“Spray Polyurethane Foam Insulation Build it Tight and Ventilate it Right” Part III

June 14, 2014

ImageIt’s time to reduce your carbon footprint and a great way to begin the process is to re-insulate your home.  You’ve been told that it’s a simple process of adding new spray polyurethane foam insulation in the attic.  You’ve been told that you can save up to 20% on your next energy bill.  You’ve also been told that you’re currently losing as much as 40% of your homes energy efficiency due to air infiltration.

Spray foam offers a solution: it performs as both insulation and an air sealant, or air barrier, closing those nooks and crannies that let air escape and add dollars to monthly energy bills. You’ve double checked what your SPF salesman has told you about the energy savings and found that the U.S. Environmental Protection Agency’s (EPA) Energy Star program estimates that by adding insulation and sealing air leaks you can save up to 20% on your monthly energy bills.

You’ve also found that the U.S. Department of Energy estimates that 56% of the energy used in a home goes to heating and cooling. Your home’s heating, ventilating, and air conditioning (HVAC) system has a big effect on your utility bills and your energy consumption because it has to work hard to keep up with all that air leakage.

You’ve done your homework and you’ve decided to move forward with your purchase and application of spray polyurethane foam insulation in your home’s attic.  You’re excited about increasing your “R” value and saving those energy bucks but still just a bit concerned about all those potential indoor air quality IAQ issues that you have been reading about while researching the energy savings of SPF.

Spray foam insulation can help reduce the workload on your HVAC system thanks to its high R-value and effectiveness. In fact, with spray foam, HVAC sizing can be reduced as much as 35% without the loss of efficiency and comfort.

With some luck you’ve read my previous articles and have asked some very critical questions prior to your decision.  Remember, there are differences between spray polyurethane foam insulation and blown or batt insulation that go well beyond the R value and energy savings.

All insulation products aren’t created equally and some insulation products provide much more than just R Value.  When you install spray polyurethane foam SPF insulation, you change the way your home performs.  You’re reducing your homes air leakage or air infiltration.  Great stuff right?  Well, yes and no.  Yes for energy efficiency – less is more analogy is a good thing; however, when it comes to your indoor air quality, IAQ, less is definitely not more and absolutely not better.

Your home’s air leakage or air infiltration rate is the source of the home’s air change rate ACH.  When you seal up your home you may also be substantially reducing your home’s ACH.  When you insulate with SPF you’re not just improving your home’s R-value, you’re changing the way your home achieves the ACH necessary to maintain good indoor air quality.

Today, we have very specific guidance documents that help both the consumer and the applicator better understand the difference between a traditionally ventilated attic and a SPF unvented attic.

Guidance on Best Practices for the Installation of Spray Polyurethane Foam established by the Spray Foam Coalition of the American Chemistry Council, ACC, Center for the Polyurethanes Industry states that the contractor and the homeowner should be aware that retrofitting an existing attic by employing an unvented attic assembly technique can result in the existing HVAC system becoming “oversized” in relation to the new demand.

This situation is of special concern in the southern and coastal climate zones where the HVAC also serves to reduce or otherwise manage moisture levels of buildings in order to improve comfort and prevent moisture related problems, such as mold and mildew. If an existing HVAC becomes “oversized” due to the increased thermal efficiency of the unvented attic assembly, the HVAC system may begin to short cycle, or to quickly turn on and off, as it works to manage temperature. This short cycling of the HVAC system may have negative impacts on the comfort and efficiency of the building and possibly on the lifespan of the system.

The guidance document recommends that the application contractor involve an HVAC consultant to adapt the system to the new, more efficient building envelope associated with the spray foam retrofit.

By far, the majority of the complaints I respond to are a direct result of inadequate ventilation and no method or design consideration for the now semi-conditioned attic.

The Spray Polyurethane Foam Alliance, SPFA Builder’s Reference Handbook, list the HVAC and Ventilation as one of their initial Design Considerations.

The SPFA Builder’s Reference Handbook recommends an Initial Evaluation “Test In” and a Final Evaluation “Test Out”
Initial Evaluation (Test-In)

The Initial Evaluation (Test-In) is a complete evaluation of the existing home before the installation of the SPF insulation.

Items to address and checked during the Test In can include:
•  Air Leakage Testing, to establish the air infiltration rate
•  Existing Attic Insulation (type location and recommended method of removal)
•  Inspection of Related Systems (e.g. HVAC, kitchen, and bathroom exhaust ventilation)
•  Combustion Appliances (reduced ACH and make-up air may be an issue as well as ventilation)
•  Energy Savings Estimate by independent trained professionals (BPI and RESNET)

The Test In air leakage testing is performed using a blower door to evaluate the home’s air leakage and natural ventilation before SPF application.  This is then used as a baseline for quality checks and energy savings estimates.  This test for existing homes should be performed before and after SPF installation.

This initial air leakage or air infiltration rate is the source of the home’s air change rate ACH with a traditionally ventilated attic.  The air infiltration rate is the volumetric flow rate of outside air into a building, typically in cubic feet per minute (CFM) or liters per second (LPS). The air exchange rate, (I), is the number of interior volume air changes that occur per hour, and has units of 1/h. The air exchange rate is also known as air changes per hour (ACHs).  ACH can be calculated by multiplying the building’s CFM by 60, and then dividing by the building volume. (CFM x 60)/volume.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has had a residential ventilation standard since 2003, ASHRAE 62.2.  The ASHRAE 62.2 minimum ventilation rate formula was set at 7.5 cfm per person plus 1 cfm per 100 square feet.

The standard assumes that the number of occupants in a home equals the number of bedrooms plus one. The ASHRAE 62.2 asserted that the formula used to determine the minimum airflow rate of ventilation equipment was based on the assumption that all homes deserve an “air infiltration credit” of 2 cfm per 100 square feet.  This was the assumption that the homes in and before 2003 had a good amount of air infiltration.  The homes built today with or without the use of SPF insulation are much tighter and have a substantially reduced air infiltration rate.

