Q: I have to do a regression for gas consumption in a mall in Romania under the whole facility approach.
I have 12-month data for total gas consumption and tenant consumption. I have subtracted both to get common area gas consumption. However, for the months May to Sep, the subtracted result of the gas consumption is zero. So, end result, I have 12 months of common area gas consumption, but, zero consumption for 5 months. In this scenario, is the regression done on the remaining 7-month data or should I consider the whole 12 months? (ASHRAE says no missing data in the baseline period, but is the calculated zero consumption considered as missing data?)

Also, HDD base 12.5 gives me a CV of 0.21. is that acceptable? My gas savings is 15%.

Kindly advise how to proceed. I have attached the file.

A: First - the calculated zero consumption should not be treated as missing data since it represents no usage. Second - the situation you describe is one that does occur for certain building types/climate zones. For example, when looking at a lot of gas data for a project in California about why natural gas savings projects are not participating in NMEC programs (which uses Option C). The issue is exactly this – low gas use during the warmer months causes the CV(RMSE) to blow up – because the average energy use of the baseline year is in the denominator of the CV(RMSE).

To get around this, we are recommending that the low use period data be separated from the high use period data, and separate baseline models developed from them. It would be useful to develop some sort of average temperature that defines low use from high use periods, e.g. when the average monthly temp is below X, then there is low usage. This would be helpful when making predictions of adjusted baseline use under reporting period conditions – knowing when to apply the low use model or the high-use model – described next:

Make a model using the low use period only, calculate the CV(RMSE) and NMBE, R2, etc. and check t-statistics of the model coefficients to make sure you have a good model. Repeat for the high use period. (Don’t rely too much on R2 as a criteria though).

There are some modeling algorithms that are piecewise linear such as ASHRAE’s change-point models. The 3-parameter model has two segments, a sloped portion and a flat portion. I would think that different software packages would find the temperature (or HDD) where these segments come together. Software packages that run change-point model exist:

Energy Explorer from Prof. Kelly Kissock https://academic.udayton.edu/kissock/http/research/energysoftware.htm

Energy Charting and Metrics tool (an Excel add-in, free) https://sbwconsulting.com/ecam/ (probably the best option for Excel users)

nmecr (R code implementation of multiple modeling algorithms) https://github.com/kW-Labs/nmecr (also free and for users of R software)

Q: I was hoping to get some insight on which M&V Option would work best for a retrofit project where the ECM involves installing Variable Frequency Drives on the Air Handling Units so as to optimize their operation and control their setpoints. Submeters will be installed and there is an IES energy model completed for the building. Would Option A or B be more fitting?

A: Thank you for the question – apologies for the delay in response.

Q: Dear all, as I'm new here, please tell me if there is an app. module that can be integrated with our existing monitoring platform and could send us alarms when the consumptions are deviated from the IPMVP standard, thank you!

A: IPMVP does not have or endorse a specific app module but there are many tools available in the Industry that could most likely overlay or integrate to your monitoring system to provide the functionality you are looking for to monitor and alarm on key parameters etc from an IPMVP adherent M&V Plan.

Q:I have recently been given a project in Romania to propose EPC, shared savings. However, what I have noticed in their bills is that the monetary value per kWh changes every month, both in baseline and reporting years (vary between 400 to 200) In such a scenario, how do we come to a conclusion on cost savings? are IPMVP and CMVP valid in Romania? Do we have any examples in IPMVP that discuss such scenarios?

A: The first step in this project should have been to fix the energy rate between the building owner (the client) and the firm (the ESCO) that will implement the project. The electricity tariff structure must be analyzed to determine why energy rate was changing so much, and defining a contractual tarif structure accepted by all stakeholders.

In the case the project is already in reporting period, as it can be understand by the question, It still is possible to come to an agreement between the owner and the ESCO fixing the electricity rate or a tariff structure.

If that first option is not possible, using the effective monthly energy rate may be a suitable option. No doubt it was know at project initiation that there was a huge variation of monthly energy rate.

It is never too late to come to an agreement between each stakeholders. However, depending of the owner (private or public corporation), there could be legal regulations for adjudication. Those may prevents from applying a significant modification to the Energy Performance Contract as energy rate modification is.
Regulations should be carefully analyzed before attempting to implement a solution.

