Dilbert Needs a Home Energy Rater!

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1. I’m a little confused by your
   I’m a little confused by your comment that you don’t need an engineer to do HVAC design. You reference your previous post on HVAC load calculations and the importance of Manual J. You also state that it is mostly done by computer tools these days. Anyone who has worked with and been critical of building load and energy simulation tools knows that often a tremendous amount of engineering judgment must be used. Can you please clarify your position? Regarding relying on architects, my experience is that architects spit a lot of misinformation when it comes to the details of smart HVAC design, better to have an engineer or experienced tradesman on your team.

2. From my experience, most
   From my experience, most mechanical engineers are trained for commercial systems designs, which is a different animal than residential. In many commercial designs the primary concern is internally generated heat and residential is more about the gains/losses through the building shell. Residential HVAC designers need to be someone who is very knowledgable about the dynamics (physics) of that shell, specifically residential construction materials/ methods.

3. Mike, thanks for your
   Mike, thanks for your question. I guess my statement could use some clarification. First, I’m not saying never to use an engineer. What I’m saying is that there’s no reason to believe that an engineer is the only one who can do the job. As Hunter said, most engineers are more familiar with commercial than residential buildings and may or may not understand how to do the HVAC design correctly for a home. 
    
   Likewise, I’m not saying that you should always use an architect because most don’t know HVAC design. My comment about using a physicist and an architect was a reference to myself and Chris Laumer-Giddens, Energy Vanguard’s head of design. 
    
   Also, your point about the uncertainties in energy modeling tools is well taken. That’s why whomever you choose, whether they be an engineer, architect, physicist, or tradesman, should be experienced with the software and understand its inadequacies. The best load calculation you get is still going to be an approximation. 
    
   Hunter, thanks for your comment! You’re a great example of the kind of person we need working on homes – an architect who’s also a home energy rater and getting educated on HVAC design.

4. Allison, 
   
   Allison, 
   I am curious about a couple of things in this article. 
   1) I have some experience modeling buildings. In school I used eQuest to look at what if scenarios by changing HVAC equipment, lighting, building orientation, etc… I noticed that, in order to model a building (or a house), the amount of time needed to input all the parameters is significant. A simple building could easily take 40 hours of time inputting the walls, windows, doors and all the specifics needed to estimate the energy use of the building. This process is prone to error. It may be useful if you want to see what difference adding more insulation will make, or reducing the window area on the south side of the building, for example. However, getting absolute values for the energy use of the building is problematic. There still are too many variables that can affect the calculations. Even occupant behavior has a big effect. My question is: How much would it cost someone to pay to get their proposed home modeled and (rated)? And the next question is how accurate are the projections in terms of annual energy use? I realize that you would probably use Rem/Rate for this and this software is a little more user-friendly than eQuest. Thanks.

5. David, modeling homes in REM
   David, modeling homes in REM/Rate takes much less than 40 hours. An experienced rater can do a simple house (like a Habitat for Humanity house) in less than an hour after they have all the field inspection data.  
    
   And yes, the absolute numbers you get can be significantly different from the actual energy consumption data. A home energy rating yields an asset label, not an occupancy label, which means that its an attempt to rate all houses assuming they’ll be lived in the same way.  
    
   There’s a lot of work going on right now to come up with modeling tools that combine the power of asset labeling software with occupancy data so that we can get better absolute numbers. As for cost, that can be all over the map. I’ve seen rating fees anywhere from about $250 to $2000, depending on the size and complexity of the house.

6. One reason why you don’t see
   One reason why you don’t see Energy Raters used on custom homes is because architects from the beginning are trying to get paid for the work that they do. So to introduce another fee into the mix is a very touchy subject, plus some just don’t see the benefit. My old boss was that way. That is why with my designs, energy modeling is part of my standard service. Also now that the tax credit for Energy Star homes is gone, the production builders (at least in my area) have stopped providing Energy Star homes. 
    
   As for costs, I have seen companies charge $0.10 a square foot for basic modeling services, up to $0.40 a square foot for manual J & D calculations as well. I have done some modeling for a local architect to at least give generic system sizing and help make decisions on the envelope. I know it has saved us at least once from a contractor installing a furnace that was 3 times larger than the design load.

7. Thanks for your architect’s
   Thanks for your architect’s perspective, Josh. It certainly makes sense that the design team wouldn’t want someone else involved if they might create more work for them or veto some of their design ideas.  
    
   I guess my main problem with this whole thing, though, is that Adams was doing his homework. He wanted to build green. Yet somehow he never found out about the possibility of involving a home energy rater. It’s one thing when you go up to someone on the street and find out they’ve never heard of the HERS rating, but it’s an indictment of the industry’s marketing that someone who’s trying to build green can’t find us.  
    
   Similarly, almost everyone I ask has heard of ENERGY STAR, but few of those know they can buy an ENERGY STAR home. We’ve got our work cut out for us.

8. There is an excellent article
   There is an excellent article that focuses on five key issues that we, as energy auditors/ home performance contractors face: 
   1) Lack of awareness 
   2) Negative perceptions 
   3) Distrust 
   4) High Prices 
   5) Low Availability 
   The article is in the Stanford Social Innovation Review,Cultivating the green consumer:http://www.ssireview.org/articles/entry/cultivating_the_green_consumer/ 
    
   We need to work harder to overcome these five barriers. Perhaps we need to work together as a group to get the word out and give a consistent clear message to the consumer. Homeowners want to save energy and save money. Bottom line: if we can guarantee that their utility bills will be below a certain amount every year, that may generate some interest. Rick Chitwood, of Chitwood Energy Management does exactly that-for heating & cooling. See this article in Home Energy: 
   http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/97/970915.html 
   I attended a PG&E; sponsored class on hydronic space heating last week that Rick taught and he talked about a home project he was involved in in 2006. The project was a new, 3500 ft^2 home in Redding California where he guaranteed the annual air conditioning bill would be $76/year and the heating bill would be $241/year. He did this with conventional architecture, conventional framing, & conventional insulation. The home was performance monitored by the DOE Building America Program. This was a new home. For existing homes, this type of guarantee may be more difficult. 
    

9. #6 – No proof of previous
   #6 – No proof of previous ability to deliver on promise.  
    
   I don’t think guarantees are the answer except at scale or for boutique situations. I recently bought a $70 disposal. The identical disposal quit after 15 years. They wanted me to pay $30 for a 5 year warranty. No kidding.  
    
   Let’s translate this to energy warranties. You were promised $347 in savings and achieved $326, you really initiating a claim? What is hitting the target? Where do you draw the line?  
    
   No, most homeowners will look at a warranty as total bunk, as they should. 
    
   Let’s use systems that don’t require hard lines.  
    
   Consider if retrofits are not significant, how much confidence can you have that the trailing savings aren’t anecdotal? You educated the homeowner to a lot of things they weren’t previously paying attention to. Even if no work were done, they’re energy bill went down just because of you. They are now aware where they weren’t before.  
    
   Tracking savings by contractor increases sample size and squeezes out anecdotal savings. Technology could make this tracking as easy as going to zillow. And the consumer could see realization and standard deviation by contractor, affording very high levels of confidence.  
    
   “Johns HVAC Inc achieved .94 realization with deviation of 4 cents at 85% confidence” or some such… That tells the client they can be feel very confident if the model promises $1, they are likely to realize at least 90 cents.  
    
   This allows for net cost design and decisionmaking, And creates a new competitive playing field for contractors. It completes the circle from projected savings to realized savings, and makes it bankable.

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