So while your home’s recommended minimum ventilation rate remained unchanged for many years, ASHRAE has recognized the tighter construction of today’s homes and 10 years after the initial ASHRAE 6.2, there are new changes to the 2013 version of ASHRAE 62.2.  Under the new formula, newer tightly built homes will need to be ventilated at a much higher rate, namely 7.5 cfm per person plus 3 cfm per 100 square feet. This means that for a tightly built 2,400-square-foot home with 3 bedrooms, the minimum airflow rate of the ventilation equipment has jumped 89%, from 54 cfm to 102 cfm.  Long story short, the 2013 version of ASHRAE 62.2 has eliminated the air infiltration credit on new tightly built homes.

Once you apply the Spray Polyurethane Foam Insulation in your attic, your home’s air leakage or air infiltration rate will be greatly reduced.  This is why the SPFA Builder’s Reference Handbook recommends the Test In and Test Out with the use of a blower door to establish your homes air leakage or air infiltration rate.  The Test Out your air leakage or air infiltration rate will determine the amount of outdoor air your home will require to meet the minimum ventilation rate or the ACH of 7.5 cfm per person plus 3 cfm per 100 square feet.

Final Evaluation (Test-Out)

The Final Evaluation (Test-Out) is also a complete evaluation of the existing home after the installation of the SPF insulation.

Complete Evaluation After Installation can include:
•  Air Leakage Testing
•  Repeat blower door test after installation
•  Inspect for air leaks in foam and repair
•  Confirm energy savings projections

The Test Out air leakage testing is once again performed using a blower door to evaluate air leakage and natural ventilation after the spray polyurethane foam insulation application.  This test is then used as the actual as-built air leak and natural ventilation rate.  The blower door test will provide you with your ACH by measuring your home’s actual amount of air leakage.  With this information, you will now know how much additional outdoor air the home will require to meet the minimum ventilation rate.

Among other issues the Test Out as compared to the Test In is the potential need for HVAC Modifications.  The SPFA Builder’s Reference Handbook states that “If application of SPF renders the home to be insufficiently ventilated, work with HVAC contractor to add mechanical ventilation or HRV/ERV.

SPFA Builder’s Reference Handbook clearly informs the application contractor that creating an unvented attic (UVA) with SPF can alter a home by:
•  Reduce uncontrolled air leakage
•  Lower HVAC energy costs
•  Improved insulation performance
•  HVAC system inside the building envelope operates under more moderate temperatures

Most HVAC systems are oversized to account for excess air leakage which directly affects the energy efficiency as well as effectiveness dehumidification.  The application of spray polyurethane foam insulation may actually allow for the downsize of the HVAC system for better performance.

Adjustments or downsizing of HVAC system may be needed to:
•  Achieve Good IAQ
•  Meet the minimum mechanical ventilation rate via outdoor air supply and a dehumidifier or ERV/HRV
•  Avoid short-cycling of AC system for proper dehumidification
•  Supplemental humidification/dehumidification to control relative humidity

To definitively establish the needs for any home once SPF has been installed and the traditional vented attic has been changed to an unvented attic, the use of a blower door must be used to establish the home’s natural ventilation rate and the homes mechanical system requirements must be properly calculated using a Manual J for load calculation, a Manual S for equipment selection, and a Manual D for proper duct design.

Without the known natural ventilation rate, you can only guess at the amount of outdoor air necessary to meet the minimum ventilation rate.  That is if you have even taken the ACH into consideration and added the necessary outdoor air supply.  With the known natural ventilation rate and the new R values, the homes HAVC can be correctly calculated and designed.

You would think knowing the impact of changing from a vented attic to a spray polyurethane foam insulated unvented attic that most home owners are performing the Test In and Test Out procedures.  In actuality, less than 10% of the homes I assess have had any form of Test In or Test Out performance evaluation.  It’s rare that the issue of ventilation or the home’s HVAC system is discussed at all.
Remember earlier in this article we discussed the Guidance on Best Practices for the Installation of Spray Polyurethane Foam states that the contractor and the homeowner should be aware that retrofitting an existing attic by employing an unvented attic assembly technique can result in the existing HVAC system becoming “oversized” in relation to the new demand.

The guidance document also recommends that the application contractor involve an HVAC consultant to adapt the system to the new, more efficient building envelope associated with the spray foam retrofit.

The Guidance goes on to further address the home’s ventilation system:

Important note about air Handlers
If a ventilation system that uses the HVAC air handler fan to provide the needed outdoor air (as is the case in many supply ventilation strategies) is used, it is imperative to ensure that the air handler fan operates often enough to provide sufficient fresh air. During periods of mild weather, or at night in the summer, the air handler fan may not be called on to run for several hours, so the house would get no outdoor air during these times. To address this, control units are now available that will ensure the house always gets the needed ventilation. If the air handler does not operate enough for sufficient ventilation, the monitors will call for the fan to operate and provide sufficient fresh air.

Typically, most homes need for the fan to run for between 10 and 20 minutes each hour to meet the home’s ventilation needs. An example of this type of fan control unit is the Aprilaire 8100.

The introduction of outdoor air not only affects the temperature in the house, it also impacts the humidity in the house. Here in Florida, the humidity can be a critical factor that is often overlooked. Our hot humid southern Florida outdoor air supply will require mechanical dehumidification. It’s critical to include ventilation air in the ACCA Manual J, Eighth Edition (J8) HVAC sizing calculations.

Mechanical System Calculations
Residential Mechanical System guidelines include:

•  Manual J:* Load Calculation
•  Manual S: Equip. Selection
•  Manual D:* Duct Design

Manual J
Manual J is the name for a specific protocol (often called “Heat Load Calculation” or “Cooling Load Calculation“) used to determine how much heating/cooling a home needs to stay cool and dry in the summer and warm in the winter. This load calculation process was developed by engineers in the heating and air conditioning industry and has been used for decades to accurately size heating and air-conditioning equipment. After completing this load calculation process, one can choose a properly sized piece of machinery to satisfy the load.

