1. Richmonders promote energy star homes

2. Structural insulated panels product guide

3. Brief Guide to Mold, Moisture, and Your Home.

4. SIPS 15 times tighter than stick & batt, new study says

5. SIPs on the outside, SIPs on the inside too?

6. "R" your getting what you "R" paying for?

Richmonders promote Energy Star homes

RICHMOND - Advanced Construction Systems International Ltd. recently helped to dedicate the "Idlewood" tum-of-the-century-style home in Richmond. The 19OOs- style

Not only are the homes priced at very competitive market rates, but each guarantees a low monthly heating and cooling bill. Through the National Home Energy Resources Organization, the Idlewood, with its 2,025 square feet of living and conditioned storage space, is guaranteed a monthly bill of $27. if the energy savings were applied to a yearly 13' payment, the combined interest savings over a 30-year fixed-rate loan could approach some $30,000, according to Consumer Reports magazine.

The dual 12 SEER heating and 7.7-7.8 HSPF air conditioning system is one of the most highly efficient in the industry. The homes also feature low-to-no maintenance exteriors, steel-reinforced vinyl railings, baked-on enamel aluminum decorative porch posts, energy-saving vinyl windows, decorative insulated steel doors, and aggregate porch floors, walkways and parking pads.

Currently, homes are being built and/or planned for four of the nine Major development areas of Richmond. For more information about these Five Star/Energy  Star homes,  call Dr. Samuel L. Hancock at (804)378-3742. 

SIPS 15 TIMES TIGHTER THAN STICK & BATT, 
NEW STUDY SAYS.

Drafts don't stand a chance in a structural insulated panel (SIP) structure. That's the conclusion of a new study conducted by the government's Oak Ridge National Laboratories (ORNL).

A SIP test room radically outperformed a 2x6 stick-framed and fiberglass-insulated room in controlled testing under identical laboratory conditions. Results from the climate simulation laboratory prove that SIP construction is inherently far more airtight than stick- frame construction.

"We can put a number on it," says Bill Wachtler, director of the Structural Insulated Panel Association (SIPA). "When it comes to stopping drafts, we're 15 times better than the competition."

The test setup created identical climate conditions for both rooms and measured both the air tightness and the heating energy requirement of the two rooms. Under blower door testing, a room with 4" SIP was, an SIP ceiling, windows, a door, pre-routed wiring chases and electrical outlets showed 10 to 15 times less air leakage than an otherwise identical room built with 2x6 studs, OSB sheathing, fiberglass insulation and drywall. In fact, the SIP room exceeded the capacity of the blower door.

The test protocol calls for the room to be depressurized in a range from 15 to 50 pascals of pressure, but Oak Ridge reported, "we were unable to go below 35 pascals because the SIP room was so airtight." At 50 pascals of negative pressure, the stick- built room leaked 121 cubic feet of air per minute (CFM), while the SIP room leaked only eight CFM.

"The CFM50 for the SIP test room was almost 15 times less leaky than that measured in the wood-frame,' says the Oak Ridge report. "By comparison with the wood4ramed room, the SIP room is extraordinarily airtight. These results show that, with care, a very near airtight construction is possible with SIPs." The test results can be reliably extrapolated to the real world, notes the Oak Ridge study. Lab test results for the stick house very closely track the testing data from actual stick houses. While Oak Ridge did not have data from SIP houses to compare to the SIP test room, blower door testing data in SIPA's possession indicates that SIP houses can readily achieve natural air change rates under normal atmospheric conditions of around .05 air changes per hour (ACH), compared to typical stick house values on the order of .5 to 1 ACH.

Additionally, the room with 4" SIP walls used 9% less heating energy than the stick-built room under identical conditions (an indoor temperature of 70-F and an outdoor temperature of O^oF). These results were verified by continuous monitoring of temperature and heating system data.

The implication is that building with 4" SIP walls more effectively meets energy code requirements than building with 6" stick walls while pro- viding far superior air tightness. "People look at the insulation R-values for a 6" stick wall (R-19) and a 4" SIP wall (R-15), and they think the stick wall is four points better," says Wachtler. "But these tests prove that the stick wall is really 10% worse. Let's stop making false comparisons between the two systems. It's time to change the energy rating systems and the energy codes to reflect the true performance of SIPS."

The Oak Ridge testing confirms observations from identically designed homes built with SIPs and conventional stick and batt. For example, in 1998, three identical Habitat for Humanity houses were built in Plains, GA. Two houses used SIP walls and roof, while the third house was built with standard stick framing and fiberglass insulation. All three houses were monitored by scientists from the Florida Solar Energy Center (FSEC).

