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Martin’s Useless Products List

A roundup of energy-related products that you can do without

Posted on Sep 25 2009 by Martin Holladay

Every day, marketers convince hundreds of people to spend money on useless “energy saving” gadgets. Since these marketers show no signs of going away, it’s time to highlight their products with a ten-worst list.

The order of the products described in the following list is random. I had to remove an eleventh item from this list: “insulating” paints, a product category that I debunked in a recent blog. If you know of a deserving product that should have been included in this list, feel free to post nominations for the list’s second edition.

The Ten Most Useless Energy-Related Products

1. Tyvek ThermaWrap

In 2006, this “low-e” housewrap suffered from a disastrous launch by bumbling DuPont marketers who bragged that the “insulating” properties of the housewrap were due in part to its low emissivityAmount of heat radiation emitted from a particular body or material. Emissivity is expressed in a fraction or ratio, with the lowest values indicating low emissivity and the highest indicating the high emissivity of flat black surfaces.. Reviewing the product for Energy Design Update, I asked ThermaWrap representatives to specify the emissivity of the membrane, only to be told that “due to company policy,” DuPont was “not at liberty to reveal the actual emissivity number for Tyvek ThermaWrap.”

Later, when my journalistic investigations revealed that DuPont had failed to produce a ThermaWrap fact sheet as required by the Federal R-ValueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. Rule, DuPont reluctantly admitted that ThermaWrap has an emissivity of 0.2 — exactly the same value that EDU predicted in its September 2006 review. The emissivity of ThermaWrap is too high to qualify as either a radiant barrier or a reflective insulation.

DuPont no longer repeats its earlier claim that “Tyvek ThermaWrap changes the dynamics of heat flow across the entire wall system and dramatically helps improve the insulating value of the wall system.” In fact, if ThermaWrap is installed facing an air space, it will change the R-value of the air space from R-1 to R-2 — a change that few would characterize as “dramatic.” In response to my reporting, ThermaWrap’s product manager eventually wrote EDU a letter noting that “DuPont regrets any lack of clarity in its DuPont Tyvek ThermaWrap literature, as well as the incomplete nature of the information supplied to EDU.”

2. Fafco plastic solar collectors

A California manufacturer, Fafco, produces an unglazed plastic solar collector called the Hot2o. Although plastic solar collectors are often used to heat swimming pools, the Hot2o is marketed for domestic hot water systems, which require much higher temperatures than swimming pools. The Hot2o collector has an expected lifespan of only 12 or 15 years, and it will never be able to heat water to the same high temperatures as a glazed collector.

Even the founder of the company, Freeman Ford, admits that “it represents a value breakthrough, not an efficiency breakthrough.” My own advice: save your money until you can afford a glazed collector.

3. Passive fresh air inlets

These small round vents are basically holes in the wall. Produced by several manufacturers — including Airex, American Aldes, Condar, Panasonic, and Therm-Stor — these vents are supposed to provide a way for fresh outdoor air to enter a home whenever exhaust fans are operating. Unfortunately, air responds to pressure differences; it doesn’t obey the “smart arrows” in the diagrams. That’s why air is just as likely to exit the vents as to enter.

Researchers have shown that almost all houses have enough random air leaks to allow exhaust fans to operate without these useless devices. More information on passive air inlets can be found here.

4. Vinyl siding laminated to rigid foam

Manufacturers have figured out how to laminate vinyl siding directly to thin pieces of expanded polystyrene (EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest.) insulation. “Insulated” vinyl siding is available from several manufacturers, including CertainTeed, Crane Plastics, Heartland, Norandex-Reynolds, and Resource Materials Corporation. Don’t expect “insulated” vinyl siding to add much R-value — most of these products are in the R-3 to R-4 range. The real problem with the product is that the flat-backed foam fills the corrugated air space behind the siding, limiting drainage and reducing the wall’s drying potential.

In other words, the added foam interferes with one of the best aspects of vinyl siding: its built-in rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. .

5. Powered attic ventilators

Powered attic ventilators are exhaust fans installed in an attic to keep the attic cool. Whether powered by ordinary 120 volts AC or by a solar panel, powered attic ventilators are a waste of money. Since most U.S. homes have leaky ceilings, powered attic ventilators commonly draw conditioned indoor air into the attic through ceiling cracks, increasing energy costs.

Attic ventilators are powerful enough to depressurize a house, potentially causing water heaters to backdraft. Instead of wasting your money on a powered attic ventilator, you’d be better off spending your money on canned foam to seal leaks in your ceiling — or, if your ceiling is already airtight, on additional insulation for your attic floor. For more information on these useless gadgets, see Fans in the Attic: Do They Help or Do They Hurt?

6. Programmable thermostats

Okay, these devices aren’t really useless — they’re just unnecessary and insufficient. I’m happy to stipulate that anyone who actually programs and uses a programmable thermostat will save energy compared to someone who never performs thermostat setbacks.

That said, study after study has shown that installing programmable thermostats makes no difference in energy use. The reasons are simple: when it comes to thermostat setbacks, homeowner behavior is far more important than the hardware on the wall, and many homeowners are frustrated by the difficulty of programming these devices.

