← Better-Built Homes series • Article 8 of 9
A tight, comfortable home should also have an intentional plan for the air inside it. That plan combines pollutant-source control, ventilation, filtration, and moisture management. For a custom home or substantial remodel, these choices belong in the mechanical design before equipment and ducts are ordered.
Separate the four jobs
| Job | What it addresses | Example to discuss |
|---|---|---|
| Source control | Reduces pollutants where they originate. | Material selection, garage separation, and managing combustion sources. |
| Local exhaust | Removes pollutants or moisture at the source. | Kitchen and bathroom fans vented outdoors. |
| Whole-house ventilation | Introduces controlled outdoor air and dilutes indoor pollutants. | A designed supply or balanced ventilation system. |
| Filtration / air cleaning | Removes selected contaminants from air passing through the device. | A suitable HVAC media filter or supplemental portable unit. |
EPA identifies source control, ventilation, and air cleaning as complementary approaches; filtration alone does not eliminate every indoor pollutant.[1] A filter that recirculates indoor air does not automatically bring fresh outdoor air into the house.
Understand MERV without choosing by number alone
MERV describes particle-filtration performance under a standardized test. EPA recommends MERV 13, or the highest-rated filter the HVAC system can accommodate.[2] Accommodation matters: the filter’s resistance, cabinet dimensions, airflow, fan capability, and maintenance condition must fit the system.
Request a filter cabinet and duct design that are evaluated together. A deeper media cabinet may be worth comparing with a shallow filter slot, but depth alone does not establish a pressure drop. Ask the HVAC professional to check the selected product and system operating conditions. The most expensive filter is not useful if it is bypassed, neglected, or incompatible with the equipment.
What about HEPA, carbon, and electronic devices?
A correctly sized portable particle cleaner can supplement central filtration in a particular room. EPA advises comparing clean air delivery rate (CADR) for the intended room and distinguishes particle removal from gas removal. Some gas-removal devices use sorbent media, but their capacity and performance vary. Avoid ozone-generating air cleaners; EPA states that ozone can harm health and should not be intentionally introduced into occupied spaces.[2]
For a whole-home accessory, ask which contaminants it addresses, what independent performance data applies, what airflow it requires, and what recurring service costs it adds. Do not treat marketing claims about “sterilizing the home” as a substitute for a defined ventilation and filtration plan.
Ventilation needs humidity management
An HRV recovers sensible heat; an ERV also transfers some moisture between air streams. Neither name guarantees that the house’s humidity is controlled. DOE explains the distinction between these recovery systems.[3] In humid weather, incoming outdoor air still brings a moisture load that must be evaluated.
PNNL describes ventilation options and notes that some homes need active dehumidification during periods with limited cooling demand.[4] Ask how outdoor airflow is sized and verified, where the intake is located, and how controls work when the air conditioner is not running.
EPA generally recommends indoor relative humidity around 30–50 percent.[5] Treat that as general guidance, not a promise that every building can hold one setting year-round. Watch trends, investigate persistent moisture, and have the mechanical designer evaluate the actual conditions.
Compare three complete scopes: the proposed HVAC system with an evaluated filter; that system plus controlled outdoor-air ventilation; and the same design with additional humidity control or room-specific particle cleaning where needed. Each addresses a different need. Price controls, installation, commissioning, replacement filters, and service access.
Design the house and mechanical system together
Discuss garage air separation, duct leakage, return-air paths, exhaust discharge, and material priorities during planning. Additions and major remodels can change room loads and airflow needs, so reusing existing equipment should be an evaluated decision rather than an assumption.
At handover, request measured ventilation airflow, filter specifications, controls instructions, replacement intervals from the selected manufacturers, and a maintenance schedule. A system that is difficult to service is more likely to be neglected. Indoor-air-quality construction supports a better-controlled environment; it does not guarantee freedom from allergens, illness, or all contaminants.
Plan a better-built home with ADDRAC.
Planning a custom home, addition, or major remodel? Contact ADDRAC Construction to discuss comfort and indoor-air-quality priorities alongside your construction scope. Request an estimate that accounts for coordinated mechanical design, installation, and verification.
Request a project estimateCall (512) 948-5922 • Email josh@addrac-construction.com
Sources and further reading
Public guidance checked October 10, 2026. Product instructions and project-specific requirements govern the final design.
Homeowner planning guidance for Austin, Cedar Park, Leander, Georgetown, Liberty Hill, Lago Vista, Jonestown, and Dripping Springs. Code requirements, climate conditions, existing construction, and product approvals vary. The comparisons and clearly labeled examples are not ADDRAC bids, performance guarantees, or a claim of certification.