Indoor Air Quality Improvement — Kearns, UT Case Study

A Kearns customer with a 1968-built home contacted us about indoor air quality concerns. Multiple household members had been experiencing increased respiratory symptoms during winter inversion periods, the home had a persistent stuffy feel during heating season, and recent CO detector chirping (low battery, not actual CO event) had increased awareness of combustion-equipment safety. The customer had researched various IAQ products online — UV lights, ionizers, ozone generators, REME-HALO systems — and wanted advice on what would actually help.

This case study documents an honest IAQ assessment and improvement project that focused on proven approaches (filtration, ventilation, source control) rather than the gimmick products that often dominate IAQ marketing.

Customer Situation

• Home: 1968-built Kearns single-story, approximately 1,520 sq ft, atmospheric-vent furnace (replaced 2009)
• Existing equipment: 92% AFUE Goodman furnace, R-410A AC, standard 1″ pleated filter
• IAQ concerns: Household respiratory symptoms during inversion periods; stuffy feel during winter; general air quality awareness
• Customer priorities: Improve actual indoor air quality, avoid gimmick products, reasonable budget
• Customer research interest: Had researched UV lights, ionizers, ozone generators, REME-HALO; wanted honest assessment

Initial IAQ Assessment

On-site assessment (60 minutes):

Existing IAQ baseline:
– CO measurement: 0 ppm indoor, 0 ppm in equipment ambient ✓
– VOC measurement: elevated during cooking and during off-gassing from recent furniture purchase
– PM2.5 measurement: variable, elevated during inversion days
– Humidity: 18% during heating season (low — Salt Lake’s winter air is dry, indoor heating drops further)
– Air exchange: estimated 0.4 ACH (typical for vintage construction)

Combustion safety verification:
– Combustion analysis on furnace: CO 22 ppm air-free, well within safe range ✓
– No back-drafting observed
– No CO contamination in supply air
– Heat exchanger borescope: sound condition

Filter inspection:
– Existing filter: 1″ pleated, MERV 8, approximately 6 weeks old
– Filter slot: 1″ — limits filter options without modification
– Visible accumulated debris on filter surface

IAQ Improvement Strategy — What Works vs. What’s Hype

We discussed evidence-based IAQ improvements with the customer:

What actually works (recommended):

1. Higher-MERV filtration — MERV 11 or 13 filters capture significantly more particles than standard MERV 8
2. Filter housing upgrade — 4-inch media filter housing enables higher-MERV filters without static pressure issues
3. Fresh air ventilation — controlled fresh air supply reduces accumulated VOCs and CO2
4. Source control — addressing combustion equipment, moisture sources, off-gassing materials
5. Humidity management — appropriate winter humidification reduces respiratory irritation

What’s mostly hype (not recommended):

• UV lights — limited evidence of meaningful air quality improvement at residential exposure times; primarily marketing-driven product category
• Ionizers — produce ozone as byproduct; effectiveness disputed; ozone production is itself an air quality concern
• Ozone generators — ozone is itself a respiratory irritant; should not be operated in occupied spaces
• REME-HALO — produces hydrogen peroxide and ions; effectiveness not well-supported by independent research; we don’t install these
• “Whole-home air purification” gimmicks — most don’t deliver measurable air quality improvement

The customer appreciated the honest assessment and elected to proceed with evidence-based improvements.

IAQ Improvement Project Scope

Equipment installed:

1. 4-inch MERV 13 media filter housing (Honeywell F100F1004) — $385 installed
   – Replaces 1″ filter slot
   – 5x more filter surface area
   – MERV 13 captures particles down to 0.3 microns including most allergens, smoke particles, viruses
   – Annual filter replacement vs. quarterly with thinner filters

2. Fresh air ventilation damper (AprilAire 8126) — $475 installed
   – Brings controlled fresh outdoor air to return air stream
   – Programmable through smart thermostat
   – Operates during regular fan cycles
   – Dilutes indoor pollutants with outdoor air

3. Bypass humidifier (AprilAire 600) — $625 installed
   – Adds humidity to dry winter air
   – Operates only during heating system operation
   – Target humidity 30–40% indoor RH during heating
   – Helps respiratory comfort during heating season

4. Hardwired CO detectors (Kidde KN-COSM-IBA, 2 units) — $295 installed
   – Replaced existing battery-only units
   – One main level near furnace, one bedroom hallway
   – 10-year sealed lithium battery backup
   – Wired to existing smoke detector circuits

What we did NOT install:

• No UV lights, ionizers, ozone generators, or REME-HALO systems despite customer initial interest

Installation

Duration: 1 day

Work performed:

• Filter housing installation in return air duct (cut new opening, sealed with mastic, installed housing)
• Fresh air damper installation in return air duct (cut new opening, installed damper with outdoor air intake through wall with screened termination, wired control to thermostat)
• Humidifier installation on supply plenum (cut opening, installed bypass damper, water line connection, drain connection, humidistat installation)
• Smart thermostat configuration for fresh air and humidity control
• CO detector installation in two locations with proper wiring
• System commissioning across all new components

Commissioning and Verification

System measurements after installation:

• Filter static pressure: 0.12″ wc (well within manufacturer spec, vs. 1″ filter at 0.15″ wc — actually slightly improved despite higher MERV)
• Fresh air damper operation: confirmed open during scheduled fresh air cycles
• Humidity output: 35% indoor RH achieved after 24 hours operation
• CO detectors: both units tested with manufacturer test feature, both responded properly

Three-month follow-up measurements:

• Indoor PM2.5: substantially reduced during normal operation
• Indoor humidity: maintained 33–37% RH during heating season
• VOC reduction: noticeable during fresh air ventilation periods
• Customer reported: significant reduction in respiratory symptoms during inversion periods; improved sleep quality from humidity adjustment

Final Cost and Outcomes

Customer’s project cost:
– Filter housing + initial filter: $385
– Fresh air damper system: $475
– Humidifier: $625
– CO detectors: $295
– Total: $1,780

No applicable rebates for IAQ equipment in current programs.

Customer outcomes (6-month follow-up):

• Respiratory symptoms during inversion periods significantly reduced
• Winter stuffy feeling eliminated
• Humidity comfortable during heating season
• Filter changes required only annually with MERV 13 4-inch filter
• Customer specifically appreciated honest assessment vs. gimmick product upsell

Annual operating costs:

• MERV 13 filter replacement annually: $45/year
• Humidifier pad replacement annually: $30/year
• CO detector self-checks: free
• Total annual operating cost: $75/year

What This Case Study Demonstrates

• Evidence-based IAQ approach — focused on proven improvements (filtration, ventilation, source control, humidity) rather than gimmick products
• Honest product recommendations — declined to install UV lights, ionizers, REME-HALO despite customer initial interest in these products
• Combustion safety verification — confirmed CO levels safe before recommending other improvements
• Filter housing upgrade enables better filtration — 4-inch housing accepts MERV 13 with actually lower static pressure than 1″ MERV 8
• CO detector upgrade matters — hardwired with sealed battery backup vs. battery-only with annual replacement
• Fresh air ventilation often overlooked — air exchange dilutes accumulated pollutants; sometimes the most impactful single intervention
• Realistic outcomes — significant improvement without exaggerated claims; customer respiratory symptoms reduced but not eliminated entirely

Considering IAQ Improvements?

If you’re researching indoor air quality improvements in Kearns, contact us or call (385) 250-0687. We provide honest assessments based on what actually works rather than gimmick product upsells.

• Phone: (385) 250-0687
• Address: 4454 Manhattan Ct, West Valley City, UT 84120

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