor of 1.0 QT-surface = Areasurface × U-Valuesurface × ∆T 68 F 10’-0”

7.9 F

Areasurface = 10’ × 30’ = 300 ft2 U-Valuesurface = 0.050 Btu/hr-ft2-F ∆T = (68 F – 7.9 F) × 1.0 = 60.1 F

30’-0”

This is the climate’s outdoor air temp

QT-surface = 300 ft2 × 0.050 Btu/hr-ft2-F × 60.1 F QT-surface = 901.5 Btu/hr

24 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

12

Nov. 11, 2017

Example 2: Correction Factor of 0.25 QT-surface = Areasurface × U-Valuesurface × ∆T 68 F 10’-0”

7.9 F

Areasurface = 10’ × 30’ = 300 ft2 U-Valuesurface = 0.050 Btu/hr-ft2-F ∆T = (68 F – 7.9 F) × 0.25 = 15.0 F

30’-0”

QT-surface = 300 ft2 × 0.050 Btu/hr-ft2-F × 15.0 F QT-surface = 225 Btu/hr bldgtyp

25 / 55

How to Calculate the Reduction Factor?

26 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

13

Nov. 11, 2017

How to Calculate the Reduction Factor?

bldgtyp

27 / 55

Surface Modeling in DesignPH

NYPH: DesignPH Technical Workshop

14

Nov. 11, 2017

Modeling is Done Using SURFACES with no thickness

bldgtyp

29 / 55

First, Model the Thermal Zone as a Mass

30 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

15

Nov. 11, 2017

Modeling is Done Using SURFACES with no thickness

bldgtyp

31 / 55

Model Windows as Flat Planes (for now)

32 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

16

Nov. 11, 2017

Split Any Surfaces with Multiple Exposure Types (AG/BG)

Cellar Wall (Above Grade)

Cellar Wall (Below Grade)

bldgtyp

33 / 55

How to Deal with the Details?

?

34 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

17

Nov. 11, 2017

That’s What Psi-Values are For! PSI Sketchup Face

Sketchup Face

! bldgtyp

35 / 55

Surface ‘Exposure’ in DesignPH

NYPH: DesignPH Technical Workshop

18

Nov. 11, 2017

Group Type for Each Surface

bldgtyp

37 / 55

Start by turning ‘on’ DesignPH Hide all but the ‘Geometry’ Layer

Click the DesignPH button

38 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

19

Nov. 11, 2017

Surface Exposure Type Right-Click

bldgtyp

39 / 55

Split Surfaces with Different Exposures Roof/Ceiling - Ambient

Wall - Ambient Wall - Ground

Floor Slab / Basement Ceiling

40 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

20

Nov. 11, 2017

Split Surfaces with Different Exposures

It is one wall surface, but it has two different exposures, so split it into two surfaces for the thermal model

bldgtyp

41 / 55

Surface Exposure Type

Partywall

42 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

21

Nov. 11, 2017

Surface Exposure Type Roof/Ceiling Ambient

Partition Wall To Neighbor

Ambient Floor Slab / Basement Ceiling

bldgtyp

43 / 55

Add Shading, Site, etc. in Separate Groups

44 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

22

Nov. 11, 2017

Add Shading, Site, etc. in Separate Groups

bldgtyp

45 / 55

Context Data: OpenStreetMap.org

46 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

23

Nov. 11, 2017

Context Data: OpenStreetMap.org

bldgtyp

47 / 55

Context Data: OpenStreetMap.org

48 / 55

NYPH: DesignPH Technical Workshop

bldgtyp

24

Nov. 11, 2017

Tag All Shading Surfaces: ‘Non-Thermal’

49 / 55

bldgtyp

50 / 55

bldgtyp

NYPH: DesignPH Technical Workshop

25