Home Green Home: Sealing the Envelope

By Tom Zeller Jr.

Home Green Home

The following is the latest in a series exploring the ways Americans are improving the efficiency and reducing the footprint of their homes. Green Inc. readers are encouraged to share their thoughts and experiences in the comments section, or by sending e-mail messages to greeninc@nytimes.com.

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As readers will note from the video above, we decided to invest in two of the most fundamental strategies that homeowners can deploy in the effort to save energy — and money: air sealing and insulation.

We hired Green Tree Energy to do the work, and here’s the down and dirty for our 1,200-square-foot home:

SERVICE COST
Outdoor air sealing around all windows; air sealing around exterior doors; foam sealer applied to leaks around chimney; air sealing of attic; foam insulation applied along rim joists (where house frame meets foundation) $1,150
Removal of old insulation from attic; Application of 10 inches of blown-cellulose insulation to attic $2,310
Installation of door between upstairs and basement $300

As readers of our last installment will recall, our initial blower-door test, before any of the work was done, revealed an air-infiltration rate of 3,857 cubic feet per minute.

What are you doing in your home? Send us an e-mail message and tell us about it.

— Green Inc.

After things were buttoned down, that was reduced to about 1,800 c.f.m. — a sizable improvement, and one that, even in the short time since we had the work done, we’ve noticed.

Of course, plenty of other work could be done, but this is what we could afford — for now. We’ll continue to document our own energy-efficiency projects as we undertake them, but at this point, we’d like to turn the Home Green Home lens on you, Green Inc. readers.

Are you undertaking efficiency improvements of your own? Have you explored alternative forms of energy — from small-scale solar to geothermal — and are now ready to take the plunge? Are you in the midst of installing a pellet stove, or building your own solar-thermal array? Are you a mad scientist cooking up some other energy improvement technology in your garage, or an energy minimalist living life off, or nearly off, the grid?

Send us a note at greeninc@nytimes.com. We just might want to talk to you.

And in the meantime, feel free to discuss all these topics in the comments section below.

Comments are no longer being accepted.

Curious Chris April 20, 2009 · 1:52 pm

So, hold on a second here Tom. I really, really enjoyed following your progress and the videos, but you have to give us a bit more on the results here :). I mean, how does it feel ? Do you really feel a difference ? Do you feel the more even temperature they talk about ? Is it much nicer already ?

Hi Chris – Sorry if you felt I gave the “experience” short shrift. To answer your questions: Yes, we really truly felt a difference — even on the first night, when temps were down in the high 20s, we noticed that the furnace was kicking on far less often to maintain the overall temperature of the house, and it was perceptibly less drafty. On top of that, the house was quieter. Now, that doesn’t mean the back room isn’t noticeably colder than the rest of the house (only putting some insulation in the walls and perhaps altering the venting system will help with that, I’m afraid). But all told, yes, we noticed a big difference. -TZ

Dan April 20, 2009 · 2:35 pm

I’m curious why the old insulation must be removed? Even nasty old fiberglass works ok with a decent amount of cellulose blown over it.

Hi Dan – We had the old stuff removed so that the areas along the perimeter of the attic floor could be air sealed. It had also become, after 30 years or more, quite dirty and mouse-ridden. (A side benefit of the blown cellulose is that it is made flame retardant using boric acid, which keeps critters at bay.) -TZ

abby0802 April 20, 2009 · 4:39 pm

My question is how can people like my husband and I who live on fixed incomes afford to redoing what needs to be done?
Neither of us have the physical and or financial ability to do the things we would love to do to improve our “carbon footprint” and save energy dollars.
Who helps senior citizens on fixed incomes?

Dan April 20, 2009 · 5:52 pm

I’ve been told by a local contractor the following: “Fiberglass insulation works better in attic applications than cellulose. The nature of fiberglass insulation, being a long fiber product, stacks up better and maintains its loft better than cellulose. Cellulose works best in walls because it is a short fiber product, thus allowing it dense pack better than fiberglass.”

He uses a product by Knauf Insulation – called Jet Stream #65997-17-3. It is has the “Green Guard” rating, which confirms that is safe to use around children and schools.

What do you think?

Dan April 20, 2009 · 9:15 pm

abby0802 –
Look into the Low Income Weatherization Program near you (more commonly known as Weatherization). Each state has a program that should provide similar services for income qualified households. In fact, weatherization (wx) funding has been drastically increased as a part of the Stimulus package.

