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HomeMy WebLinkAbout2020 energy code documentALLEN COUNTY, INDIANA BUILDING DEPARTMENT 200 E. Berry Street/Suite 180 FORT WAYNE, INDIANA 46802-1299 PHONE: (260) 449-7131 FAX: (260) 449-7596 JOHN E.CAYWOOD, Building Commissioner To: All Residential Contractors July 1, 2020 Re: Energy Code Compliance and the 2020 IRC This is just a reminder letter that Indiana has adopted a new 2020 Indiana Residential Code. Changes include Energy Code requirements that differ from the previous code. These changes will likely result in additional costs to the builder. Many events have happened in 2020 so far that bring difficulty to rolling out training and enforcement. This includes not having code books available until almost the end of Q1 as well as the ongoing pandemic. We will make every effort to transition smoothly to the new code in a manner that minimizes financial impact. However, we feel that this memo along with some additional training opportunities is sufficient notice. Therefore, contractors should expect full enforcement of the new energy code for all permits issued after October 1, 2020. Please note this is a State Code regardless of local enforcement. *IMPORTANT* Effective October 1, 2020, permit applicants will be required to submit initial energy code paperwork when applying for permits. This will prevent non-compliance issues related to energy code prior to the final inspection. This needs to be turned in just like the engineered wood affidavit is required. Attached is some helpful information that will provide some guidance The Building Department is working with the HBA on some additional training opportunities related to energy code this fall. I have at least two sponsors and will be looking for more. If your business is interested in partnering with us for training, give me a call. John Caywood Building Commissioner What has changed with the Indiana 2020 Energy Code Following the Prescriptive Code very little has changed from the 2009 IECC and the 2018 IECC as far as the home envelope insulation requirements for Climate Zone 5. Prescriptive Code: Was and is still is: Walls 2X4 = R-13(cavity) + R-5 Continuous Foam board on the outside. Note: No amount of insulation added to the wall cavity offsets the prescriptive requirement for continuous foam- board on the outside. Walls 2X6 = R-20 cavity insulation. This can commonly be achieved by spray foam + R19 batt or an R21 HD batt. Note: An R-19 fiberglass batt compressed into 5.5 inches cavity has an R value of 18. (The overall R-value of a R13+5 or a R-20 wall assembly are almost identical at R-17.25.) Windows: U-Factor .35 or better with no SHGC requirements. Attic Insulation: R-38 Under the 2012 Indiana Energy Code(2009 IECC), the air leakage rate was 7 Air Changes per Hour (ACH) to pass code. The 2020 Indiana Building Code requires it to be 5 ACH or less. Duct leakage was set at 8 cfm per 100 sq ft. Under the new code it has been reduced to 4 cfm per 100 sq ft. This is a significant change. It will require diligence for the HVAC contractor to meet this number. Sealing beyond this for additional credit will likely not happen. Under the old code, computer modeling shows a house built with 2x4 walls and OSB, better windows, better house leakage, better duct leakage, would perform the same or better than a prescriptive built house built with the maximum allowed leakage numbers. UNDER THE NEW CODE, THE LEAKAGE NUMBERS ALLOWED FOR THE HOUSE (ACH) AND DUCTWORK HAVE BEEN SEVERLY CUT. THIS FORCES IMPROVMENTS IN THE ENVELOPE/SHELL TO MAKE UP SOME OF THE CREDIT WE WERE PREVIOUSLY GAINING BY BUILDONG A TIGHT HOUSE. In really simple terms, the old computer simulated house had good insulation, but was very leaky. Under the new code it has good insulation and is not leaky. That is the basis for comparison. In order to continue using 2X4 walls with OSB there will have to be shell upgrades to compete with the computer simulated house. Energy Codes: Indiana adopted much of the 2018 IECC, but with an air leakage maximum of 5.0 ACH50 instead of 3.0 ACH50 for all pathways. This means every house must be blower door tested. All Pathways will require duct leakage of ≤ 4 CFM leakage to the outside. This means all homes will need duct tested if any part of the ductwork is outside the conditioned space. There are 4 pathways to the energy code compliance: 1) 2018 IECC Prescriptive 2) 2018 IECC UA Compliance 3) 2018 IECC Simulated Performance (with Indiana specific Cost Compliance) 4) ERI (Energy Rating Index Score 61) *Please note all pathways require blower door testing* **All pathways require duct testing if any portion of the ductwork is outside the conditioned space, this includes ductwork running under the slab** ***Every house will be required to have ASHRE compliant Mechanical Ventilation*** After reviewing all of the pathways, We have laid out a few templates to help comply with the new energy codes and address a few of the common questions we receive. The details are included on the attached pages. These are proven templates that will meet code. Work with your energy rater to dial in details to your specific home design. The simulated performance path will always provide you the most flexibility while still ensuring compliance. Common Performance Paths to Energy Code Compliance 2x4 walls with OSB: Wall Insulation: R- 15 or above. Most common R-15 HD Batts or ½ spray foam & R13 batt Attic Insulation: R 45 to R 49 depending on other house components (Energy raters can tell you with supplied plans) Windows: .32 U Value or better. Blower Door Testing at approximately 3 to 4 ACH. Exact requirement’s will be determined by your energy rater during planning. This will require strict attention to detail on all air sealing practices. Sealing all base plates, caulking around outlets, switch plates, light boxes, register boots, and any other penetrations through drywall. All walls, including top plates of ATTIC WALLS (Knee Walls) will need to be backed on all six sides (Top, Bottom, Front, Back, and Sides. *This includes top plates of walls connected to vaulted ceilings.