Category Archives: sustainability

Some Preliminary Results: Mini-split heat pump saves energy (and cost) but has poor temperature regulation

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As I have indicated, this heating season I will be using my guest house in Maine to study the energy performance of two Mitsubishi mini-split heat pumps.  Already some interesting results are emerging.  So far this season, with outside temperatures 23°F and above, the heat pumps demonstrate considerable energy (and cost) savings as compared with electric, baseboard heat.  My students and I are starting to quantify the savings.  Here I report on some preliminary results.

We have three ways to heat the guest house: 1) Two Mitsubishi mini-split heat pumps (one 6kBtu/h and the other 18kBtu/h), 2) A 20,000 Btu/h Rinnai propane vented wall furnace, and 3) three 1.5 kW ceramic electric heaters (together, 15,400 Btu/h) distributed throughout the open space.  Each of these three systems has its own remote thermostat.  The heat pumps each have a wireless remote thermostat mounted on the wall across the room.  The Rinnai is controlled remotely by an Emerson Sensi thermostat, also wall-mounted across the room.  And the three ceramic electric heaters are individually plugged into smart outlets that are controlled by Home Assistant using software to mimic a simple on/off thermostat, with temperature measured by a Govee WiFi thermometer sitting on a cabinet near the Sensi thermostat.  Because the Govee thermometer reads in 0.1°F increments, it is the common metric used for determining the Cottage inside temperature.

My Home Assistant Heating Dashboard is shown below. All of the heating and monitoring systems can be remotely accessed.

Solar gain is a big factor during the day, so our heating experiments are conducted at night.  Last night we heated the guest house for several hours using three of the four heating systems (just used one heat pump).  The results are shown below.  The first graph shows the Govee temperature from 4 PM yesterday through 10 AM this morning (11/14).  Until 4 AM space temperature was maintained by the 18 kBtu/h heat pump.  Early yesterday the set point for the heat pump was 65°F but was lowered to 63°F around 6:40 PM yesterday.  At 4 AM the heat pump was turned off and the interior temperature was maintained for the next two hours with the three 1.5 kW electric heaters.  At 6 AM heat switched from electric to propane.  Both the propane and electric heat had set temperatures of 64°F.  At 8 AM the propane heat was terminated and control was given back to the 18 kBtu/h heat pump.

The outside temperature, measured with our Ambient weather station is graphed below. The purple lines indicate when the heating system was changed.  From midnight on the outside temperature stayed within 2°F of an average value of about 31°F.

The electric power to the heat pump and the electric heaters were continuously monitored.  The average electric power to the heat pump between midnight and 4 AM was 553 Watts.  From 4AM to 6AM the electric heaters had an average power of 1830 Watts.  That is, the electric heaters used 3.3X the power used by the heat pump.  Without adjusting for the change in outside temperature this implies a heating COP = 3.3.  This is great news.  It means 3.3X lower heating cost than with electric resistive baseboard heat.

But there seems to be a small price to pay for this energy savings.  The temperature regulation with the heat pump is not nearly as good as with either of the other two heating systems.  The heat pump caused temperature swings of about 2°F while the other two systems have swings of only 1/5th  this amount.  Moreover, the average temperature maintained by the heat pump is well above its 63°F set point.  (Even when you graph the temperature determined by the heat pump’s remote wireless sensor you see that it is always above the set point.)  One has to wonder why the control software for the heat pump is not able to do a better job of maintaining the desired temperature.  There appears to be no ability to change the “deadband.” for this unit.

We are still working on metering the propane flow in order to understand the energy use for the propane heater.  We hope to have this metered soon, it has proven more difficult than we imagined.

But even without metering the propane, I know how much propane should have been burned from 6 – 8AM.  From 4-6 AM the electric heaters provided 1.830kW x 2 h = 3.7 kWh of heat.  I am paying $0.30/kWh for electric so my cost for this electric is $1.10.  3.7 kWh of energy is equivalent to 12,500 Btu.  My propane furnace is rated at 80% efficiency.  So to deliver this amount of heat requires that it burn 15,600 Btu of propane.  The energy content of a gallon of propane is 91,452 Btu.  So I would have had to burn 0.171 gal of propane which, at a cost of $4.29 per gallon, would cost me $0.73.

