[{"data":1,"prerenderedAt":165},["ShallowReactive",2],{"guide-erv-hrv-makeup-air-nyc-en-US":3},{"guide":4,"related":146},{"title":5,"seoTitle":6,"description":7,"summary":8,"sections":9,"faq":109,"cta":116,"date":118,"updated":118,"service":119,"order":120,"sources":121,"slug":144,"locale":145},"ERV vs HRV and makeup air for New York homes","ERV vs HRV and Makeup Air in New York Homes","ERV vs HRV for New York homes, how much fresh air a tight house needs, range-hood makeup air under NYC and NYS codes, bath exhaust and MERV 13 filters.","Once a home is air-sealed, re-windowed or gut-renovated, it needs planned mechanical ventilation. For most New York City and Long Island homes the default is a balanced energy recovery ventilator (ERV), because it retains some winter moisture and reduces summer humidity from incoming air. Powerful range hoods need makeup air, and New York City's Mechanical Code sets its own requirement, separate from the rest of the state. Good bath exhaust and MERV 13 filtration complete the system.",[10,16,43,54,65,74,79],{"heading":11,"paragraphs":12},"A tighter house needs planned ventilation",[13,14,15],"Air sealing, new windows, spray foam and dense-pack insulation cut the accidental air exchange that once ventilated older houses. Moisture, carbon dioxide, odors, cooking particles and, with gas ranges, nitrogen dioxide now stay indoors longer. Energy codes pair tighter construction with whole-house mechanical ventilation, so a gut renovation of a brownstone, a Queens two-family or a Long Island cape should carry a ventilation plan before walls and ceilings close.","Three different rate rules can apply to a New York home. ASHRAE Standard 62.2, the national reference, requires 0.03 cfm per square foot of floor area plus 7.5 cfm per person, with occupancy taken as the number of bedrooms plus one; a 2,000 square foot house with three bedrooms needs about 90 cfm. The New York State Residential Code, which governs Long Island and most of the state, uses the IRC formula of 0.01 cfm per square foot plus 7.5 cfm per person, or about 50 cfm for the same house. The [NYC Mechanical Code](https:\u002F\u002Fwww.nyc.gov\u002Fassets\u002Fbuildings\u002Fapps\u002Fpdf_viewer\u002Fviewer.html?file=2022MC_Chapter4_VentilationWB.pdf&section=conscode_2022) (Table 403.3.1.1) sets 0.35 air changes per hour but not less than 15 cfm per occupant, which for that house with 8-foot ceilings is about 93 cfm. We design to the rule that governs the property and, where the owner wants it, to the higher ASHRAE figure.","ASHRAE 62.2 allows a credit for measured air leakage in detached single-family homes, based on a blower-door test, but not for apartments in multifamily buildings. The model codes and ASHRAE 62.2 also allow intermittent operation if the fan is sized up to deliver the same daily volume.",{"heading":17,"table":18,"after":41},"Exhaust-only, supply-only or balanced",{"caption":19,"head":20,"rows":25},"Whole-house ventilation strategies",[21,22,23,24],"Strategy","How it works","Effect in a New York winter","Best suited to",[26,31,36],[27,28,29,30],"Exhaust-only","A quiet bath fan runs continuously and air enters through gaps","Depressurizes the house, pulling cold air through walls, the garage or the basement, and can backdraft natural-draft water heaters and boilers","Small, all-electric homes and apartments with no atmospheric appliances",[32,33,34,35],"Supply-only","An outdoor-air duct with a motorized damper feeds the furnace return","Slightly pressurizes the house, pushing warm moist air into walls and attics, and can over-dry the house if the damper is not controlled","Forced-air houses on a limited budget, with careful controls",[37,38,39,40],"Balanced (ERV or HRV)","Separate fans supply and exhaust equal amounts of air through a heat exchange core","Neutral pressure and recovered heat, with an ERV also retaining part of the indoor moisture","Tight renovations, new construction, apartments and homes with a humidifier",[42],"Supply-only systems and humidifiers combine poorly, because slight pressurization drives humid indoor air into cold wall and attic cavities. Balanced