Dan April 20, 2009 · 9:20 pm

TZ –
So it was more for air sealing preparation than anything else? I’m more accustom to moving the old insulation to get to the air sealing, but the evacuaters do make the air sealing much easier, especially if your contractor were using those 2-part froth packs.

Mike J April 20, 2009 · 9:24 pm

Tom has got the right idea here. Addressing your home’s envelope and insulation are the best “bang for the buck” in reducing the carbon footprint from home heating and cooling. But for those on fixed incomes, like abby0802, even this can be beyond your means. Follow Tom’s lead and first get a home energy audit, which can usually be obtained for free through ones electric or natural gas provider. This will give you a complete assessment of your heating and cooling losses. If you are on a modest income, low-cost improvements such as installing programmable thermostats, door and window caulking and foam gaskets over light switches and electric outlets to reduce air infiltration can be a big help. If air infiltration around basement rim joists or attic floor joints is an issue, a low cost solution may be a few cans of expanding foam insulation may be your ticket. If your energy auditor suggests big ticket items need replacing, such as a new furnace or air conditioner, ask if your electric or gas utility company offers a rebate programs to help with the purchase. Develop a 5-year plan for upgrading your home and making it more energy efficient. That will help you focus on the reasonable, appropriate and cost effective goals.

Jan April 21, 2009 · 1:47 am

As a possible answer to abby, many states have weatherization programs for low income people. If you meet the income guidelines, they will do a lot for free.

Start searching your state energy and environment agencies or call your local energy supplier and they may be able to tell you who to contact.

Holly Martin April 21, 2009 · 9:17 am

Yes, weatherization may give you the best bang for your buck, but for those of us with limited time and budget, the lowest hanging fruit is light bulbs….After installing about 30 energy efficient bulbs in my home, I saved an average of $48 per month on my electric bill over the next three months. My e-book, designed to help others realize similar savings, is available at //www.EnergyEfficiencyExplained.com.

PeggyinToronto April 21, 2009 · 9:29 am

You asked – “Are you a mad scientist cooking up some other energy improvement technology in your garage, or an energy minimalist living life off, or nearly off, the grid?”

Actually, we are doing the opposite. We’re putting our energy usage on the web, in real time, for anybody to see. In addition to having an audit,(big wake up call!) the EnergyCircle house has been monitoring energy usage using a whole house monitor. Simply knowing how much electricity you are using (and how much it costs) makes most people start reducing use. That has certainly been true of the EC family. In honor of Earth Day, we’re putting the founder’s usage log on the web for anyone and everyone to see using a direct link from the monitor to the Internet. Will going public make the EC house even more efficient? Will watching the EC household – 4 humans and a dog – spike and dive in real time make others think about usage? We’re going live on the grid to find out. //www.EnergyCircle.com.

Vanessa April 21, 2009 · 9:48 am

Tom –

Thanks for your informative posts! We purchased our 1950s home in Dec 07 and have been going through it to improve our energy efficiency. We started by adding insulation in the attic, and have been going through caulking and weatherstripping. We even purchased a new boiler to replace the original dinosaur in the basement. I think we’re ready for an energy audit to see our next steps, so it’s been helpful to see what your experience is like.

We have explored energy alternatives (small wind turbines, solar) but financially they are out of our means. We also found that it’s best to reduce our energy usage as much as we can first, before taking the plunge anyway. Our next project is to install a PowerSave, which makes our electrical system run more efficiently, reducing overall usage by 30%. This is a big deal in a state (Pennsylvania) that is going through electricity deregulation. We expect our electricity expenses to jump at least 35% next year.

Patrick April 21, 2009 · 10:13 am

Hi Tom- please be sure you have adequate fresh air for heating system combustion and be sure the living spaces are isolated from the basement or wherever the potential fume leaks are. You must have a carbon monoxide alarm.
Take care, pat

Bruce Ray, Johns Manville April 21, 2009 · 10:50 am

I am a bit disappointed that you made your insulation decision without mulling over the different types and their advantages and disadvantages. I see that there are some comments on loose fill cellulose vs. loose fill fiber glass. Here are some comparisons:

Settling over time
Cellulose Insulation – Settles about 20%
Fiber Glass Insulation – Does not settle

Fire retardancy
Cellulose – up to 20% by weight added fire retardant chemicals – an average 1200 square foot attic insulated to R-38 with cellulose insulation would introduce up to 300 pounds of fire retardant chemicals into the home
Fiber Glass – Inert fibers naturally fire resistant