Hence, 2 hours of heat last night cost me $1.10 using electric heat, $0.73 using propane, and $110/3.3 = $0.33 using the electric heat pump, this with an outside temperature of nearly freezing. The only downside of the heat pump is the lack of temperature control.  I am optimistic, however, that we can learn how to use the heat pump better to achieve better control.

One final thing to note is that when I look at the specs for this Mitsubishi compressor, MUZ-FS18N it appears to me that for a wet-bulb outside temperature of about 30°F and a dry-bulb inside temperature of 65°F the heating COP should be 3.21, consistent with my measurement of 3.3.

Excessive Heat Pump Energy – Update

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A few weeks ago in my post I described how one of my four Mitsubishi mini-split heat pumps was using excessive energy. Today’s post provides additional information about that. Apparently the excessive energy is by design! For background please revisit my August 12 post.

Just a quick recap — In the last three years I have had four, low-temperature, mini-split heat pumps installed on my property in Maine. The oldest of these is a 15 kBtu/h unit that is installed in my house living room. The model number for its outdoor unit is MUZ-FH15NA. The other three units were installed over the next two years. Their outdoor units have model numbers: MUZ-FS06NA, MUZ-FS18NA, and MUZ-FS06NA. (Apparently the “FS” models are improved over the “FH” models.) All four compressors use R410A refrigerant.

These units have seen minimal use since the beginning of May. On rare occasions we have used them for a bit of cooling or heating. They have simply remained in standby mode for nearly 120 days. Three of these use 3-4 W of continuous standby power but the oldest, the 15 kBtu/h unit, particularly during the night, experiences 70W power spikes every two hours or so that last for about 10 minutes. This causes this unit to use about 0.2 kWh per day more energy than the other three. For three months I have been seeking to understand what is going on.

Back in June I emailed my installer, Dave’s Appliance, questions about this performance including graphs and other details. I have always found Dave’s to be extremely helpful. They could not explain what was going on so they passed the information along to their Mitsubishi support team. A couple of months went by with no answer.

I pestered them some more. Finally, in mid-August, two technicians from Dave’s drove the 50 miles from Winthrop to my house to make measurements on the compressor while on the phone with their Portland Mitsubishi tech support. With the travel time, these guys spent a half day addressing my issue. The only measurements they made were to confirm that a certain thermistor had the correct value.

One of the techs who came to my house was Ean Laflin, the heat pump service manager with Dave’s Appliance. After he was done troubleshooting and speaking with Mitsubishi he explained that there was a 70 W heater in the compressor, and that the control board turned it on whenever the ambient temperature was below 68F. Presumably after the heater ran for 10 minutes the temperature of the thermistor rose above the set point causing the heater to turn off. (It is my impression that there is oil in this compressor, and this heater is intended to keep the viscosity of this oil low so the compressor will start easily when called upon.)

But this begs the question, why would this heater be activated when the ambient temperature ranges from 60F to 68F? I could see the need to heat the oil during the winter. But in my part of Maine from May – October the ambient temperature is usually above 68F for much of the day and usually drops below 68F late at night. For nearly four months I have not needed this heat pump yet the heater keeps using energy, night after night. The only way I can avoid this is to shut off the circuit breaker. This is obsurd!

So why doesn’t this same thing happen with my other three heat pumps? Ean tells me that the control board on these slightly newer models is shipped with a jumper that can be set so as to disable this feature — apparently this is the default setting. He can change the jumpers on the other three heat pumps so that all four of my heat pumps run this heater and waste energy. But there is no jumper to change on my Living Room heat pump to reduce its standby power to 3W like the other three heat pumps.

I conclude from this that Mitsubishi, after shipping thousands or perhaps millions of heat pumps with this control strategy determined it was not necessary and “improved” the next generation of control boards. The only way to “improve” my heat pump would be to install a new control board. I recognize this is not a cost effective way to save the $15/year wasted by this heater.

Which leads me to my last point. Each one of my four heat pumps is connected to the internet and can be controlled using the Kumo Cloud App. Why can’t Mitsubishi download updated firmware over the internet to fix this bug? Hundreds of millions of devices (phones, etc.) that only cost a few hundred dollars can receive updated firmware over the internet. Why can’t Mitsubishi figure this out for heat pumps that cost many thousands of dollars? The technology really needs to be updated.

