Tuesday, May 31, 2011

California’s Complicated New Code

California’s newly adopted green building code will have a direct impact on home building in the state, affecting energy details, plumbing, ventilation, and management of the construction sequence. But for home builders, figuring out just what the code requires could be complicated.
How complicated? Here’s one indication: When the state’s Building Standards Commission posted a draft of the new code on its Web site, they color-coded the PDF document in seven colors: black, green, yellow, violet, blue, orange, and brown.
That’s because the new green standard is a combined code that modifies the regulations administered by five different state agencies. The rainbow-like online presentation is meant to help citizens sort out which parts of the code belong to which agency (or agencies) and which sectors of the construction industry the language affects.
(“What’s interesting is that they can only do that online,” muses Justin Dunning, program coordinator for California Green Builder (CGB), a voluntary certification program founded by the state builders group. “They don’t print the hard copies of the code in color—they print them in black and white.”)
As Dunning notes, only part of the new code is mandatory. Other parts are scheduled to switch from mandatory to voluntary in future years, while additional provisions will stay voluntary indefinitely, as the state considers whether to make them mandatory. In any case, only part of the code—the sections adopted by the state department of Housing and Community Development—will apply to home builders. As it happens, however, all those residential parts are mandatory—although they won’t all take effect at once, or even at the same time.
So how do builders locate the sections that apply to them? “The orange wording is the part that is specific to housing. And the best way I have found to read the code is to look for the checklists at the back. The HCD checklist [adopted by the state Department of Housing and Community Development] is basically the residential component,” Dunning says.
Here are a few of the big changes builders will have to make.
Water Conservation. The new code aims to cut indoor water consumption (which does not include landscape irrigation) by 20 percent. “They’re doing that through the fixtures,” says Dunning. “Basically, if you take all the fixtures and reduce the flow rate by 20 percent, that reduces the inside water use by 20 percent … For a three-bedroom house, that is going to save about 10,000 gallons of water per year.” This adds up to less than the 20,000-gallon reduction over existing code required in the California Green Builder program, Dunning notes, but the CGB program includes outdoor water use. (CGB builders achieve their outdoor savings by reducing the area devoted to lawns or water-loving plants, emphasizing naturally drought-tolerant plantings, and installing high-tech irrigation controls that respond to natural moisture conditions.)
Energy Conservation. As far as homes are concerned, the new green code amounts to adopting the next version of the California Building Energy Efficiency Standards, the state’s energy code, which updates in July 2009. “Depending on where you are in the state, that will represent a 15 percent to 20 percent increase in stringency over the old code,” says Dunning. This is mostly the result of a change in window heat transmission values, or “U values” required. (The default window U-value will drop from .56 to .40.).
Waste Management. Under the new code, builders will have to ensure that at least 50 percent of the scrap and waste material generated on site is diverted from landfills and recycled or re-used.
Indoor Air Quality. The new code requires exhaust ventilation fans for every bathroom and high-efficiency filters on all air-duct systems. In addition, it lowers the allowable volatile organic compound (VOC) content for interior finishes, sealants, and carpet, as well as the formaldehyde emissions from composite products such as particleboard.
Construction Moisture Control. To keep mold and mildew at bay, the new rule requires vapor barriers under foundation slabs, and it requires builders to ensure that framing lumber is drier than 18 percent moisture content before installing drywall.
Air-Sealing Details. Joints and openings that might allow uncontrolled airflow between building interiors and the outdoors or attic, such as window edges, duct registers, or penetrations for plumbing, wiring, and gas piping, must be effectively sealed against air movement.
Site Design. All projects—even on small scattered sites of less than one acre—must implement measures to control erosion and manage stormwater runoff.
Homeowner Education. A maintenance and operation manual must be provided as guidance for building occupants.
How much will this cost builders—and home buyers? Experience gleaned from voluntary programs may be helpful.
 “For a builder who is building to today’s code—not the new green code, but existing baseline code—to get up to what the California Green Building program requires, costs on average about $2,700 per house. More than half of that is the energy efficiency portion,” says Dunning. The most costly change in the new code for many builders, he says, will probably be the low-flow toilets: “You’re looking at about a $250 premium to go from 1.6 gallon-per-flush to 1.2 gallon-per-flush.” Tighter VOC requirements will involve little cost, according to Dunning. (The new lower standards are already in effect in Southern California, where smog problems have led to strict controls). Complying with moisture control measures is largely a matter of keeping lumber covered during construction, although during the state’s brief winter rains, the new rules may cause some schedule delays. As for waste management, says Dunning, most waste haulers in the state already provide recycling or salvage for 75 percent of the waste stream or better, exceeding the 50 percent code minimum.
In the end, says Dunning, the management challenge may be the industry’s biggest hurdle: “The hardest part may just be for builders to make sure that all this stuff is getting done correctly on site.”
But the increased attention to detail may also be the source of the greatest long-term benefit, he says. “The more that the curtain is pulled back and builders can see that hey, this stuff really isn’t that hard to do — then maybe you start getting them to ask, ‘Well, what else can I do that is easy, that might give me a marketing edge?’” Dunning says. “I think the raising of the awareness within the home building community is probably the biggest impact this green building code is going to have.”

Sunday, May 29, 2011

Energy Efficiency in Remodeling: House Air Leakage


All homes, through various connections to the outside, allow some amount of air leakage. The air exchange rate is highly variable from house to house, and within a given house, depending on construction details, environmental forces (wind and air temperature), and the use of exhaust fans, dryers, etc. Homes must have some minimum amount of air exchange in order provide oxygen for people and appliances, control humidity, eliminate odors, etc. While some homes experience problems due to insufficient air exchange, most homes leak more than necessary most of the time. Very few homes have the ability to truly control ventilation rates, which is only possible with a very tight house and some form of mechanical ventilation such as exhaust fans or heat recovery ventilators.
Older houses, in particular, tend to be very leaky. While the rate of air leakage can vary greatly, it is not unusual for all the air in older homes to be replaced once each hour. ASHRAE Standard 62.2 recommends a minimum ventilation rate of 1 cfm per 100 sq. ft. of floor space, plus 7.5 cfm per bedroom, plue one bedroom. For example, for a 2,500 sq. ft. home with three bedrooms, it would be (2500/100)+(7.5*4) = 55 cfm fresh air. Very energy efficient today may have leakage rates as low as 0.05 natural air changes per hour, using controlled mechanical ventilation to ensure occupant health and comfort.