"The three houses were intentionally built with their calculated energy performance [HERS score] similar to each other [ail three had HERS ratings of about 83]," reports FSEC. "The frame house featured energy-related details typical for the affiliate, which resulted in an ACH50 of 5.3. With the home's whole-house fan cover installed, the ACH dropped to 3.9, very good for frame construction. However, testing results revealed much better performance in the SIP houses with a measured ACH50 of 1.8. Considering the average indoor-outdoor temperature difference of 30'F, the SIP houses saved 25% [on heating energy] compared to the frame house [during December and January 1998-99]."

Obviously, the identical Home Energy Rating System (HERS) ratings did not reflect the true differences between these houses- the ratings underestimated the actual energy saving value of building with SIPS. These identical houses received the same energy rating, even though the SIP house proved to use 25% less energy. With that real-world performance, the SIP houses deserve a HERS rating of 87, not 83. Clearly, the HERS rating, as applied in this case, did not meet the intent of Congress-the identical ratings would not have helped the potential home buyer to understand that the SIP house was, in fact, a better energy buy. 

Building Systems Magazine, May/June 2002

SIPs ON THE OUTSIDE, SIPs ON THE INSIDE TOO?

Thinking about who the reader of this newsletter is most likely to be, tells me that an article citing the familiar and conventional list of SIP construction advantages over stick construction would have you turning this page right about now……but not so fast! There are additional applications where SIPs might successfully replace conventional interior framing as well as be the material of choice for external "envelope" framing.

We were involved some time back with a proposal for in-fill housing in some pretty rough neighborhoods in a major east-coast city. It seems that the policy of the local community development not-for-profit organization was to bulldoze any abandoned dilapidated housing before it would become a crack house or continue to blight and depress the remainder of the housing on the street. There was great psychological advantage to having a blank lot rather than a dangerous ruin on the block. But soon enough, the empty lot might turn into a dumping ground or hangout for trouble waiting to happen. The best plan was to quickly get a new house up and operating on the site right away. 

The idea was to focus on speed. A design was arrived at that had kitchen, bathroom and stairwells worked into one module about 8-feet wide that would be factory plumbed, wired, furnished and finished that could be trucked to the site and craned into place. The rest of the building - two or three stories - was shipped as SIPs usually are, except with windows installed. There were so few remaining walls that it was decided to make them of SIPs for two reasons; it was thought that "changing horses in mid-stream" - using either metal or wood sticks, would only be less efficient in terms of organization, and that again, the SIPs would all be factory pre-cut and go up faster. We all have had experience with SIP envelopes going up in as little as two days, what was hoped for here - and priced into the proposal - was that the whole building would be up, closed in and locked up in less than a week.

Conventional construction with its associated conventional timetable allowed more a huge amount of "shrinkage." An open construction site was like a neon sign saying, "Come and get me!, Help yourself to plenty of Good Stuff!" This would significantly contribute to jacking up the cost of the project and make working on the project a nightmare. For example, just when the project was rough-plumbed and the walls scheduled for rocking, the contractor would show up the next morning only to discover that much of the piping had been ripped out so sheet-rocking couldn't take place. You can see how the cost and schedule would quickly spiral out of control. Being able to lock up very quickly didn't just have enormous value - it was everything! Unfortunately, this project did not get past design-development and pricing stage, but it was made clear by the development corporation that they didn't care about energy efficiency, or "green" anything, but just the security advantage, only possible with SIPs utilized for all the components. This project would have been a great success.

Another project that is still in the design stage at the time of this writing plans to utilize SIPs for the front and rear walls of this multi-story row housing and pre-cast, pre-stressed concrete for floor slabs bearing on steel framed party walls. The structure would require temporary construction bracing to prevent racking until the perpendicular interior frame walls are installed - and they would have to be engineered and built with diagonal bracing to resist racking through the life of the structure. All this would be tricky and expensive, with gobs of diagonal bracing in the way and then trashed when no longer needed. We could see that by installing the interior partitions of pre-cut SIPs as each floor went up, all the temporary bracing could be eliminated and the assembly schedule would be jumped ahead; all adding up to a significant savings for the project. Here we would be capitalizing on the tremendous racking resistance of SIPs.

