Home Energy Consumption

[Paul Tomasi]

The goal of the Home Energy Consumption portion is to reduce electicity usage and fuel consumption. In order to get things going each household should establish baseline data (Lyndonville Electric shows a one year usage chart on each bill). Take a look at your electric bills and heating fuel costs for the past year.

As a group, we should come up with ideas and ways to save electricity and fuel. Even though many of us are already implementing energy saving measures there is always more that can be done. Below is a list of things that can done to get started. As you think of additional measures post them here as part of this "discussion" for others to see.

*Turn off lights when not in use
*Swith to compact flourescent lighting
*Turn thermostat down
*Unplugging electronic devises when not in use OR putting them on a powerstrip
*Insulate home
*Flushing toilet only when necessary
*Utilizing weatherstripping to seal around leaky doors and windows
*Cleaning the heating coils on your refrigerator regularly
*Turn down the temperature on your hot water heater
*Do only full loads of wash
*Dry clothes on a drying rack

[Ryan McCue]

Identify heavy load items such as electric coffee makers and hair dryers
Replace old appliances
Service furnaces(change nozzles and filters)

[Sali Tetreault]

I use a french press instead of an electric coffee maker. I have to heat the water like I would for tea, but in the winter there is zero wasted energy as I have a wood stove. I just keep a teapot warm.

[James P Eniti]

In the East Montpelier Energy WalkThru training it was pointed out that one of the best return on investment things to do to cut energy use and fuel bills was to fix the air leaks. Drafts indicate air leaks that allow warm air out and cold air in sealing the leaks is usually cheap and reduces fuel use a lot.
The Drying rack was discussed and we were told that due to humidity issues (mold and such) we were not to recommend indoor drying racks. We were told that an outdoor line was good and effective even in the winter (this was a big surprise for some of us)
Note that computers use lots of power and should be turned off when not in use.

[Brad Vietje]

Good Points, James -- thank you.

Regarding computers, laptop or notebook computers use a lot less power than desktop models.

This may not apply to many in the transition movement, but Television and video equipment can have very large phantom loads. Satellite receivers and cable TV boxes are huge energy hogs! A satellite receiver uses around 30 - 50 watts when turned on, and about 30 - 50 watts when turned off! Only the LED seems to change. That's between 720 and 1200 watt-hours per day, every day, all year long, or 260 - 438 kWh per year. It all adds up -- to waste.

Dealers and installers often tell customers they should leave it on 24/7, so it can download new programming updates as they become available. This is to avoid any dissatisfaction from having to wait a few moments for the unit to re-acquire its signal and download any updates when you switch it back on. I tell them if they can wait 2 - 3 minutes a day, they can save a lot of electricity.

Color TV's left plugged in never really go "off", they just go on standby, and continue using power so we can enjoy color images and sound at an instant when we push the button on the remote... If people watch TV for 2 hours per day, the TV probably uses more power when off, than when it's on.

Often our largest environmental impact is not the electricity we consume, but the fossil fuels we burn for transportation and thermal energy. Besides transportation, our biggest energy gobblers are heating our buildings and heating our water. I recommend addressing conservation, insulation & infiltration -- then solar hot water.

Clear skies,

Brad Vietje
Newbury, VT

[Libre Drouin]

a suggestion for those who cannot (or should not) use an indoor drying rack. Try to do all laundry in one day, if using a clothes drier, this way drier doesn't have time to cool down and you will be using residual heat for next load.

[Andrew Graves]

Weatherstripping is particularly important because nearly 60% of heating losses are a result of unwanted air infiltration. Be careful not to make the house to tight, you need at least 1 air change per hour to maintain good indoor air quality.

[Brad Vietje]

Weatherstripping is huge, and can be the best bang-for-the-buck thing a homeowner or renter can do, especially in existing buildings. I agree with Andrew entirely on that.

The idea of "too tight" is one that may need a little more discussion, though. There are two schools of thought here, and new construction may differ from retrofit work.

One option is to leave enough leaks to provide fresh air, and the other is to provide mechanical ventilation with a heat recovery ventilator, or HRV. Passive air ventillation (well, leakage) might be preferred, since it never breaks, and doesn't require electricity to run. However, outside air leaking into your home is not always a good thing, so neither is a perfect solution.