Dehumidifier Energy

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The town of Oberlin, OH was essentially built on a swamp. Oberlin basements commonly experience water problems. When we first purchased our Oberlin home in 1988 there were a few storm events that left water puddles in our basement. Various measures eliminated this problem, but high summer humidity remains an issue. For years we have employed a basement dehumidifier to prevent mold and mildew.

Our house in Maine also has humidity issues. We are on the Atlantic coast where the relative humidity is always above 70%. Both our house and guest cottage are built on granite ledge sloping down to the water. I wouldn’t have thought so, but it turns out the granite ledge is relatively porous to water flow. After every rain storm, water flowing down the hill towards the river creates water issues in our crawl spaces. Dehumidifiers have proved to be important to prevent condensation on our water pipes and mildew on the wood.

I have read that you need to keep the relative humidity level in your crawl space below 60% to prevent problems. The usual way to accomplish this is to 1) prevent water from entering the crawl space using water and vapor barriers, and 2) use a dehumidifier to remove what water does enter.

I have three dehumidifiers located in 1) our guest cottage crawl space, 2) house basement/crawl space, and 3) our Oberlin house basement.  All three are plugged into smart plugs that record their energy use. The two Maine units are commercial units from AlorAir and the Oberlin one is a Honeywell residential unit.

In Oberlin I have a heated basement, so the dehumidifier never has to remove water from cold air.  The Honeywell unit can handle that.  I do not run it during the winter. In contrast, the Maine crawl spaces are not heated and get quite cold.  The AlorAir commercial dehumidifiers can remove water even when the air temperature is in the 40’s.  I ran both of them last winter — not sure if I need to and will try to figure that out.

The graph below shows they day-to-day energy use of our guest cottage. As the graph shows, the dehumidifier uses 4-5 kWh of energy daily.

The AlorAir unit uses 600 W when the compressor is running. I normally leave its set point at 60% relative humidity and the compressor cycles on and off. A typical graph of its power vs time is shown below.

When I lower the set point the duty cycle increases (i.e., time that the compressor is on is longer) and the daily energy increases — all as expected.

I am a bit worried about the frequent cycling of the above dehumidifier. I don’t understand why the control doesn’t include a larger “deadband” so that the compressor does not switch on and off so frequently. I attempted to reach out to AlorAir to learn more but I found their technical support to be unresponsive.

The first graph above shows that the dehumidifier used much more energy on July 17. The reason for this is that I decided to try cooling the guest cottage air by circulating it through the crawl space. This exposed a continuous source of humid, warm air to the dehumidifier and it ran nearly continuously. After one day I concluded this was not the optimum way to cool the cottage.

The average energy used by the dehumidifier in my Maine house for July has been 3.4 kWh/day. The area of the house crawl space is larger than that of the cottage, but it is better sealed. Unlike the cottage the crawl space floor in the house is fully sealed with concrete.

The average energy used by the dehumidifier in in Oberlin for July is about 12 kWh per day. Our house there is over 100 years old and all the walls lack modern vapor barriers. The graph below shows the power used by this dehumidifier. This unit removes about 60 pints of water daily and runs almost all the time during the summer.

This dehumidifier is about a year old. My experience with these “basement units” is that they work well for a few years. After a few years they continue to use lots of energy but don’t remove much water. When I bought this Honeywell unit last fall, the dehumidifier it replaced was 4 years old. I ran the two of them side by side for a few days and found the new unit removed water at a rate 5X that of the old one (even though they had the similar specs and were using similar energy). It is hard to throw the old one away because it still removes water — just not good at it.

What I don’t know is the importance of keeping the relative humidity of my Maine crawl spaces low in the winter. My instinct is to believe that mildew and mold won’t grow during the winter in my cold crawl spaces even if the relative humidity is high. But when the temperature warms in the spring I need to keep the humidity level below 60%. But this is just a hypothesis. So far I am erring on the side of caution and running the dehumidifiers year round. They just use less energy in the winter.

I would like to reduce the energy and carbon emission associated with dehumidification. That would be accomplished by raising the relative humidity set point on the dehumidifier. But under no circumstances can I tolerate mold or mildew. I would be interested in learning what people have to say about this issue for cold and warm weather. Is RH% a relevant metric when the air temperature is low as is the case in the winter? Does it make sense to use lots of energy to achieve 60% relative humidity in a crawl space whose temperature is below 45F? I don’t know the answer to these questions and would value informed input.

