Collinsville Dracut Triple-Decker Multi-Zone Conversion — Case Study

Property: Late 19th-century three-family triple-decker residential, Collinsville Dracut
Owner: P.O. (landlord property owner alias)
Scope: Complete replacement of three separate aging heating systems (one per unit) with per-unit multi-zone Mitsubishi Hyper-Heat MXZ ductless heat pumps; each unit converted independently allowing continued tenant occupancy during phased installation
Timeline: Diagnostic and design 3 weeks, installation 14 days across 3 units (phased scheduling to maintain tenant occupancy)
Investment: $58,400 combined all 3 units, $30,000 Mass Save Whole-Home Heat Pump rebate ($10,000 per unit), $6,000 IRA 25C federal tax credit ($2,000 per unit), 10% landlord portfolio discount, net $16,560

Situation

P.O. owns a late 19th-century three-family triple-decker residential property in the Collinsville neighborhood of Dracut. Collinsville is one of Dracut’s historic mill worker neighborhoods with substantial triple-decker housing stock from the late 19th and early 20th centuries when Dracut’s textile mill operations drew workforce needing multi-family housing near mill locations.

P.O.’s triple-decker is a standard Collinsville configuration: three-story wood-frame construction with one residential unit per floor, separate exterior entry to each unit via shared side stairway, individual unit configurations approximately 1,000-1,100 sq ft each with living/dining/kitchen and 2 bedrooms per unit, and shared basement with separate mechanical space allocations for each unit’s HVAC equipment.

Original heating: three separate gas furnaces (one per unit) each with matching central AC or window AC configuration. Age distribution: first-floor furnace 18 years, second-floor furnace 22 years, third-floor furnace 26 years — all past typical service life range with declining reliability. Third-floor unit had window AC only (no central AC); first and second floor units had matching central AC installed with the gas furnaces.

P.O. maintains three-tenant occupancy in the property (all three units occupied under standard 12-month lease agreements). P.O.’s tenants are stable long-term residents; P.O. was concerned about installation disruption impact on tenant relationships and potential vacancy risk during installation.

P.O. requested Rivic assess replacement options with priorities: (1) coordinated replacement of all three aging HVAC systems given similar end-of-life timing, (2) fossil-fuel elimination through heat pump conversion for maximum Mass Save Whole-Home Heat Pump rebate ($10,000 per unit × 3 units = $30,000 total qualifying rebate), (3) minimize tenant occupancy disruption during installation, (4) landlord portfolio scope coordination (P.O. owns 5 triple-decker properties across Dracut and Lawrence — discount tier consideration applies).

Diagnostic and Assessment

Andrew Samples conducted the initial diagnostic assessment. Ryan Sullivan handled multi-zone ductless configuration analysis (Ryan’s Dracut residency provides direct familiarity with Collinsville triple-decker configuration). Kathleen Brennan coordinated landlord portfolio verification confirming 5-property portfolio status qualifying for landlord portfolio discount tier.

Key findings: (1) all three gas furnaces past typical service life with progressive efficiency decline; first-floor and second-floor central AC units also past service life, (2) existing ductwork configuration: each unit has independent ductwork (not shared between units) — first-floor and second-floor have functional ductwork suitable for heat pump conversion; third-floor unit has no existing ductwork (window AC only historically), (3) 100A per-unit electric service adequate for per-unit heat pump installation without service upgrade (Collinsville triple-deckers typically have per-unit electric service at 100A which accommodates modern heat pump installation with careful load coordination), (4) shared basement mechanical space with existing separate mechanical space allocations per unit; each unit’s heat pump air handler placement independent of other units, (5) roof space adequate for three separate outdoor condensers (one per unit) with landlord-approved placement locations.

ACCA Manual J load calculation per unit determined heating load at 4°F winter design of approximately 24,000 BTU/hr per unit and cooling load at 88°F summer design of approximately 16,000 BTU/hr per unit (modest loads reflecting compact 1,000-1,100 sq ft unit sizes).

Solution: Per-Unit Multi-Zone Mitsubishi Hyper-Heat MXZ Configuration

Rivic recommended Mitsubishi Hyper-Heat MXZ 3-zone multi-zone ductless configuration per unit — three separate independent systems (one per unit) rather than shared multi-unit configuration. Each unit configuration: (1) living/dining/kitchen 12,000 BTU/hr concealed ceiling cassette or wall-mount depending on ceiling configuration, (2) primary bedroom 9,000 BTU/hr wall-mount cassette, (3) second bedroom 9,000 BTU/hr wall-mount cassette. Per-unit outdoor condenser capacity 30,000 BTU/hr with capacity margin.

