Archive for December, 2008

Granite vs Marble

Monday, December 8th, 2008

Many people want to know if marble or granite is better for countertops in their kitchens and bathrooms. After all, both are beautiful materials, both lend beauty and elegance to any home, and both are available in many varieties to suit any preference.

On the other hand, there are a few differences between these two stones that you should seriously consider before choosing between them. Rather than making this decision for you, why don’t we let the facts speak for themselves.

The Pros and Cons of Marble

First of all, Marble is a metamorphic rock. Its basic ingredient can be found everywhere from limestone to baking soda, from

calcium carbonate to lime (white wash). The basic ingredient goes by many other names depending on its application and its form. Limestone, a sedimentary form of calcium, which is found naturally in the earth, undergoes intense heat and pressure within the earth to be formed into what we know as marble.

This rock can also be exposed to heat and grinding to become a filler ingredient for medications, writing paper, plaster of

Paris, lime (white wash), and cement hardener. This means that marble, although beautiful and durable, is porous and very easily destroyed by any type of acid, heat, or water. Even with a seal coating applied religiously every year, no types of chemicals may be used to wash the countertops made from it. It cannot take much abuse from water, acids such as lemon or orange juice, or high heat from pans. These will all destroy the seal coating and the marble beneath.

Since marble is so porous, it is also easily stained. One single scratch can allow liquids or even oxidation from the air to

leak under the seal coating and stain the marble. This doesn’t mean that it should not be used. Marble is ideal for use in low traffic areas or for sculpting amazing art out of. But for the high traffic use of a kitchen countertop, a floor, or a bathroom countertop, marble just means high maintenance.

The Pros and Cons of Granite

Granite is also a metamorphic rock. It is a composite of quartz, silicon, feldspar, mica, and several other minerals. It too

is formed under high pressure and heat. It is also just as beautiful. It is not as porous as marble and is resistant to chemicals and acids. The presence of quartz in granite provides the granite with a durability and hardness unlike that of soft marble.

Granite is more stain resistant and wear resistant than marble. While it is not perfect, granite holds up far better in high traffic uses such as counter tops and flooring. With a proper seal coating on granite and with proper care, granite will last for many years without scratching, staining, chipping, or wearing away. If properly cared for, granite may not need to be resealed every year.

Granite can also be quarried locally. This means that, unlike marble, granite will not have to be shipped from South America or Europe. Granite can be quarried in Arizona, New Mexico, and some northern states. Granite is also easier to ship. Even if the granite you select comes from South Africa, China, Asia, or Europe, there is more granite available. This means it’s easier to obtain and less expensive to use.

Ultimately It’s Up To You

Whether you choose granite or marble is up to you. When asked which one is better for the high traffic use of countertops, the answer should be clear, granite will simply hold up better. When properly cared for under normal conditions, granite is easier to care for and is resistant to staining, chemicals, heat, and fracturing. Granite is available in more colors and patterns and can be custom ordered for less than marble

Choosing the right size Central Air Conditioner

Monday, December 1st, 2008

Choosing the right size Central Air Conditioner
As with sizing furnaces or boilers, it is important to have an HVAC Contractor perform a load calculation before you decide which size air conditioning system to buy. If you install an air conditioner which is too large, it will cycle on and off too often, substantially reducing the efficiency of the system. Too small, and your air conditioner may not be able to meet the demands of a hot, humid day.

The industry standard load calculation is called the Manual J calculation. It takes into account the size of your house, the amount of insulation installed, the square footage, and a host of other factors.

SEER ratings
SEER (Seasonal Energy-Efficiency Rating) is a comparative indicator of an air conditioner’s efficiency. The typical central air conditioning system of the early 1990s had a SEER of about 6. It rose to 10 early in this decade. All central air conditioners manufactured since January 23, 2006 must have a SEER of 13 or higher. Older unsold units were grandfathered under this government regulation. At this point, if any of those units are still available, they represent false economy. Guides that recommend them as a budget alternative are out of date. Current central AC units have SEER ratings that range from 13 to 23. The rating can be easily understood as a percentage. For instance, a 14 SEER air conditioner is 40 percent more efficient than a 10 SEER air conditioner.

Capacity and efficiency are major factors in the price of an air conditioner. A more efficient unit costs less to operate. We found worksheets for estimating how much, but electricity prices throughout the United States change often and usually rise. If you currently have gas or oil heat and a central air conditioner, you can compare your summer and winter electric bills to get an idea of how much more electricity you use during the summer.

Air ConditionerExperts say the average life of a central air conditioner is 15 to 20 years. If yours is that old, they say the break-even period is short if you replace it because your new system will be much more efficient by default. When announcing the current SEER standard, Energy Secretary Samuel Bodman asserted, “Homeowners who choose to buy more energy-efficient air conditioning systems will realize significant savings in their energy bills and greatly reduce their energy use.” The Rocky Mountain Institute encourages, “Buy a new air conditioner if your existing model is more than ten years-old, as such models are often only half as efficient as contemporary models.”

The value of efficiency much beyond 13 SEER is somewhat controversial. Government and environmental organizations advocate for the highest efficiency you can afford. The American Council for an Energy-Efficient Economy (ACEEE) recommends SEER of at least 14.5. The professionals at AllExperts.com disagree about the value of high-efficiency air conditioners. Some point out that more expensive units may have other virtues, such as a longer warranty. The majority of experts believe that a 13 SEER air conditioner is the best value for most people (but see the Rebates section below). If you can afford greater efficiency, however, you will use less electricity and make a contribution to the environment, but you may not recoup the extra cost in energy savings. Be aware that experts say an air conditioner must be connected to an appropriate coil to achieve the published SEER specification. If you are replacing an existing system, make sure you get a new coil.