FAQ's

LaGrange Consulting does not contract out to do any home improvements. We are strictly a consulting company. However, over our years of experience inspecting homes and hearing customer feedback, we have amassed a list of quality installers who are knowledgeable and who care about quality and efficiency. We would be happy to share their contact information with you. Simply visit our referral website at www.PaulsHouse.com, choose the area in which you live and the contractor type you need and a list of preferred contractors will show on the screen.

Open cell foam is usually more suitable for residential roofline applications for several reasons, while closed cell foam is often more appropriate for commercial applications and for residential subfloor applications. Open cell foam is more flexible than closed cell foam. If you press on it, there will be a "sponginess" to it, while closed cell foam will be hard to the touch. Another difference between open and closed cell foam is that, when used at the roof rafters, if a roof leak develops, the closed cell foam will not allow the water to weep through the foam because it is a vapor barrier. This can lead to rotting of the roof deck before the roof leak is ever discovered. Open cell foam is not a vapor barrier, so it allows the water from the roof leak to weep through the foam to the space below. After the roof leak is repaired, the open cell foam can be allowed to dry and its thermal properties return, unlike other insulations that must be replace when they get wet.

Closed cell foam is often the best choice for subfloor applications because it is a vapor barrier and can block most moisture in the crawlspace from entering the home. Open cell foam will insulate but not block moisture from coming into the floor assembly. In addition to these differences between open and closed cell foam, open cell foam is usually less expensive than closed cell foam.

A vapor barrier is also called a vapor retarder; this is a material that retards the movement of water vapor through a building element (such as walls, floors, and ceilings). It is important to have a vapor barrier such as building wrap or tar paper on the exterior walls of your home to prevent moisture from getting into your walls and causing mold and rot to occur. The building wrap should be located on the outside of the stud between the sheathing and the stud wall.

Low E stands for “low emissivity” with regards to the glass on windows. Low E glass is coated with a microscopic, virtually invisible, metallic oxide layer that improves thermal performance. The primary function is to reduce the U-value by suppressing radiative heat flow. A secondary feature is the blocking of short wave radiation to impede heat gain. Low E is not just effective at keeping heat out in the summer, but at keeping heat in in the winter time. The lower the Solar Heat Gain Coefficient (SHGC), the better, when selecting windows. See this website http://www.efficientwindows.org for more information.

According to an LSU subfloor study (http://www.lsuagcenter.com/NR/rdonlyres/D33F711D-D...) the most effective subfloor insulation in our hot humid climate is rigid foam board with all seams and penetrations sealed. However, because the labor and material costs of installing rigid foam board is so high, it is often a good solution to insulate the subfloor with closed cell spray foam (which also performed well in the LSU study). Because this foam is a vapor barrier, the moisture-laden air of southeast Louisiana cannot move through the insulation to bring heat and humidity into the home. Also, the foam insulation will not fall out or become home to small animals that might like to live in other types of insulation. Fiberglass insulation is never a good idea when it comes to insulating the subfloor.

Air Conditioning Contractors of America (ACCA) Manual J is used primarily to size the HVAC system. It is an accurate procedure which can be used to estimate the heat loss and heat gain for conventional residential structures. Residential heating and cooling systems must be selected and designed to provide comfort conditions in all occupied spaces regardless of season. Temperature, humidity, air movement and ventilation must be controlled by the system. In addition, the system must perform these functions at maximum efficiency in order to minimize energy consumption. The load calculation is the basis for the system design. Loads must be analyzed if the furnace, condensing unit, fans, coils, ducts, and air terminals are to be sized correctly. Comfort, efficiency and reliability are closely related to correct sizing and selection of equipment. A load calculation must be made for each room so that the room cooling and heating requirements can be determined. This information is needed for machine selection, fan and duct sizing. A load calculation must be made for the entire structure in order to properly size the heating and cooling equipment. If there is no manual j-load performed, the system may be oversized and this can lead to moisture problems in your home.

When AC systems are properly sized, you can expect lower initial equipment costs, proper air flow, greater occupant comfort, longer equipment life, quieter equipment operation, greater operating efficiency, lower operating costs, and lower maintenance costs. Call LaGrange Consulting if your HVAC contractor cannot perform a manual J calculation to properly sized your AC system.

Storage tank water heaters are being made to be more and more efficient every year. There are two things to consider when making a decision between a storage unit and a tankless unit. Do you have a problem with not having enough space to fit a storage tank water heater? Also, does your family use large amounts of hot water all at once, such as two adults and three kids all taking showers in the morning from 6:00 AM to 7:00 AM each day? If you answered “yes” to either of these questions, then you may want to consider paying the extra money to install a tankless water heater. However, If you answered “no” to both questions, then, chances are, that you would not benefit from a tankless water heater any more than you would from a storage tank heater and the storage tank costs significantly less to purchase. When choosing between using a gas water heater or an electric one, consider that the electric tank is more energy efficient than a gas water heater. Also, if your water usage in your home is fairly predictable, the electric water heater can be attached to a timer to save even more money. The bottom line is that electric storage tanks are the most cost effective for the average homeowner.

While the information given on this website is good, solid advice, it is only the tip of the iceberg when it comes to building an energy efficient home in a hot humid climate. Each home is unique in its needs and design, so each homeowner needs specific advice on his or her home. Each house works as a system, so, for example, if the efficiency of the windows is increased, this could affect the way the HVAC functions. LaGrange Consulting can offer that specific advice on how to make your home work as a whole system, without causing problems on the back end. We can give you options so that you can make an educated decision on what is best for you and your home.