ventilation avoids that and is what we recommend for most tight homes.",{"heading":44,"paragraphs":45,"list":48},"ERV or HRV",[46,47],"Both units exchange heat between outgoing and incoming air. An ERV also transfers part of the moisture. In a New York winter that keeps some indoor humidity in the house, which helps homes that run dry and can reduce [the need for a humidifier](\u002Fguides\u002Fwhole-home-humidifier-nyc-winter); in summer it reduces the moisture carried in by ventilation air. An ERV is not a dehumidifier, and air conditioning or a dehumidifier is still needed in humid weather. [Green Building Advisor](https:\u002F\u002Fwww.greenbuildingadvisor.com\u002Farticle\u002Fwhy-you-probably-need-an-erv-not-an-hrv) describes the winter moisture benefit as real but modest.","An HRV removes indoor moisture in winter, which suits only houses with too much winter humidity, such as a small, very tight house with a large family. Our default is an ERV for New York City and Long Island, with the choice made case by case for colder upstate homes, where core frost and defrost cycles matter more.",[49,50,51,52,53],"Dedicated ducts give the best results. Connecting to furnace ducts is possible but requires an interlock with the blower and careful balancing.","The outdoor intake must be separated from exhaust outlets, vents and other contaminant sources, at distances set by the applicable mechanical code.","Airflow is balanced with a flow measurement after installation, so that every room receives its share.","Filters are cleaned or replaced on schedule, and the unit is placed where it can be serviced.","Apartments can use compact ceiling ERVs or through-wall single-room units, subject to co-op or condo board approval for façade openings and, in landmarked buildings, Landmarks Preservation Commission review of visible louvers.",{"heading":55,"paragraphs":56,"list":60},"Range hoods and makeup air",[57,58,59],"High-heat cooking, wok cooking included, calls for a ducted hood. In a tight house or apartment a hood cannot move its rated airflow unless the same volume of air can enter. Without makeup air a large hood pulls the house into strong negative pressure: doors whistle, odors arrive from neighboring units, and natural-draft water heaters or boilers can spill combustion gases into the home.","Outside New York City, the residential code is based on the International Residential Code. The model IRC requires makeup air for kitchen exhaust above 400 cfm, and since its 2018 edition only where the home has natural-draft fuel-burning appliances, with a damper interlocked with the hood. We confirm the current New York State text for each project.","New York City's 2022 Mechanical Code takes a different approach from the IRC. [Section 505.2](https:\u002F\u002Fwww.nyc.gov\u002Fassets\u002Fbuildings\u002Fapps\u002Fpdf_viewer\u002Fviewer.html?file=2022MC_Chapter5_ExhaustWB.pdf&section=conscode_2022) does not use a cfm trigger: wherever a kitchen exhaust hood is required under Chapter 4, makeup air must be provided at the Table 403.3.1.1 rate through an opening with a motorized closure that runs with the hood. Earlier editions of the city code used the 400 cfm threshold, and much online advice still quotes it. The code also permits listed recirculating hoods in dwellings when they are installed to the manufacturer's instructions and the kitchen has the general ventilation Chapter 4 requires.",[61,62,63,64],"Size the hood to the cooking, not to the showroom. Rated cfm is measured at zero static pressure, and a long apartment duct with elbows and a wall cap often delivers about half.","Capture matters as much as fan size. A deep canopy that extends beyond the cooktop often outperforms a larger fan with a shallow hood.","Makeup air enters through a motorized damper interlocked with the hood, filtered, and tempered in winter so that cold air does not spill onto the cook.","Ducted hoods need smooth metal ducts and a backdraft damper. Opening a window is not a code-compliant makeup-air solution.",{"heading":66,"paragraphs":67,"list":69},"Bath exhaust",[68],"Model codes call for at least 50 cfm