Letters: November/December 2009
Insulating Cathedral Ceilings
Codes aside, what is your opinion on dense-packing closed-vault roofs with fiberglass or cellulose? Yes, this means packing the entire cavity full so insulation is in contact with all six sides of the box—no more roof “ventilation.”
The issue? We come across closed vaults all the time that are insulated with filterglass—er, I mean fiberglass—batts. We see from infrared images that air moves easily through these cavities, degrading the effective R-value. Building science tells us we can get rid of roof ventilation if we add rigid foam over the roof deck—but this is expensive. Or we can rip off the drywall and spray closed-cell foam in from below—but this is also expensive. Both approaches control moisture migration by not allowing it, but these are not options for many clients with existing homes.
So if we control moisture in the home, have good airtight drywall, and dense-pack the cavity, isn’t this a decent option?
I mean, its got to control air and moisture and the danger of condensation more than the leaky fiberglass batts in there now, right? What are your thoughts?
GB3 Energy Solutions
Bill Hulstrunk, a technical manager for National Fiber, a cellulose manufacturer located in Belchertown, Massachusetts, replies:
The Weatherization Assistance program, one of the first building science-based energy efficiency programs, has been dense-packing unvented cathedralized and flat roof assemblies with cellulose throughout the Northeast for over 20 years. The reason that dense-pack cellulose works is that the 3.5 lb/ft3 density prevents moisture-laden air, the major transport mechanism for moisture, from entering the unvented roof assembly. Any diffusional moisture is handled by the hygroscopic properties of the cellulose and dispersed, preventing the formation of liquid water and its associated mold or rot. The borate-based fire retardants may also be of some help, due to their antimicrobial qualities. Some of the more forward-thinking cellulose insulation manufacturers even warrantee this use of their insulation in this application for the life of the building. Some day, maybe our building codes will catch up with the tens of thousands of durable and energy-efficient dense-pack cellulose unvented roof assemblies out there.
Rating Software Questions and Concerns
I always look forward to Steve Mann’s articles in Home Energy and most recently, thoroughly read his article “EnergyGauge HERS Rating Software” (May/June ’09, p. 18). As a certified rater and someone who has performed tons of performance ratings, I am always on the lookout for software to aid with achieving our company’s goals. We are creators of a program called How$mart, through which we help finance energy improvements for our clients. The software program uses performance cost savings as the driving force in determining how much financing the customer can get. In short, if the improvement pays off economically, we can help them finance more of it—if not all of it—depending on the savings versus cost.
The largest problem we’ve encountered with almost all the software out there is this: Few offer any means to adjust energy usage to reflect actual usage history. In REM:Rate and in many other software programs, one can input rates and other data. But even with that information, the resulting energy costs are seldom within a mile of reality. Since we already used Writesoft for HVAC load calculations, we discovered that the Sales Report section of the Cost section allows one to alter data factors to reflect historically accurate energy usage. With that, we can then “repair” the home with air leakage reduction, thermal shell improvements, and so on, and see a realistic estimated energy usage (assuming all other factors remain equal, such as family size, weather conditions, and energy habits).
In brief, my concern is that estimated savings generated from most all software are so far out of line that I trust none of them, except Writesoft. This won’t change until someone else steps up to the plate and offers data calibration adjustments to reflect reality. This seems to be a low priority for software designers, yet so many auditors are called upon to offer energy cost management (ECM) recommendations along with savings associated with those improvements.
Bottom line—help me out here. How can our industry offer financing or any legitimate suggestions if the energy usage and estimated payback calculations are so inaccurate? What means do you use to accomplish this task? Why do you feel it is being overlooked and/or placed on a low priority by software designers? Look at any online energy audit tool, and it is amazing the inaccuracy in energy usage and costs assumed. Consumers have been led down the wrong path time and again expecting huge results and receive embarrassingly poor savings on so many ECMs due to inaccuracies.
Midwest Energy, Incorporated
Software expert and author Steve Mann replies:
Thanks for your e-mail. I’m glad you find my articles interesting.
Regarding your comments about software: You raise one of the critical questions for which I don’t really have a good answer. Every modeling program I’ve ever used is usually way off estimating utility costs, just as you point out, sometimes by a horrendous amount. The good news, at least for consumers, is that when modeling is used to get an energy-efficient mortgage or to rate a house for some other official purpose, it seems that the people receiving and reading the reports don’t really care about the fact that the numbers are pure fiction. I don’t know of any nonconsumers that use these reports to verify the savings after a year has gone by. It’s a big flaw in the whole process.
When I do an analysis for a homeowner, and not an official agency or bank, if I get the impression that they’re going to rely on the savings numbers generated by the software, I tell them at least three or four times that this is only a simulation, and that it doesn’t have any bearing on reality. That’s very easy to show, for instance, if you have a year of history and compare it to the consumption figures the software generates for the existing, baseline home.
