Definitions and terms :

California Title 24 -2008 = California Energy code 2008 = CEC 2008 = CalGreen

HERS (Home Energy Rating) is a scale where 0 = zero net-energy, and 100 = average energy consumption in 2000. Its a good approach to resolves the issue of the moving baselines. Architectural Energy Corporation has written some white papers on the subject of energy code benchmarking for both residential and non-residential.


A historical footnote: CEC 2005 = ASHRAE 90.1-2007 = HERS 75.
ASHRAE 90.1-2007 and Cal Energy Code 2008 are NOT equivalent (as I had thought).

ASHRAE-90.1-2007 is the LEED benchmark, however, and LEED-NC requires a 10% minimum improvement. Therefore LEED-NC minimum = HERS 67.5

It is pretty common for LEED buildings to get a 20-30% improvement on ASHRAE 90.1-2007. Those buildings HERS rating = 59 to 52.5

CEC 2008 is CalGreen minimum = HERS 53. About the same as common results in LEED-NC

ASHRAE 90.1-2010 is approximately = HERS 50, (has not been adopted by anyone as of 12/31/2011).
CalGreen Tier 1 = HERS 45
CalGreen Tier 2 = HERS 37.

Summary

National Renewable Energy Labs says HERS 37 is the maximum technically feasible without resorting to onsite energy production methods. The rest of the way to net-zero needs alternatives to the typical gas/oil/electric regime.
Pretty stringent stuff that requires much due diligence. As you get lower and lower in energy intensity, envelope hvac, lighting types and process-loads become more important to the rating game. I am just skimming the surface here.

Here’s a good article on building performance. At the left is a graph: a picture worth a thousand words. There are links to many more reading sources on that page.

I think this covers it for now. Anything else you want to learn? Feel free to contact me.

By the way, most of those politicians oughta forget it and get a job!

I am driven to help building owners. Designing and analyzing HVAC, lighting and plug-in energy for over 30 years! If you need building energy auditing, expert energy consulting, and commissioning of existing or new commercial and industrial facilities, please do not hesitate to call on my associates and I. Visit CPM Scheduling for more information.

The 250,000 sf World Wildlife Fund headquarters in DC is about to complete retro-commissioning and is applying for LEED-EB (Existing Building) certification. I managed and documented an “enhanced commissioning process” and have helped complete an application to the US Green Building Council for LEED certification that should land them the highest rating, Platinum. Also completed and finalized the commissioning of a LEED Commercial Interiors renovation project for the building. Lastly, I have just validated their U.S. Department of Energy – Energy Star application for the entire building, with a rating of 86 (based on 100).

Another recently completed commissioning job included 80,000 sf of new interiors for the European Commission in DC.

I am providing this service as a contractor to CPM Scheduling, LLC. CPM is a highly respected and growing LEED commissioning consultant that has successful work in over a dozen states from Colorado to the East Coast. I currently act as Senior Commissioning Authority on their behalf.

I have a half dozen other projects, encompassing at least another 600,000 sf, in various stages, and as they are completed, I will tell about them here.

Building Commissioning: A Golden Opportunity for Reducing Energy Costs and Greenhouse Gas Emissions
By Evan Mills, Ph.D.
Lawrence Berkeley National Laboratory for: CEC (PIER) July 21, 2009

This white paper contains some compelling arguments in favor of re-commissioning. Money and energy are two items. A building is a kind of organism. We tend to forget that nature and behavior tend to tear and break things down. The passage of time wears things out and we have to maintain our buildings, and just like cars, they need to be tuned up regularly. It’s amazing how much money is being lost by neglecting to do a tuneup. Government and institutional buildings are especially prone to this benign neglect. In government, its often a case of out of sight, out of mind.

Here is a flow chart that I like. Charts are great for reducing complicated processes down to one glance… I like a good flow chart because they are visual, and I tend to be visual, maybe because of my defective ears.

This chart was borrowed from ASHRAE by the National Institute for Building Sciences (NIBS), and is posted on their Whole Building Design Guide web site. Click on the thumbnail to see the full size version.