Reducing air leakage from the house envelope and ductwork is typically among the most significant improvements that can be made to reduce energy use, as well as improve comfort, health, and building durability. In winter, less cold, outdoor air would replace heated air, reducing drafts and cold areas. In summer, more hot, humid air would be kept out of the house. Pollen, dust, and radon entry can be reduced. The potential for structural damage resulting from moisture being carried into walls or attics with leaking air would be decreased. Another potential benefit associated with reducing air leakage, as with most other upgrades such as improved insulation or windows, is the ability to downsize heating and cooling equipment when it is replaced.

Factors to Consider

One factor to consider is the ultimate level of tightness desired. With more extensive air sealing, some form of mechanical ventilation may become necessary. A general rule is that exterior-vented bathroom and kitchen fans, equipped with timers, can provide adequate ventilation for homes with 0.20 to 0.35 natural air changes per hour. Mechanical ventilation provides location-specific control of moisture and odors and lower energy use. However, this approach is more expensive initially due to the additional time and material needed to tighten the house and the cost of any exhaust fans or heat recovery ventilators.
The present leakage rate of the house may also affect your decision to implement any air sealing. Obviously, the more leaky a given house, the greater the potential benefits.

Installation Issues

Ventilation - Ensuring adequate house ventilation is important. A blower door can be used to determine if a particular house meets the standard(s) mentioned above for average air leakage/ventilation rates while also ensuring it is reasonably tight to minimize energy use.
Typical leak locations - Building air leakage typically occurs at several common locations. Penetrations through the ceiling plane, for ducts, pipes, chimneys, etc., are common and are the most important holes to seal as they tend to be relatively large and the stack effect ("hot air rising") tends to drive air out of the top of the house. For homes with naturally-drafted combustion appliances, air leakage from these holes may cause backdrafting. Other typical leakage locations are around windows and doors, at the bottom of walls where they meet the floor, and the first floor/foundation wall joints.

Related Issues

Moisture - Moisture is produced by a number of sources including cooking, bathing, plant respiration, human activity, and combustion within the living space. When a home is tightened, the average level of moisture (humidity) in the home almost always increases. Controlling sources of moisture can be critical in a tight home to prevent condensation on windows, and within walls during cold weather. Sources of excess moisture may be the result of any of the following:
  • Rainwater - check condition of roof, siding, caulking, gutters and downspouts, drainage of water away from home.
  • Plumbing leaks.
  • Cooking and Bathing - are there properly vented exhaust fans that can be used during, and up to 30 minutes after, cooking and bathing?
  • Clothes drying - is the dryer vented to the outdoors?
Venting/Drafting - Proper drafting of combustion appliances is an important health and safety issue. Drafting patterns can be greatly affected by air sealing. To verify proper drafting, tests can be performed which simulate worst-case house depressurization. These tests generally involve turning on exhaust fans, opening and closing interior doors, and operating combustion appliances in various combinations to determine if and when backdrafting occurs.

Material Options and Testing

Reduction of leaks in a house involves sealing holes and cracks with a variety of materials including caulk, expanding foam, and sheet metal or other sheet materials (plywood, foam). Densely installed insulation can also be effective in reducing air leakage through walls and ceilings. In new construction, or retrofit where framing is exposed, polyethylene can be installed as an air and vapor barrier. With proper installation, drywall and housewraps (such as Tyvek or Typar) can act as a good air (not vapor) barriers.
Equipment is available that allows us to measure the leakiness of buildings and ductwork, as well as locate the source of leaks. Called blower doors and duct blowers, these pieces of equipment pressurize or depressurize houses and duct systems, allowing measurement of air leakage and identification of specific leakage sites.
A number of other tests can also be performed using this and related equipment. These include testing for proper flow of "return" air, proper operation of exhaust fans, and proper drafting of combustion appliances. This last test is very important, as backdrafting of gas- and oil-fired furnaces, boilers, and water heaters can pose a serious health risk, and is more likely in tight houses.
These tests can usually be performed in 2-4 hours and are completely non-destructive. Observing some of these tests can be very interesting and informative. Therefore, it is strongly recommended that you be present to observe these tests if they are performed.

Remodeling Scenarios

Existing Homes

Consider having air leakage testing performed early in a remodeling project. The results of the tests may help you decide what approaches to take in regard to wall retrofit, window replacement, and duct improvements. Decisions on the need for, and sizing of, new heating or cooling equipment may be affected by the results of leakage tests and any air sealing work subsequently performed. If testing is performed by a contractor offering air sealing services, the air sealing can be performed at the same time as the testing. Strongly consider having air leakage-related tests performed after sealing the house or ductwork, especially tests for proper drafting of combustion appliances.

New Construction

Compared to retrofit methods, reducing air leakage is much easier in new construction. If you are adding any new rooms to the house, you should consider including some special air leakage detailing. This detailing is easy to do and adds minimal first cost, while saving energy, increasing comfort, an extending the life of the house.
Sealing all horizontal and vertical construction joints, such as where two exterior walls meet or where a wall sits on a floor, should be considered standard practice.