Having said that, it doesn’t solve the problem. I suspect that over the next few years, we’re going to see modeling programs that factor in utility history and adjust accordingly, but so far, I don’t know of any software that does that. Of course, I haven’t looked at everything available, either. Maybe our readers can weigh in here.
More Praise for Steve
I have read several of Steve Mann’s articles and am impressed with his deep knowledge of the various aspects of a home performance contracting business. I own a small remodeling company in Michigan and could use some advice. Currently I do not participate in the home performance contracting market, but I want to expand my company’s services to include home performance contracting. It seems that HERS and BPI accreditations are more tailored toward companies that are already participating in home performance or larger companies with deep pockets to absorb start-up costs and accreditation fees. Any suggestions on how a small company with limited financial resources can become established in this market?
Steve Mann replies:
Thanks for seriously overestimating my knowledge. That’s always appreciated, as long as it doesn’t get me in trouble.
In my opinion, HERS/RESNET and BPI certifications are avenues for learning basic building science—information and knowledge you probably haven’t picked up in the course of running a remodeling business. A HERS certification is required to do certain types of home performance work, such as energy modeling, federal tax credit calculations, and official HERS reporting. BPI certification is certainly optional, but it seems to be recognized in some regions as a necessary competitive credential for a home performance contractor. (That’s not the case here in California.) On your own you can acquire the knowledge that these certifications provide, if you’re motivated. There are quite a few books and Web sites chock full of building science.
If you’re confident that you can learn how buildings as a system work; if you don’t think any special certifications will help you either market your services or successfully serve your customers; and if there are no local or state requirements, then I wouldn’t bother getting the credentials at this stage. Your limited budget would be better spent on some of the equipment you’ll need. On the other hand, I see home performance contracting and related fields as a lifelong learning process. The more ways I can expose my brain to the material, the more likely I am to remember it and use it properly. I don’t mind getting the credentials as long as the costs aren’t too exorbitant.
Having addressed the certification side of your question, I’m hesitant to discuss any marketing strategies for two reasons: I don’t know your market, and I’m not a terribly savvy marketing person. Our Home Performance Contractor’s Business Development Guide (HE Sept/Oct ’09, special supplement) has lots of useful advice in that regard. I recommend you read it cover to cover and then go back and read it again six months later.
Lead-safe Work Rules for Contractors
As a contractor, you play an important role in helping to prevent lead exposure. Ordinary renovation and maintenance activities can create dust that contains lead. By following the lead-safe work practices, you can prevent lead hazards. Contractors who perform renovation, repairs, and painting jobs in pre-1978 housing and child-occupied facilities must, before beginning work, provide owners, tenants, and child-care facilities with a copy of EPA’s lead hazard information pamphlet Renovate Right: Important Lead Hazard Information for Families, Child Care Providers, and Schools (available in English and Spanish).
Contractors must document compliance with this requirement. EPA’s pre-renovation disclosure form may be used for this purpose.
Understand that after April 22, 2010, federal law will require you to be certified and to use lead-safe work practices. To become certified, renovation contractors must submit an application for firm certification and fee payment to EPA. EPA will begin processing applications on October 22, 2009. The Agency has up to 90 days after receiving a complete request for certification to approve or disapprove the applica tion. Read more about EPA’s rules and lead-safe work practices in EPA’s pamphlet Contractors: Lead Safety During Renovation (in English and Spanish).
For the documents mentioned above and more on EPA’s lead safe work rules, go to www.epa.gov/lead/pubs/renovation.htm#contractors.
Safer Solar Showers
I am writing in regard to Ed Minch’s frustrating situation he has experienced with his new home solar-powered shower systems.
(Editors note: In the letter, Mr. Minch complains that three shower faucets he purchased for showers fed from a solar water heater did not come with volume controls. See “Shower Faucets Frustration,” May/June ’09, p. 3.)
I used to be in the decorative plumbing industry and a manufacturer’s representative for Hansgrohe. I suspect one of two things has happened here. Either Mr. Minch did not inform the salesperson of his solar-powered shower systems, or the salesperson was not trained properly.
I am not trying to point blame at the salesperson. It is very rare for someone to have a solar-powered water system for a complete house. In fact, in the 11 years I was in the industry, I never came across one, unfortunately. If Mr. Minch did inform the salesperson of his solar-powered water system, then the salesperson needs additional training.
All three manufacturers [Moen, Kohler, and Hansgrohe] offer volume control valves. I always instructed all my customers (plumbing wholesalers) to include a volume control for all points of water exit on a shower system. Granted, this does add cost. This also is an area where a customer will “try to save money.” Bad idea. Either way, no one wins here. Mr. Minch is an unhappy customer with a problem. The plumbing wholesaler has an unsatisfied customer. The salesperson is not happy either.
I would suggest that the wholesaler, a plumber, a drywall repair contractor, and the customer sit down and work out a way to resolve this. I know if I had this unfortunate situation I would give the customer the valves and trim at our ultimate bottom line cost. I bet this situation could be resolved if all parties agreed to give a little.
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