It seems that I always come back to this theme: just utilizing SIPs in building stick translations which ignore the full range of strengths of the material does not serve the industry or the public fully. By selling SIPs "short" - by merely selling SIPs - we delay the time when SIPs will be the dominant material for combustible construction. The two examples cited above came out of group design efforts that had developers, architects, and panel manufacturers represented on the team. This non-traditional approach to the design process allowed for non-traditional solutions to rise to the top. Don't get me wrong, I've got nothing against building traditions - they are the best response to traditional problems. But these are new times with different, non-traditional problems. SIPs are a revolutionary material that can help solve many of the new issues we face in designing and creating today's built environment. New thinking must come along with this new material. I think we're just beginning to see what SIPs can do.

"R" Your Getting What You "R" Paying For?

When choosing an insulation, don't just compare the R-values generated under laboratory conditions. "Although the fundamental heat transmission characteristics of a material or system can be determined accurately, actual performance in a structure may vary from that indicated in the laboratory (20.3)*." The R-value of fiberglass insulation can be particularly deceiving, because the published R-values are based primarily on conductive heat. "For all types of insulating materials, conduction is not the sole mode of heat transfer (20.3)*." "The total conductance is the sum of a component resulting from radiation and a component resulting from convection and conduction combined. These components can vary independently of each other (20.8)*."

Fiberglass insulation manufacturers don't like to test their products for all forms of heat transfer because "The movement of air through an insulation system, either by natural or forced convection, has a deleterious effect on thermal performance (20.2)*." "Typical leakage rates in most structures are 6 to 10 air changes per hour (22.7)*". "Air movement by infiltration through a building envelope must be limited if the space is to be maintained at a condition different from outdoors (21.9)*." "Control of infiltration is an important strategy to assure thermal comfort and minimize energy use in buildings (22.7)*." Some "insulating materials can reduce air infiltration and provide additional fire resistance and noise control. Insulation also increases interior thermal comfort by controlling interior mean radiant temperatures resulting in more uniform air temperatures within the enclosure. Proper use of insulation can reduce the size of heating, cooling and ventilating equipment, reducing initial costs as well as annual operating costs (20.14)*." "It should not be assumed that leakage through the building envelope occurs primarily at doors and windows where there are visible joints. Studies have shown that leakage attributed to windows and doors constitute only about one-fifth of the total leakage. Leakage cracks and openings in walls and ceilings, especially at intersections, although not as obvious, make a far greater contribution to total leakage. Up to 70% of the total leakage openings were in walls, and up to 67% were through the ceiling, depending on the particular structure (21.9)*." "The infiltration of a building is proportional to its leakage area. Reducing the leakage area by 20% reduces the average infiltration of the building by the same percentage (22.16)*."

"The effectiveness of thermal insulation is seriously impaired when it is improperly installed. Where there is a 4% void area in R-11 wall insulation, the heat loss is increased by 15%. A 4% void in the insulation of an R-19 ceiling results in an increase of 50% in heat loss.* When thin wall insulation is installed vertically with air spaces on both sides, air interchange around the insulation increases the heat loss by 60% (20.8)*." "To attain published or claimed thermal resistance values, it is essential to provide convection and infiltration barriers, to seal cracks in joints and to install insulation so that gaps and voids around and within the materials do not occur. It has been established that 3% edge gaps (stapling batts on the inside of the studs) around insulation can produce 30% loss in effective R value (20.2)*." "A continuous air infiltration barrier is one of the most effective means of reducing air leakage through walls, around windows and door frames and at joints between major building elements (22.11)*." "Effectiveness can be greatly reduced if openings, even very small ones, exist in the retarder. Such openings can be caused by poor workmanship during application, poorly sealed joints and edges, insufficient coating thickness, improper caulking and flashing, uncompensated thermal expansion, mechanical forces, aging and other forms of degradation." Even an excellent vapor retarder is of little benefit if it can be bypassed by a current of air (20.10)*." "The function of insulation is clear; it reduces energy loss from a surface operating at a temperature other than ambient. Optimum use of insulation can: (1.) reduce operating expenditures for energy, (2.) improve process efficiency, (3.) increase system output capacity or reduce required equipment capacity and its capital cost and (4.) reduce overhead, maintenance, fire and personnel insurance, and other plant expenses. The most important benefit of insulation is the energy conserved and resulting savings in fuel and power costs (20.10)*."

In the average structures being built using fiberglass insulation, it is not uncommon to see 45% total heat loss in walls and 50% in ceilings. These figures do not take into account any loss of R-values due to compression in the cavities, which can add up to an additional 30%.

*Note: The above quotations are taken from the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) Fundamentals Handbook.