Mini-split Heat Pumps and Heat Pump HW Heater

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I think it has been two years since I have posted on this blog. This post is the beginning of a new direction for me.

A couple of years ago my wife and I built a small guest cottage on our property in Maine. Mostly we will use this in the summers, but we decided to go ahead and make it a year-round house. I also decided to make it a laboratory for understanding the performance of a couple of heat pump technologies.

The house is outfitted both with a Rinnai direct vent propane furnace as well as two Mitsubishi, low-temperature, mini-spit heat pumps. We were going to use an electric hot water heater but, instead, decided to install a Rheem hybrid heat-pump hot water heater. Heat pump hot water heaters offer the potential for considerable energy savings in the summer, but savings in the winter are less obvious. I am anxious to study this.

For the next year I intend to report on my findings for this guest cotttage. I have some systematic experiments planned to answer questions such as:

  • what is the efficiency (or heating COP) for these heat pumps at different outside temperatures
  • how does the cost of heating with propane compare to those using electric heat pumps
  • how does the carbon footprint compare between propane and heat pumps
  • do night time setbacks produce energy savings with heat pumps as they do with propane
  • how does the energy use of my heat pump hot water heater compare with an electric hot water heater
  • what is the impact of the heat pump hot water heater on my winter heating costs

I hope to yield definitive answers to some of the above questions. No doubt other questions will come up along the way.

I am primarily interested in the winter performance of these systems.

During the summer we will have guests using the cottage and that will make it difficult to control various parameters. During the winter my wife will be using the cottage during the day as her office. In the evenings it will be unoccupied — which leaves me excellent opportunity to control the environment. Both day and night the indoor temperature will be closely controlled and documented.

To record data and to control parameters we are running Home Assistant (HA) on a Rasberry Pi 4. All of the relevant devices in the cottage communicate with HA. This allows me to both read and control the heat pumps, hot water heater, propane heater, various temperature and humidity sensors, lights, dehumidifier, electric heaters, etc. Iammeter energy monitors have been installed on the main electric panel and both heat pumps. These communicate with HA, as well. There is also a weather station about 100 ft away from the cottage connected to Weather Underground.

Our main house also contains two Mitsubishi mini-split heat pumps. These, too, along with iammeter power meters attached to each, are monitored with HA.

While a lot of the instrumentation was being developed and installed this last year, we do have some preliminary results worth sharing. These will be the subject of upcoming posts.

Energy and GHG emissions savings for U.S. LEED-certified Office buildings

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We have completed the largest peer-reviewed study of measured whole building energy use for LEED-certified commercial buildings ever published. Our paper, “Energy and Greenhouse Gas Savings for LEED-Certified U.S. Office Buildings” can be downloaded from the web site of the open access journal Energies. The abstract is found here.

Our study is based on public municipal building energy benchmarking data from 10 US cities for the year 2016. The entire dataset contains annual energy use and energy-related greenhouse gas emission for over 28,000 properties, of which about 4500 are classified as office. By cross-referencing the benchmarking data with the USGBC LEED Project Database we were able to identify 551 office buildings that were certified in LEED systems that address whole building energy use. These systems were LEED for New Construction (NC), Core & Shell (CS), and Existing Buildings (EB). We have compared the 2016 site energy, source energy, electric energy, non-electric energy and greenhouse gas (GHG) emission of these LEED-certified offices other offices in the same cities in order to understand energy savings associated with LEED certification.

In this post I will talk about the site energy savings observed for LEED offices.

LEED offices in every city were found to use less energy on-site than non-LEED offices, adjusting for size, of course. Except for Washington DC, however, the variability in LEED performance was so large that these savings were not statistically-significant at the usual, 95% confidence level. In aggregate, however, the savings were statistically significant. The results are shown in the figure below.

 

The red symbols indicate savings in site EUI by LEED office buildings relative to other office buildings in the same city. The error bars represent the 1-sigma standard errors in these savings. In aggregate (ALL CITIES) and in Washington DC the savings are two standard deviations or more above zero. In other cities the savings have larger error. In aggregate the LEED site energy savings is 8.5 kBtu/sf, which represents an 11% savings relative to the site EUI for non-LEED offices. These results are consistent with those we have reported earlier based on 2015 data for Chicago.