Plenty of homeowners with simple non-programmable thermostats routinely set back their thermostats when they go to bed or leave for work, while the majority of homeowners with programmable thermostats never use them. So here’s the bottom line: whether you have a simple Honeywell Round or a complicated electronic gizmo on your wall, it’s important to set back your thermostat. The hardware you use is irrelevant.

7. Inexpensive LED lamps

Most LED lamps on the market are less efficient than compact fluorescent lamps (CFLs), which have an efficiency of 48 to 60 lumens per watt. (By the way, straight T-5 and T-8 fluorescent tubes are even better than CFLs, with efficiencies of 98 to 105 lumens per watt.) Although the best LED lamps on the market are about equal in performance to CFLs — Cree produces LED downlights rated at 46 to 60 lumens per watt — they cost significantly more than CFLs.

The majority of LED lighting products on the market produce only 10 and 19 lumens per watt — about the same as an incandescent bulb. Moreover, testing of LED lights by the U.S. Department of Energy in 2006 and 2007 revealed that most LED manufacturers were exaggerating lumen output. LED devices that were touted as producing 36 to 55 lumens per watt actually produced only 11.6 to 19.3 lumens per watt. Caveat emptor.

[Author's postscript, December 2013: In the four years since this article was written, the quality and efficiency of LED lamps has improved and prices have dropped. It now makes sense to consider LED lamps for many applications, especially for down-lights that require a directed beam.]

8. Foil-faced bubble wrap

Distributors of foil-faced bubble wrap “insulation” have a rich history of exaggeration and fraud. A September 2003 exposé in Energy Design Update documented several wild exaggerations by manufacturers. Although foil-faced bubble wrap has an R-value of about 1 or perhaps 2, several manufacturers have falsely claimed R-values ranging from 5 to 10.

In hopes of avoiding FTC enforcement action, the manufacturers, caught red-handed, sent EDU a comical cavalcade of apology letters. The bottom line: foil-faced bubble wrap costs just as much as — and in some cases much more than — 1-inch-thick rigid foam. As building scientist John Straube pointed out, “I might recommend it if it were half the price of R-5 rigid foam, but if it costs more than R-5 foam then you have to be crazy or stupid to use it.”

9. Power factor correction devices

These “black boxes” — brand names include the KVAR Power Factor Optimizer and the Power-Save 1200 — purport to provide energy savings by correcting the power factor of electricity. Some of these devices are intended to be “whole-house” boxes, while others are designed to “correct” the power factor of an individual plug-in appliance. Manufacturers claim that the gadgets reduce the amount of electricity used by appliances with coils or capacitors (pumps, fans, and fluorescent light ballasts) with power factors less than 1 — that is, appliances with electricity wave forms with the current and voltage out of phase.

But residential customers aren’t even billed by power factor — residential electricity meters can’t even measure it. Since homeowners aren’t penalized for low power factors, these devices can’t possibly save you any money. To learn more about this scam, see or

10. Vent-free gas space heaters

Like powered attic ventilators, so-called “vent-free” gas space heaters deserve a special award, since they’re not just useless — they’re potentially dangerous. Several critics have pointed out that these appliances aren’t really vent-free — they just use your living room (and your lungs) as a chimney.

Illegal in California, these heaters shouldn’t be used anywhere. To learn more, see Alex Wilson’s recent blog, “Avoid Unvented Gas Heaters.”

Last week’s blog: “Pinpointing Leaks With a Fog Machine.”

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Sep 25, 2009 2:07 PM ET

by Michael Blasnik

I think this is a pretty good list, but I'm not so sure about programmable thermostats., yes, there are some studies that show no impact on energy use but there are also studies that show savings. The Philadelphia Gas Works low income weatherization program has produced significant savings from thermostat installations based on multiple impact evaluations (that I performed). The thermostats paid for their installation costs in 1 year or less. There was also a study by a group of gas utilities (Gas Networks) that found savings for customers receiving rebates for thermostats.

I think the impacts will be determined by the context. If the thermostats can make setback more likely or consistent, then they will save energy. If someone would have practiced setback manually without the thermostat, then of course there won't be savings.

Sep 25, 2009 2:25 PM ET

by Anonymous

If the KVAR unit does not work, how do you explain residential bills I've seen that show a significant savings by utilizing one?

Sep 25, 2009 3:17 PM ET

Thanks for the information
by Martin Holladay

Thanks for citing new studies that show that programmable thermostats can result in energy savings. I imagine that these studies included homeowner education; without the education, programmable thermostat installation programs don't have a good track record. That raises the question: what if a program provided information on the advantages of thermostat setbacks without swapping any thermostats?

Here are excerpts from two Energy Design Update articles — perhaps somewhat out of date, but still relevant:

EDU, November 2000: “An Unexpected Setback for Programmable Thermostats”

New field studies from Wisconsin and Florida suggest that programmable thermostats aren’t the prodigious energy-savers we’ve been led to believe and may in some situations actually increase energy use. “Before we did this study, I was sold on programmable thermostats,” says researcher Monica Nevius with the Energy Center of Wisconsin (Madison, Wisconsin). “It was a shock to me when we discovered that they have virtually no effect on energy savings.”