Fire hazard
Cellulose – Regulated by Consumer Product Safety Commission as Fire Hazard so must be treated with fire retardant chemicals
Fiber Glass – No fire hazard

Weight
Cellulose – Much heavier (including fire retardant chemicals) – amounts above R-30 over ½” drywall can cause sagging
Fiber Glass – Much lighter – up to R-70 over ½ inch drywall without sagging

Mold/fungus growth
Cellulose – Must be heavily treated to protect it from mold growth
Fiber Glass – Inert fibers naturally mold resistant

Product safety data
Cellulose – None
Fiber Glass – Many peer-reviewed scientific studies in animals and human epidemiology study of nearly one million person-years of exposure

Cost
Cellulose – Tends to be cheaper per pound but more required to achieve given R-value
Fiber Glass – Tends to be more expensive per pound but less is required to achieve a given R-value

Bruce Ray
Johns Manville

Bruce Ray, Johns Manville April 21, 2009 · 11:01 am

Dan – you referred to Greenguard in your comment. People need to realize that the Greenguard certified “low-emitting” products programs are not intended for residential environments. And there is controversy about whether the Greenguard programs are adequately health protective.

The Greenguard low-emitting certified program uses a ventilation rate (i.e., assumed dilution air for indoor air pollution) for commercial office buildings with continuous mechanical ventilation equipment. The Greenguard for Children and Schools follows California’s ES-1350 standard for a classroom environment, again with higher ventiliation (dilution) rates not present in most homes.

Unfortunately, this critical difference is frequently not noted or glossed over by manufacturers who want to promote thier products as low-emitting in a residential environment.

The difference is important as making homes more energy efficient is largely about making them tighter and tighter homes can be more prone to indoor air pollution. The best solution to indoor air pollution is not dilution (real or assumed) – it is pollution prevention. California EPA recommends building matrials, including insulation, made without added formaldehyde.

Bruce Ray
Jonns Manville

Dan S. April 21, 2009 · 1:32 pm

Thanks to Bruce Ray for clarifying the importance of ventilation rates when evaluating insulation. When I looked at the MSDS for the Knauf Insulation – called Jet Stream #65997-17-3, it was hard to tell if the seemingly low levels of emissions are acceptable in a residence. I would be more comfortable with a formaldehyde-free product.

Dan S.

Russ Finley April 22, 2009 · 1:10 am

You don’t need to pay for a blower-door test. You can seal leaks without testing for them. You also don’t need to pay to have someone look at your house using infrared imaging. That’s also just a gimmick.

Installers will always try to talk you out of fiberglass because it has a lower profit margin for them.

It will be interesting to see how this impacts your heating bills next year.

//biodiversivist.blogspot.com/2009/03/weatherization-nation-how-i-reduced-my.html

Bob April 23, 2009 · 8:08 am

Bruce-

I think your employment skews your understanding of what really happens out there. I am an installer who stopped using fiberglass because of the lack of performance that it has compared to cellulose. Allow me to respond to your accusations against cellulose.

Settling – In an attic, cellulose settles about 10% but it in no way effects the real R-value. Fiberglass may not settle but the real R-value is lower when air is allowed through it. I can’t tell you how many houses I have fixed with ice daming because it had fiberglass allowing the heat from the house to flow through it.

Fire Retardancy – Cellulose adds about 15% borate (a natural and harmless mineral to humans). Borate is simply the same thing as Borax that our grandmothers had under their sink. The borate does not add any significant weight that can cause sagging. I have done hundreds of attics and NEVER had a sagging issue.

Fire Hazard – Cellulose has hundreds of UL listed fire walls that actually prolong the time a fire takes to spred. Fiberglass melts like a plastic bag in a bon fire exposing the studs to the fire. I have talked to many of my firefighter friends who say cellulose insulated homes are easily contained compared to fiberglass.

Mold/Fungus growth – I know from experience that when I have removed a wall with fiberglass in it, there was alot of mold especially around the light switches and outlets. Because air passes through fiberglass (which can’t be good for heat savings) the moisture and dust particle flow with it. That’s what mold spores feed on and now you have a problem. Cellulose stops the air flow and does not allow moisture and dirt (food for the spores) to travel through – thus keeping the house warm and free from mold.

Product Safety – Cellulose is a simple product made from Borax and recycled paper. It is completely safe and is tested by US Labs – it is stamped on the bag. When I installed fiberglass, I noticed the fiber particles in the air and always thought it was a very bad thing.