Q:  I coordinate M&V projects in lighting systems in public buildings. In an ideal scenario, we use option A: measurement of the key parameter, power (W) and estimation (through measurement) of time. In times of pandemic where buildings are not functioning, how to proceed?

A; Per your ideal scenario above, since the operating hours is the estimated value in the Option A M&V plan and the key parameter measurement of fixture wattage is not impacted by Covid building operation, you need to work with the project owner on the best path forward to be in alignment regarding the purpose of the M&V for this project ( ie verification of savings to support payments in a performance contract; verifying savings to support customer internal reporting; support of an utility/other program savings reporting; etc). As stated, the pandemic is resulting in the buildings to be not functioning - if the project and M&V plan baseline is still being developed, the room by room audit and the measurement of baseline fixture wattage could still be conducted however the operating hours establishment without the ability to do a sample operating hour measurement, would need to be determined based on any historical energy data available (such as via an end use analysis to determine lighting system energy contribution) in conjunction with discussion and agreement with the owner on typical historical operating hours. If the project is in post-retrofit phase, the post wattage must still be measured and the operating hours situation discussed with the owner. If the building is not functioning at all, then there must be the agreement with the owner regarding the baseline operating hours and the savings of the project based on those baseline hours and the measured baseline and post wattages - this would be what the savings would have been under those agreed operating hours and the actual measured wattages. Again, if the building is not functional at all (no lighting operating hours), the operating hours in this pandemic situation could or should be viewed as a non-routine adjustment and the savings presented under the current actual situation (zero if zero operation) and then the agreed to baseline or post operating hours used to reflect the adjustment to determine savings under the scenario of the typical building operation in the non-pandemic world. Actual savings are obviously reduced but the adjusted savings would give the indication of performance of the project in the "normal" non pandemic situation. Once the building resumes operation post-pandemic, the operating hours situation should be revisited and discussed with the owner to realign under the requirements of the project and original purpose of the M&V.

Q: I was hoping to get some insight on which M&V Option would work best for a retrofit project where the ECM involves installing Variable Frequency Drives on the Air Handling Units so as to optimize their operation and control their setpoints. Submeters will be installed and there is an IES energy model completed for the building. Would Option A or B be more fitting?

A: Thank you for the question – apologies for the delay in response.
First, a few questions to help clarify and frame the situation for your VFD retrofit project “Installing Variable Frequency Drives on Air Handling Units”:

1.  Are the existing AHUs VAV? This is key to understanding the retrofit intent and associated savings.
     -  If the systems are already VAV, and this is purely replacing the existing fan modulation device with a VFD, resulting in the majority, if not all, of the savings focused on the reduction of fan motor electrical energy.
     - If the existing units/systems are not VAV, then this is retrofit may be better characterized as a VAV conversion utilizing VFDs versus just installing VFDs. In this case the savings would be a combination of fan energy and heating and cooling loads/energy reductions.

2  Where are the submeters being installed; on what energy streams? Fan electric submeters as well as submeters on the heating and cooling loads or energy sources? This response is directly related to the question above regarding the nature of the retrofit and the associated energy savings streams. Also, are the submeters being installed to capture the existing, baseline energy or only as part of the retrofit?

Understanding that we do not know the answers to the questions above, the following are insights into the use of Option A or B and associated items to consider.

Typically, the VFDs allow a reduction of the electricity consumption from the motors. But if the retrofit involves modifying the air system delivery (conversion to or optimization of VAV), the main benefits can come from the reduction on heating and cooling load (less air).

Key parameters:
• Since we do not have any detail about the fresh air ratio, I consider this is to be a key parameter (to be monitored).
• Airflow (mixed fresh air and recirculated air) is a key parameter too.
• If the air handling units (AHU) do not represent a major part of the heating-cooling load for the building, the heating-cooling plant efficiency may not be affected. The efficiency could be estimated in this situation. Otherwise, it should be part of the key parameters. Which we assume it is, since the question mentioned many AHUs.