In 1998 and 1999, Nevius and fellow researcher Scott Pigg surveyed 299 homeowners in Wisconsin, constituting a representative sample of the state’s population and housing stock. As shown in Table 1, about two-thirds of those surveyed used manual thermostats to regulate their heating systems, while the rest owned programmable models. In-depth personal interviews were subsequently conducted with 30 of the homeowners to probe their personal attitudes toward energy conservation and thermostats. In fact, one of the main purposes of the study was to find out how homeowners’ attitudes toward energy conservation affect the way they use their thermostats and other energy-related behavior.

The results suggest that the owner’s attitude toward energy conservation is much more important than the technology. “We found that homeowners who are inclined to set their thermostats back will do so regardless of the type of thermostat they own and those who are not so inclined won’t do it regardless of the type,” Pigg explains. “Forty percent of the homeowners with manual thermostats set their thermostats back. Those who don’t aren’t eager to have a programmable thermostat and probably wouldn’t use one if they had it.” ...

Even Worse Results in Florida?
Preliminary findings from a Florida study on programmable thermostats appear to be even more negative than those from Wisconsin. Researcher Danny Parker, with the Florida Solar Energy Center, tells EDU that he’ just completed a field study for Florida Power Corp. (FPC) that monitored the end-use heating and cooling in 150 homes and broke out the results according to the type of thermostat installed.

“Within our project, we had 19 homes with programmable thermostats that showed evidence of increased consumption and peak demand,” Parker says. “This is just the opposite of what the HERS rating and Energy Star Home Program now estimate.” Parker says that he measured interior temperatures and space-cooling demand profiles at 15-minute intervals and found that people with manual thermostats were “much more likely to set up their thermostats than those with programmable models — just the opposite of conventional wisdom.”

Part of the problem, apparently, has to do with that old bugaboo: complexity (or, if you prefer, the “technological nuisance factor,” which is what keeps a lot of people from programming their VCRs). The manual thermostats are easy to operate and set back, Parker theorizes. But people with programmables tend to leave them at a constant setting because they’re too hard to program.
* * * *
EDU, January 2001: "Surprise! There are People Inside Those Buildings — Or, Why Programmable Thermostats Don’t Deliver the Promised Savings," by Craig Conner

A large field study conducted by Pacific Northwest National Laboratory concluded that the energy savings delivered by programmable thermostats are significantly less than advertised. Our findings square with those documented by the Energy Center of Wisconsin and reported in the November EDU. We concluded from our work that the value of programmable thermostats has been greatly overestimated because the mere presence of the thermostat doesn’t necessarily alter the homeowners’ behavior. In fact, our measured data suggests a nearly equal probability of setback with and without programmable thermostats. In short, the occupants control the thermostat and not the other way around.

Sep 25, 2009 3:20 PM ET

More information, please
by Martin Holladay

Dear Anonymous,
Your claims don't amount to much without a few more details.
1. What's your name?
2. Were the homes you're talking about enrolled in a study?
3. If these are anecdotal reports, they don't mean much, since utility bill vary from month to month and from year to year for a wide variety of reasons.

Sep 25, 2009 3:57 PM ET

Great list
by Paulo Nery

I'm delighted you stood up and exposed these products. Some are downright scams. I'd love to see you do a 10 best as well.

Sep 25, 2009 5:02 PM ET

attic ventilators
by Chuck Tackett

I appreciate your list but I would make one caveat to attic ventilators. I live in an older home (75 + yrs old) and have vents directly in the attic walls. I installed an attic ventilator to help keep air moving and reduce the tempurature in the attic during hot summers days when wind speeds are low to non-existent. It does a decent job of performing that task without drawing much air from the conditioned spaces. I will not make any claim about reduced energy usage or cost savings though it does seem to help with water vapor / humidity in the attic space. To that end I would not say it's useless. Then again I may just be rationalizing a foolish exercise. Thanks for the article.

Sep 25, 2009 5:09 PM ET

by Michael Blasnik

The thermostat studies you cite actually don't address the issue very directly. The real question is -- if I install a setback thermostat, will I save energy? The two studies you cite did not look at differences in energy before and after installing a thermostat in a home, but looked at different homes and concluded no real difference in usage by thermostat type. Since many homeowners simply have whatever thermostat was already in the home when they bought it, such comparisons don't tell you very much.

The Gas Networks study I mentioned did not have any education component -- it was an in-store rebate program. The Philadelphia study did have in-home installation, but all homes were educated about reducing their setpoint and managing temperatures. For customers who wanted the thermostat (about 65%) the energy savings were much larger.

I think the before/after energy usage comparisons are much more powerful than the studies that simply look at differences between homes.

Sep 26, 2009 5:36 AM ET

How much air is escaping through your ceiling?
by Martin Holladay

You wrote that your powered attic ventilator "does a decent job of performing that task without drawing much air from the conditioned spaces." Here's the problem, though: it's almost impossible (without performing a blower door test on your house) for you to determine how much conditioned air is leaking through your ceiling into your attic. A tremendous amount of air can be leaking out that way, sucked by your fan, without you noticing. You won't necessarily feel any drafts.

A good summary of the problems associated with powered attic ventilators can be found in prepared by the Dominion energy group. The fact sheet notes, in part:

"At some point, the original purpose for attic ventilation was forgotten and/or replaced, in cooling climates, with the belief that it was to reduce roof and attic temperatures, thus lowering cooling expenses and increasing shingle life. This was further compounded by the leap of faith that increased or powered ventilation would be even better. While sounding logical, there is simply no research to validate it. In fact, scientific testing has shown that attic ventilation has almost no effect on roof surface/ shingle temperatures and very little effect on attic temperatures. There is however, a growing list of research, computer modeling and field data that indicates powered attic ventilation can be a detriment to health and safety and actually increase cooling costs."

