Green/Eco Remodeling, Contracting & Construction- St Louis Missouri

Many people do not think of Indoor Air Quality as a “Green” concept.  If you think about it though, reducing the contaminants in the air we breathe plays as important a role in our quality of life as decreasing the trash we generate or the energy we consume.  The more that we crowd our air with unwanted contaminants, the less clean, usable air we have left to breathe.  In a confined interior environment, the opportunity to find clean air to breathe is greatly reduced because of the limited space and the cleansing of the existing air.  If we can reduce the contaminants that are introduced into an interior environment, then we have less to purge in order to make the air “safe” for breathing.

Definition:

Contaminants that are released into the air are called Volatile Organic Compounds or (VOC’s).  These are a large group of carbon-based chemicals that will evaporate at room temperature (Minnesota-Health).  Several important characteristics of VOC’s are:

Common Sources:

There are many consumer products that release VOC’s into the air.  Some of the everyday sources are:

One of the largest sources of VOC emissions is painting.  In fact, the only source of VOC’s that is higher than painting is automobile emissions.  The reason that paint is such a large source of VOC’s is due to the chemical process that occurs when painting.  The process is due to the connection of the three components of paint.  These are:

Solvents are the largest contributors to VOC’s emissions.  The solvent evaporates quickly after the painting process so that only the pigment and binders are left on the wall.  It is important to note that the level of VOC emissions immediately following painting can be 1000 times higher than standard outdoor levels.  Even though VOC levels are high immediately after painting, we need to realize that they will continue to emit for years to come.  In fact, it is possible that only 50% of the VOC’s will be gone after the first year (Howstuffworks).

Exposure Problems:

Decreasing VOC levels is important because they have many adverse and harmful effects on our health (Minnesota-Health). 

Short term exposure can result in:

Long term exposure can cause:

Solution:

We can limit the problem of VOC emissions by using products that are low in VOC content.  The area that we can have the most impact is with our paint products.  No-VOC paints have fewer than 5 grams of VOC’s per liter.  Low VOC latex paints must have levels less than 250 grams per liter while the majority has less than 50 grams per liter (TreeHugger).   It is important to remember that these measurements are taken before pigments have been added which can increase the VOC content by as much as 10 grams per liter (Howstuffworks).

When using these low VOC products, remember that they will not react the same as the high VOC products that you are used to.  Some common differences include:

Conclusion:

Using low VOC products is extremely beneficial to the micro environment in our homes and the larger environment around us.  The best way that we can reduce the emission of VOC’s after limiting the use of our automobiles is to change the paints that we are using.  Using low-VOC paints will significantly reduce our exposure to harmful chemical vapors and will increase our chances for a healthy body.  Reducing the use of other high VOC products such as cleaners, adhesives and caulk will help to improve air quality but to a much lesser degree.  In the end, every effort that we make, no matter how small, is important in our challenge to decrease our carbon footprint and sustain our planet for the next generation.

Problems with Fiberglass Insulation

Insulating your home from the outside elements plays a large part in determining your energy bills each month.  As much as 90% of the homes in the US are insulated with fiberglass batt insulation.  For many years, fiberglass has been the standard product of choice with builders and remodelers.  The problem is that fiberglass insulation has several downfalls.  These include:

Solutions provided with Blown Cellulose Insulation

Blown Cellulose insulation is fast becoming a popular alternative to Fiberglass insulation.  Blown Cellulose has been in use for many years but in limited amounts.  The advantages to blown cellulose are significant.  These advantages include:

Discussion of Benefits

Cellulose is made of 80% post-consumer recycled newsprint.  A 1500 square foot home insulated with cellulose will recycle the amount of newspaper that an individual would generate in 40 years.  If all new homes were insulated with cellulose, they would use up over 3 million tons of newsprint each year.  Yet fewer than 10% of the homes built are using cellulose insulation.

Cellulose is excellent in preventing the flow of air through a wall system because of its ability to fill voids when installed.  The moistened cellulose packs tightly around all electrical boxes, wiring, plumbing pipe and any other obstacles in the wall cavity.  This tightly packed product will reduce air infiltration through the wall by 36% to 38%.  This reduction in air flow can be as high as 70% in conjunction with a good caulk and seal package.

Cellulose is treated with chemicals to increase resistance to fire.  These products along with the densely packed cavity make it almost impossible to start a fire in the wall cavity.  Without air movement in the wall, any flame that tried to ignite would have difficulty acquiring oxygen.

Cellulose insulation requires 8 times less energy to produce when representing cost per installed R-value unit.  Some experts claim that it requires 200 times less petro energy to produce than fiberglass insulation.

Densely packed cellulose produces and R-value of 4.0 per inch of thickness compared to Fiberglass batts which only produce and R-value of 3.2 per inch of thickness.  In a 2x6 wall that has a cavity depth of 5 ½” the cellulose will produce an R-value of 22 compared to the fiberglass at 17.6.  Over the exterior of your house, this makes a huge difference in heat transfer through the walls (UMass Amherst).

Moisture Concerns

The one question that many people have about blown cellulose is the issue of the moisture that is required to make it “stick” in the stud cavity of a new home.  It is necessary to allow the walls to dry for several days after installation.  Installers can return to check moisture levels prior to covering the walls.

Initial installations of blown cellulose need to reach moisture content lower than 25% before they are covered with drywall or interior finishes.  Chemicals on the cellulose will keep mold from cultivating while the product is drying.  They also protect from future mold, as air moisture passes through the cellulose during the normal course of heating and cooling. 