If all air leaks are stopped up, the air gets stale, and air quality issues like mold and mildew can be real problems, and can make the place uninhabitable or unhealthy. In that case, either windows or vents must be allowed to introduce fresh air, or a mechanical ventilation device could be used.

If drafts are left, then every time there is unsealed combustion (woodstove, pellet stove, gas stove for cooking, or propane on-demand water heater), outside air is sucked into your home, which is not always good. First, as hot air goes up the chimney, cooler outside air comes in to replace it. This can defeat the purpose of insulation, since insulation does nothing to the air that goes around it, and result in more fuel needed to heat the structure. Another very common problem is that when the gas or propane water heater or furnace roars to life, the air they gobble can come right down the chimney, and either fill a room with cold, sooty air, or even blow out pilot lights of other combustion devices. This is a problem in many badly designed homes where the air sealing was not thought through, and energy-wasting fireplaces were built in the bedrooms for that cozy "Country Living" look. When the oven is roasting the Thanksgiving turkey, all the bedrooms are 40 degrees, and the furnace is just a roaring, since the oven, furnace and vent hood are pulling in cold air a lot faster than the furnace can replace it with burned-oil Btu's.

In leaky homes with wood heat, cold air entering leaks can mean frozen pipes near outside walls, cold floors near drafts, and the sensation that facing the woodstove is hot, while the side away from the stove is cold -- which is why high-backed stuffed (insulated) arm chairs were invented.

During certain times of year, allowing warmer, moist air to leak in to cool the home can lead to condensation on some surfaces inside the walls or the attic or the roof structure, which can cause wood rot, mold and mildew, and can offset the air quality we were seeking by leaving some drafts unsealed. For passive venting, I'd suggest sealing the heck out of your home, and a daily routine of opening certain windows for a while morning and night, so you know where the air is going, and don't have to wait for a problem to develop where you can't see it.

The other route -- HRV mechanical ventilation, works great, and saves about 80% of the heat in the vented air -- BUT -- requires electricity, and, as a motor-driven mechanical device, is certain to break down someday. In a post-petroleum world, where will the electricity come from, and how will you replace the motor when it fails?

Most of these units draw 40 - 160 watts, and newer units have ECM variable-speed motors, that run on very little power (around 15 watts) except when high speed is needed, such as for bathroom exhaust. This power can be made locally with a solar or hydro-electric system, but that will increase the size and expense of the system you need for your home. As for eventual failures, the parts most likely to fail are motors and switches. I advise people to pre-buy a replacement motor, and store it in a sealed plastic bag for whenever it's needed in the future. The company that made it may be long gone, and our economic system might not allow a German-made motor to be rushed to you via FedEx, so this can effectively double the life of an HRV unit.

Simce mechanical ventilation is required for new construction in most cases by the building code, there could be millions of failed units out there someday.

I'm facing all these issues right now, in my own home, currently under construction. I'm going for as tight as we can achieve, which may not be really tight, since it's a straw bale house, and using a small high-efficiency HRV unit, since that will work best with the solar heating system. I'm buying a spare motor for the unit (many have 2 motors, BTW), for that eventual failure, and figuring that when things really go haywire, we can always open a few windows for 30 minutes morning & night as a daily routine.

Leaky houses have been around for thousands of years, and in the past, just meant more fuel used, and warmer and colder areas of the home. With the population we now have, a small increase in fuel consumed to make up for cold air leaks can be a really big deal, and could mean worse winter air pollution or even more global warming if we're using more fuel than we need to (or not reducing that fuel use as much as we could). I'm all for the PassivHaus model which insulates- and air-seals the hell out of a building to reduce the heating and cooling loads, and provides fresh air via mechanical devices or carefully designed passive air ventillation methods.

Sorry for such a long reply!

Clear skies,

Brad

[Andrew Graves]

Wow, didn't think my response such an in depth discussion of ventilation issues. Lot of good thoughts. If you can afford it, I would totally agree, mechanical ventilation with a heat recovery unit is definitely the way to go. I can't imagine that the payback period can be more than three or four years. Even if you don't want to use a mechanical ventilation system, you can still do controlled natural ventilation, you certainly don't want air movement willy nilly through your exterior wall, roof and floor assemblies. Good points about combustion air requirements too, all fuel burning equipment requires it.