Firm Launches Calif. Land Bank Program to Assist Home Builders

Greencrossing Real Estate Cos., LLC, founded and operated by two former Lennar executives, is aggressively seeking homebuilders that want to “land bank” lots in California. 
Land banking was a popular way for builders to take down lots held by a third-party during the run-up of the last cycle, but the practice largely disappeared in the wake of the worst real estate downturn since the Great Depression. 
Now, Greencrossing, based in Aliso Viejo, Calif., and headed by Tom Banks and Jason Perrin – who have more than 40 combined years of experience in real estate and together have acquired, entitled and developed more than 20,000 lots – is one of the first companies in the aftermath of the housing crisis to create a fund to land-bank properties on behalf of builders. 
“Now is the ideal time for builders who want to buy finished and partially finished lots to meet expected housing demand, but don’t want a large initial cash outlay,” said Perrin. “By participating in our land bank program, builders improve their balance sheets by keeping the land and horizontal improvements off their books until they need it with an option purchase agreement.” 
Greencrossing is looking to place up to $60 million in land banking deals over the next 12 months. The fund is primarily targeting mid-sized to large private builders and all public builders planning to construct homes in desirable California markets. 
“Everyone is aware by now that the land market in key areas of California has heated up over the past year – prices are rising and competition is fierce, especially for finished or blue-top lots,” Banks said. “If you’re a home builder with your eye on a particular piece of property, our program can provide the financial flexibility that works for your company.” 
Typically, Greencrossing’s program targets deals with 100 single-family lots or less and the property should be in some sort of a developed state. The projected peak capital including land plus horizontal improvements, excluding impact fees, typically would be between $5 million and $15 million per deal.


Tuesday, May 24, 2011

If you’re building your houses to high-performance standards, the last thing you want to do is overlook the little things. The proper ventilation of the bathroom is one of them.
Because homes are so tight these days, moisture and odor in the bathroom will linger unless you remove them. “A properly installed bathroom exhaust fan will rid the bathroom air of excess moisture, humidity, odors, and other pollutants,” says the Wauconda, Ill.–based Home Ventilating Institute (HVI), a nonprofit association of ventilating product manufacturers. “It also helps to remove water vapor that has accumulated on mirrors and walls.”
Everyone can agree that venting the bath is a good idea. The question, however, is how to do it correctly. There’s more to it than you might think.
First, you must choose the right size exhaust fan. At a minimum, the fan should be rated to move 1 cubic foot of air per minute (CFM) for every square foot of space. For bathrooms larger than 100 square feet, HVI suggests CFM ventilation rates based on the number and type of fixtures in the bathroom: 50 for a toilet, 50 for a shower, 50 for a bathtub, 100 for a whirlpool.
Placement of the fan also is a big consideration. Fans should be located over or near the shower or tub and in an enclosed toilet, HVI advises. “With windows closed, exhausted air will be replaced by makeup air from adjacent rooms or forced air system registers,” HVI notes on its Web site, adding that exhaust points should be “located away from the supply, thereby pulling the supply air through the room.” In addition, bathroom doors need to have at least a ¾-inch clearance from the floor to allow makeup air to enter. Spaces with ceilings measuring more than 8 feet may require additional ventilation.
Lastly, fans should remain on for 20 minutes after use of the bathroom, though home buyers seldom do this. For this reason, manufacturers such as Secaucus, N.J.–based Panasonic and Hartford, Wis.–based Broan-NuTone are offering products that automatically activate either through moisture sensing or motion detection so homeowners will not have to worry about it. Follow these steps and your baths will remain fresh and moisture-free for years to come.

Step Outside: Unlike most vent fans, the motor for the PBW110H mounts on an exterior wall, so homeowners will not hear the unit when it’s activated. It features insulated flex duct and uses either a 50-watt halogen or a 14-watt compact fluorescent light. The unit is rated at 110 CFM, and the housing measures 5 1/2 inches. Fantech. 800-747-1762. /http://www.homeproductsinc.com/.


Silent Whispers: WhisperGreen is outfitted with a SmartAction motion sensor that knows when a person enters the bath and elevates the fan to its full power of 80 CFMs. When the person leaves, the fan returns to a lower power level after a predetermined time, which is set by the homeowner. Fans can be equipped with light and nightlight features. Panasonic Home and Environment Co. 866-292-7292. http://www.homeproductsinc.com/

Sense and Sensibility: SmartSense is an ingenious ventilation system that connects all of the company’s Ultra Silent fans installed throughout the home. A master control monitors the manual usage of the fans and automatically activates and adjusts the units to achieve optimal ventilation. Fans are available at 0.3 and 0.7 sones and are rated at 80 and 110 CFMs. Broan-NuTone. 800-558-1711. http://www.homeproductsinc.com/.

Friday, May 20, 2011


As a part of its commitment to assisting and educating building professionals, Panasonic Home & Environment Company has launched a new online resource specifically targeted to Heating, Ventilating, and Air Conditioning (HVAC) distributors and contractors. The new site, Panasonic.com/hvac, provides resources and information about Panasonic ventilation fans that meet various green building standards and improve overall indoor air quality – issues relevant to HVAC professionals.

“The demand for airtight constructions has made the HVAC’s role in building indoor environments even more critical,” said Anita So, Marketing Specialist, Panasonic Home & Environment Company. “By providing an online tool that gives the HVAC professionals an easy-to-use and immediate overview of Panasonic’s ventilation solutions – we hope to help them meet new indoor air quality standards and grow their business.”

Select Panasonic ventilation fans, such as the company’s flagship WhisperGreen models, are ENERGY STAR® rated, Home Ventilating Institute (HVI) certified and ideal for complying with ASHRAE Standard 62.2, which is the ventilation platform adopted by LEED for Homes, ENERGY STAR Indoor Air Quality Program, and California Title 24.

For more information on Panasonic ventilation products, please visit: http://www.homeproductsinc.com/.

Wednesday, May 18, 2011

Poor communication is a root cause of customer dissatisfaction

A few years ago during the height of remodeling fever, when a customer would report low satisfaction with his or her remodeler it was most likely due to communication, scheduling, and punchlist issues. “Since 2007, those same three areas correlate most strongly with an unhappy customer, though schedule has fallen to the third spot and problem resolution [which closely relates to communication] has risen to the first,” says Geoff Graham, CEO of GuildQuality, a customer survey organization whose clients include nearly 600 builders and remodelers.
Graham analyzed 10,000 customer satisfaction surveys from 2003 to 2006 and has reviewed about 6,000 surveys since 2007. Ten different reasons for customer dissatisfaction were ranked (see list below). While communication and scheduling, in particular, would seem to be obvious stress points, it’s surprising how many remodelers lack processes and procedures dedicated to those two areas.