Sep 26, 2009 5:42 AM ET

Good point, Michael
by Martin Holladay

Good point about the three studies I cited (they compared homes with programmable thermostats to homes without programmable thermostats, instead of comparing homes before and after a non-programmable thermostat was swapped with a programmable thermostat). I'm encouraged to hear that thermostat-swapping programs can work, and I'm willing to consider removing programmable thermostats from my Useless list. Perhaps I'll put programmable thermostats on my Overrated list.

Sep 26, 2009 7:16 AM ET

Michael Blasnik
by John Brooks

You should spend more time here....
Somebody needs to "correct" /challenge Martin every once in a while ;-)

Sep 26, 2009 7:25 AM ET

High Performance homes
by John Brooks

Programmable thermostats do not provide very significant improvements in High Performance homes.

One reason that setting back thermostats may not yield as great a savings as expected is because of the thermal mass of the house and contents....
the house and contents need to be re-heated or re-cooled.

Sep 26, 2009 11:26 AM ET

by Michael Blasnik

Martin -- I'm glad to hear that you'll consider an upgrade to "over-rated". I can live with that, ;}

I'd just want to be sure that you don't confuse people into thinking that setting back temperatures doesn't save much energy. Just putting in a setback thermostat won't necessarily save energy -- but setting back the temperature will -- in most cases.

John Brooks makes the good point that temperature setback doesn't save much in homes with either high thermal mass or that are high efficiency (and especially both). If the indoor temperature doesn't drop much during the setback, not much can be saved.

Sep 26, 2009 2:44 PM ET

by John Romansky

If you reread the part on setback thermostats, it reads not that they don’t work and achieve energy savings; it is that many people don’t bother to use them in a setback cycle. If you look at the energy triangle that is comprised of the building envelope; building systems (setback thermostat) and occupant behavior, the statement indicates that the occupants (operator) are the issue. The setback thermostat will provide consistent scheduled setbacks to the occupant’s schedule and hence a smaller delta T (inside to outside), and the occupants will almost always awake or arrive to a home or building that has the right thermal comfort level.
Great List,

Sep 26, 2009 3:53 PM ET

I'm not interested in confusing people either
by Martin Holladay

Like you, I'm not interested in confusing people. Here's what I wrote: "I’m happy to stipulate that anyone who actually programs and uses a programmable thermostat will save energy compared to someone who never performs thermostat setbacks. ... So here’s the bottom line: whether you have a simple Honeywell Round or a complicated electronic gizmo on your wall, it’s important to set back your thermostat."

I hope it's clear! Setbacks are good! Programmable thermostats are optional.

Sep 26, 2009 5:18 PM ET

Programmable thermostats
by Richard Linderman

The conversation is irrelevant - the IRC requires them.
And just as a side-bar, education is important. I rehabed some housing (section 8) for a local community action agency and installed among other energy saving devices, programmable thermostats. As part of my duties I went back six months later to see how every was working. I found to my dismay that often the thermostats were set at 80 and the residents controlled comfort by opening windows.

Sep 26, 2009 5:32 PM ET

Useless products and the Code
by Martin Holladay

Oh, darn. I didn't know that I couldn't include code-mandated products on my Useless list. It must be I was evaluating them using the wrong criteria.

Sep 26, 2009 11:23 PM ET

by Michael Blasnik

I realize that you were clear in the text about why you listed thermostats (even if I disagree about the empirical evidence). My concern about confusion is that , in my experience, people see a list like this and then tell others -- "I read that setback thermostats are useless". The full nuanced message gets lost in the shuffle and confusion is spread -- even if unintentionally.

It sort of reminds me of the confusion I have recently seen about the recent FSEC study showing 11% cooling savings from painting exterior walls white. I have seen and heard several people take away that one piece of info even from the Home Energy article even though it isn't what the authors actually said -- the 11% savings were for a test hut where wall heat gain should be expected to be a larger fraction of the cooling load than in aa real house. People will grab a sound bite and miss the details.

Sep 27, 2009 5:26 PM ET

energy scams and useless products
by Anonymous

By far, the biggest scam lately is the huge advertising blitz for the claimed 50% savings by the Edenpure, Amish fireplace and similar space heaters.

Sep 28, 2009 3:11 AM ET

Ah, yes — the Amish heater scam
by Martin Holladay

The Amish heater scam certainly could have been included in the Useless Products list. This outfit is selling 1,500-watt electric heaters (widely available for $25 or $30) for $300 or more. The ironic twist to the story, of course, is that the real Amish don't use electricity. (Because of their gentle nature, they also don't sue scam artists who use the word "Amish" — a useful fact to know if you want to capitalize on their honorable reputation to dupe the gullible.)

If anyone cares to read more, here are some Web sites debunking the scam:

Sep 28, 2009 11:56 AM ET

A Product is Useless if You Pay For It But Don't Get It
by Rick Miller

Here's a useless product for you, Martin. Based on your comment in a blog, "The best book on designing and installing a solar hot water system is Solar Hot Water Systems by Tom Lane." I went to the website on September 15, paid 80$ by paypal to order the in-vivid-color version of the book, and have not received the book or heard anything at all from Mr. Lane or ecs-solar since. Everything I have ever ordered from websites would be here by now. Last week I emailed ecs-solar and I did not even get a response to the email--nothing. That's what I call extra useless.