Cost – Fiberglass is cheaper by the job – no doubt. But it’s the long term effectiveness where cellulose is a hands down winner. Fiberglass is a filter – the R-value rating is given as a result of a lab test that does not introduce air movement. I don’t know about your house, but I have wind where I live. The “vapor barrier” required is a menace as it is on the wrong side of the wall 6 months out of the year in the northeast and moisture can develop as condensation and cause mold and rot as it runs to the studs and baseboards. Again, because cellulose does not allow air throught it, it does not have these issues. The typical return on investment of a cellulose house is about 2-3 years.

These are the real facts. There is so much mis-information about cellulose it is a shame. Cellulose is a great product. In fact, on the green side of things, it uses less energy to produce than fiberglass or foam by at least 10 fold. It has a higher recycled content and saves up to 40% more on your utility bill than fiberglass!

If you want the real answers, ask a weatherization expert.

Brian Robinson April 29, 2009 · 9:18 am

Please help inform consumers about the reality of energy auditing & thermal imaging so improve the credibility of the audit process & maximize this opportunity to help lead homeowners toward a more sustainable energy future.

An IR imaging device such as the FLIR shown in your video cannot “see cold air”, nor can it see into a wall or other cavity. What it can do is represent different surface temperates in various colors. This allows the operator to “see” the effect of outside air cooling the interior surface to help locate building shell air leaks rather than seeing cold air.

Also, I hope that the insulation contractor actually foamed the entire the sill plate / foundation junction when foaming the box sills & band joist cavities in the basement as substantial leakage is often present at this intersection as well.

In fact, they probably should have recommend to insulate the basement walls to 18″ below ground level to bring it into the conditioned space since all your concrete foundation walls have an R-value of about 1, equivalent to a 1″ thick pine board. The box sill / band joist cavities were actually more well insulated (R-1 for each 1″ of wood) than the walls though probably less well air sealed.

Please also follow up with a post weatherization audit to document the effectiveness of the work performed. I highly recommend a “performance based contract” to all our clients where the consumer only pays for documented results not installed products. The reason being all the good intentions and great products in the world are a very ineffective substitute for proper application. Remember the goal was improved comfort & energy savings not installed foam or cellulose. Measure & pay only for progress achieved toward the attaining the goal not attempts toward that goal.

Lets hold the industry/installers accountable to a high set of standards so consumers will have increased faith in the process & thus be encouraged to make the investments in weatherization.

For expert advice, please consult one of the building science gods, Joe Lstiburek at //www.BuildingScience.com.

Brian Robinson
//www.EconergyAudit.com
Maine Certified Energy Auditor
Maine Certified Weatherization Technician

Brian Robinson April 29, 2009 · 9:31 am

For a terrific free video about the pros & cons of cellulose vs. fiberglass visit parpac.com. You will be blown away the fraud perpetrated by the fiberglass insulation industry. In fact, their own installation recommendations now only recommend fiberglass be installed in air sealed six sided building cavities not in open ceiling or floor joist cavities.

Brian Robinson
//www.EconergyAudit.com
Maine Certified Energy Auditor
Maine Certified Weatherization Technician

Dwight McLeod July 29, 2009 · 5:04 pm

Tom,
I spent money to buy low e windows and lowered my consumption of fuel by about 40%. Only to have Con-Edison slap a surcharge on our lower usage that equaled the price of the poor performing windows. When is this Green Revolution going to hit the fat cats that profit from the oil and energy cycle.

Evelyn August 31, 2009 · 3:09 pm

My builder did a good job with insulation and windows. I just added a tankless water heater (1400 installed) and am currently working on my solar array for 1st quarter 2010.

John Barksdale January 9, 2010 · 8:33 pm

I love the article and videos Tom. I’m a “dollars and sense” man, so I’d love to see an itemized list of improvements made and the cost/payback of each energy efficiency retrofit.

Unfortunately the green craze is going overboard. In Austin Texas, an energy efficiency audit is mandatory at the point of sale for single family homes that are more than 10 years old. Condominiums and mobile homes without a permanent foundation are exempt. The amount of electricity a homeowner purchases and consumes is none of Austin Energy’s business.

Incentives and rebates for energy efficiency upgrades, not mandatory audits like the Energy Conservation Audit Disclosure ordinance that violate property-owner rights are the answer.

John Barksdale
//stoptheaustinecad.blogspot.com
//www.youtube.com/watch?v=KxbT2T-mfkA