It should be noted that these savings are substantially lower than the 30-35% energy savings frequently asserted for LEED buildings – but are nonetheless positive and significant.

I will discuss savings in other metrics in upcoming posts.

 

 

Harvard Group publishes flawed estimate of the environmental benefits of green buildings

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Late last year a group from Harvard’s T. H. Chan School of Public Health published a paper entitled, “Energy savings, emission reductions, and health co-benefits of the green building movement” in Nature’s Journal of Exposure Science & Environmental Epidemiology.  In their paper MacNaughton, Cao, Buonocore, Cedeno-Laurent, Spengler, Bernstein, and Allen consider the cumulative energy savings of some 20,000 commercial buildings, world-wide, that have been certified under the U. S. Green Building Counci’s Leadership in Energy and Environmental Design (LEED) since the program’s inception.  Their focus is to calculate environmental co-benefits associated with this (assumed) energy savings.  Unfortunately their entire thesis is predicated on assumptions that are not supported by facts.  Their paper, masquerading as a peer-reviewed journal article, is little more than a marketing brochure for the USGBC and is devoid of credibility.

MacNaughton et al. make the naive assumption that LEED-certified buildings demonstrate, year after year, the energy savings their design teams predicted during the certification process.  This was essentially the same assumption that underpinned the now-discredited Kats report from 2003.  Numerous studies have shown that buildings in general, and green buildings in particular, use significantly more energy than predicted by their design teams.  This so-called “building performance energy gap” is pervasive and well-documented.  The Harvard paper is entirely based on the results of the 2008 NBI study which has long been discredited.

Frankly these energy-performance assumptions are sophomoric.  The authors cite only three references to support their assumptions — all published a decade ago — and they misrepresent the results of one of these papers — I know, because I wrote it!  They apparently are unaware of upwards of 12 studies published in the last decade that look  at energy performance of LEED buildings.

The Harvard paper should have been rejected in the review process.  If I were at liberty to do so I would publish the reviews of my critique as they affirm essentially all the claims I have made.  One of the Harvard authors served on the Board of the USGBC which should have raised a red flag.  The paper was received by the Journal on October 12, 2017 and accepted for publication five days later.  This accelerated time frame raises questions about the substance of the peer-review process.  And finally, the authors make several factual claims about LEED buildings in their paper that are simply incorrect.

To their credit the editors of this Nature journal allowed me to submit and publish a critique of this Harvard paper.  My paper is entitled, “A critical look at ‘Energy savings, emissions reductions, and health co-benefits of the green building movement.'”  Interested readers should read my critique of the Harvard paper which contains numerous references and relevant facts.

 

2015 Benchmarking data show LEED-certified buildings in Chicago save no primary energy

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As more and more building energy data become available a consistent picture is emerging that shows that LEED-certified buildings use no less primary energy than other buildings.  The latest contribution in this area is a paper soon to be published in Energy and Buildings entitled, “Energy Performance of LEED-Certified Buildings from 2015 Chicago Benchmarking Data.”  This paper compares the annual energy use and green house gas emission for some 130 LEED-certified commercial buildings in Chicago with that of other Chicago buildings in 2015.  Chicago, it turns out, has one of the highest rates of LEED-certification among major U.S. cities.

The data clearly show that the source energy used by LEED-certified offices, K-12 Schools, and multifamily housing is no less than that used by other similar Chicago buildings.  In the case of K-12 Schools, LEED-certified schools actually use 17% more source energy than other schools!

Many studies that address building energy use only discuss energy used on site, called site energy.  We found that LEED-certified buildings in Chicago use about 10% less energy on site than do other similar buildings.  No doubt green building advocates will emphasize this apparent energy savings.

But energy used on site – called site energy – is only part of the story.  Site energy fails to account for the off-site losses incurred in producing the energy and delivering it to the building – particularly important for electric energy that, on average, is generated and distributed with 33% efficiency.  The EPA defines source energy to account for both on- and off-site energy consumption associated with a building; building Energy Star scores are based on source energy consumption.  The issue is similar to one encountered when comparing the environmental impact of electric vehicles with internal combustion vehicles — you must trace the energy back to the electric power sector.

How is it that LEED buildings use less energy on-site than other buildings while consuming more source energy?  Simple — more of their (indirect) energy use occurs off-site in the electric power sector.  They use less natural gas but more electric energy than other buildings.  Essentially a larger fraction of their energy use occurs off-site in the electric power sector.