A Manual-J load calculation report provides three main pieces of information regarding heating and cooling load:
Heating Load: This is how much heat your house will require on the almost-coldest day of the year, in the middle of the night (when there’s no help from the sun). This is the number, or load, used to select a piece of heating equipment.

Sensible Cooling Load: This is the amount of sensible heat (the type you measure with a thermometer) that your system should be able to remove on the almost-warmest day of the year, during the daytime (when the sun is heating up the building). This is used, IN COMBINATION WITH the next load-type, to select the cooling equipment.

Latent Cooling Load: This load describes how much moisture your system should be able to remove under “worst-case” conditions. Worst-case for latent loads are typically when it’s hot and wet outside (daytime in the summer).

These three loads are used to select a piece of machinery that fits the loads (heat losses or gains) of your home. When selecting air conditioners or heat pumps, the two cooling loads should be used. And, the selected piece of machinery should be able to supply the proper amount of BOTH latent and sensible cooling, and be less that 15% over-sized, based on the Manual-J load calculation. This will ensure your system is capable of proper dehumidification (assuming the distribution system is performing properly).

Manual S
Proper equipment selection important and achieving occupant satisfaction is the principal goal of any HVAC design. Occupant satisfaction is maximized when the heating and cooling equipment are the correct type and size to meet the capacity requirements from the Manual J load calculation.  For residential equipment selections, ACCA’s Manual S, is the only procedure recognized by the American National Standards Institute (ANSI). If the Manual J load calculation is done then the next step is to select the equipment that will deliver the necessary heating and cooling.

Undersized equipment will not meet the customer’s comfort requirements at the design specifications.

Oversized equipment will create other problems:
•  Degraded humidity control in the summer.
•  Occupants may suffer the effects of an increased potential for mold growth. These same conditions also may contribute to asthma and other respiratory conditions.
•  The temperature may feel right at the thermostat but the temperature in other rooms will suffer from the oversized equipment going through short operation cycles. Short cycles can cause temperature swings as the equipment over-conditions, stops, then over-conditions, etc…
•  Hot and cold spots between rooms because the thermostat is satisfied but the room is not.
•  Oversized equipment generally requires larger ducts, increased electrical circuit sizing and larger refrigeration tubing. These cause higher installed costs and increased operating expenses.
•  The equipment starts and stops more frequently, this causes excessive wear and can increase maintenance costs more service calls.
In these unfavorable conditions occupants will experience discomfort and dissatisfaction.

Manual D
The next step is the duct design.  For residential air duct designs ACCA’s Manual D is the procedure recognized by the American National Standards Institute (ANSI) and specifically required by residential building codes. Air is the first word in air conditioning. If the network of ducts carrying the air is not properly designed then the health and safety of the occupant are at risk, the equipment could fail more quickly, the energy costs could rise, and occupant comfort might be sacrificed.

In order for home owners to be comfortable, a duct system must be designed to carry the right amount of air, at the right speed, into the right room. If the ducts are the wrong size then the wrong amount of air will enter the room and may cause:
•  The room to be too warm or too cool
•  The air to be too drafty and disturb people while they sleep, eat, read, etc…
•  The air to be too noisy and drown out conversations, TV or radio programs, etc…
•  The air to be too slow – the conditioned air will not circulate or mix well in the room.
•  The fan to work harder, possibly fail sooner, and use more energy to move air
•  The furnace or air conditioner safety devices to stop equipment operation
•  Pressure differentials that may increase energy costs by pushing out conditioned air or drawing in unwanted air

The design and installation of your homes HVAC system with your new spray polyurethane foam insulation SPF insulated home.
The issue of home performance and ventilation must become a more critical aspect of the spray polyurethane foam insulation SPF retro-fit sales pitch.  Understanding the performance changes within a home by altering the attic from traditionally vented to spray polyurethane foam insulation SPF unvented would eliminate a large portion of the SPF occupant odor complaints.

You might be thinking that the new construction homes have it made right?  Well, not so much.  Believe it or not, many new homes are designed with no alterations to the home’s ventilation system in the area of the ventilation rate (outdoor air) and the semi-conditioned attic space.  Many new homes actually have a reduction in size of the HVAC equipment as discussed earlier.  There is absolutely nothing wrong with altering the home’s HVAC system to accommodate the new tighter design and improved R-value; however, there is a huge issue with the builder not taking into consideration the reduced air infiltration, ventilation rate, or air changes per hour ACH. Carbon dioxide, CO2 emissions from the new building material and the dilution of the volatile organic compounds, VOC’s due to the homes ACH.

In a tightly sealed spray polyurethane foam insulation SPF home, the VOC’s accumulate in the attic. The VOC laden warm indoor air rises to the attic as the living space is cooled.  Over time, this accumulation, if not properly diluted, can actually make its way down into the living space from the attic.  The necessary outdoor air supply needs to properly dilute the new construction VOC’s.  It’s the accumulation of these volatile organic compounds, VOC’s that is often directly associated with the SPF.  Fortunately, we have well established studies of new construction homes with traditionally vented attics and no SPF insulation.  These SPF free new construction VOC’s can then be compared to the samples collected from new construction homes with SPF insulation and unvented attics.  If the SPF is bad, the VOC signature will be different than that of a traditional home with no SPF. It seems simple right?  Well, there remain those that sample heavy and look at nothing when it comes to SPF insulation and simply point to the SPF insulation without addressing the home as a whole.

When assessing the condition of any home with SPF insulation and occupant complaint, the home must be inspected as a whole.  The inspection must include the design and performance of the home.  For these new construction inspections there are two specific areas of concern other than the physical inspection of the installed SPF.  First, is the home’s ventilation rate.  We need to know what the home’s ACH is and we need to know if we are at least attaining the minimum ACH recommended by the ASHRAE 62.2.  Second, is the ventilation design of the semi-conditioned attic space.  How is the homes semi-conditioned attic being addressed and ventilated?

These are the primary factors in a home’s ability to properly condition and maintain the indoor environment.