Regular Check-In

Graham correlated that about one out of every five businesses that deliver a poor customer experience — those with a recommendation rate below 80% — fail, whereas just one out of 50 superior performers fail. “Said another way,” notes Graham in a recent blog, “superior service providers are [10 times] more likely to stay in business than poor performers.”
To remain on top, remodelers such as Peter Michelson, CEO of Renewal Design Build, in Decatur, Ga., and a GuildQuality client, says that consistency from the first sales call to the end of the punchlist is key. The company’s design team makes an appointment and follows up with a posted letter and an e-mail. During the design process, there are a lot of regular check-ins. “We don’t want people going a whole week without hearing from us,” Michelson says.
When remodeling clients are under contract but have not yet broken ground on their project, Renewal Design Build gives clients its “expectations book,” which describes the company’s communication process. Finally, during the project, the project manager sends weekly e-mails of what happened and what’s ahead. “You can never overcommunicate,” Michelson says.

Monday, May 16, 2011

Panasonic Home & Environment Company as a 2011 ENERGY STAR® Partner of the Year

For the second consecutive year, the U.S. Environmental Protection Agency (EPA) has named Panasonic Home & Environment Company as a 2011 ENERGY STAR® Partner of the Year for its outstanding contribution to reducing greenhouse gas emissions by manufacturing energy-efficient products and helping to educate consumers about those products. Panasonic’s accomplishments will be recognized at an awards ceremony in Washington, D.C. on April 12, 2011.

Panasonic Home & Environment Company, an ENERGY STAR partner since 2001, will be honored for its leadership in manufacturing products that earn the ENERGY STAR rating, the government-backed symbol of energy efficiency. With the highest efficacy (up to 14.4 cubic feet per minute/Watt) of any of the ventilation fan ENERGY STAR partners, Panasonic continues to exceed standards with its entire product  line where guidelines exist. 

“Panasonic is honored to be named an ENERGY STAR partner for 2011 because it validates our continued commitment to improving the energy efficiency of products, homes, buildings and businesses,” said Anita So, Marketing Manager, Panasonic Home & Environment Company. “The award not only acknowledges our high-performing energy-efficient ventilation fans and their role in preserving indoor air quality, but it also recognizes our commitment to educating both industry professionals and consumers on the importance of sustainability.”

Last year alone Americans, with the help of ENERGY STAR, prevented 170 million metric tons of GHG emissions – equivalent to the annual emissions from 34 million vehicles – and saved $18 billion on their utility bills.

The 2011 Partner of the Year Awards are given to manufacturers and retailers that successfully promote and deliver ENERGY STAR qualified products, saving consumers money and reducing greenhouse gas emissions. Award winners are selected from more than 20,000 organizations that participate in the ENERGY STAR program.

"Today, EPA is recognizing Panasonic Home & Environment Company for their leadership in addressing climate change through energy efficiency," said Elizabeth Craig, Acting Director of EPA's Office of Atmospheric Programs. "Panasonic is producing and promoting energy-efficient ENERGY STAR products that help American consumers join in the effort to increase our nation's energy efficiency and reduce our emissions of greenhouse gases. We look forward to continuing to partner with these winners as they create the next generation of energy-efficient products."

Friday, May 13, 2011

Humidity Sensing Fans

The solid state humidity sensor is an electronic, temperature compensated sensor that is linear between 30% and 90% relative humidity with a nominal tolerance of 5%. The device includes a manual override switch that turns on a fan for an internally preset time (12 minutes) before restoring the system to automatic operation. The control also includes a Fan On light, indicating the operation of the controlled device. The internal SPDT (single pole, double-throw) switch allows the control of either humidifying or dehumidifying devices for the constant operation of a ventilation system, or a motorized cover or fan.
The manufacturer offers a fixed set point (FS) model, an adjustable (AS) versions, a remote sensing model (R) and a differential humidistat (D). The FS version has fixed summer and winter settings (35% and 55% relative humidity). The AS version is adjustable from 10% to 90% relative humidity. The remote sensing model R can control humidity up to 200' away with a remote lead (regular phone wire) . The differential humidistat (D), senses humidity remotely and at the control. If the remotely sensed relative humidity exceeds the relative humidity at the control, the system will not turn on on humidity rise. This device is used when multi zone humidity control is neccessary.

Environmental Performance Humidity control can improve indoor environmental quality by managing moisture that can lead to mold and deterioration.
Quality and Durability By controlling interior humidity, a home can be more comfortable for its occupants.

Unless controlled by relays, the maximum load for fans, dehumidifiers or motors can not exceed 1.8 amps. The recommended operating temperatures are between +5° to +45° C (41° F to 113° F).
U.S.Code Acceptance In progress

For accurate humidity sensing, the 4 3/4" x 3" x 1" (HxDxW) control device is surface mounted and installs on a single ganged work box. Remote sensors can be placed outside, must be protected from direct weather exposure however.

Continuously monitoring relative indoor air humidity not only can maintain the desired comfort level for habitants or plants, it also helps improve indoor air quality by lowering the risk of fungus, mold or meldew and cuts heating and/or cooling costs all year long.