This is the trend in newer buildings, to use more electric energy and less natural gas or district heat energy.  Part of this is convenience and part of it is driven by the belief, or rather hope, that the electric power sector will soon be dominated by renewable energy.  It is true that the contribution of renewable energy (solar, wind, etc.) in the electric power sector is growing, but this is a very slow process and, for many years to come, natural gas and even coal will remain the dominant source for electricity.

This trend is not unique to LEED buildings — it is present in all new buildings.  When you compare Chicago’s LEED buildings with other Chicago buildings of similar vintage you find that they use similar site and source energy.

Bottom line, 2015 Chicago data show that LEED-certified buildings are not providing any significant reduction in energy use or GHG emission.

These results are similar to those observed earlier for LEED-certified buildings in NYC.

Hotel at Oberlin — poster child for “Green Wash”

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In May 2016 Oberlin College opened its newly constructed Hotel at Oberlin.  The New York Times ranked the Hotel third in its list of 5 Hotels and 5 Tours for the Eco-conciousTraveler.  It is all part of the ongoing marketing effort to paint Oberlin College as a sustainable and green institution.  Hard to believe that any amount of eco-spin can convince people that a view of Oberlin’s Tappan Square is  environmentally rewarding.

Of course what makes the Hotel at Oberlin a green destination is not it surroundings — it is the building itself.  Like the Taj Mahal, committed environmentalists will simply swoon in the presence of this green wonder.  The second (and larger) of Oberlin College’s highly-publicized green buildings, the College has claimed that the Hotel is the first 100% solar powered hotel in the world and one of only five Hotels in the world to win the coveted LEED Platinum rating.  In addition to claims of solar power the building is said to be heated by a geothermal well field and to include other green technologies — including radiant-cooled rooms.  Its web site boldly claims that it has achieved the LEED platinum rating.

Truth is the hotel is not powered by the sun nor is it LEED-certified at any level.

I  wrote about this Hotel nearly two years ago when it opened.  The main focus of that post was to address the solar claim.  I will not rehash the evidence here — please read the blog.  The claim is a brazen and clever lie — Donald Trump would admire its creativity!  Simply stated, the Hotel is no more solar powered than is my century-old home.  There is not one solar panel on the building site.  The 2.2 MW OSSO array that is claimed to power the Hotel was built years before the hotel, is located a mile away, and, by contract, sends all of its electricity to the City of Oberlin until 2037 at a price of $85/MWh.

Today I write to share the Hotel’s energy-performance data and to discuss its LEED rating.  The Hotel is well into its second year of operation and we now have 21 months of utility data.

In my 2016 post I suggested that the Hotel would use two million kWh annually, more than double the 800,000 kWh used by the Oberlin Inn it replaced.  For 2017 the Hotel actually used 1,400,000 kWh of electric energy.  This is 75% more electric energy than was used by the former Oberlin Inn, but less than my estimate.  It is consistent with the annual electric use projected for the Hotel by its design team.

But the Hotel also uses natural gas.  The marketing literature for the Hotel says that the building is heated with ground-source heat pumps.  Natural gas, we are told, is primarily for heating domestic water (laundry, showers, etc.) — available, but not anticipated for backup heat.  The design team projected the annual gas use to be 8,350 therms (Ccf).

In fact, for 2017 the Hotel at Oberlin used 39,000 therms (Ccf), nearly 5X that predicted by the design team.  This is more natural gas than is used by any other Oberlin College building save one — the 130,000 sf Science Center!  The Science Center, constructed 17 years ago, contains numerous research and teaching laboratories and chemical hoods and has never been described as a green building.  It used 58,000 therm of natural gas in FY2017.  The natural gas use of the Hotel at Oberlin exceeds that of any other College building including the Firelands Dormitory (26,000 therm), the new Austin E. Knowlton complex (26,000 therms) and Stevenson Dining Hall (23,000 therms).