Sep 28, 2009 12:42 PM ET

by MichaelAnschel

This my cause you to lose consciousness for a brief moment, but I AGREE WITH THE ENTIRE LIST! I know crazy right? We never agree on anything.

I recently spent a great deal of time explaining to a homeowner why purchasing a Power Save 1200 was not going to get her the savings a salesperson had promoted. Power vented attic fans are a true hazard, Vinyl is just gross no matter how you look at it, Fresh Air Intakes were a sad idea from conception.

You are spot on with your comment about thermostats. Setting them back is what is important, so an un-programmed thermostat is just as useless as a manual thermostat. Behavior is what has to change. I read a study a couple years back where the homes that had received new stats were not showing the savings the computer models had predicted and when they went back to try and determine why, they discovered that the thermostat had never been programmed and the homeowner didn't understand how to use it. They had continued to use the up and down buttons to manually adjust the temp for comfort.
Your list just goes to show that Education is, as most things, the least expensive and most impactfull solution.
Good job!

Sep 28, 2009 12:45 PM ET

I'm not sure about the delay
by Martin Holladay

Well, you ordered the book 13 days ago. I'll admit that most book orders arrive sooner than that — but it's not as if it's been a month. (When I was young, every mail-order advertisement included this tag line: "Please allow 4 to 6 weeks for delivery.") I just called Energy Conservation Services, and was told that your book is on its way. I certainly hope you get the book soon. When you do, I hope you'll agree with me that the book is not useless.

Sep 28, 2009 1:53 PM ET

I'll Bet the Lane Book is Not Useless at All, When Present
by Rick Miller

I have some time ago read the book Solar Water Heating, by Bob Ramlow and Benjamin Nusz, and I think it is well done, with some good details. However, there looks to be considerably more detail with the Lane work. Thanks, Martin, for your recommendation and the phone call. Now, all I need to do is sit back and figure out what the heck's wrong with me because, sorry, I had no business bringing you into it.

Sep 28, 2009 2:22 PM ET

Another nomination...
by Garth Sproule 7B

I don't know if these are sold or promoted in the US, but here in Canada, we have a product called the whirly-bird attic ventilator. It is wind driven and does in fact draw air when it spins...but it has been shown that when the wind blows, there is enough of a pressure differential created to circulate air through the soffits without any help from a fan. Of course when it is calm, neither system works. Eventually, they wear out and blow right off the roof leaving a rather large hole that often goes unnoticed for some time...

Sep 28, 2009 3:04 PM ET

I agree about whirlybirds
by Martin Holladay

You're right about whirly-birds. Of course, if you cut a hole in your roof near the ridge on a hot day, the stack effect will cause the hot air near the ridge to rush out the hole, while make-up air comes in at the soffits (assuming you have soffit vents). All fine and good, I suppose, but the effect has nothing to do with the twirly aluminum gadget that builders install over the hole. All that the aluminum device does is slow the air down as it leaves your attic.

If you want passive attic ventilation, install a conventional ridge vent. You don't need those aluminum spinners.

Sep 28, 2009 4:07 PM ET

Programmable thermostats - is this an urban myth?
by Ann Monroe

See my blog post at .

Sep 28, 2009 7:59 PM ET

It's true that many programmable thermostats are used
by Martin Holladay

In your blog, you wrote, "Nowhere could I find an actual study - or an actual expert - with any hard information about the habits of programmable thermostat buyers. Which is, when you think about it, not surprising. After all, does it make sense that millions of people would pay good money for a gadget designed to save them even more money, and then not use it?"

While your statement may be literally true, we can certainly infer the behavior of programmable thermostat owners from the data collected by researchers.

Danny Parker of the Florida Solar Energy Center studied programmable thermostats in 1999-2000.
As reported by EDU, "Within our project, we had 19 homes with programmable thermostats that showed evidence of increased consumption and peak demand," Parker says. This is just the opposite of what the HERS rating and Energy Star Home Program now estimate. Parker says that he measured interior temperatures and space-cooling demand profiles at 15-minute intervals and found that people with manual thermostats were "much more likely to set up their thermostats than those with programmable models — just the opposite of conventional wisdom."

Craig Conner, a researcher at the Pacific Northwest National Laboratory, conducted his study in 2000. He wrote, “Our analysis of thermostat-related behavior was based on measured data from about 150 electrically heated, single-family homes located in the Pacific Northwest. … Interestingly, there was little difference on average between the setback behavior of people who own programmable thermostats and those who don’t. In both groups there are people who set their thermostats back almost every day and people who almost never do so. On average, both groups set their thermostats back about half the time. In other words, homeowners with programmable thermostats don’t set back any more often than owners of manual thermostats. Thus, we concur with researchers Scott Pigg and Monica Nevius at the Wisconsin Energy Center: the attitude of the occupants has everything to do with the way that thermostats are operated. The presence or absence of a programmable thermostat doesn’t have much effect on setback behavior.”

So, people who buy programmable thermostats do use them, and do perform setbacks -- but not any more or less than people with old-fashioned manual thermostats.

