User manual

FAQ for CBECC-Res 2013

building meeting the criteria. The requirements for this credit (from Residential Appendix RA3.5

apply to all ceilings/attics, knee walls, exterior walls and exterior floors.

FAQS POSTED ON AUGUST 29, 2014

1. Will results change from Version 2c to Version 3?

Yes, in some cases. For example, results will change in these cases:

• 2-story dwelling unit results will change due to natural ventilation assumptions (see

question 6 below for more information);

• A building with electric storage water heaters was corrected to include 50% solar fraction as

part of the standard design, even when natural gas is not available;

• All buildings with small water heaters; and

• Below deck roof insulation calculations were corrected to show the insulation covering the

cavity and frame.

2. A HERS requirement for return duct design shows up on every job I upload to the HERS provider.

How can I get this feature removed?

This is not a feature you are modeling. You are seeing this requirement because of the mandatory

measure found in the Standards. Section 150(m)13 requires >350 CFM/ton and <0.58 fan efficacy (or

none if there is no cooling). It is up to the builder to choose how to comply with this requirement—

conduct the tests or meet the requirements from Table 150.0-C or D—so both are shown until the

builder completes the installation forms.

3. My building will have no cooling. If I enter 0 for the unique number of cooling systems (or the

count), my file will not run. How am I supposed to show no cooling?

The cooling system is defined as a system type “no cooling” (versus a package or split system). The

number of systems is 1. The program does not allow an inconsistent number of heating and cooling

systems (e.g., 1 heating unit and 2 cooling units). Enter the smaller of the number of systems (but at

least 1) and during installation the builder can install more systems than are defined in the input file.

4. Is there an update with regard to the HERS reporting for “no cooling”?

Yes. With the release of version 3 of CBECC-Res, if the cooling system type is set to NoCooling, as

shown in the HVAC – COOLING SYSTEMS section of the CF1R, the HERS requirements will all appear

as Not Required on the CF1R.

The builder will confirm that no cooling was installed when completing the CF2R-MCH-01-H (Space

Conditioning Systems, Ducts, and Fans). If a cooling system is desired, the compliance will need to

be revised to reflect the appropriate system type and features (and uploaded to the HERS provider).

At that point, all of the mandatory requirements will apply, as well as any HERS verified features

(such as refrigerant charge or verified EER) that were included.

5. Why do I still have a watermark for an addition that should not require any HERS measures?

With the release of version 3 of CBECC-Res, if the project meets all of the exceptions (as discussed in

FAQ #5 from 07/17

), there will be no watermark on the performance CF1R. If you still have a

watermark, look closely at the CF1R for either verified existing conditions (shown just above the

signature page) or another field that shows “Required” for a HERS verified measure. The status of a

feature can also affect HERS requirements (see the CBECC-Res User Manual, Chapter 10).