Tuesday, May 10, 2011

Ventilation Control Systems

Today's energy efficient homes do a great job of keeping conditioned air in. But, the downside of a well air sealed and insulated home is that reduced stale air exhaust and air exchange with the outside can result in poor indoor air quality which may lead to occupant health and structure durability problems. Even air systems that are designed with a fresh air intake do not provide ventilation or exhaust when they are not operating.
Economical and affordable ventilation controls are ideal for use with exhaust or supply fans, air handlers, heat recovery ventilators, intermittent whole-house exhaust systems, or anywhere specific ventilation rates are desired. Mixing the house air with fresh outdoor air can reduce concentrations of moisture and contaminants indoors and recharge the indoor air’s oxygen content.
There are many types of ventilation controls that including the simplest devices - manually operated twist-timers. Some of the controls that are available to automatically operate mechanical ventilation systems that are integral to most homes are described here.
Programmable Microprocessor Exhaust Fan Controls
Microprocessor-based controls can balance ventilation with energy conservation because they can be programmed to operate intermittently. Different models allow for single or dual fan speed operation. For instance, a multi-speed exhaust fan might be operated by this type of control at low speed to provide ventilation and then boosted, via occupant use of the wall switch, to high speed when local high volume exhaust is desired for mist removal after a shower. These controls eliminate user error by automatically coordinating fan speed and cycle time based on the overall volume of air in the home and occupancy, while still allowing occupants access to a full-speed fan cycle. Controls can be paired with a quiet, energy-efficient fan so that occupants are not aware of the fan’s operation. Some units come with a battery backup that will hold the programmed setting during a power failure. Tamerack’s Airetrak™ is one example of a programmable microprocessor fan control.
Controllers for the Central Air Handler Fan
Central air handler fan controllers can be pre-programmed to engage the central system fan to periodically mix indoor air (when the system is not running) and to control a motorized damper in a fresh air supply duct that connects outside air with the system’s plenum. Controlling the system’s fan operation with a control that is independent of the thermostat avoids continually running the fan. The same control can be used to engage the fresh air intake duct damper. Otherwise, air intake dampers are often triggered when the system’s fan is in operation which can over-burden a system in extreme hot or cold climates. AirCycler™ is one such control.
Integrated Exhaust Fan and Microprocessor Control Systems
An integrated ventilation system, SmartSense®, is available as a kit that includes low sone exhaust fans and switches that can be installed in any room in a home. Once the system is in place and programmed, one switch becomes the master control and all others become slaves (via a phase coupler mounted near the circuit breaker panel.) The system can be operated with up to 10 slave switches. All switches can manually operate the local fan. The master can operate any given fan based on a pre-programmed ventilation level that factors in the manual use at each location.


These systems introduce fresh air and/or remove stale air at timed intervals

Ease of Implementation

Ventilation controls are easy to include in the specifications of a new project. Like the thermostat, these controls are the domain of the HVAC contractor who should provide the design and equipment and co-ordinate the installation.
Controls or systems can also be employed in remodeling and retrofit projects.
Initial Cost  
Controls cost between $50 and $100, dependent on features and manufacturer. Whole systems, which include two or three fans and switches, will cost more.
Operational Cost  
The operational costs of any mechanical ventilation strategy will be dependent upon the fan characteristics operating schedule, and climate.
U.S.Code Acceptance
Switches, controls, fans and motorized dampers or other electrical equipment should be UL listed.
Field Evaluations
Warren Builders: Site 1. Albertville, Alabama
New construction activities related to providing for ventilation controls can be performed during typical site visits for rough-in and final mechanical/electrical installations. Controls can be fit into a single gang electrical box. Controls require an electrical current source and a direct connection to the fan that will be operated, just like switches.
Manufacturer’s warranties vary between one and three years dependent on product and use. See manufacturer’s literature for complete details.
Ventilation controls can be programmed to fit specific occupancy patterns and indoor air volume so energy losses may be minimized while comfort is maximized. Dependent on the ventilation approach that is selected, controls can operate individual room fans or the central system’s fan to exhaust stale humid air or mix and circulate room air. Some controls can also operate a mechanical damper in fresh air ducts.
The ventilation methods described here are unbalanced, or exhaust- or supply-only methods. Exhaust-only ventilation removes stale humid air while relying on air leakage through the building envelope to provide the fresh air make-up. Exhaust-only ventilation may depressurize a house while the opposite is true in the case of a supply-only ventilation scheme. Balanced ventilation strategies are explained at the link below. These ventilation controls may be used for whole house balanced ventilation systems, as well.

Monday, May 9, 2011

Solar Powered Attic Fans

Many manufacturers now offer solar powered attic fans to ventilate attics and help keep attics cooler. Solar powered fans rely on a small (typically 10- or 20-watt) solar panel to power a DC motor when the sun is shining. The fans, which exhaust air at a rate of 800 to 1200 cfm, are installed with intake vents (such as soffit and gable vents) to provide high-capacity powered ventilation without electric operating costs. Most vents are mounted high on the roof, near the ridge, and combined with soffit or gable vents for balanced intake and exhaust air streams. Solar powered gable ventilators are also available.

Because they cost nothing to operate, solar attic fans are more affordable to operate than conventional powered attic fans.

By reducing attic temperature, attic fans can help reduce summertime cooling loads while at the same time providing ventilation without added utility load.

Ease of Implementation

In new construction applications, roofers will usually install powered ventilating units. The solar units eliminate the need for an electrician to rough and finish wire the units.
For retrofit projects, a roofer or do-it-yourselfer can install a solar-powered attic fan using conventional materials, tools, and techniques

Initial Cost  
Retail prices range from about $350 to $600 depending on ventilation capacity, manufacturer, and optional features of the unit, such as a thermostat.

Operational Cost  
Solar powered fans are fueled by the sun, so there is no cost of operation.

U.S.Code Acceptance
Section R806.2 of the International Residential Code specifies the amount of ventilation required for attics in newly-constructed homes. The required vent area can be reduced with installation of a ceiling vapor barrier or ventilators located in the upper portions of the space to be ventilated. The code does not require powered ventilation for attics.
There may be difficulty using solar attic fans in Dade County, Florida, and areas where building products must approved by the inspection department. The concern in high wind zones, such as coastal Florida, is that roof penetrations of any sort provide a potential weak point in the building envelope. High winds can blow away protrusions leaving the building susceptible to damage from the rainwater that accompanies the wind.

Units typically come fully assembled and are self-flashing. Installation is straightforward and most manufacturers offer clear installation instructions, often with diagrams and pictures. Powered attic vents are designed to be used in conjunction with sufficient intake air vents, such as soffit or gable vents. Units can typically be supplied and installed by a roofing trade contractor.

Warranties range from five to twenty-five years depending on component and manufacturer.

Compared to powered vent fans, there is no need for electrical wiring, and a solar ventilator uses no electricity (hence avoiding operating cost). Although equipment costs are greater for solar powered attic fans than conventional powered fans (about $200 more), the cost to bring electrical wiring to the attic to supply a conventional ventilator closes the gap on installed cost.
Ventilation is only provided when there is ample sunshine to power the fan motor. The highest solar insolation (and, hence, fan speed) typically coincides with the time of greatest need for attic ventilation.
If there is inadequate attic intake air and poor sealing between the conditioned space of the home and the attic, powered attic fans can potentially draw air from the house into the attic. Not only can this compromise energy efficiency, it can increase the risk of attic moisture problems as well as increase the risk of drawing the byproducts of combustion into the house (a process called backdrafting).

