Wednesday, June 6, 2012

How Does Your Home Perform

Here are some tips based on inspecting Hundreds of Homes
installing ventSize Matters
An efficient heating system needs to be sized properly, yet most residential contractors don’t take the time to do a Manual-J heat loss calculation or Manual-D duct design calculation to make sure that the system is designed correctly.  Improperly sizing the system will mean years of discomfort and inefficient energy utilization.  It is good to ask questions. Ask your contractor or their heating subcontractor, to provide you with copies of their calculations. Then go find an outside heating contractor to evaluate and verify what they gave you.
Bigger Is NOT Better
Bigger is not better when it comes to sizing an air conditioner; a properly sized air conditioner will operate more efficiently and will not subject occupants to extreme temperature changes between “too cold” and “too warm”.  It is so easy to be “sold” a big air conditioner as we tend to equate “big” with “better”.  In reality a properly sized air conditioner running over a longer period of time will operate more efficiently, and will be more comfortable than one that turns on and off all the time.  If you have an Air Conditioner that does this “short cycling”, then chances are it was oversized when it was first installed.
installing vent
installing ventThink System, not Furnace
Your heating system is more than your furnace, it includes the furnace, filtration, duct system, and the envelope of the house. No matter how efficient a furnace is, if the ducts leaks and your home leaks - you are wasting energy. 
Duct Tape: NOT for Ducts!
In older homes air ducts were sealed with duct tape.  Like most tapes, after a few years the adhesive wears out and you no longer have a sealed duct system. To make matters worse, in some homes nothing but tape was used to seal the duct system.  The ducts are the delivery system of conditioned air through your home. When we test duct systems, we typically find 30-50% leakage, meaning that only a portion of  expensively heated or cooled air is actually being delivered to your home, the rest is leaking out in the attic, walls, or crawlspace.  Your ducts should be sealed professionally and then pressure tested to confirm that duct leakage is 6% or less than total system airflow. Most heating contractors do not have the training or experience to test and seal ducts, but the good ones do.
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Sealed Ducts
Duct leakage is more than wasteful; it also can create pressure imbalances in your home.  I won’t go into the details here, but if you have leaky ducts in the crawlspace or attic, this can draw pollutants into your home or can cause back drafting of indoor combustion appliances. Again, ducts needs to be tested and sealed.
Clean Ducts
Also regarding ducts, I cannot tell you how many times I have found sawdust, construction debris, coke cans, Doritos bags, water, and other construction debris in brand new ducts in brand new homes.  Once the duct is installed, it should be sealed to prevent the entry of all the things you don’t want to be breathing for the next 30 years in your home.
installing vent
installing ventFurnace Filters
Most filters were designed to protect the furnace from debris, they were not designed to protect our lungs from fine particulates.  Go look at your furnace. If you can see your hand through it, then you know it was designed to protect your furnace, not to filter particulates to protect your lungs. Have your HVAC contractor install a easy to access, disposable 4-6 inch, MERV 13 or better filter. I don’t believe that cutting edge, expensive, UV, filtration equipment is necessary.  But ask questions, don’t just accept the default. 
Noise Issues
Not related to the furnace, but still important is the sound of appliances.  Believe it or not, kitchen range hoods do not have to be noisy.  You can now purchase remotely located fans that can be placed in the attic that will be very quite. If you don’t ask, you won’t be offered this option.  For bathroom fan, Panasonic has a terrific line of very quiet bathroom fans called “Whisper Quiet”
installing vent
installing ventDon’t Mistake Leakage for Ventilation: Ventilation air in a home is important.
Pollutants, humidity, odors, and chemical compounds will accumulate in a home that is not ventilated properly.  Homes used to be so leaky that getting enough ventilation air was never a problem.  You will hear contractors say a home can be “too tight”. This is old school.  A better approach is to “seal it tight, then ventilate right”.  Rather than leaving ventilation to chance penetrations in a structure, all penetrations should be tightly sealed and the home should be pressure tested with a device called a blower door to confirm that proper ventilation rates are achieved.
Insulation, done well, is perhaps the single most important, and least expensive upgrade we can make to make a home energy efficient.  Unfortunately, insulation is often not done well.  There a myriad choices an approaches, from fiberglass batts, dense-pack or loose-fill cellulose to closed cell foam insulation.  Closed cell foam insulation is expensive, but ideal because it provides both a thermal barrier and an air barrier. Insulation is both art and a science. The difference in price between a quality insulator and low-ball firm is peanuts when you consider the impact a poorly done insulation job will have on the long-term energy utilization of a home.  Start researching insulation solutions early in your remodeling or construction project.  It may even help to have an independent third party come in and verify that the insulation was properly installed. Also, prior to insulation the home should be pressure tested, air leaks in the building envelope should be identified, and efforts should be made to seal all gaps around plumbing and electrical penetrations between the attic garage, crawlspace and the home.
installing vent
installing ventAir Leaks
Improving the insulation in an attic is only part of the story: it is important to seal up air leaks between the attic and living space before adding insulation.
Recessed Lighting Fixtures
This popular architectural feature, are also a huge air leakage pathway between the home and the attic.  Air sealed canister light fixtures that are IC (Insulation Contract) rated should be used, but many contractors don’t even consider using them because they are a few bucks more expensive or they don’t know.
installing vent
installing ventIndoor Pressure Imbalances
Kitchen range hoods, indoor clothes dryers, and bathroom exhaust fans all contain powerful fans that can cause a tightly sealed home to become slightly depressurized.  This can create a safety issue when the negative pressure in home overpowers the natural drafting of indoor combustion appliances such as furnaces or fireplaces and can lead to the accumulation of toxic carbon monoxide, a byproduct of combustion, into the living areas of the home.  If your home has indoor combustion appliances, then a worst case depressurization of the home is advised.
Out of sight is out of mind, yet these overlooked areas of the home have a huge impact on the quality of air in a home.  Due to some basic physics and a phenomenon called “the stack effect”, hot air rising through the structure draws cool air into the home from the crawlspace. It is estimated that 30% of a home’s indoor air comes from the dusty, and frequently odiferous crawlspace.  If your home has a crawlspace, it should be designed for easy access for inspection and maintenance For new construction, there is no excuse for a crawlspace not to be well lit, dry, clean, free of debris and dirt. It should be covered with a wall-to-wall, sealed vapor barrier.  If you have a finished basement, then exterior water proofing, insulation, and drainage systems are important to be designed and implemented well.

Visit Sandium.Com today to schedule an appointment to determine how your house performs
installing vent

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