No air circulation in the unvented attic will lead to an elevation of heat, humidity, and VOC’s.  There must be a specific method of circulating air through the semi-conditioned attic space.  If you don’t take ownership of this space in your ventilation design and you assume that the space will be passively semi-conditioned, be prepared to meet me on site at a future date.  We’re not talking about fully conditioning the space by installing supply and return vents in the attic. You need to move air through the semi-conditioned attic.  If you don’t, the attic simply isn’t semi-conditioned.  It’s unconditioned unvented attic space that will soon be a source of odor and occupant complaint.

So you may be asking just how we establish the new construction ventilation rate and method of semi-conditioning the attic.

Final Evaluation (Test-Out)
The Final Evaluation (Test-Out) is also a complete evaluation of the new-construction home after the installation of the SPF insulation.

Complete Evaluation After Installation can include:
•  Air Leakage Testing
•  Blower door test after installation
•  Inspect for air leaks in foam and repair
•  Confirm energy savings projections

The Test Out air leakage testing is performed on the new construction home by using a blower door to evaluate air leakage and ventilation with the unvented attic insulated with spray polyurethane foam.  This test is then used as the actual as-built air leak and natural ventilation rate.  This test and amount of measured actual natural ventilation will tell us exactly how much additional outdoor air is necessary to meet the minimum ventilation rate.  The SPFA Builder’s Reference Handbook states that “If application of SPF renders the home to be insufficiently ventilated, work with HVAC contractor to add mechanical ventilation or HRV/ERV.”

You hear the real estate professionals repeating it’s all about the “Location, Location, Location.”  Well the indoor air quality guy says it’s all about the “Ventilation, Ventilation, Ventilation!”

So at the risk of being overly redundant, ventilation cannot be stressed enough in a home with spray polyurethane foam insulation and an unvented attic.

Any home with spray polyurethane foam insulation and an unvented attic must have a method of semi-conditioning the unvented attic to provide the necessary air circulation to prevent the accumulation of heat, humidity, and VOC’s.  That can’t be found in expensive air sampling for VOC’s.

Any home with spray polyurethane foam insulation and an unvented attic must establish the necessary minimum ventilation rate necessary to prevent occupant complaint while providing good indoor air quality.  That can’t be found in expensive air sampling for VOC’s.

However, both can be identified by measuring the homes performance and the use of a blower door test.  And both can be improved and/or corrected once the actual performance testing has been completed.

So reduce your carbon footprint and save those energy bucks.  Spray polyurethane foam insulation is a great home improvement method of saving energy.  Just remember one thing; if your home is ventilated the same way after the installation of spray polyurethane foam insulation you haven’t finished the home improvement process.

Ventilation, ventilation, ventilation……………..

To learn more about Mr. Lapotaire or Indoor Air Quality Solutions & Microshield Environmental Services, LLC, please visit www.FloridaIAQ.com, email info@FloridaIAQ.com or call (407) 383-9459.

About Indoor Air Quality Solutions & Microshield Environmental Services, LLC

Since 2001, Florida residents have turned to the indoor environmental experts at Indoor Air Quality Solutions & Microshield Environmental Services, LLC.  The family owned and operated companies, based in the Orlando area, offer a comprehensive approach to identifying and correcting comfort and indoor air quality problems.  Their expert staff utilizes the latest technologies and industry recognized standards to identify and resolve indoor environmental issues.

John P. Lapotaire, CIEC

#IAQS

 


“Is Spray Polyurethane Foam Insulation right for you?”

June 14, 2014

ImageSpray Polyurethane Foam SPF insulation is a great way to tighten up your home and save a few of these precious energy dollars.  We are seeing more SPF use in new construction than ever before and the retrofit market is a boomin.

This article will discuss some of the critical questions all prospective SPF consumers must ask when deciding if Spray Polyurethane Foam Insulation is right for them.  As good as SPF insulation is for energy savings, sometimes it’s just not a good choice for an existing home.

The takeaway… I hope readers understand that there are specific issues that should be taken into consideration when making the decision to install Spray Polyurethane Foam SPF insulation in your home.

We should probably begin with a short explanation of the objective for installing SPF insulation.  It seems simple, right, you’re just adding R-value to your home to save a few energy bucks.  Well, yes and no.  Most importantly is the how you would be improving your home to save those energy bucks.  The SPF will literally seal your home with the intent of preventing air infiltration and exfiltration.   Infiltration is the unintentional or accidental introduction of outside air into a building, typically through cracks in the exterior walls, ceilings, attics, and through use of doors and windows. This outdoor air infiltration is often refered to as air leakage.  In laymans terms, unconditioned outdoor air from getting in your home and conditioned indoor air from escaping your home.

In typical newer U.S. homes, about one-third of the HVAC energy consumption is due to infiltration, so reducing air infiltration saves energy bucks.  Controlling the air infiltration in turn makes it easier for your home’s HVAC Heating Ventilation and Air Conditioning system to heat, cool, and maintain your indoor thermal comfort.  That’s right, were talking about indoor thermal comfort not indoor air quality.

The energy savings is the direct result of substantially reduced air infiltration and exfiltration due to the sealing capability of the SPF insulation.  It truly is great for reducing the amount of energy bucks needed to heat and cool your home.  Your homes HVAC system now only has to contend with the newly sealed indoor environment which now includes the semi-conditioned attic.

We’ll get to the “semi-conditioned” attic in a bit but for now, let’s first talk about something else that is substantially reliant on the home’s air infiltration and exfiltration rate.  That would be the home’s necessary ventilation rate.

The infiltration rate is the volumetric flow rate of outside air into a building, typically in cubic feet per minute (CFM) or liters per second (LPS). The air exchange rate, (I), is the number of interior volume air changes that occur per hour, and has units of 1/h. The air exchange rate is also known as air changes per hour (ACHs).  ACH can be calculated by multiplying the building’s CFM by 60, and then dividing by the building volume. (CFM x 60)/volume.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has had a residential ventilation standard since 2003, ASHRAE 62.2.  The ASHRAE 62.2 minimum ventilation rate formula was set at 7.5 cfm per person plus 1 cfm per 100 square feet.

