Proposal 1:

Remove the requirement of a projection factor of 0.5 for prescriptive measures for shell buildings

TABLE 502.1.1.1 (1)

ENVELOPE PRESCRIPTIVE MEASURES FOR SHELL BUILDINGS^1,2

Building Element

Mandatory

Roof:

Absorptance

R-value (U-value)

≤ 0.22

R-40 (≤U-0.025)

Wall:

Above grade wall:

Absorptance

R-value (U-value)

Below grade wall:

≤ 0.3

R-30 (≤ U-0.032)

No requirement

Raised Floor Insulation

R-value (U-value)

R-30 (≤ U-0.032)

Window:

U-factor

SHGC

0-40% WW Ratio

40-50% WW Ratio

> 50% WW Ratio

Overhang Projection Factor (PF)

≤ 0.45

0.25

0.19

Not allowed³

~~0.5~~⁴

Door:

U-value

Swinging

Non-swinging

U-0.70

U-1.45

Skylights:

SHGC

Skylight U-value

≤ 0.19

≤ 1.36

¹Equipment and lighting shall meet the efficiencies of Section 503, 504 and 505, respectively.

²Per Section 101.4.9 of the FBC-EC, the building shall demonstrate compliance with Section 506 when completion of the building is permitted.

³Buildings with greater than 50% WW Ratio shall comply with Section 506.

⁴ PF 0.5 = Projection half the distance of window height.

Justification: A projection factor will not provide enough return on investment in terms of energy savings for fenestration having SHGC values as low as 0.25.

Proposal 2:

A new renovations/alterations prescriptive values table is proposed for the 2010 Florida Building Energy Code. The proposed table is as below:

TABLE 502.1.1.1 (2)

ENVELOPE PRESCRIPTIVE MEASURES

FOR RENOVATIONS AND ALTERATIONS¹

Building Element

Mandatory

Roof:

Absorptance

R-value (U-value)

≤ 0.22

~~R-40 (U≤0.025)~~ R-38 (U≤ 0.033)

Exterior Wall:

Above grade wall:

Absorptance

R-value (U-value)

Below grade wall:

≤ 0.3

~~R-30 (U≤0.032)~~ R-19 (U≤ 0.032)

No requirement

Raised Floor Insulation

R-value (U-value)

~~R-30 (U≤0.032)~~ R-19 (U≤ 0.052)[MX1]

Window:

U-factor

SHGC (by window area)

0-40% WW Ratio

>40 WW Ratio

≤ 0.45

0.25

~~0.19~~ 0.25

Skylights:

SHGC

Skylight U-value

≤ 0.19

≤ 1.36

Opaque Door U-value

Swinging

Non-swinging

≤ U-0.7

≤ U-1.45

Justification for suggested changes:

1) Roof R-value change: Justification is that both the latest ASHRAE and IECC codes have those as the maximum recommended values. Also, during the analysis conducted earlier, it was found that there are clearly diminishing returns for increasing R-values for the roof beyond this number

2) Wall R-value change: Justification is that both the latest ASHRAE and IECC codes have those as the maximum recommended values. Also, during the analysis conducted earlier, it was found that there are clearly diminishing returns for increasing R-values for the exterior walls beyond this number

3) Floor R-value change: Justification is that the latest ASHRAE and IECC codes have R-19 as the maximum recommended insulation.

4) SHGC: SHGC was changed to accommodate suggestions that very low SHGC values impede visible light transmittance (VLT) leading to curtailment of daylighting as a viable energy saving measure

Proposal 3:

A modification for the reference HVAC system fan power calculation when using Method A (whole building simulation) for Florida Energy Code compliance is proposed.

The current code always uses the baseline prescriptive value from Table 503.2.10.1(1) for fan power of the reference building HVAC system regardless of the values used for the design building HVAC system. It is proposed that this be modified to use the smaller of the fan power value from Table 503.2.10.1(1) or the design building HVAC system fan power value.

The justification for this is that, contrary to our earlier reading, the intent of the ASHRAE 90.1 Energy Cost Budget Method (ECBM) code compliance in case of fan power suggests this methodology to be the correct approach.