How does the Hotel at Oberlin’s energy performance compare with that of other hotels?  Consider its Energy Star score.  This can be estimated using the EPA’s Target Finder web site that allows quick data entry to estimate scores.  Entering the Hotel’s floor area (103,000 sf), number of guest rooms (70), cooking facility (Yes), 100% of the space heated and cooled, and actual FY2017 energy use, and accepting other default parameters, the Hotel at Oberlin is awarded an Energy Star score of 56.  According to the EPA — just a bit above average.  Don’t get me wrong — I am a huge critic of the Energy Star benchmarking score.  But it is one way to compare energy use with other hotels.

The monthly gas usage for the Hotel at Oberlin is shown below.  The excessive use in months Nov. – Feb. is clear evidence that significant gas is used for heating.  But even if you eliminate this heating use, the remaining use is nearly 3X the design estimate.

Finally, let me address the claim that the Hotel at Oberlin is certified LEED Platinum.  It simply is a lie.  I downloaded the USGBC LEED project database today.  The Hotel at Oberlin was registered on March 8, 2013 as “Confidential.”  Its LEED project ID is 1000031165.  As of today, February 23, 2017 the Hotel at Oberlin is not LEED-certified at any level.  The LEED project database says it has achieved 53 points — not enough to even achieve certification at even the Gold level.

Perhaps one day the claims being made for the Hotel at Oberlin will become true.  There is a lesson to be learned by looking at Oberlin’s Green building, generation-I, the Adam Joseph Lewis Center.

Oberlin College’s Adam Joseph Lewis Center  opened in 2000 to much acclaim.  Its proponents claimed it was a zero energy building (ZEB) for more than a decade when it just wasn’t true.  The claims were repeated by two Oberlin College presidents, College literature, and the College web site. The College never issued a retraction — it spent hundreds of thousands of dollars to correct flaws in the building’s HVAC design hoping to lower building energy use to a level that could be met by its 45 kW rooftop PV array.  The College eventually switched from “sticks” to “carrots” and in 2006, with the gift of a million dollars, built a second, 100 kW PV array over the adjacent parking lot and, with tripled electric production, renewed its ZEB claim for the building.  The building continued to use more energy than all of its arrays generated through 2011.  Even when faced with incontrovertible evidence that the claim was false the College continued to print the claim for another year in admissions literature distributed to students.  The College has never issued a public retraction or correction.  In 2012, after hiring a full-time building manager, the building finally used less energy that year than its PV arrays generated.  These arrays now feed two buildings, the AJLC and its adjacent annex.  Energy-intensive functions have been located in the annex and, collectively, these two buildings use more energy than the arrays produce.

Maybe in the next decade the College will build a parking garage next to the Hotel at Oberlin and put a huge PV array on it.  This could make the Hotel at Oberlin solar-powered — but not 100%.  Not sure how it will solve its natural gas problem — but clever minds will think of something.

The era of Donald Trump is here.  It is not illegal to lie, and no lie is too big to sell.

The bottom line is this.  The Hotel at Oberlin is just a normal, expensive hotel that purchases both electricity and natural gas from the local utility companies.  It uses more energy than the hotel it replaced.  It is the perfect symbol of modern green wash — 20 % substance, 60% exaggeration, 20% lies.

When will the USGBC come clean about their energy data?

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Ever since the U.S. Green Building Council (USGBC) certified its first LEED building, questions have been raised as to whether LEED-certified buildings actually save energy.  For years LEED proponents have attempted to answer these questions by putting forward energy simulations — calculations performed by the design team before a building is ever constructed (or renovated) that demonstrate how much energy the proposed building design should save.

The problem is that intentions do not equal performance, and numerous studies of buildings have demonstrated a wide gap between the actual measured energy performance of a building and its design simulations.

I have undertaken several studies that compare the energy performance of LEED-certified buildings with other, similar buildings.  One of the key barriers to such studies is the difficulty in obtaining measured energy performance data for LEED-certified buildings.  Municipal energy benchmarking disclosure laws are beginning to crack this “green wall of silence” but, even so, you will find energy data for only a few hundred LEED-certified buildings in the literature.

One of my regular end-of-the-year rituals is to download the current version of the LEED Project Database posted by the USGBC.  This database lists all registered LEED projects, including information about the LEED system, certification, number of points received, etc.  Below I will share some interesting statistics calculated for these data.

As of December 26, 2017, there are 23,137 LEED-certified commercial buildings (*) in the U.S., certified in programs that address whole-building energy (NC, EB:OM, CS, School).  This is nearly 100X the aforementioned number of LEED-certified buildings whose annual energy consumption have been studied in the peer-reviewed literature.  Obtaining energy performance data is a critical road block to understanding building energy performance.

