Proposed Amendment on Calculation of Retrofit Savings

Comment #1

Amendment: Proposed Amendment on Calculation of Retrofit Savings
Page Number: 33
Paragraph / Figure / Table / Note: 303.6.4.1
Comment Type: Technical

Comment:

What are the implications of putting 0.4 in the equation for equivalent electrical energy?  I was taught that 3412 BTU's = 1 kWh.  In fact, Why do this conversion at all? 

Isn't justification to mortgage lenders all about costs?  You will still have to calculate the proposed projected costs of electricity plus fossil fuels (not 0.4 times fossil fuels) and compare it with the current building's projected costs of electricy plus fossil fuels to calculate annual savings.

I would also like to see a clear path to data to be used for escalation of fuel costs in the Economic Summary report of REM_Rate.  Such as providing a simple table in the Help section and updating it each year.

Furthermore, The Economic Summary Report does not take into account the different life expectancies of improvements lumped into one proposed project.  For example, insulation and lighting improvements may well be put into one mortgage loan proposal, but these items have different economic lives.  Guidance for consistant, but simple treatment of this problem is needed if REM_Rate is to be useful for these analyses.

Another issue that Retrofit Savings has not and may never consider is recommended upgrades to ASHRAE 62.2.  How do we in one REM_Rate report recommend those upgrades and then have no cost justification to put that item into an energy efficient mortgage? 

These are some of the issues I am faced with in a current project to upgrade a 1960's era house.

Thank you,

Steven Bradley, HERS, BPI, Energy Star certified.


Comment #2

Amendment: Proposed Amendment on Calculation of Retrofit Savings
Page Number: 1
Comment Type: Editorial

Comment:

It is my hope that RESNET will consider a deemed saving approach for existing homes in which values for recommendations are averaged across climate zones. Utility companies can help to make this approach possible since they have records of actual usage and degree day data.

If RESNET decides instead to lead with the modeling approach for existing structures, the resulting programs will be complex, inaccurate, and ineffective. Our utility has been the victum of this type approach over a period of (5) years in which we participated first with CMC and then CSG programs of this type. In both cases, the programs proved themselves cumbersome to the point that an effiecint and conscientious organizaiton could not participate. The solution for many has been to falsify data entry in order to satisfy the software. ----- Not only are these type computer modled programs inherently complicated, they are also very inaccurate as to actual savings.  

Retrofit is differnt than new construction!!----I sincelry hope RESNET will not take the easly route with an adjusted new construction software as has been done all over the country. Instead, work with utility distributors to produce deemed savings for each climate zone through the use of averaged usage data. This approach will simplify programs immensley and will allow energy technicians the time to concentrate on the audited home instead of unfriendly software. The modeled approach is great for new construction as a comparison tool and it is pretty accuarte in regard to savings becuse we are dealing with brand new HVAC equipment and becsue we know what is behind the walls. This is not the case in a retrofit situation and as a result, the modled approach is very inacurate. Blower door tests increase costs unecessarily becasue the reccomendations they produce are almost always exactly the same as those recommendations given after a visual inspection. This is the most cost in-effective thing you could do to a homoeowner but it is necessary for the modeling software. We have learned a lot over the last five years of surveys.    

Please reconsider before you follow a path that has ruined retrofit programs all across the country and that will offer flawed savings data. New constuction is differnt than retrofit and shoud be approached through a method of deemed savings. Averged savings are more accurate and allow technicians to concentrate on the audit instead of trying to trick the software into producing a reasonable result. We would be happy to help resnet establish a list of deemed savings for in climate zone 3 that come from actual utility accounts taken before and after implemented recommendations. .  

 Larry Denman /Community Relations Superintendent / Huntsville Utilities

 

 


Comment #3

Amendment: Proposed Amendment on Calculation of Retrofit Savings
Page Number: 3-29, 3-30
Paragraph / Figure / Table / Note: 303.5.1.4.1.7, and 303.5.1.4.2.8
Comment Type: Technical

Comment:

These two sections need to be revised. Heat pumps should not be sized to heating load in any case.

Justification for Change:

A heat pump's capacity at design conditions (which is unlikely to be known to the rater) is significantly less than nameplate capacity. Sizing the heat pump so that it can satisfy the design heat heat load will lead to gross oversizing in cooling mode in most climates. This is why supplemental heat is necessary.

Moreover, it would be incorrect to leave these sections as written by simply relegating supplemental heat as being part of the heat pump's capacity as there are many options for providing supplemental heat with varying capacities. This would only obfuscate the guidance intended by this standard.

Proposed Change:

303.5.1.4.1.7  Heat pump equipment shall be sized to equal the cooling design load in accordance with these procedures with sufficient electric supplemental heat to make up the difference between the heat pump's capacity and the heating design load.

303.5.1.4.2.8 Heat pump equipemnt shall be sized to equal the cooling design load in accordance with these procedures with sufficient supplemental heat to make up the difference between the heat pump's capacity and the heating design load.

(Notice the reference home has electric supplemental heat, whereas the rated home many have another type of supplemental heat.)


Comment #4

Amendment: Proposed Amendment on Calculation of Retrofit Savings
Page Number: 3-31/303.6.1
Comment Type: Editorial

Comment:

 The Retrofit Savings Amendment should include a provision for utility bill calibration including:

  • A standard for quality of utility bills and success of regression analysis
  • A standard for accuracy of calibration
  • An exception to the detailed audit requirements for building features that are not to be improved and that can be calibrated successfully.

Models of existing homes that are successfully calibrated to utility bills are much more accurate than un-calibrated models. When a model is calibrated to utility bills it becomes unnecessary to execute a detailed audit of features that are not upgraded, because the basic energy characteristics of the home can be established by the utility bills.


Comment #5

Amendment: Proposed Amendment on Calculation of Retrofit Savings
Page Number: 3.32
Paragraph / Figure / Table / Note: 303.6.3.1 Table 303.6.3(1)
Comment Type: Technical

Comment:

The Baseline Home Input Constraints should allow the rater the flexibility to measure the steady state efficiency and use the measured results in the model if an acceptable procedure is performed.


 

Justification for Change:

Using actual measured efficiencies in the model will result in a more accurate estimate of energy savings for upgrades when compared to the base home.

Proposed Change:

Table 303.6.3(1) Baseline Home Input Constraints
*Exception: Where the labeled equipment efficiency exists for the specified piece of existing equipment, the labeled or measured steady state efficiency shall be used in lieu of the these minimum input constraints.


Return to Proposed Amendment on Calculation of Retrofit Savings