Sep 29, 2009 9:22 AM ET

So would you include programmable t-stats in a retrofit program?
by Melissa Malkin-Weber

Michael, thanks for jumping into this thread. If you were designing a retrofit program, would you invest the $ in including programmable thermostats? Or would you do something else to the house with that money?

Are the Philadelphia gas and Gas Networks studies published somewhere for us to read in more detail (if we happen to be "more detail" kind of people)?

Sep 29, 2009 1:02 PM ET

more thermostat info
by Michael Blasnik

Melissa- The CEE web site has lots of reports on thermostats. Just Google for "gas networks thermostats CEE" and you can find the gas networks report about halfway down the page. That study showed 75 ccf savings per thermostat.

The Philadelphia reports that I did are not published anywhere as far as I know, but I think I could share them with you directly if you email a request. The high savings were mostly achieved by one of the two contractors. In the 2005 and 2006 evaluations (each with about 2,000 homes of pre and post billing data) thermostat savings were estimated at 132 ccf and 141 ccf respectively for one contractor and 25 ccf and 19 ccf for the other contractor. Even the lower performing contractor's savings are quite cost-effective.

I think I should also mention that the Wisconsin study that is one of the key reports used to justify the "useless" tag actually showed that energy usage was about 2.5% lower in homes with the programmable thermostats. That difference would translate into maybe a 1-2 year payback on the cost of the measure. I think that's pretty good for something "useless" -- actually a quicker payback than retrofits like air sealing or insulation.

Personally, I find a programmable thermostat useful because it automatically sets the temperature to where I want it when I want it. I know I would sometimes forget to setback without it and I also like that it turns up the heat a little earlier in the morning (which does use a little more energy). I may not be savings a lot energy compared to what I could achieve with careful manual setbacks, but to me it's a very useful device that helps me save that energy with greater comfort and convenience. It certainly doesn't belong on a list of "useless" items.

Sep 29, 2009 3:56 PM ET

Thank You
by Ben Ainslie

Thank you for putting tyvek on top of your list. It is a tool in the fiberglass scam and nothing more. I would also like to take this oppertunity to introduce my "Amish bubble-wrap" which wil not only insulate your home but also works as solar panels, siding and floor joists :)

Sep 30, 2009 8:20 AM ET

New data on "vent-free" space heaters
by Martin Holladay

I've just read the results of an interesting indoor-air monitoring study conducted by a group of researchers, including William Rose. They installed extensive air monitoring equipment in 15 homes equipped with unvented gas space heaters. Among their findings: "Two of the 15 homes did have measured 8-hour average carbon monoxide levels that exceeded the threshold value of 9 ppm. In both of these cases the threshold value was exceeded during a time of extended continuous use of the appliance. Nitrogen dioxide was the gas that most frequently exceeded published guidelines. In 7 of 15 homes the Canadian threshold of 250 ppb was exceeded and in 11 of 15 homes the WHO threshold of 110 ppb was exceeded. If the three homes for which NO2 values were adjusted are excluded, the frequency changes to 6 of 12 homes exceeding the Canadian threshold and 10 of 12 exceeding the WHO threshold."

Rose's research report, is available online.

Sep 30, 2009 9:08 AM ET

One more attempt at explaining myself
by Martin Holladay

Thanks again for pointing out the potential usefulness of programmable thermostats.

You're right that I was setting myself up as a target by including programmable thermostats on a list headlined "Martin's Useless Products List." I tried to deflect a few arrows with my lead sentence, "Okay, these devices aren’t really useless ..." But I still received an earful from fans of the gadgets, including you.

Here's my takeaway point: gadgets will never be our salvation. Designing a gadget-filled home — even a home filled with the items from "Martin's Best Products List," which I haven't written yet — won't make anyone any greener. Ultimately, a green lifestyle is about behavior. This nugget of truth has been clearly highlighted by the programmable thermostat studies I cited. While there may be some benefit to the devices, ultimately human behavior matters more than the gadget on the wall.

If you are a setback type of person, you are likely to set back the thermostat wherever you live, regardless of the thermostat type. If you're not a setback-type person, you won't set back your thermostat, even if your thermostat speaks 12 languages and is connected to the Internet.

I think it's an important, humbling truth. How we behave matters more than what we buy.

Sep 30, 2009 9:21 AM ET

LED lamps
by Dave Brach

I'm interested where you got your data on the LED lamps. Are there certain manufacturers that can be trusted to not exagerate their lumens per watt claims?

Sep 30, 2009 9:39 AM ET

LED data
by Martin Holladay

The LED data came from an excellent DOE program, the Caliper program, which is part of the DOE's Solid-State Lighting Program. More information can be found here:

The Caliper researchers have performed several rounds of testing. While editor of EDU, I was particularly interested in the results of Round 4 testing, which highlighted exaggerations made by Cyberlux (manufacturer of Aeon LED lights) and Permlight Products (manufacturer of the Enbryten LED light). Permlight has since entered into a partnership with Progress Lighting.

Cyberlux advertised that the Aeon Pro produced 55 lumens per watt. The DOE's test showed the product actually produced 16.1 lumens per watt.

Permlight advertised that its 15-watt Enbryten dowlight produced 40 lumens per watt. According to DOE testing, it only produced 12.8 lumens per watt.