To address this, the USGBC, starting in 2009 with its version 3 certification programs, instituted a requirement that all LEED-certified buildings must report to the USGBC for five consecutive years following certification, whole building energy use data.  It was hoped that such data would demonstrate the success of the program in saving energy and would guide future improvements in the LEED standard.

So, what have we learned from these data gathered by the USGBC?  We have learned that the USGBC does not want to publicize these data.  Four buildings were certified in version 3 programs in 2010 — so their first year energy performance data would have been reported in 2011.  That number has grown dramatically in successive years.  The graph below shows the total number of buildings certified in relevant LEED.v3 or LEED.v4 programs as of January 1 of the year shown.  By January 2017 this number had grown to nearly 10,000.  When 2018 arrives these buildings will have another year of energy use data to report to the USGBC.  Moreover, 1,931 of these buildings certified by the first of 2013 should be reporting their fifth year of energy consumption.  Where are the reports that analyze these data?

So why isn’t the USGBC making these data available for analysis?  The answer is simple — the data show that LEED-certification is not saving the 30-35% energy that the USGBC has claimed for years.  This is no different from General Motors suppressing data that show Corvairs are not safe, tobacco companies hiding data that show cigarettes cause cancer, or the Catholic church protecting priests accused of sexual misconduct.  All organizations, first and foremost, care about self-preservation.

But the LEED project data show another interesting trend.  Again, looking at the commercial LEED systems that address whole-building energy, it is interesting to look at the numbers of U.S. buildings that were certified by year.  This graph is shown below.  The graph shows a trend that you can detect when you talk to builders and building managers.  Interest in LEED is waning.  2013 was the peak year for LEED certifications in the US.  Since that peak the annual number of U.S. commercial buildings receiving LEED certification in these programs has steadily declined.  Builders and property owners are catching on to the fact that LEED buildings are not saving energy, and the novelty of certification is wearing off.

The graph above actually over-estimates the number buildings certified each year.  The reason is that some buildings get certified a second, and even a third time.  These certifications are counted above, even though these “re-certifications” do not add new buildings to the list (just new certifications).

The USGBC, of course, does more than just certify U.S. buildings in the whole-building energy systems considered here.  Marketing green is their strength — they have exported their wares to many other countries and they have invented new LEED certification systems that can make small tenants in large buildings feel good (e.g., commercial interiors, CI).  No doubt global USGBC sales continue to rise.

But make no mistake about it — the core product of energy efficiency is falling flat with U.S. commercial building owners because the product is highly flawed.

* The numbers provided from the LEED project database refer to registered projects.  It is not quite right to say each project corresponds to a building.  A

Hot air emanating from the Windy City

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This week Chicago mayor Rahm Emanuel hosted the North American Climate Summit attended by more than 50 mayors from major cities around the globe.  President Obama joined his old Chicago crony to address the summit.  Mayors joined together to sign the Chicago Climate Charter expressing their collective commitment to lower greenhouse gas emissions.

According to an article in HPAC Magazine Chicago Mayor Rahm Emanuel announced that Chicago had “reduced its carbon emissions by eleven percent from 2005 to 2015, bringing the city to forty percent of the way to meeting its Paris Climate
Agreement goals.”

What bullshit!  The same claim can be made by essentially every city in the United States (some more, some less).  This reduction has nothing to do with any unique accomplishments in Chicago — it is due to the simple fact that GHG emissions for the entire US from 2005 to 2015 went down by 11%.  All boats rise with the tide or, in this case, recede.

The main reason for this national GHG reduction is the fact that over the last decade cheap, fracked natural gas has replaced vast amounts of coal in the electric power sector.  This single change is responsible for the majority of the reduction in US greenhouse gas emission this last decade.  It isn’t energy efficiency, green buildings, renewable energy, or conservation — it is the economic impact of cheap natural gas and the increased cost of coal power due to EPA regulations.

Below is a graph lifted from an EPA report showing total US GHG emissions from 1990 through 2014.  The last bar for 2015 (black) was added by me using data pulled from another article.  The blue bars in this graph shows emissions associated with the electric power sector.

Rahm Emanuel’s claim is true but meaningless — just a lot of hot air emanating from the Windy City.