Quick answer
Read in 4 minERVs and HRVs bring outdoor fresh air inside while recovering most of the energy from the air they push out. HRV recovers heat only; ERV recovers heat and moisture. For tight, modern homes (post-2010 build or recently air-sealed and insulated) in SW Indiana, ERV is almost always the right call — our 75°F summer dew points mean you want to keep outdoor humidity out as much as possible. For older leaky homes, the answer is air sealing first, ventilation second.
- 01 Tight homes (ACH50 under 5) struggle with stale air, VOCs, and high CO2 — ERV/HRV solves this.
- 02 ERV recovers heat AND moisture — right call in humid SW Indiana climate.
- 03 HRV recovers heat only — right for very dry climates, rarely the answer here.
- 04 Install cost: $2,200-$4,500 depending on duct integration.
- 05 Older leaky homes (ACH50 over 10) usually don't need ERV — air sealing first, then reassess.
Section 02
New construction or major renovation
If you're building or renovating to modern code, blower-door tightness is typically ACH50 under 5 — tight enough that mechanical ventilation is required for indoor air quality. Code in most Indiana jurisdictions now requires ASHRAE 62.2 ventilation rates in new homes. ERV is the standard solution.
Section 03
Stale or stuffy indoor air
If the house feels stuffy when you walk in, or CO2 monitors read over 1,000 ppm regularly, you're trapping indoor air pollutants — VOCs, cooking byproducts, body odor, formaldehyde from furniture. The fix is fresh air; ERV is how you get it without losing heating/cooling energy.
Section 04
Cooking, candles, or hobbies that create pollutants
Strong cooking smells, candle soot accumulation on walls, or hobbies like soldering and woodworking create indoor pollutants that filtration alone can't address. Source ventilation (range hood, bath fans) is first; whole-house ERV is the supporting layer.
Section 05
After major insulation and air-sealing upgrades
If you've added insulation, sealed rim joists, replaced windows, and changed weatherstripping, your house likely went from leaky to tight in one season. Many homes that didn't need an ERV before suddenly do — fresh-air strategy changes when the building envelope changes.
Compare your options
The choice, honestly compared.
Option A: No ERV/HRV — natural ventilation only
Right call for older leaky homes (pre-1980, never tightened up) where natural air change through the envelope already provides enough fresh air. Cost: $0 — you already have it. Wrong call for tight homes (post-2010 construction or recently air-sealed and insulated) — natural ventilation isn't enough and indoor air quality suffers. Lifespan: forever, but doesn't solve the indoor air quality problem in tight homes.
Option B: HRV (heat recovery only)
Right call in cold dry climates where keeping moisture in matters more than keeping it out. HRV from Lifebreath or Fantech installed runs $2,000-$3,800. Recovers 70-85% of the heat from exhaust air. Wrong call in SW Indiana — our humid summers mean you don't want to pull moisture in, and our winters aren't dry enough to need to retain it indoors. Lifespan 15-20 years.
Option C: ERV (heat + moisture recovery)
Right call for tight SW Indiana homes — handles our humid summers and dry winters in one unit. Panasonic Intelli-Balance 100 or Aprilaire E80 installed runs $2,200-$4,500 depending on duct integration. Recovers 70-85% of heat and 50-70% of moisture, balancing indoor humidity against outdoor extremes. Quiet, integrates with existing furnace ductwork or runs standalone. Wrong call only in leaky homes that haven't been air sealed first. Lifespan 15-20 years; filter changes annually.
Key terms in context
Vocabulary you'll see on a real estimate.
This guide is written for indoor air & comfort decisions in Southwest Indiana. It uses the same terminology you'll hear from techs, inspectors, and the permit office.
Failure mode 01
Installing ERV before air sealing
Putting an ERV in a leaky 1970s house is solving the wrong problem — the house is already over-ventilating uncontrolled. We blower-door test first; if ACH50 is over 8, air sealing is the better first dollar.
Failure mode 02
Picking HRV in a humid climate
HRV is great in Minneapolis; it's wrong in Evansville. Pulling humid summer air in without moisture recovery dumps the dehumidification problem on your AC. ERV handles both directions.
Proof, process & local validation
- 01 Every ERV recommendation starts with a blower-door test — we know the tightness before we quote.
- 02 Sizing follows ASHRAE 62.2 ventilation rates based on home volume and occupants — not square footage rules of thumb.
- 03 Install includes commissioning balance (supply vs exhaust CFM) measured at each port, in writing.
How we build this guidance
- We install Panasonic Intelli-Balance and Aprilaire E80 ERVs — units sized to the home, not square footage.
- Every ERV install includes a blower-door test result so we know what tightness we're working with.
- Pat won't sell an ERV to a 1960s drafty house — air sealing first, then reassess.
Methodology · Recommendations based on blower-door measured ACH50, ASHRAE 62.2 ventilation requirements, and occupant load — measured, not guessed.
Last updated 2026-06-24
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Common questions
Questions, answered.
01 How do I know if my house is tight enough to need an ERV?
A blower-door test gives the definitive answer — measured ACH50 under 5 typically means mechanical ventilation is needed. Symptoms suggesting tightness: stuffy air despite the HVAC running, condensation on windows in winter, CO2 monitors reading over 1,000 ppm, lingering cooking smells. We blower-door test on every ERV evaluation.
02 Does an ERV use a lot of energy?
Surprisingly little. The fan draws 50-100 watts at typical operation (about the same as a ceiling fan), and the heat recovery means the heating/cooling system doesn't have to condition fresh air from scratch. Net energy cost is typically $5-$15/month — far less than running the system without recovery.
03 Will an ERV solve my radon problem?
No — radon needs a dedicated mitigation system (sub-slab depressurization). An ERV reduces indoor air pollution but is not a radon strategy. We test radon when relevant and recommend a proper mitigation system if levels exceed 4 pCi/L.
04 Can I run the ERV continuously?
Yes — most ERVs are designed for continuous low-speed operation with a high-speed boost during cooking or high-occupancy periods. Continuous operation is how the system maintains steady indoor air quality. Auto controls can also speed up based on CO2, humidity, or VOC sensors.
05 How does an ERV affect humidity?
ERVs recover 50-70% of moisture from the exhaust air, which means in winter you keep more moisture inside (less dry-air symptoms) and in summer you keep more moisture outside (less load on the AC). Net result: more stable indoor RH year-round. The AC and humidifier work less.