The question of an interior vapor barrier is a popular topic of discussion.  According to the majority of literature on the subject, a vapor barrier is not required on the interior of the wall.  By not installing an interior vapor barrier, the moisture that naturally accumulates in the wall cavity during the life of the house can pass out into the home and be eliminated.  The cellulose is treated to resist mold and is very suited to the minor humidity accumulation that occurs in this process.  A vapor barrier could restrict this flow of moisture passing out of the wall and contain it in the wall cavity, possibly causing moisture problems. 

Conclusion

Blown cellulose insulation is a good weapon in the fight for energy conservation.  It provides excellent resistance to heat transfer and enables us to reuse one of our most popular recycled products in a positive way.  The added cost to use blown cellulose is usually recovered in 3 to 4 years, which makes it a very affordable way to “green up” your home.  Consider using cellulose in the “wet” form for your next new home project or using it in the “dry” form to improve your existing home.

The average annual operating cost for a standard hot water heater is $500 or higher.  This is for a 50 gallon water heater with a life expectancy of 8 to 12 years.  A solar hot water heater, on the other hand requires an annual operating cost of only $50, has a capacity of 80-120 gallons and has a life expectancy of 15 to 30 years (SolarDirect.com). 

The payback for a solar hot water system is approximately 7 years.  This is due in part to the tax credit that is available from the government.  This tax credit is for 30% of the system cost and eligibility has been extended to the year 2016.  The system cost in a new home or existing is approximately the same.  The cost for an 80 gallon tank using 1 to 2 solar panels is approximately $5400 and the cost for a 120 gallon tank using 2 to 3 panels is approximately $7000(MissouriSolarLiving.com).  

Another payback from solar hot water heat is the environmental benefit.  The use of solar power reduces the use of fossil fuels for heating purposes.  Carbon dioxide emissions can be reduced by approximately 2000 lbs per year for each solar hot water heater.  Nitrous oxide emissions can be reduced by approximately 1 lb per year for each solar hot water heater. 

Theory of Solar Heating and Terms

Solar Constant - The rate of solar energy hitting the earth’s atmosphere assuming no loss is 429.2 BTU’s per hour per square foot.  This energy if collected for three hours without any inefficiency could power the entire earth for one year. 

Insolation - Since the earth’s atmosphere filters out much of the sun’s energy, the most efficient we can be inside the atmosphere is about 70% or 320 BTU’s per hour per square foot. 

Wavelength Conversion - Solar radiation is a stream of short wavelengths that becomes thermal energy when it is absorbed.  The thermal energy is composed of a new stream that is wavelengths that are 10 times longer. 

Greenhouse Effect - Many materials like the atmosphere will allow the passage of the shorter wavelengths of light but will not allow the returning longer wavelengths of heat to exit.  This “Greenhouse effect” is used in many solar collectors to maximize thermal energy.  

Black Body - Materials that are good at absorbing radiant energy and re-radiating that energy are called black bodies.  The most efficient black bodies can re-radiate up to 96% of the energy that arrives. 

Absorber - An absorber is that portion of the solar collector that contains the black body.  It is usually a flat black surface with a high absorbance rate.  It is responsible for converting the radiant energy into heat. 

Flat Plate Collector - This is the most efficient type of collector in areas where the temperature can get below freezing.  It is made of an absorber, heat exchanger and also includes insulation, glazing, plumbing and the casing to enclose the entire assembly.  These collectors are usually set up facing to the South and tilted at an angle to catch the most amount of radiant energy.  The other advantage to Flat Plate Collectors is that they can absorb diffuse radiation that is produced on cloudy days. 

Convection - This is the basic form of heat transfer that occurs in a solar collector.  A cool liquid or gas is heated in the collector and then moves away to be replaced by more cool material.  This simple process allows for the continual heating of water during times when radiant energy is available (SolarExpert.com/Heat-theory). 

Basic System Operation

The solar hot water system can be either a one-tank or two-tank system.   

A One-tank system has one tank that is heated from the solar system as well as the conventional heating system. 

Two-tank systems have one tank that only heats water using the solar heat system.  This water is then transferred into a second tank that can be heated using a conventional heater if needed.

In an existing home scenario, there is a cost saving option that is available.  In certain circumstances, the existing water heater can be integrated into the solar hot water system.  The cost savings in utilizing the existing hot water heater can be as high as $800.  There are a few basic requirements that are necessary:

Existing electric hot water heaters can be utilized in a one tank system to work with a solar hot water system if thery are less than 5 years old and are at least 80 gallons.  The reason not to use electric hot water heaters older than 5 years is because they will have deposits in the bottom of them that can cause problems in the functioning of the solar hot water system.  If they are smaller than 80 gallons, they do not have enough capacity to be retrofitted to include the solar system.  With the electric hot water heater, the tank will be retrofitted to act as the storage tank and the back up heat source in one. 

Existing gas hot water heaters can be used as the back up in a two-tank solar hot water system.  A separate solar storage tank is installed and then feeds in to the cold water supply of the gas back up heater.  The back up heater will only ignite if the heated water from the solar tank cannot keep up with demand.  The problem with the two-tank system is that it requires additional space that some people may not have in their basements.  The gas hot water heater can be an older heater and can be as little as 50 gallons since it is only being used as the backup.

In warm climates, the cold water is transferred to the roof using a pump and lines to the solar collectors on the roof.  The water is heated and then is returned to the storage tank.  The water from this solar tank is now the supply water that goes into the conventional water heater portion of the system.   

In colder climates, a non-freezing transfer fluid is pumped to the roof and passes through the solar collectors.  It returns to the water heater and then gives off heat through a heat exchanger inside the water heater (EnergySavers.gov).   

The conventional portion of both systems will only ignite if the solar portion cannot keep up with the demand for hot water.  Most solar systems will provide 70% of the required hot water.  The burner element in the conventional portion of the heater will take care of heating the other 30% of the water (SolarExpert.com). 

Conclusion