Friday, May 6, 2011

Energy Efficiency in Remodeling: Ducts


Many remodeling projects involve some addition to, or modification of, the HVAC system, which in many cases includes ductwork. Leaky and poorly insulated ductwork located outside of the sealed and insulated building envelope (i.e., in exterior walls, garages, crawlspaces, and attics) is very common. As many as 1 in 12 homes have major ductwork problems such as disconnected ducts, pinched or crushed ductwork, missing or badly torn duct insulation, or poor duct layouts. Remodeling is an excellent time to consider ductwork improvements, when existing ductwork is accessible and new ductwork is being designed and installed.


Reducing duct air leakage and improving duct insulation has enormous potential to reduce utility bills and prevent or eliminate associated comfort and health problems. Specifically:
  • Heating and cooling costs can be reduced by as much as 20-30%
  • Comfort can be improved by ensuring adequate delivery and return of conditioned air
  • Downsizing of heating and cooling equipment is possible
  • Entry of mold, radon, dust, and moisture into the house can be reduced
  • The likelihood of house depressurization leading to backdrafting can be reduced

Factors to Consider

Location - Ducts placed within conditioned spaces are more efficient than those placed in unconditioned spaces. If located within conditioned space, conductive and radiative losses, leakage losses, and equipment cabinet losses are reduced or regained into the building space. If possible, locate new ductwork and relocate old ductwork within the house envelope. This means avoiding exterior walls, garages, crawlspaces, and attics. In some cases, it may be easier to alter the location of the insulated and sealed (thermal) envelope so that the existing ductwork is then within the house where leakage is of less concern (i.e., crawlspaces). If it is not feasible to locate ductwork within conditioned space, the ducts should be properly sealed and insulated.
Sizing - With all ducts, care must be taken that the ducts are large enough to deliver the needed volume of air. Smaller ducts tend to be noisier and more leaky than larger ducts due to higher air speeds and pressures. In order to deliver the same volume of air, flexduct and ductboard systems must usually be sized larger than metal ducts as their interior surface is much rougher, leading to more restrictive air flow. Any new ductwork should be sized according to recognized industry standards such as Manual-D, published by the Air Conditioning Contractors of America (ACCA).
Return air - Many homes have one or more supply registers in each room but often have a total of only one or two return registers, usually located in hallways. If interior doors are left open, this arrangement usually works well. However, when these doors are closed, as is often the case with bedroom doors, an adequate volume of air often can not get back to the these centrally located return registers. This causes higher pressures in the rooms with closed doors. This condition greatly increases the amount of heated or cooled air forced out of the house from these rooms. The higher pressures in these rooms may also make it difficult for the rooms to receive enough supply air. The result can be an uncomfortable room and higher energy use. Meanwhile, the rest of the house is at a lower pressure, causing outside air to enter at a faster than normal rate. Backdrafting of exhaust gases from combustion appliances may then result as air is drawn down flues or chimneys in an attempt to equalize the pressure. While undercutting doorways can improve air return, it simply may not be adequate in many cases. Alternate solutions include installing return ducts in each room, or installing transfer ducts or bypass grills which connect the affected bedroom(s) to the hallway, for example.

Installation Issues

In order to achieve a good seal for a long time, it is important that ducts be sealed with mastic and fiberglass mesh (where required). Flexduct should be adequately supported along its length and not pinched. Standard six-inch round flexduct should not generally be used in lengths over 16 feet.
Tests of duct systems may be used to identify leakage sites and to confirm the effectiveness of sealing measures. To test, ducts are pressurized with a fan at a return register or the air handler cabinet.

Material/Equipment Options

Sealing leaks in ductwork involves the use of special duct "mastic" and mesh which is extremely durable, long-lasting, and effective. This work may be done by some insulation or general contractors or weatherization specialists. The cost of reducing leakage is very dependent upon the number, type, and location of the leaks, as well as the particular contractor. A range of $200 to $400 would be typical for retrofit work.
Selection of duct material is based on its price, performance, and installation requirements.
Sheet Metal
  • Most common
  • Durable
  • Can be customized to fit odd sizes/locations
  • Smooth surface offers low resistance to air flow
  • Many connections, joints, and seams, each having potential leakage
  • Must be insulated when located in unconditioned spaces
  • Made with a plastic inner liner inside a tube of insulation, covered with a vinyl vapor barrier
  • Few duct connections and joints
  • Low installation and material costs
  • Easily torn, crushed, pinched, or damaged, with damage to inner lining not visible
  • Has higher resistance to air flow than metal ducts, must be properly specified
  • Made from stiff, high-density sheets of fiberglass with foil facing bonded to one side
  • Insulation is integral to duct material
  • Material costs higher than sheet metal
  • Installed costs may be comparable when sheet metal must be insulated
  • Lightweight and particularly adaptable to attic systems
  • Vapor barrier is part of the duct material
  • Provides excellent sound attenuation
  • Durability is highly dependent on closure method (tapes and mastics)
  • May be damaged or crushed during construction
  • Relatively air tight when properly installed
Transfer ducts/Bypass grills
  • Used in lieu of individual returns for each room
  • Used to connect bedrooms, etc., to a hallway having a central air return
  • Typically made using short pieces of ductwork, or grills above a door or other location
  • Installed in attic or through walls
  • Paste applied to joints and connections in ductwork
  • Becomes hard and very durable when dry
  • Can be used on cracks up to 1/4-inch wide
Fiberglass mesh
  • Used to help seal holes larger than 1/4-inch wide
Butyl-backed foil tape
  • Can be used to seal holes or cracks
  • Can not be used to seal awkward connections, such as where a round duct meets a rectangular one
  • Its long term durability is not known
Foil tape
  • Shown to come loose after just a few years, especially in hot attics
  • Many joints can not be properly sealed with tape at all, such as where a round duct connects to a rectangular duct

New Options

Duct sealing technology which seals the ducts from the inside with a latex-based spray -- will soon be commercially available.