In the Round 4 testing report, the accuracy of manufacturers' claims was summarized: "In earlier rounds of testing, discrepancies were observed between the light outputs and efficacies published by manufacturers and their CALiPER-tested performance. In Round 4 of CALiPER testing, these discrepancies continue to abound. Fifteen SSL products were included in this round; the remaining five products, tested for benchmarking purposes, use fluorescent or halogen sources. Out of the 15 SSL products, the accuracy of manufacturer performance reporting can be summarized as follows:
• Accurate performance reporting (1): One manufacturer provided accurate performance information for its luminaire (CALiPER 07-43—publishing luminaire output and efficacy values within 10% of the CALiPER measured results).
• No performance reporting (4): For four products, no manufacturer-published information was found regarding output or efficacy.
• Understated performance reporting (1): For one product, the manufacturer literature understated the output and efficacy of its SSL product by 50%.
• Overstated performance reporting (9): For the other nine SSL products, information published by manufacturers regarding product output and/or efficacy overstated performance (by factors ranging from 30-600%)."

Sep 30, 2009 9:39 AM ET

by Bill Rose


As I mentioned to you in an email, we like to present our research on unvented heaters where the discussion begins with questions about these devices, and we shy away from injecting our research findings into discussions where the question and answer period appears to be over. Of course, in a forum like this, taking a strong advocacy position as you and Alex Wilson do, shouldn't preclude open-minded review of research results. We did not take an advocacy position regarding these appliances. Jeff Gordon, a Co-PI, explains it this way:

"To take an advocacy position requires us to make a judgment on the health-based thresholds. The thresholds exist, and they were prepared by qualified people, but research on health impacts of low level concentrations are not conclusive, and naturally there is some guesswork involved in establishing thresholds (Health Canada 250 ppb NO2, WHO 110 ppb NO2, clearly each group is taking a stab at it). We are not health professionals, and thus are not qualified to make a judgment on the competency, quality, and conclusions of health-based research, or on the subsequent derived thresholds. We are qualified to measure and document combustion gas concentrations and present them in the context of the thresholds, which we did well. "

I sent you some links for our research. One of the links, which you cite above, was for a preliminary report (15 homes) and the rest were for the full report (30 homes). I encourage readers to go to the full report here . (Martin: feel free to HTML edit for better linking.)

Sep 30, 2009 1:06 PM ET

behavior - most over-rated excuse ;}
by Michael Blasnik


I have to say that I completely disagree with your apparent claim that we need to change behavior to save energy. I don't care how "green" your behavior is - if you have a 1970's refrigerator it will use much more energy than a new refrigerator -- even if you never open the door! In general, it takes fairly extreme lifestyle choices to compensate for inefficient homes and appliances. I think technical improvements are much more likely to have an impact on our energy usage than encouraging green lifestyles -- although we should do both.

I think it's a common scapegoat to blame occupants for why things don't save energy or why building simulation models are so bad. Sure, in extreme cases behavior can have a huge impact, but in the vast majority of cases, behaviors are in a fairly narrow range based on people seeking comfort, services, and convenience. Better gadgets can allow people to dramatically reduce the energy needed to maintain a comparable lifestyle.

Sep 30, 2009 1:24 PM ET

This discussion won't be settled here
by Martin Holladay

I'm thinking about the questions raised by the Jevons Paradox — the idea that efficiency improvements alone are unlikely to lead to a reduction in energy consumption. As I wrote in that previous blog, "Communities that have a low environmental impact and live in harmony with nature are not particularly efficient. Our planet’s future is being threatened not by traditional rural communities with old-fashioned methods of livelihood, but rather by industrial economies where efficiencies are highest."

When one considers the entire range of human lifestyles — from rural African villagers to suburban Americans — it's hard to conclude that gadgets will save us. But I'm all in favor of using tools that use as little energy as possible.

Sep 30, 2009 2:59 PM ET

Jevon's Paradox
by Michael Blasnik

Jevon's paradox is widely misinterpreted. It is true that when you make a dramatic improvement in the efficiency and usefulness of something, you may actually use even more of it -- like Jevon found with coal after the invention of the steam engine. But these relationships aren't boundless. If my car gets double the mpg it doesn't make me want to drive twice as far. The key issues (speaking as an economist) are elasticities -- price elasticity and income elasticity . It is easy to get confused about the two and think that just because overall energy usage has gone up that therefore efficiency hasn't helped. That belief is just nonsense.

If you think that comparing our energy use to that of primitive societies is going to help save energy by convincing first world people to give up things like lighting, refrigeration, space conditioning, computers, etc... -- all I can say is good luck with that. But back here in the real world, most people want the benefits of modern society and it will require lots of great gadgets and efficient use of resources to provide those benefits to as many people as possible.

Oct 1, 2009 8:32 AM ET

Behavior change for efficiency
by Anonymous

Michael Blasnik: To increase the efficiency of this forum, you should not write, since you suffer from confusion an illogic.

Oct 2, 2009 12:07 AM ET

CO levels
by Danny Kelly

Great article and discussion. Do you know of a national standard or anything that shows the ppm of CO that is actually harmful. BPI uses 35 but most of the CO detectors that are sold do not go off until they read 60 ppm for a period of 45 minutes (or something close to that, numbers may be off slightly)

I have told many people that vent free fireplaces are a no no and harmful. Am typically challenged by how long they have had it without any problems and "things the salesman told them" Very low levels of CO - if the CO level gets too high, the flame will not burn since there will not be enough oxygen and that the moisture released is not bad since many people like to humidify their homes during the winter anyway. Building science and common sense tell us they are not safe but would like some documentation to back up our theory.