* ßBiggest area missed on all homes Duct leakage of 4 CFM per 100 sq ft leakage to the outside: This is a very tight requirement. Special attention must be paid to sealing furnace cabinets, all duct connections, mastic must be applied at a thickness to ensure seams are sealed “thick as a nickel”. Flex connections to takeoffs and boots must be mastic then zip tied. Adjustable elbows mastic or foil taped. Returns ran down the wall cavities paned, caulked, and completely isolated from any surrounding wall cavities. Floor cavities should be avoided as return pathways. If they are to be used they must be caulked, sealed, panned. Special attention should be paid to joist to sub floor seams, wire penetrations, partition walls, subfloor seams. Approved fresh air ventilation. Energy rater can tell you how much ventilation is required based size and volume of the home. Final adjustments can be made after blower door testing. Common Performance Paths to Energy Code Compliance 2X6 Walls with OSB Sheathing ***This is a proven path to compliance, adjustments can be made with specific plans and component information for the home being built*** Wall Insulation: R-19 batt or above. Most common R-19 or ½ spray foam & R 19 batt. Attic Insulation: R-38 to R-45 depending other home components (Energy raters can tell you with supplied plans). Windows: .33 U Value or better. Blower Door Testing at < 5 ACH depending on design details. This will require good attention to detail on all air sealing practices. Sealing all base plates, caulking around outlets, switch plates, light boxes, register boots, and any other penetrations through drywall. All walls, including top plates of ATTIC WALLS (Knee Walls) will need to be backed on all six sides (Top, Bottom, Front, Back, and Sides. This includes top plates of walls connected to vaulted ceilings. Duct leakage of 4 CFM per 100 sq ft leakage to the outside: This is a very tight requirement. Special attention must be paid to sealing furnace cabinets, all duct connections, mastic must be applied at a thickness to ensure seams are sealed “thick as a nickel”. Flex connections to takeoffs and boots must be mastic then zip tied. Adjustable elbows mastic or foil taped. Returns ran down the wall cavities paned, caulked, and completely isolated from any surrounding wall cavities. Floor cavities should be avoided as return pathways. If they are to be used they must be caulked, sealed, panned. Special attention should be paid to joist to sub floor seams, wire penetrations, partition walls, subfloor seams. Approved fresh air ventilation. Your Energy Rater or HVAC Contractor can tell you how much ventilation is required based size and volume of the home. Final adjustments can be made after blower door testing. Mechanical Ventilation 2020 Indiana Residential Energy Code The 2020 IRC, Indiana will require fresh air ventilation on all new houses. The amount of fresh air required will depend on the size and air tightness on the home. The most common ways to meet the requirements are: Exhaust only: Exhaust fan that is usually ceiling mounted and directly vented to the outside that contains an ECM motor and variable flow rate. See Panasonic Whisper series fans for different models. Pros: Easy to install, can often take the place of a bath fan, low cost and energy efficient. Some feature automatic humidity controls. Cons: More than one may be required. If installation specs are not followed, they can be noisy. If not wired correctly, they can be shut off easily. Air Cyclers: ·a duct running from the outdoors to the return plenum ·an automated mechanical damper in this duct ·controls to ensure the air-handler fan runs periodically when there is no heating or cooling load When the air handler runs, fresh air is drawn in through the duct, mixed with return air, conditioned, and distributed through the duct system. During periods of low load, the CFIS controller will turn on the air handler fan periodically to guarantee that fresh air requirements are met. Pros: Relatively easy to plan for and install. Can be sized for almost any square footage. Cons: Cold dense air is being pulled into the HVAC system during the winter. Hot and humid air being pulled in during the summer. ***Note on Air Cyclers: Ducting fresh air to the return plenum without controls does not qualify as a mechanical ventilation system under RESNET Standards. It is just considered duct leakage, and will be included in the duct leakage measurement. This amount of duct leakage alone would make many houses fail. *** Balanced Systems: Commonly known as HRV and EVR systems. You will need to consult your HVAC contractor for system design. Pros: The best way to supply fresh air into the home. It makes heat recovery possible via an air to air heat exchanger. It is the most adaptable. Cons: It is the most expensive option.