intermittent or 20 cfm continuous exhaust per bathroom, and 100 cfm intermittent or 25 cfm continuous for kitchens. The NYC Mechanical Code has its own table, which we follow on city projects.",[70,71,72,73],"Duct the fan to the outdoors, never into the attic or a soffit. Bath fans vented into the attic are a common cause of attic mold in Long Island capes.","Use a short, smooth duct with a backdraft damper and a quiet fan with a low sone rating.","Control the fan with a humidity sensor or timer so it runs for about 20 minutes after a shower.","In apartment buildings, windowless bathrooms often share a roof exhaust shaft. Registers clogged with paint or dust are common, and booster fans cannot be added to a shared shaft without building approval.",{"heading":75,"paragraphs":76},"Combustion safety and radon",[77,78],"Tightening a house that still has natural-draft gas appliances takes care. The [standard method for combustion air](https:\u002F\u002Fwww.energy.gov\u002Fsites\u002Fdefault\u002Ffiles\u002F2013\u002F12\u002Ff6\u002Fcombustion_safety_codes.pdf) provides at least 50 cubic feet of room volume per 1,000 Btu\u002Fh of appliance input, so a 40,000 Btu\u002Fh water heater and an 80,000 Btu\u002Fh furnace together need about 6,000 cubic feet. Before a large hood or exhaust fans go into such a home, the appliance area gets a worst-case depressurization test, and sealed-combustion or electric replacements are worth considering.","Radon is a separate concern. On the [EPA Map of Radon Zones](https:\u002F\u002Fwww.epa.gov\u002Fsites\u002Fdefault\u002Ffiles\u002F2014-08\u002Fdocuments\u002Fnew_york.pdf), all five boroughs, Nassau, Suffolk, Westchester and Rockland are Zone 3, the lowest predicted potential, while Orange, Putnam, Dutchess and much of upstate New York are Zone 1. EPA advises testing every home regardless of zone, fixing at 4 pCi\u002FL or higher and considering a fix between 2 and 4 pCi\u002FL. Exhaust-only ventilation can increase soil-gas entry. Radon testing and mitigation are performed by a certified radon professional, and we coordinate the ventilation design with their findings.",{"heading":80,"paragraphs":81,"table":83,"after":107},"Filtration and a starting point by home type",[82],"EPA recommends [a filter rated at least MERV 13](https:\u002F\u002Fwww.epa.gov\u002Findoor-air-quality-iaq\u002Fwhat-merv-rating), or as high as the system fan and filter slot allow. A 1-inch MERV 13 filter in an undersized return restricts airflow and can cause coil icing, noise and higher energy use; a 4 or 5 inch media cabinet usually solves this. ERV filters protect the core and need upgrading if they are also meant to clean the air. Homes without ducts rely on portable HEPA purifiers, which earned their place on the 2023 wildfire smoke days.",{"caption":84,"head":85,"rows":88},"Typical starting recommendations by home type",[86,87],"Home type","Recommended approach",[89,92,95,98,101,104],[90,91],"Forced-air house with a gas furnace","ERV with dedicated ducts or interlocked with the furnace, 4 inch MERV 13 media filter, combustion safety check",[93,94],"Heat pump house","ERV with dedicated ducts, media filter sized to the air handler",[96,97],"Radiator or steam-heated house","Ceiling or wall ERVs serving bedrooms and living areas, quality bath fans, portable HEPA purifiers",[99,100],"Gut-renovated brownstone","Ducted ERV planned before walls close, hood makeup air designed to the NYC Mechanical Code",[102,103],"Co-op or condo apartment","Compact or through-wall ERV and a right-sized hood, subject to board approval",[105,106],"New all-electric building","Balanced ERV ventilation and a ducted hood, with makeup air confirmed during design",[108],"A kitchen with a powerful hood, a gut renovation or a newly tightened house is the moment to design ventilation. We design ERV or HRV systems, range-hood makeup air and bath exhaust to the code that applies to your property, handle board and permit requirements, and install the work with [our licensed HVAC partner](\u002Fservices\u002Fhvac).",[110,113],{"q":111,"a":112},"Does my range hood need makeup air in NYC?","In most