Oct 2, 2009 5:25 AM ET

Debating health issues
by Martin Holladay

As William Rose pointed out, building energy specialists need to be aware of their professional limitations. A question about the medical effects of different CO or CO2 levels is best conducted on a medical forum, not a building science forum.

Rose's research did find that many houses with unvented gas space heaters had elevated levels of nitrogen dioxide: "Nitrogen dioxide was the gas that most frequently exceeded published guidelines. In 7 of 15 homes the Canadian threshold of 250 ppb was exceeded and in 11 of 15 homes the WHO threshold of 110 ppb was exceeded."

Oct 2, 2009 7:29 AM ET

More on LED scofflaws
by Martin Holladay

After I posted this ten-worst list, the New York Times blog on green energy issues published a story about LED scofflaws with exaggerated lumens-per-watt claims. Read the article here:

Oct 2, 2009 9:09 AM ET

More on behavior and conservation
by Martin Holladay

For those who have been following the debate on how human behavior affects energy use levels, here's an interesting article describing how providing information on neighbors' energy use can lead to lower levels of energy consumption:

Oct 2, 2009 11:51 AM ET

LED Light Output
by David Wasserman

I would not argue with the statement that CFLs produce more total lumens/watt. However, the majority of LED fixtures being sold are for task lighting. I would argue that for task lighting, LEDs produce much more usable lumens/watt than CFLs or any fluorescent lamp for that matter. Consider this example: a CFL bedside lamp uses 18 watts and is used for reading. It illuminates the page of a book well, but also lights up the ceiling and walls of the room. If this lamp is replaced with a 20 LED reading lamp that uses less than 2 watts (including the power inverter), you will get as good or better lighting on the page of the book but with 1/10 the power. Making a blanket statement that CFLs are more efficient than LEDs is misleading and should be qualified.

Oct 2, 2009 3:51 PM ET

Insulated Vinyl Siding
by Tim Holt

Mr. Holladay,
Have appreciated learning from you through EDU over the years and so was disappointed to learn that insulated vinyl siding made your list. While R-3 or R-4 may be considered modest improvements compared to deep energy retrofits, they do provide a measureable benefit and are always better than new siding with no exterior insulation at all. In any case, the higher the R-value the better.
On the rainscreen issue, why is it assumed that insulated vinyl siding limits drainage or reduces the wall’s drying potential? Is this based on commonly accepted theory alone or on some direct observation? There is a growing body of evidence from more than 10 years of exceptional field performance as well as 3rd-party field inspections, field experiments, and lab studies that documents the ability of insulated vinyl siding to keep wall systems dry.

Oct 2, 2009 4:02 PM ET

Limiting drying potential
by Martin Holladay

Filling the corrugated space behind vinyl siding with form-fitting flat-backed foam limits a wall's ability to dry to the exterior in two ways:

1. The ventilated air space between the vinyl siding has been largely removed. Countless wall drying studies show that a ventilated air space between siding and sheathing improves wall drying.

2. The addition of the EPS layer reduces the vapor permeance of the siding layer.

Oct 3, 2009 10:34 AM ET

Expect this list to be expanded!
by Tong

Consumers really need such a list to eliminate their redundant expenditure on uesless devices.

I hope this list could be expanded. For instance, PV panels may be lower cost-efficient than solar thermal collector in some areas. Some techniques in fact may consume more energy during the whole life cycle.

In addition, there could be a list for time-honored, high energy-efficient strategies and devices.

Thanks for your inspiring work!

Oct 3, 2009 12:36 PM ET

Insulated Vinyl Siding
by Tim Holt

Mr. Holladay,
There is no question that the corrugated space behind standard vinyl siding promotes wall drying. It does not necessarily follow that filling in that space with insulation creates an unacceptable restriction to wall drying.
The countless studies you refer to probably evaluated a variety of standard cladding materials and systems. It is unlikely they studied insulated vinyl siding specifically. If this is the case, I would appreciate your consideration of a new study that does just that.
Insulated vinyl siding has been included in a year-long wall moisture study along with other claddings at the NAHB Research Center’s outdoor testing facility. The study monitors the moisture levels in the wall cavities, studs, and structural sheathing on both north-facing and south-facing walls. Bulk water was also “injected” into the wall cavity to supplement what could be learned from the study.
Eleven months into the study, the preliminary results clearly document that insulated vinyl siding performs as well as, or better than, all other claddings in the study.
Please let me know if you’d like to review the most recent summary of this study along with related information.

Oct 3, 2009 12:43 PM ET

Edited Dec 16, 2013 6:55 AM ET.

Sure, I'm interested
by Martin Holladay

I'm always interested in reading research reports. Please send me a copy of the report on the study you mentioned: martin [at] greenbuildingadvisor [dot] com


Oct 4, 2009 3:33 PM ET

What about the wind washing
by Garth Sproule 7B

What about the wind washing effects on insulated vinyl siding? Wouldn't the air flowing behind the siding/foam short circuit the insulation?

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