Assessing the Existing Code and Identifying Potential ChangesMark Halverson and Meredydd EvansPacific Northwest National Laboratory

Seminar on Analysis For Energy Code Development in VietnamHanoi – Jan 12, 2016

Outline

Approach for Developing RecommendationsExisting requirementsNew requirements

Prioritization of ChangesClarifications and simplifications to make the code easier to use and enforceImprovements in stringency

Approach for Developing RecommendationsFor existing requirements

For each existing requirement in the VBEEC, evaluate if the requirement

Is missing applicable testing and rating requirements that are needed to determine if a numerical requirement is being metIs derived from an outdated code or standard that could be updated to use newer terminology or newer conceptsCould be replaced with an alternative requirement that may be more understandable or enforceableCould be made more stringent to increase the efficiency of the VBEECCould be clarified to make it more usable or enforceable

For new requirementsReview the VBEEC to evaluate if there are requirements typically found in international energy codes that are not found in the VBEEC

For example, some new US codes regulate computer rooms and data centers explicitly. These are not explicitly regulated in the VBEEC. Would existing maximum allowed installed power in Table 2.18 permit the development of a data center in Vietnam?

Example of Missing Testing and Rating Standard

Window solar heat gain coefficient (SHGC) is regulated in the VBEEC

But no specific testing or rating standard for SHGC is specified.This is true for window U-factor and window visible light transmittance (VLT).

Examples of Outdated Codes and Concepts

Some of the VBEEC HVAC equipment requirements are based on ASHRAE Standard 90.1-2001 and 90.1-2004.

ASHRAE has published three newer versions of Standard 90.1 since 90.1-2004 was published. These references and the requirements based on these references could be updated. Example – New version of table for requirements for electric air conditioners and chillers contain part load requirements based on newer versions of ARI (now AHRI) testing standards.

The VBEEC refers to “Visible Light Transmittance (VLT). ASHRAE has moved to use the preferred international term “Visible Transmittance (VT)”.

Examples of Alternative Requirements

The VBEEC currently requires use of OTTVAn alternative way to provide flexibility to designers might be to allow use of whole building simulation, which can provide a tradeoff across all building systems and not just envelope.

The VBEEC could consider allowing use of alternative testing, rating, and labeling approaches from neighboring countries or major trading partners.

This may facilitate the use of products from those countries and reduce added costs associated with multiple sets of testing and rating be required.

Example of Increasing Stringency

Scope of the VBEEC could be expanded to include:Smaller buildings than the current 2500 m2 limitExisting buildings

Numerical Requirements in VBEEC could be made more stringent.

For example, rather than requiring a U-factor for roofs of 1.0, the requirement could be lowered to 0.95 or 0.9.

For example, ASHRAE Standard 90.1-2013 requires a flat roof U-factor between 0.22 and 0.27, significantly more stringent than 1.0Note that there would likely need to be a good justification for this type of change.

Examples of Clarification to Improve Usability or Enforceability

Any requirement in the VBEEC that could be interpreted in multiple ways could be clarified to make the code more usable.

For example, the term “upscale residential” is used to describe some buildings in Section 2.5 on electric power consumption (Table 2.18). But there is no definition of “upscale.

Prioritization of Changes

All countries have limited capacity to make changes to their energy codes.

Making changes may require time, money, data, or analysis capabilities that simply are not available.

So all countries need to prioritize changes somehow.

Possible Prioritizations

The easiest and most beneficial changes tend to be clarifications and simplifications to make the code easier to use and enforce.

If a code is not being used by designers because it is “too complex” or “too hard”, then a focus on clarification and simplification may be appropriate. If a code is not being enforced by code officials they can’t understand it, then a focus on clarification and simplification may also be appropriate.

If a code is being used and enforced adequately, then improvements in stringency can be considered.

But changes in stringency typically involve consideration of costs and benefits.

How to Find Out if a Code is Hard to Use or Enforce

The only way to find out if a code is hard to use is to ask designers who must use the code.

The only way to find out if a code is hard to enforce is to ask code officials who must enforce the code.

If either designers or code officials have a problem with the code, they should encouraged to report it so that it can be fixed.

Care must be taken to differentiate between true “misunderstanding” and “dislike of being forced to use a code”.

How to Decide if a Code is Not Stringent Enough – New Technologies

If a new technology or construction technique becomes popular in a country, the stringency might be increased.

Example – In the US, when LED exit signs became widely used, the code was changed to require that exit signs use no more energy than a typical LED exit sign. There were no comments made on this change.

Caution – Most energy codes are “technology neutral” to avoid giving an unfair advantage to any technology or manufacturer. This approach should only be used if there really is something new happening in the building construction sector.

How to Decide if a Code is Not Stringent Enough – Cost Benefit Reasons

If a material suddenly becomes much cheaper (perhaps because a new local factory is producing the material), then a code change may be justified if it is cheaper to use that material.

If fuel prices increase, then a code change may be appropriate if the savings from additional stringency can be more easily justified.

See Cost Benefit Presentation in this Training Event.

Questions and Discussion