Duct Insulation

For metal ducts, insulation may be installed on the inside and/or outside of the duct. If on the outside, a vapor retarder, usually integral to the insulation itself, should cover the insulation. This is to prevent condensation on the duct which would severely degrade the effectiveness of the insulation and may lead to damage of the house. Remember that insulation does nothing to prevent air leakage -- ducts must be properly sealed before insulating. For ducts of any kind located in an attic, insulation of the ducts can be improved by placing batt or blown insulation over the ducts.
Flexduct and Ductboard
  • Insulation is part of the duct itself
  • R-4.2 insulation is most common on flexduct
  • R-6, R-8, and R-11 flexduct is also available
  • Ductboard is typically made from R-4.3
  • Ductboard also available in R-6.5
Fiberglass Duct Liner (for metal ducts)
  • Used to line the inside of rectangular metal ductwork
  • Made of specially-treated, rigid fiberglass insulation
  • Typical R-values are 3.6, 3.7, and 4.2 per inch
  • Available in ½, 1, 1-½, and 2 inch thicknesses
Fiberglass Wrap Insulation (for metal ducts)
  • Used to cover outside of ducts located in unconditioned spaces
  • Typical R-values are R-3.6, 3.8, and 4.1 per inch
  • Available in 1-½, 2, 2-¼, and 3-inch thick rolls
  • Available with or without a vapor barrier (an outer covering of reinforced foil)
  • Insulated better than duct liner

Remodeling Scenarios

Existing construction

For existing duct work, there are basically three options for improving any given portion of ductwork. Depending on where the ducts are currently located, their present condition, and the costs involved, you can:
  • Relocate the thermal envelope
  • Relocate the ducts
  • Seal and better insulate the ducts
While it is generally preferable to locate the ducts within the thermal envelope, it may be physically impossible or very expensive to alter the location of the thermal envelope or the ducts themselves. If re-location is not possible, ducts should be sealed with mastic and possibly better insulated. This can be a very worthwhile measure even if it is necessary to remove and reinstall the existing insulation.

New construction

At the beginning of a project, consideration should be given to:
  • Location of the duct work
  • Duct type and size
  • Sealing method
  • Insulation method, R-value
As mentioned above, it is preferable to locate ducts within the building envelope. However, this option is not always possible, even with new work. Again, in this case, ducts should be sealed with mastic and perhaps better insulated.


As mentioned above, sealing ductwork and improving duct insulation can reduce your heating and cooling costs by as much as 20-30 percent.

Thursday, May 5, 2011

How to Install a Bathroom Fan

Have you bought a bathroom fan and want to install it yourself? Let's go through the steps and see if it's something you want to tackle.
Determine where you want to install the fan. If this is a remodel and you are replacing an existing unit, this is pretty easy. If this is a new installation you will typically need to install the fan in a location where it can be attached to a ceiling joist, which you can locate using a stud sensor or any other method you prefer.
Cut a hole in the ceiling larger than the finished opening (unless you have access from above) in order to get the fan housing into the ceiling and to attach it to the joist for support. A good method to do this is to use a rotary cutting tool, like a rotozip, or a drywall saw.
Turn off power at the breaker and be careful not to cut any electrical wiring if this is a remodel). Be sure to wear goggles and a dust mask!
Instructions for Replacing Existing Fan
Disconnect the electrical connections from the existing fan and remove the housing through the previously cut hole. Be careful as the housing is attached to the vent duct and you will want to re-use this.
Prepare the new fan for installation by verifying the exhaust duct is the same size as the exhaust on the housing. Determine what kind of electrical cable is running to the fan and put the appropriate cable clamp in the electrical housing knockout.
Attach the new fan to the ceiling joist, connect the exhaust duct, and run the electrical cable through the previously installed clamp into the housing.
Connect all the electrical cable to their approriate wires/terminals and make sure the fan unit is properly grounded.
Turn on power at the breaker and test the fan to ensure proper operation. Once tested, turn off power until install complete.
Skip New Installation instructions and proceed to "Common Instructions"
Instructions for New Installation
Recognize that a new installation can be quite complex and might be best undertaken by a pro. However, it can be easily accomplished if it is for a bathroom where you have access from above and a clear path to run exhaust duct.
Find power for the fan. You will need to run one or more switched circuits to the fan location from your switch location. A single circuit is typically all that is needed for the fan, light and heat unit, if equipped. You will need to refer to another reference source for instructions on accomlishing this.
Find an exhaust duct, which is typically vented to the outside through the roof or through the side of the house. Again, you will need to refer to another source for these instructions.
Know that you can now install the fan. Prepare it for installation by installing the appropriate cable clamp in the electrical housing knockout(s) for the cable that was run to the unit.
Attach the fan housing to the ceiling joist, attach the exhaust duct and connect up the electrical to the appropriate wires/terminals.
Test the fan for proper operation by turning on power at the breaker and testing the switch(es). Once operation is verified, turn off power until install complete.
Common Instructions
Know that now we have a fan attached to the joist and all hooked up, with a nice gaping hole in the ceiling surrounding it. We need to fix this hole...
Do this by cutting back the ceiling material (typically greenboard or drywall) so that you have a square or rectangle that has at least 1/2 of the ceiling joist edges on either side of the fan exposed to screw a new piece to.
Cut a new piece of drywall/greenboard to fit in the enlarged hole and mark the location of the housing flange on the backside of the piece to cut out the opening for the fan. (A simple method of doing this is to use an old lipstick to run on the edge of the fan housing. When you push the drywall against it, it leave a nice cut line.)
Cut out the fan opening and hold up the piece to test the fit. Adjust as necessary.
Install the drywall using 1 5/8" drywall screws along the ceiling joists and either drywall clips and screws or backer boards and screws along the unsupported edges.
Tape and mud the joints (you will have to learn to do that bit elsewhere). Now, install any bulbs in the fan unit, put on the cover and turn on the power at the breaker.
Buy the bathroom fan from a reputable retailer.
Be sure to get a fan that moves enough air for the size of bathroom you are venting.
Get a fan as quiet as you can afford, you will be happier in the end.
Use a step-ladder for high ceilings.
If you aren't comfortable doing electric work, drywall or running the ducts, hire someone to do it for you. You will end up saving time and frustration and it will be worth the money.