The standard assumes that the number of occupants in a home equals the number of bedrooms plus one. The ASHRAE 62.2 asserted that the formula used to determine the minimum airflow rate of ventilation equipment was based on the assumption that all homes deserve an “air infiltration credit” of 2 cfm per 100 square feet.  This was the assumption that the homes in and before 2003 had a good amount of air infiltration.  The homes built today with or without the use of SPF insulation are much tighter and have a substantially reduced air infiltration rate.

So while your home’s recommended minimum ventilation rate remained unchanged for many years, ASHRAE has recognized the tighter construction of today’s homes and 10 years after the initial ASHRAE 6.2, there are new changes to the 2013 version of ASHRAE 62.2.  Under the new formula, newer tightly built homes will need to be ventilated at a much higher rate, namely 7.5 cfm per person plus 3 cfm per 100 square feet. This means that for a tightly built 2,400-square-foot home with 3 bedrooms, the minimum airflow rate of the ventilation equipment has jumped 89%, from 54 cfm to 102 cfm.  Long story short, the 2013 version of ASHRAE 62.2 has eliminated the air infiltration credit on new tightly built homes.  Guess where SPF insulated homes fall?  Right smack dab in the middle of the (as designed) tightly built category.

Questions to Ask Your SPF Contractor Prior to Install
SPF Consumer Question Number 1; How will you determine whether or not my home will meet or exceed the minimum ventilation rate once the SPF insulation is installed?

This is one of the most important questions every prospective SPF consumer must ask.  It involves the necessary air changes per hour (ACHs) to ensure that your home does not accumulate indoor contaminants and you have healthier air to breathe.  With SPF insulation, you will most likely require dedicated outdoor air supply to meet the minimum ventilation rate.  If your newly SPF insulated home does not meet the minimum ventilation rate, your home will accumulate contaminants and there will be occupant complaints.

I’ve inspected homes with reported SPF nusiance odors that are well over 50 years old all the way to homes that are only a year or two old.  The issues with new and old homes by and large remain the same.  The most critical is the ventilation rate of the home.  Unfortunately, the extremely important and necessary ventilation rate of the home is rarely discussed and almost never addressed when the home is changed from traditionally ventilated to sealed and semi-conditioned.  Your home’s HVAC system and ventilation rate must be discussed.

Now let’s talk about the “semi-Conditioned” attic.  Semi-conditioned means that your attic that was once naturally cooled through traditional attic “outdoor” air circulation, soffit, gable, and roof vents, is now cooled or conditioned through “indoor” air circulation.  The code refers to these two attics as vented and unvented attic assemblies.  With your new sealed attic you must seal these soffit, gable, and roof vents.

The unvented or semi-conditioned  state of the attic is critical.  For example, if the old attic insulation is left behind to save a few bucks the attic cannot be properly cooled.  If the home’s attic isn’t properly cleaned, the accumulated attic debris will enter the home and cause issues with the occupants.  To put it to you straight, what’s in the attic will now be circulated within your home.  It’s as simple as that.

SPF Consumer Question Number 2; How will you clean my attic and prepare it to be a semi-conditiond attic space?
Anyone interested in installing SPF in their attic must take into consideration the age of their home and the condition of their attic.  Any home that is retrofit with SPF can have some rather odd contributors to occupant discomfort and nuisance odors that will now become much more concentrated when the SPFI is installed.   Most of these contributors come from the old now sealed and semi-conditioned attic.

Some of these contributors to occupant discomfort include the storage of materials in the now sealed space, attic insects and/or rodent activity, routine household pest control applications, the previous insulation including the condition and material, and the proper ducting of kitchen and bath fans.  The possibilities are endless and all must be considered and reviewed prior to the installation of the SPF.  Remember, what has accumulated in the attic is now trapped within the now sealed semi-conditioned attic.  The semi-conditioned attic now shares circulated air with the living space of the home.

Our Example Home
To help our readers understand the SPF sales process a little better, let’s establish an example home; one that I actually assessed.  Let’s say our example home is a three bedroom, two bathroom, two car garage, 60 year old single story ranch style home.  Our homeowners have lived in the home for the last ten years and have decided to save a few energy bucks on their quest to be greener. Their first step was to install open cell SPF insulation at the roof sheathing.   This was a pricy step in the green direction, but they were able to shave a few bucks off the bottom line by not removing the old insulation or cleaning the attic.  No big deal according to the SPF applicator.

So what, who really cares if the insulation remains in the attic and the attic wasn’t cleaned? It’s really about the energy savings right?

Oh and what about the bathroom exhaust fans in that 60 year old home.  The 60 year old code allowed the bathroom exhaust fans to be ducted to the old ventilated attic and that’s exactly where they are now, ducted to the newly sealed attic.  Many homes built back then also had the kitchen exhaust hood ducted to the attic.  These bathroom exhaust fans must be ducted to the exterior of your home or you may continue to save energy but you’ll slowly be filling your home with humidity and contaminants.

Oh and what about the bathroom exhaust fans in that 60 year old home.  The 60 year old code allowed the bathroom exhaust fans to be ducted to the old ventilated attic and that’s exactly where they are now, ducted to the newly sealed attic.  Many homes built back then also had the kitchen exhaust hood ducted to the attic.  These bathroom exhaust fans must be ducted to the exterior of your home or you may continue to save energy but you’ll slowly be filling your home with humidity and contaminants.

I’m not stretching the example here.  These are real issues with many retrofit SPF applications.

What about the series of rodent issues in that 60 year old home?  Let’s face it; there are a lot of homes out there with rodent and insect issues.  Some pest control companies trap the feisty little critters while others choose to poison them.  In our example home, a liberal use of poisons and traps were used.  There were several remaining bait pods and traps with rat carcasses at different stages of decomposition.  The remaining pesticides can be a serious threat to occupants if not properly cleaned. The rodent urine and fecal matter are a substantial concern when trapped inside a now sealed semi-conditioned attic that shares circulated air with the living space of the home.

