A Taylorsville customer in a 2008-built two-story home with a finished basement contacted us about adding zoning to their existing HVAC system. The home had three distinct comfort areas — main level (kitchen, living, dining), upper bedroom level, and finished basement — each with different cooling and heating needs based on use patterns, solar exposure, and occupancy. Single-zone HVAC produced comfort complaints across all three areas at different times of day. This case study documents a three-zone retrofit installation that addressed the multi-area comfort challenges.
Customer Situation
- Home: 2008-built Taylorsville two-story with finished basement, approximately 3,200 sq ft total
- Existing equipment: 2008 Trane 96% AFUE furnace, 2008 Trane 16 SEER AC, both still functional
- Symptom: Main level too warm during evening cooking; upper bedrooms too cold in summer; basement too cold in winter; thermostat location compromises always favored some zone over others
- Customer priorities: Independent zone control, equipment age appropriate for major work, preserve existing equipment
Equipment Assessment
Before recommending zoning, we verified existing equipment compatibility:
- 2008 furnace: variable-speed ECM blower ✓ (compatible with zoning)
- 2008 AC: single-stage, will work with zoning but two-stage would perform better
- Customer decision: keep existing equipment, install three-zone system, plan for AC upgrade in future when equipment fails
Zone Configuration
Three zones designed:
- Zone 1 — Main level (1,200 sq ft): kitchen, living, dining, office
- Zone 2 — Upper bedroom level (1,000 sq ft): 4 bedrooms, 2 baths
- Zone 3 — Finished basement (1,000 sq ft): family room, guest bedroom, bath
Per-zone load analysis:
– Zone 1: 14,500 BTU/h cooling / 23,000 BTU/h heating
– Zone 2: 12,500 BTU/h cooling / 18,500 BTU/h heating
– Zone 3: 8,000 BTU/h cooling / 13,000 BTU/h heating
Equipment Selected
- Honeywell HZ432 zone control panel (up to 4 zones, 3 zones used)
- Three zone dampers in main supply trunks
- Bypass damper for excess airflow management during single-zone calls
- Three Ecobee Smart thermostats with proper staging configuration
Project cost: $4,800
Installation
Duration: 1 day
Work performed:
– Accessed existing ductwork through unfinished mechanical room areas
– Cut openings in supply trunks for damper installation
– Installed three zone dampers with proper sealing
– Installed bypass damper between supply and return trunks
– Mounted zone control panel in mechanical room
– Ran low-voltage wiring to three thermostat locations
– Installed three Ecobee Smart thermostats
– Configured staging and zoning logic
– Verified operation across all single-zone and multi-zone combinations
Commissioning
Zone operation verified across all combinations:
– Zone 1 only: damper 1 open, dampers 2 & 3 closed, bypass partially open ✓
– Zone 2 only: similar pattern ✓
– Zone 3 only: similar pattern ✓
– Zones 1+2: dampers 1 & 2 open, damper 3 closed, bypass mostly closed ✓
– All zones: all dampers open, bypass fully closed ✓
Static pressure verification:
– Single-zone operation: 0.45″ wc (within manufacturer max 0.5″ wc) ✓
– All zones: 0.36″ wc ✓
– Bypass operation prevents overpressure during single-zone calls
Final Cost and Customer Outcome
Customer’s cost: $4,800
Six-month customer feedback:
- Each zone maintained at preferred temperature independently
- Evening cooking in main level no longer affects sleeping comfort upstairs
- Basement temperature maintained for use vs. sitting cold and unused
- Equipment operates with longer, lower-capacity cycles producing better efficiency
- Estimated efficiency improvement: 12-15% reduction in equipment run time
- Three-zone control enables nighttime setback by zone (cooling bedrooms while letting main level drift)
What This Case Study Demonstrates
- Zoning works with existing single-stage AC (though two-stage would optimize further)
- Three-zone systems appropriate for homes with three distinct comfort areas
- Bypass damper prevents pressure problems during single-zone calls
- Variable-speed furnace blower essential for proper zoning operation
- Zone-by-zone setback enables comfort customization and efficiency improvements
Considering Zoning?
If you have a Taylorsville home with multiple comfort areas, call (385) 250-0687.
- Phone: (385) 250-0687
- Address: 4454 Manhattan Ct, West Valley City, UT 84120