An excellent commentary in this months Engineered Systems magazine, entitled Tomorrow’s Environment: A Failure to Plan Is A Plan To Fail by Howard McKew, exposes the weak link in the chain between energy efficient design and the long term operation and maintenance of said design. How do we know they are getting what they paid for?

Too often, we don’t know. McKew explains that measurement and verification is often left out of the design due to budget constraints. I think operations often falls under the radar for lack of understanding the need for verifying. And CMMS software, intended to help rectify this problem by making it easier to manage and maintain the many moving parts of a building, apparently doesn’t get used!

I have mentioned ACCOUNTABILITY in previous posts, and here is another sample of what I am talking about. My worrying is well-founded. Filters need to be changed, pump bearings need lubricating, dampers need to be observed in operation, temperature sensors need to be calibrated and so on. HVAC, even when it is designed to be as simple as possible, is still complicated in practice.

I quote:

“This report responds to a widely held concern that end-users do not have confidence in the nature and level of energy savings that can be achieved through the commissioning process.”

This is what I think of when they say “sustainable”: The report states that there is a 16% median annual rate of return on investment for existing buildings and and 13% median annual return on new construction. EXCELLENT. How many other investments bring in that rate of return on a sustained basis?

The report continues:

Applying … [this] to … non-residential buildings corresponds to an annual energy-savings potential of $30 billion by the year 2030… An industry equipped to deliver these benefits would have a sales volume of $4 billion per year and support approximately 24,000 jobs.

EXCELLENT!

An important aspect of good design is simplicity. HVAC can be complicated enough, given the need to maintain various spaces at set temperatures, relative humidity and cleanliness. HVAC systems are also expected to maintain certain pressurization and [code required] outside air exchange. All while keeping to the highest possible energy efficiency. We also need and expect them to respond precisely and correctly to changing variables.

Simplicity in controls are also key to this. The simplest controls are on-off. Simplicity is not obvious everywhere. But in reality, as software development theory teaches, you can find the simple by decomposing the complicated.

Consider these concepts before the initial Basis of Design is established. Decompose the various functions needed and decide how the system will be controlled. Many designers have their personal preferences and presumptions, but these must be put aside in favor of open-mindedness in the beginning of the decision making process. Yes, energy and size calculations may be useful, but not as important as what and how to control the various environmental parameters.

Diagrams of the systems,

Mass-flows, temperatures, and pressures. For lighting, its watts and lumens per square foot. And using natural ambient light wherever available.

Get these right the first time, and you will save all kinds of hassle. During design, keep the diagrams as a guide and reference. It will keep also you focused and directed.

Next subject: Dedicated outside air systems (DOAS) These kinds of systems separate the ventilation "function" from the building internal HVAC. Tens of millions of buildings have no way to split this from the basic heating and cooling. Which makes the controls complicated. DOAS is especially good for high occupancy rooms and in situations where air change requirements are more exacting. Its an economic question and we have to decide how and whether this is worth the trouble. Most significant in schools, assembly rooms, theaters, health care,

In many existing buildings, DOAS, which require separate main ducts, may be impossible to retrofit due to space limitations and structural issues. But DOAS divides the work that HVAC systems do, they can be used to recover energy that is lost by exhaust systems. Furthermore, because DOAS central units can be physically remote, so they do not contribute noise to the occupied space and finally, they incorporate the potential to increase net rentable space!

An alternative, if the above is not economically feasible, is to keep and/or update the existing systems, measure carbon dioxide levels (a proxy for stale air), and control the entering outside air according to that parameter. This is "Demand Controlled Ventilation" control, which I described in this previous post in November.

Some of the 2009 stats HVAC designs that I have incorporated recently into my office building projects are expected to use 30% less than the levels allowed by the local and state building codes. (ASHRAE Energy code 90.1-2004).

Consider that more than 70 percent of existing commercial buildings in the country were constructed prior to 1980 (according to floor area, see this 2001 study) . It is very likely that most of these older buildings consume well over the present building code allowable.