cases, yes. Section 505.2 of the 2022 NYC Mechanical Code does not use a cfm threshold: a kitchen exhaust hood required under Chapter 4 must have makeup air at the Table 403.3.1.1 rate, delivered through an opening with a motorized closure that operates with the hood. The 400 cfm rule quoted online comes from earlier editions of the city code and from the IRC. We confirm the requirement for your hood, appliances and building during design and include the interlocked damper where it applies.",{"q":114,"a":115},"Is a fresh-air system the same as an ERV?","The term fresh-air system, widely used in China, usually means a filtered supply system designed mainly for outdoor PM2.5. In New York the main reasons to ventilate are moisture, cooking pollutants, carbon dioxide and combustion safety, so we usually recommend a balanced ERV with good filtration as a supporting feature.",{"text":117},"Send a floor plan with the bedroom count and ceiling height, your heating system type, the range hood model or rated cfm, and whether the home has natural-draft gas appliances for a written estimate for the ERV, makeup air and bath exhaust. The ventilation rate calculation under the code that governs your property and the makeup-air requirement for your hood are provided as part of the contracted work or as a paid consultation.","2026-10-25","hvac",81,[122,126,130,133,137,141],{"title":123,"url":124,"publisher":125},"You Probably Need an ERV, Not an HRV","https:\u002F\u002Fwww.greenbuildingadvisor.com\u002Farticle\u002Fwhy-you-probably-need-an-erv-not-an-hrv","Green Building Advisor",{"title":127,"url":128,"publisher":129},"2022 NYC Mechanical Code, Chapter 4: Ventilation","https:\u002F\u002Fwww.nyc.gov\u002Fassets\u002Fbuildings\u002Fapps\u002Fpdf_viewer\u002Fviewer.html?file=2022MC_Chapter4_VentilationWB.pdf&section=conscode_2022","NYC Department of Buildings",{"title":131,"url":132,"publisher":129},"2022 NYC Mechanical Code, Chapter 5: Exhaust Systems","https:\u002F\u002Fwww.nyc.gov\u002Fassets\u002Fbuildings\u002Fapps\u002Fpdf_viewer\u002Fviewer.html?file=2022MC_Chapter5_ExhaustWB.pdf&section=conscode_2022",{"title":134,"url":135,"publisher":136},"Combustion Safety in the Codes","https:\u002F\u002Fwww.energy.gov\u002Fsites\u002Fdefault\u002Ffiles\u002F2013\u002F12\u002Ff6\u002Fcombustion_safety_codes.pdf","U.S. Department of Energy, Building America",{"title":138,"url":139,"publisher":140},"What is a MERV rating?","https:\u002F\u002Fwww.epa.gov\u002Findoor-air-quality-iaq\u002Fwhat-merv-rating","U.S. Environmental Protection Agency",{"title":142,"url":143,"publisher":140},"New York - EPA Map of Radon Zones","https:\u002F\u002Fwww.epa.gov\u002Fsites\u002Fdefault\u002Ffiles\u002F2014-08\u002Fdocuments\u002Fnew_york.pdf","erv-hrv-makeup-air-nyc","en-US",[147,151,155,160],{"slug":148,"title":149,"description":150,"service":119,"date":118,"updated":118},"whole-home-humidifier-nyc-winter","Whole-home humidifier settings for New York winters","Why New York homes dry out in winter, recommended indoor humidity by outdoor temperature, and how excess humidity damages windows, walls and attics.",{"slug":152,"title":153,"description":154,"service":119,"date":118,"updated":118},"basement-dehumidifier-long-island-queens","Basement dehumidifiers for Long Island and Queens","Why Long Island and Queens basements turn musty in summer, the humidity target to hold, dehumidifier sizing after the 2019 rating change, and drainage.",{"slug":156,"title":157,"description":158,"service":159,"date":118,"updated":118},"nyc-local-law-152-gas-piping-inspection","Local Law 152 Gas Piping Inspections and the 2026 Deadline","Which NYC buildings owe a Local Law 152 gas piping inspection by December 31, 2026, what the plumber checks, and the 60- and 120-day filing deadlines.","plumbing",{"slug":161,"title":162,"description":163,"service":164,"date":118,"updated":118},"whole-home-audio-vs-smart-speakers","Whole-home audio vs smart speakers in a NYC renovation","In-ceiling speakers, streaming amplifiers and smart speakers compared, with the speaker wire, fire ratings and routes to run while NYC walls are open.","low-voltage",1793066400882]