For vapor retarders which are installed on the warm side of insulation, 4 mil poly is no longer a good idea. You should use one with variable permeability to prevent wall cavity condensation from summertime reverse vapor drive. There is a 2 mil nylon product made by a national company that has good ratings. A good quality air infiltration barrier on the outside of the house is also key. Make sure that you tape the seams and use good quality peel and stick flashing around the windows and doors.

[Brad Vietje]

Hi Andrew,

My apologies for writing a novel -- probably not going to be a best seller!

I appreciate the advice on new products and methods -- I can tell you've really made a study of building performance. My own house is has straw bale walls, so I gather from people who know far more than I do that we want a wall that's more permeable on the outside than on the interior surface, so moisture can escape from the walls by evaporation to the outside. That's a very different strategy than a plastic film that creates a moisture barrier, so it's a new way of thinking for me.

After many years in the field, its beginning to look like Typar and other house wraps can do more harm than good in some situations, forming a drainage plane and condensation surface in some instances. There's a lot more to this than I ever thought. It seems the more I know, the more I know I don't know!

Clear Skies,

Brad Vietje,
Newbury, VT

[Andrew Graves]

Well I made the sometimes unfortunate choice of going into the building design business for living. I have been at it for 25 years now, mostly commercial work, but some residential.

The basic theory is that you want the exterior side of the wall assembly to breath and the interior side to be impermeable to water vapor. That is for northern climates. It is the exact reverse in Florida. In the winter time you are trying to keep warm moist interior air from getting into the wall or ceiling assembly where it can meet cold air and condense. If moisture does get into the wall you want it to be able to evaporate out and not get trapped inside through the exterior side of the wall. The cheap air infiltration barriers that go on the exterior of the wall assemblies are supposed to keep liquid moisture and air out of the wall but allow water vapor to leave. The less expensive barriers do not breath very well and can trap moisture in wall and cause problems.

The problem with vapor barriers that go on the inside of the walls, warm side of the insulation, is that they work well in the winter time, but in the summer time when the vapor drive is reversed, they cause problems. Hot humid summer air on the exterior moves into the wall assembly and condenses because the interior of the building is relatively cool. That is why they have introduced variable vapor barriers that increase in permeability in the summer so they avoid summer condensation problems.

I don't know what the permeability of the plaster coatings of the bales is, but I presume that it allows the vapor to diffuse through the bales at a slow enough rate that allows it move through the bale without condensing. I would be curious to read what the current theory is, or if there has been any problems with the bales having moisture problems.

[Brad Vietje]

Andrew, from what I read and from conversations with Ben Graham, the moisture movement issue is pretty well resolved for this climate. I want to put some moisture sensors in the walls for my own education, but Ben says he's not at all worried, since they've already collected plenty of data from stuff they've built. I gather that the key is to keep Portland cement and impermeable paints and varnishes out of the exterior walls, and pay attention to details that would not be a big deal in New Mexico or a dryer, hotter climate.

We'll be going for natural lime plasters on the inside, and I think you're right -- the moisture would slowly diffuse through the wall structure and evaporate to the outside.

The plasters are a clay/straw plaster against the bales, a clay/lime plaster in the middle, and a lime plaster on the surface -- then 3 lime washes. Ben or Ace McArleton would know lots more than I about how the layers function. I'm let to believe the clay plaster is the most water im-permeable, and more lime is higher permeability, but I could have really missed the details on that!

We're installing a small HRV unit to keep the air moving and provide fresh air, not certain yet if we'll spring for the ERV module. We'll have so much moisture at first from all the plasters that we may just get a cheap-o dehumidifier and let it run for the first 6 months.

Thanks for your sage thoughts,

Brad

[Libre Drouin]

Paul, I posted a blog w/ several more suggestions on energy conservation, they are from a book I have been reading. maybe after we all review the multitude of ways we can conserve we could all make it a goal to work on a couple we may not be using, and share at our next meeting?