Turn off the electricity supply before installing the appliance.
If using a ladder, have someone support it whilst you are installing the fan.
Make sure you follow all instructions completely.
If you know nothing about electricty, it would be better to hire someone that knows about wiring. The wrong wire connected to the right or wrong wire can cause a lot of damage which could includ a fire or killing you.
If using power tools for any portion of this project, be sure you are familiar with their operation.
Things You'll Need
Bathroom fan.
Drywall saw or rotary saw
Electrical supplies (wire, boxes, housing clamps, etc.)
Exhaust Duct (for new installs)
Razor Knife
Greenboard or drywall
Drywall tape
Joint Compound
Light bulbs for light/bathroom fan.
Power Cut-Off.:


The worlds of design and ventilation fans collide with the introduction of the new metal grille from Panasonic Home & Environment Company.  Available in July 2009, the durable and decorative FV-GL3MTL grille is perfect for professional and commercial settings.

With an understated and subtle style, the FV-GL3MTL is the newest addition to Panasonic’s optional Shaker and Victorian grille line.  Featuring powder-coated white paint, the HVI Certified FV-GL3MTL allows builders and remodelers to quickly, easily and cost-effectively change to a metal grille in multi-family, high-rise and lodging environments without compromising the performance, quality or quietness of the unit. 

Panasonic models compatible with the new grille:
·         WhisperGreen®: FV-05VK1, FV-08VK1, FV-08VKS2, and FV-13VKS2
·         WhisperCeiling™: FV-05VQ3, FV-08VQ3, FV-11VQ3 and FV-15VQ4
·         WhisperFit™: FV-05VF2, FV-08VF2, FV-11VF2
·         WhisperValue™: FV-05VS1, FV-08VS1, FV-10VS1
·         Radiation Damper: PC-RD05C3

Panasonic’s Whisper ventilation fans are renowned in the industry for their high-energy efficiency and low noise levels. All Panasonic fans and fan/light combinations are ENERGY STAR® qualified, UL listed, and feature leading-edge technology ranking them one of the quietest ventilation fans available today.

For more information on Panasonic ventilation products, please visit: http://www.homeproductsinc.com/

Tuesday, May 3, 2011

New Homes Strengthen Economy Year-Round

While the housing industry celebrates New Homes Month in April, home builders want Americans to know just how much of a positive, direct impact residential construction has on the U.S. economy throughout the entire year.
"Home building is a key driver of the American economy," said NAHB Chairman Bob Nielsen, a home builder from Reno, Nev. "By generating economic activity including new income and jobs, purchases of goods and services, and revenue for local governments, housing—which has historically accounted for around 17 percent of the GDP—can put America back to work."
Economists at the National Association of Home Builders estimate that the one-year local impacts of building 100 single-family homes in a typical metro area include $21.1 million in local income, $2.2 million in taxes and other local government revenue, and 324 local jobs.
The employment effects extend beyond the home building industry. About half of the jobs are in construction, with the other 50 percent creating employment opportunities in industries ranging from production and sales of home furnishings to service providers such as real estate attorneys and landscapers.
Those 100 new homes also provide the community with additional, annually-recurring impacts of $3.1 million in local income, $743,000 in taxes and other revenue for local governments, and 53 local jobs.
The income earned from construction activity is spent and recycled in the local economy, and the new homes that are built become occupied by residents who pay taxes and buy locally produced goods and services. Those tax revenues help pay for a wide range of government services, including local school teachers, police departments and road repairs.
In order to accommodate population growth and necessary replacement of older homes, however, a long-run trend of approximately 1.7 million new homes a year is needed. Yet as of February 2011, the annual projection for housing starts stood at less than 500,000.
"The gap between actual home starts and what is required to fulfill America's future housing needs represents more than 3 million jobs," said Nielsen. "Restoring the health of the housing industry is a crucial first step in stabilizing our country's path to economic recovery."
During New Homes Month, home builders also bring attention to the advantages of newly-built homes, including safety, amenities, energy efficiency and floor plans to fit a wide variety of modern lifestyles. Combined with today's near record-low interest rates and competitive prices, the current market offers new home buyers unprecedented opportunities.

Monday, May 2, 2011

Evaluate Your Ventilation Needs

To specify an attic ventilation system, you should first determine the square footage of your attic. You'll need this figure to make sure you install adequate ventilation. If the roof pitch is 7/12 to 10/12, add 20% to your calculation for vent requirements; 30% for roof pitches of 11/12 and steeper.  If your roof pitch is 7/12 to 10/12, plan to add 20% to your calculation for vent requirements; 30% for roof pitches of 11/12 and steeper.

Vent Requirements

According to most building codes, you need one square foot of vent area for each 150 square feet of attic floor space. The minimum is one square foot for every 300 square feet of attic floor space if there is a vapor retarder or the space is balanced between the ridge and intake vents. A balanced ventilation system means about 50 percent of the required ventilating area should be provided by exhaust vents in the upper portion of your attic with the remaining 50 percent provided by intake vents.  Please remember, building codes specify the minimum amount of ventilation. You may want to increase the requirement to ensure proper ventilation.

Common Mistakes

Too often, builders install products that short-circuit their ventilation system. When designing a ventilation system, avoid these common pitfalls:
  • Don't use a combination of different types of exhaust vents, like power vents with ridge vents. In this case, competing vents pull air from each other instead of pulling from the intake vents.
  • Don't underestimate your ventilation needs. Remember that 15 roof vents or 5 turbine vents would be needed to provide the same ventilation as 42 feet of ridge vent.
  • It is of no use to install exhaust vents without adequate intake. An effective balance of intake and exhaust must be achieved to properly ventilate the home. The flow of air in your attic is limited to the amount of intake.
  • Don't install a ridge vent that doesn't have an external baffle to increase airflow and protect from weather infiltration.