The energy model can be of use, but it has to be calibrated before implementation of the ECM. Considering that there is a calibrated energy model, Option A could be considered as follows:

For an Option A: the measurements, before and after implementation, can be done under specific conditions (external temperature and humidity level, specific airflow and % fresh air, etc.) and the result could be extrapolated with the energy model for a 12-month period. This is possible if there is no need for a long-term demonstration of the real savings.
Note: if the heating-cooling plan efficiency is estimated,.

Depending of the configuration, the heating-cooling plant efficiency can be affected significantly by the ECM. Unless it is possible to monitor the efficiency, or maybe simulate it, the precision of the determined savings will be affected under an Option A applied with an estimated efficiency.

Option B : This VFD retrofit could be a great application for Option B, and it will help you optimize savings over time. Be sure and conduct sufficient measurements of the baseline conditions – depending on the air distribution system, there may be variation in the baseline motor power which needs to be documented. Look for a correlation between baseline fan power and key system data from the controls. You may need to functionally test the system to cover all operating conditions during baseline measurements.

Also, may be interesting to rely on the length of the reporting period to provide a recommendation on the use of option B.

Length of the reporting period:
For AHUs, the normal operating cycle (reporting period) should consider a full heating cycle or full cooling cycle, with regard to the normal needs for the area where the project is located. This can be up to a 12-month period. Option B could be difficult, or expensive, to implement for many AHUs over a year.

Q: I am an Electrical Engineer CMVP: 4112 and I have doubts about the methodology to be used to measure lighting systems in public buildings in this pandemic period. Some public buildings are not functioning, others with reduced workload, however, the lamps are already being replaced. In a scenario prior to the pandemic, Option A was used: measurement of the key parameter: power, and estimated (through measurement) the time of use. How shall we proceed?

A: Option A with the key parameter measurement of lighting fixture wattage is still a valid M&V Option for lighting system upgrade projects even in the pandemic world and situation we are experiencing. Hopefully the baseline fixture wattages were measured before the fixtures/lamps were replaced to properly document the baseline conditions - along with the measurement of the post-installation fixture wattages to determine the measured performance and determine the savings. The issue raised by the Covid situation puts much uncertainty and variability into the operating hours as you noted. How to properly handle this is a function of the purpose of the M&V for your particular project and contract. For example, for a Performance Contract, the variation in the operating hours and the associated impact on reported savings would be handled based on the contract details and agreements between the owner and the ESCO regarding the Covid impact on operating hours which are beyond the ESCOs control. For other project types, the same logic would need to be applied and agreed to between the stakeholders to determine how to best handle the variation in the operating hours, from baseline, proposed and actual conditions, for savings reporting purposes - for both the short term Covid scenario as well as the long term post-Covid situation.

Q: I'm trying to get the recommendations for IPMVP protocol on the statistics : the values that should be respected for r2, t, CV RMSE, the bias, the VIF.
Could you send me the corresponding documentations? I've been trying to download the volume 3 of IPMVP because I believe it's there but i don't succeed (it links to the volume 2 page).

A:Please refer to the 2019 Uncertainty Assessment for IPMVP Application Guide available on the EVO website under the IPMVP documents.

Q: I'm trying to get the recommendations for IPMVP protocol on the statistics : the values that should be respected for r2, t, CV RMSE, the bias, the VIF.
Could you send me the corresponding documentations? I've been trying to download the volume 3 of IPMVP because I believe it's there but i don't succeed (it links to the volume 2 page).

A:Please refer to the 2019 Uncertainty Assessment for IPMVP Application Guide available on the EVO website under the IPMVP documents.

Q: I am.saikiran,CEM, from Saudi Arabia. I took AEE CMVP course in last week. In that AEE booklet(Study Material) mentioned options(A,B,C,D) categorized into 2 groups. those are Option A & B ( Retrofit Isolation) and Option C& D (Whole Facility).

As of my experience and sharing knowledge with some energy experts, Option D is Used for both retrofit & whole facility

So can you please clarify, which is correct? and explain more detail please..

A: Yes - Option D can be applied to either a whole facility or to a specific system/retrofit. Both require metering data to calibrate the simulation; either whole facility or submetering for the retrofit system.