Well, to say the least, as with our example home, you can easily have a huge list of contributors to occupant discomfort and nuisance odors if the attic space isn’t properly addressed.

Most of the SPF insulation investigations I am called in to review the above issues were overlooked simply because of the recent application of SPFI.

Indoor Environmental Professionals IEP’s conducting SPF investigations must remain unbiased and open minded and remember that it’s not necessarily the SPF insulation that is producing the odor or contaminate that’s causing occupant discomfort.  It is however the SPF insulation that is now eliminating the natural ventilation of the attic which is now preventing the odors and contaminants from leaving the home.  This causes an accumulation of odors and contaminants if the necessary ventilation rate is not met and the source has not been properly addressed.  In the above examples, that source of the odors and contaminants were the remaining insulation and debris in the now sealed attic.  The SPF was the last change in the home and therefore the scapegoat or go-to cause and origin of the odor, the straw that broke the camel’s bake so to speak.

The newly installed SPF insulation has now trapped the odors and contaminants within the semi-conditioned space.  In the cases above, the home also had no dedicated outdoor air supply necessary to meet the minimum ventilation rate.  If the home met the minimum ventilation rate, the accumulating VOC’s from daily use of products could quite possibly have been adequately diluted ending the nuisance odors and occupant complaints.

So we come to the point where you’ve decided to move forward with your SPF insulation and your contractor has agreed to install dedicated outdoor air supply and thoroughly clean your attic once he has removed all of the old insulation.  Good start.  Now you need to address the issue of exactly how the application contractor will be ventilating your home during the application to prevent the accumulation of the SPF chemicals from entering your home.

SPF Consumer Question Number 3; How will you ventilate my home during the SPF application to prevent the contamination of my home and personal belongings.

There are many factors to consider when planning your SPF installation.  One of the most important is how the application contractor will protect your home while insulating your attic.  Your application contractor should assess the home’s ventilation needs before the job starts and develop a ventilation plan to ensure the SPF chemicals do not enter the home during application.

Understanding ventilation requirements is essential. For example, shut down HVAC systems during a SPF application. System shut-down stops dust, aerosol and vapors from being drawn into the HVAC system. Once the project is completed and the spray area ventilated, SPF odors generally dissipate. Lingering odors may be the result of several contributing factors as previously discussed and can be a combination of numerous sources, making it difficult to identify them. Sources of odors in new construction and retrofit applications can include: SPF; other construction materials, such as paints, cleansers, lumber, finishing treatments; occupant life style; nearby industrial or other emissions; pre-existing (“old house”) odors; construction defects, such as misrouted plumbing vents; or high individual sensitivity.

For interior applications, this can help prevent airborne materials from being distributed from one part of a building to another. Once the HVAC system is shut down, seal the air intakes with plastic sheeting and tape to prevent dust and spray from entering the system. Some SPF manufacturers recommend that the HVAC system stay sealed and inoperable for up to 24 hours after the SPF application.
A home that is not properly protected by correctly ventilating the attic can be irreversably damaged.  The chemical odors can remain for extended periods of time.  Often, occupants can become sensitized to the remaining chemicals.  Proper ventilation during application is necessary.

In many homes, the HVAC system is located in the attic.  If your home’s air handler and ducts are in your attic, you must ensure that they are properly sealed and protected to ensure you don’t end up with an additional and costly repair to your HAVC system.  If your HVAC system isn’t properly shut down, your HVAC sytem can very easily contaminate your home by circulating the SPF chemicals through your air handler directly into your home.

Odors may be noticed within areas of the building; for example, specific rooms, or when taking or examining a core sample. Document the presence of odor, describe its characteristics with specific adjectives such as “fishy,” or “rotten egg,” along with where and under what conditions it was noticed.

U.S. Environmental Protection Agency’s “Ventilation Guidance for Spray Polyurethane Foam Application”: http://www.epa.gov/dfe/pubs/projects/spf/ventilation-guidance.html.

SPF Consumer Question Number 4;  How will you ensure that my home’s HVAC system is shut down and protected during the SPF application?

It is critical that your SPF application contractor turn off your HVAC system and seal the air handler so overspray does not enter the system.  If your home has gas powered equipment, your SPF application contractor must direct the exhaust fumes to an open environment to prevent a buildup of carbon monoxide in the work area.

I’ve seen many air handlers destroyed by overspray and chemicals that were drawn into the air handler and distributed throughout the home.  I’ve even had one contractor tell me that the shut down was not necessary because his SPF was so safe his installers didn’t need to wear protective equipment other than goggles.  By the way, that couldn’t be further from the truth and that application contractor was immediately reported to the manufacturer.

There must be a more than passive attempt at protecting your home and properly ventilating your attic during and after application.  Remember to ask for the application attic ventilation, HVAC shut down and protection plan in writing.  You will want this as a part of your permanent record.  Then prior to the start of application, ask the application contractor to walk you through and show you the ventilation and HVAC protection.  It’s your home and nobody will be as dedicated to the protection of your home and personal property than you.

Then leave your home until the application is complete and do not return until the manufacturers established reoccupancy time has elapsed. No peeking!

SPF Consumer Question Number 5;  When will it be safe for me to return to my home?

Vacate building occupants and non-SPF personnel from the building during the application of SPF and for a period of time following the completion of spraying. Where this is not possible or practical for large commercial buildings, the use of containment and ventilation techniques can be utilized. For residential applications, the homeowner needs to vacate the home and return only after the specified re-occupancy time.

Communicate with other trades working in proximity to the spray application area. Giving notice to other trades is an important aspect on larger commercial projects due to the number and kinds of workers in and around the jobsite.

Provide notice to trades and occupants The focal points for this communication are the general contractor, building owner, home owner, or other responsible personnel for the project. Educate the onsite supervisor or project manager at the start of the project long before the actual spray application starts so  they have a complete understanding of the jobsite safety requirements before the beginning of the spray application process. Critical jobsite safety concerns include proximity of open flame sources and personnel to the spray application area.