There are no laws requiring them to retrofit. The financial incentive to retrofit is all that exists, and unfortunately, this is another example of out-of sight, out-of-mind ignorance. (and HVAC and building energy use in general getting no respect).

These buildings should be retrofitted to reduce energy use a minimum of 30% and more. Up to $48-60 billion per year is being simply wasted. Wow! That is $200 a year for every man woman and child in the US. Almost half as much as we throw away on the war in Iraq. ($130 billion in 2007)

Hey, what are you waiting for, lets find out where the energy is going!

Lighting… I did not mention lighting: higher efficiency lighting and optimal daylighting could save ANOTHER $20 billion /year easy.

If you still a skeptic, please read: “Working Toward the Very Low Energy Consumption Building of the Future”

]]> http://www.noelsusskind.com/blog/archives/982/feed 0 http://www.noelsusskind.com/blog/archives/945 http://www.noelsusskind.com/blog/archives/945#comments Wed, 03 Feb 2010 21:58:13 +0000 noel http://www.noelsusskind.com/blog/?p=945 Trends: Read the chart on your buildings energy usage. Monthly charts can usually be found on the monthly utility bills. Usually, your utility company can provide a history of usage. The hourly or daily usage charts can reveal patterns of usage which can be reveal whether your building is running at its best.

What does a trend chart look like?

An example of a daily building trend chart

The US Department of Energy has a gather and track data process listing the following steps.

STEP 2: Assess Performance
* 2.1 Gather Data
* 2.2 Establish Baselines
* 2.3 Benchmark
* 2.4 Analyze Data
* 2.5 Technical Assessments & Audits

Let’s look at Step 2.1, ‘Gather data’.

Daily and hourly charts are more detailed require additional metering devices. This is a deeper and more involved, as we will see.

If your building has a control center, it is very possible, that energy consumption patterns can be found in the computer logs. In many older buildings, this may be problematic. This is where upgrades to metering should start.

Deciding on what to measure and then installing the meters and using the data correctly is the key. By studying the building systems, and determining what wires or pipes are carrying the “energy in question”, we can be sure we are installing the meter(s) in the correct physical location.

Next, installing a communication link between these meters and a data collection center, such as a desktop computer, creates the basic data collection network. The cost of this approach is extremely reasonable. Wireless measuring devices are becoming very widespread. In fact, with IP networking, whether hard wired or wireless, it is an incredibly simple and cheap way to get a handle on this.

Having the data in hand will help the engineers and operators. But we want to understand how the building system in question is being controlled. The charts can be complicated. Decomposing the building systems down to their simple points will yield a lot of valuable information. once it is charted. Having your building engineer or an outside consulting engineer experienced in HVAC controls is often necessary.

More reading about energy measurement and metering and a prior article on measurement in Noels Green Blog.

What are we measuring?

Motors, lights and electric resistance heaters are the major electric energy consumers. Boilers, unit heaters and furnaces are the major gas/oil consumers.

Of course, a major component of electric use is the ‘plug loads’, which is equipment actually plugged in. These are usually in the control of the user/occupants themselves. They include computers, task lighting, televisions, refrigerators and so on.

Electric heaters are often being used by user/occupants who feel cold and do not get their complaints/needs heard or met. This is unfortunately, a ubiquitous problem in the USA, just now getting serious attention after years of ignoring.

The next wave

Now here is a very nice “downstream” application for building information modeling. It is not getting much attention. Yet.

The same Building Information Model which is being used to design and build with, can easily be re-used as a framework for the building control center! Metering and all other energy systems mapped in the BIM? You would have a ready-made view of the Building Energy Consumption!

This has been a theoretical possibility for many decades, but the cost and complexity of it was such that no one besides a NASA or a nuclear research lab could implement it. Now we have a chance to see the possibilities of such high powered data collection and analysis being done on a desktop computer. Hooray for IT!

]]> http://www.noelsusskind.com/blog/archives/945/feed 0