If you are present during application or too soon after application, you run the risk of SPF sensitization due to exposure.
With sensitization occupants have either re-entered the property shortly after the foam is applied or well before the manufacturer recommended re-occupancy time of 24 to 48 hours. In the most severe cases of occupant sensitivity, the exposure actually took place during the application of the SPFI.

There are many occupants who have become sensitized or allergic to the odors given off from SPF for simply wanting to see the application, or refusing to leave their home during application, or returning to their home too soon.  Regardless of the reason for the exposure, the SPF application contractor should never continue to apply while anyone is present and must ensure that no body is present or reoccupies before the manufactures reoccupancy time period has elapsed.

Adding to the sensitization of the occupants is the lack of proper ventilation during the application. Venting of the off-gassing of the SPFI during application is critical and often not conducted at all. In all cases of occupant sensitization that I have been involved with, the SPFI application was not properly vented to the exterior which created a substantial accumulation of the off-gassing chemicals within the property. These trapped volatile organic chemicals VOC’s are what sensitizes the occupants who have either re-occupied too early or were present during the SPFI application.

Unfortunately, any attempt at reducing the occupant’s exposure to the newly installed spray polyurethane foam insulation may not provide any relief. I’ve had no luck in helping sensitized occupants. I’ve been involved in everything from the introduction of outdoor air through a pre-filter and dehumidifier to control the temperature, humidity, particles, path, and pressure to full SPF removal.  Unfortunately, some bells can’t be un-rung.

If you’re interested in saving those energy bucks with the application of SPF you must ensure that these steps are taken to ensure the proper application and safety of your family.

So back to our Example House
What exactly went wrong with our 60 year old example home discussed earlier?  Who was responsible for the occupant complaints associated with the newly installed SPF insulation?

Well, the application contractor sold the homeowner SPF for the purpose of greening up the home and saving a few of these elusive energy bucks.  It was an expensive step in the green direction but one that was going to pay off at the end in the form of saving a few energy bucks.  What the contractor didn’t discuss were the issues reviewed in this article.

Here is what our homeowner should have discussed with their application contractor prior to install;
1. The possible need to re-evaluate the homes HVAC system
2. The newly sealed home’s ventilation rate and possible need for dedicated outdoor air supply
3. The condition of the home’s 60 year old attic
4. The removal of the home’s existing insulation
5. The sealing of the existing open soffit and roof vents
6. The possible termination of the bathroom exhaust fans into the attic
7. The possible termination of the kitchen exhaust hood into the attic
8. The sealing of the home’s HVAC system during the application of SPF
9. The ventilation of the home during the application of SPF
10. Occupancy during the application of SPF and Re-occupancy after SPF application

Our example 60 year old home was later blower-door tested and as expected, it didn’t even come close to the minimum ASHRAE air exchange rate.  With the SPF insulation and without dedicated outdoor air supply, the home had no chance of meeting the minimum ventilation rate.  Unfortunately, for the occupants, the semi-conditioned attic had 60 years of accumulated dust, debris, fiberglass, rodent and insect urine, fecal matter, pesticides and who knows what.

In an effort to keep the bottom line sales price of the SPF as low as possible, the SPF contractor sold the SPF insulation without the following additional considerations that would have led to additional expenses and an increased bottom line sales price.  Let’s face it, while most reputable SPF contractors will review all aspects and necessary steps involved with SPF.  There remain some SPF application contractors who are there to sell SPF and don’t want to lose a sale.  Remember to pay attention to the SPF sales rep that has not listed the following in their sales price or stresses that they are unnecessary expenses.

With our example house, the SPF salesman omitted the following;
1. Sealing the existing soffit and roof vents
2. Removing the existing Insulation
3. Properly cleaning the attic
4. Relocating the bath and kitchen exhaust ducts to the exterior of the attic
5. Installing dedicated outdoor air supply to meet the necessary minimum ventilation rate

Remember the ventilation rate and dedicated outdoor air supply is a critical part of SPF insulation.   Unfortunately, I find the ventilation rate all too often overlooked.  As a professional investigating SPF insulation, you have to ask questions beyond the obvious.

You have to ask relevant questions such as;
• “What is the condition of the new semi-conditioned attic space?”
• “What have the occupants been sealed in with?”
• “How is the ASHRAE minimum ventilation rate being met?”
• “How is the semi-conditioned attic space actually being semi-conditioned?”

In addition to these permanent and critical physical changes to our example home, the SPF salesman also omitted several temporary but also very critical steps necessary to protect the occupants, their personal belongings, and the home’s HVAC system.

These very critical and necessary steps included;
1. Sealing the homes HVAC system
2. Properly ventilating the attic during and after application
3. Properly vacating the home during and after application
4. Establishing the necessary reoccupancy times for the occupants

Both the permanent and temporary steps associated with SPF insulation must be addressed for the proper installation of SPF.  Exposure to the old filthy attic can be very unhealthy to occupants.  Exposure to SPF during application or too soon after application can cause irreversible sensitivity to SPF and the related SPF chemicals.

The Bottom Line
When it comes to Spray Polyurethane Foam Insulation, the product, when correctly installed, is great and can be a wonderful energy saving feature to your home new or old.  However, all potential SPF consumers must do their due diligence and ask the right questions to ensure the proper temporary installation steps are followed during application.  In addition, you’ll need to know the questions to ask to identify any possible permanent alterations to your home to ensure that the SPF performs properly and does not have a negative impact on you and your family.

So “Is Spray Polyurethane Foam Insulation right for you?” 

The answer is in the sum of all of the above questions once asked and answered.  Ultimately, you’ll have to weigh the cost associated with properly installing the SPF insulation.  You’ll need to balance that with the possible cost associated with retrofitting your home to ensure your sealed attic and home performs as designed.  To get your long term energy savings and maintain your home’s indoor air quality, you’ll need to pony up these energy bucks up front and reapply the energy savings return over time.

It’s your money and your choice; hopefully, this article helped you make a more informative choice.

 

To learn more about Mr. Lapotaire or Indoor Air Quality Solutions & Microshield Environmental Services, LLC, please visit www.FloridaIAQ.com, email info@FloridaIAQ.com or call (407) 383-9459.

About Indoor Air Quality Solutions & Microshield Environmental Services, LLC

Since 2001, Florida residents have turned to the indoor environmental experts at Indoor Air Quality Solutions & Microshield Environmental Services, LLC.  The family owned and operated companies, based in the Orlando area, offer a comprehensive approach to identifying and correcting comfort and indoor air quality problems.  Their expert staff utilizes the latest technologies and industry recognized standards to identify and resolve indoor environmental issues.

John P. Lapotaire, CIEC

#IAQS


Spray Polyurethane Foam Insulation

June 13, 2014

ImageWelcome to part one of a four part series on Spray Polyurethane Foam SPF Insulation.  Spray polyurethane foam SPF insulation, the best thing since sliced bread, the greatest energy saving “Green” insulation available, Right?

I can’t remember a building product with such a clearly defined love or hate following.  When I say love, it’s typically described by the “Green” movement as I did above, safe, energy efficient, “Green”, and even healthy. That’s right!  It’s often touted as a product that will improve your indoor air quality.  These guys are hard core supporters and believers, a solid mix of manufactures, applicators, builders, and homeowners.

But if you’re on the hate side of the issue, you’re just as emotionally involved in the product.  You just see things from a different perspective.  Often the hate side of the love-hate relationship evolves from a regrettable spray polyurethane foam insulation experience, a botched job, miss-application, or unfortunate exposure to the SPF chemicals.  If your opinion of SPF is based on any of these issues, then your opinion is based on a vivid and tangible perspective based on a very personal experience.  That will drive passion.

How to ensure that your home has SPF installed properly and what you need to ensure your applicator knows his “stuff” is the reason for this series. While the products are all very similar, it’s the applicator and his or her training and experience that truly matters.  Following at a very close second, is your home and the impact of the sealed attic has on your existing home.
In the next few editions, we are going to discuss the unadvertised side of SPF.  Let’s face it, the industry has a great marketing department and the product works great when properly applied.  So we’ll be discussing the issues with misapplied SPF as well as the design changes that accompany altering a home’s attic from natural (passive) ventilation to a sealed mechanically semi-conditioned attic.

It’s very important to understand the specific changes that take place when you seal your attic.  There are factors that must be considered such as a 50 year old attic with an accumulation of dust, debris, and possibly pesticides that are now a sealed attic and part of the indoor environment. NOT good. I personally don’t feel that any SPF applicator can clean a 50 year old attic well enough for me to feel comfortable breathing the now shared attic air that is now semi-conditioned occupied space.  And that is exactly what will happen when you seal an attic and semi-condition it.

We’ll take a closer look at how to investigate SPF complaints and how to identify miss-applied SPF.  For example, some would prefer to collect air samples to identify the chemicals present in your home and attic as you see in photos A and B.  That will run you somewhere around $5,000.00. Ouch…

Or you can actually inspect the applied SPF and identify areas of unreacted SPF as shown in photo C or SPF on light fixtures as shown in photo D.  This approach will cost you or your builder nothing and the industry provides the guidance documents for the inspection.  Both approaches will provide you with information but the information gathered from the actual inspection of the applied product will provide more relevant information.

Whether you are a lover or a hater, these articles will provide you with solid information for spray pollyurethane foam insulation.
If you are trying to decide if SPF is going to be a part of your home’s remodel, addition, or home improvement, then the article titled “Is Spray Polyurethane Foam Insulation right for you?” will be good information.  This article will help inform you of a few issues with an existing home with a traditionally vented attic that you may be considering reinsulating with SPF.  As good as SPF insulation is, sometimes it’s just not a good choice.

If you want to know how SPF can compromise your indoor air quality even when it is correctly installed then the article titled “Spray Polyurethane Foam Insulation Build it Tight and Ventilate it Right” will be the series article for you.  A tightly sealed home will not meet the required ventilation rate and will require outdoor air supply.  Depending on where you live, this may require the use of an ERV (energy recovery ventilator), an HRV (heat recovery ventilator), or a mechanical dehumidifier.  All three will require alterations to your homes HVAC (heating, ventilation, and air conditioning) system.

If you want to know what it takes to properly inspect applied Spray Polyurethane Foam Insulation, then the article titled “Inspecting Spray Polyurethane Foam Insulation What to Look For” will be perfect for you.  So you have an issue with your installed SPF, what is your next step?  Do you hire a chemist? An IAQ indoor air quality consultant? Well, I believe you should hire someone who is extremely familiar with inspecting the SPF.  Not just someone that has performed several SPF inspections but someone familiar with SPF.  Yes, there is a substantial difference.  Many who provide SPF investigations never look at the SPF.   They simply collect air samples and declare the product as dangerous and in need of removal.  While SPF can be misapplied, the issues with SPF aren’t always the result of misapplied SPF.   This article will help clarify who and how to properly inspect your installed SPF.

Stay tuned for great information regarding the use and misuse of Spray Polyurethane Foam Insulation.

 

To learn more about Mr. Lapotaire or Indoor Air Quality Solutions & Microshield Environmental Services, LLC, please visit www.FloridaIAQ.com, email info@FloridaIAQ.com or call (407) 383-9459.

About Indoor Air Quality Solutions & Microshield Environmental Services, LLC

Since 2001, Florida residents have turned to the indoor environmental experts at Indoor Air Quality Solutions & Microshield Environmental Services, LLC.  The family owned and operated companies, based in the Orlando area, offer a comprehensive approach to identifying and correcting comfort and indoor air quality problems.  Their expert staff utilizes the latest technologies and industry recognized standards to identify and resolve indoor environmental issues.

John P. Lapotaire, CIEC

#IAQS


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