Independent per-unit systems selected over shared multi-unit configuration for several reasons: (1) per-unit tenant control — each tenant manages their own thermostat and comfort setpoints independently (important for multi-tenant properties where different tenants have different comfort preferences), (2) per-unit metering — each tenant’s electric usage tracked through existing per-unit electric meters (avoiding shared operating cost allocation complications), (3) per-unit Mass Save Whole-Home rebate qualification — each unit qualifies independently for $10,000 rebate maximizing total rebate scope, (4) per-unit warranty coverage — each unit’s Mitsubishi Diamond Contractor warranty applies to that unit’s equipment.

Third-floor unit configuration differs slightly from first and second floor: third-floor unit has no existing ductwork so multi-zone ductless is the primary heating and cooling delivery (first-time cooling installation for third-floor unit historically limited to window AC). First and second floor units use multi-zone ductless replacing existing gas furnace/central AC scope.

All three units’ gas furnaces decommissioned with proper handling; gas piping capped at previous furnace locations. Existing central AC (first and second floor) decommissioned with proper EPA Section 608 refrigerant recovery. Third-floor unit window AC units removed as part of installation scope.

Phased Installation for Tenant Occupancy Maintenance

Rivic coordinated installation scheduling to minimize tenant disruption. Approach: (1) each unit’s installation scheduled independently with the tenant — typically 4-5 days per unit installation from equipment delivery through commissioning, (2) coordination with tenant on specific days requiring in-unit access, with tenant able to be present or away from unit during specific installation activities based on individual preference, (3) transitional heating/cooling coverage during specific unit installation days (space heaters or portable AC as needed for the specific days when unit’s own equipment offline), (4) 3-day gap between successive unit installations for Rivic team scheduling and to allow individual tenant re-orientation between their unit installation days, (5) common area (basement, exterior) installation work coordinated across the phased schedule to minimize repeated common area disruption.

Total installation timeline: 14 days across 3 units (approximately 4-5 days per unit × 3 units + 3-day gaps × 2 = approximately 18 days calendar time with active installation on 14 of those days). All three tenants maintained occupancy throughout installation with no lease modifications or vacancy periods.

Landlord Portfolio Discount Tier — 3-4 Unit Tier at 10%

P.O. owns 5 triple-decker properties across Dracut and Lawrence totaling 15 rental units. Rivic’s landlord portfolio discount tier structure: 10% discount at 3-4 rental units, 15% discount at 5-9 rental units, 20% discount at 10+ rental units. P.O.’s 5-property portfolio (15 units total) qualifies for the 20% tier on the property portfolio basis; individual property installation (this Collinsville triple-decker with 3 rental units) qualifies for 10% single-property tier.

P.O. selected the 10% single-property tier for this Collinsville installation. Rivic’s landlord portfolio discount policy allows landlords to select either single-property tier (based on units at the specific property receiving installation) or portfolio tier (based on total portfolio units) depending on which delivers larger absolute discount for the specific installation. On this Collinsville installation, both tiers would deliver similar total discount ($5,840 at 10% single-property tier vs $11,680 at 20% portfolio tier); P.O. selected the 10% tier per their internal accounting preference.

Outcome

Installation completed across 3 units over 14 active installation days (18 days calendar time including gaps). All three tenants maintained occupancy throughout with minor daily disruption during their specific unit installation days. Post-installation operational verification: all three unit systems operating reliably. Third-floor unit tenant reported particular satisfaction with the first-time whole-unit cooling (previously window AC only).

Ongoing Operating Cost Change

Combined post-installation first-year utility monitoring across all 3 units: total electric operating cost approximately $2,880 for combined heating and cooling across all units. Previous year utility costs (per unit gas heating + electric window AC or central AC): approximately $4,320 combined across all 3 units. Combined annual operating cost reduction approximately $1,440/year across the property, benefiting P.O. through reduced landlord operating cost pass-through and improved property operating economics.

Investment Summary

• Total installation cost (all 3 units before discount): $58,400 (three separate per-unit Mitsubishi Hyper-Heat MXZ 3-zone systems, installation labor across phased schedule, refrigerant charging, commissioning, landlord portfolio coordination)
• Landlord portfolio discount (10% single-property 3-unit tier): $5,840
• Installation cost after discount: $52,560
• Mass Save Whole-Home Heat Pump rebate ($10,000 per unit × 3 units): $30,000
• IRA 25C federal tax credit ($2,000 per unit × 3 units): $6,000
• Net investment: $16,560 after landlord portfolio discount, Mass Save rebates, and IRA credits
• Annual operating cost reduction: approximately $1,440/year across property
• Additional value: 12-year Mitsubishi Diamond Contractor warranty per unit; property value improvement through complete HVAC modernization; tenant satisfaction improvement (particularly third-floor unit’s first-time whole-unit cooling)

Frequently Asked Questions About This Case Study

Why per-unit independent systems instead of shared multi-unit configuration?

Per-unit independent systems selected for multiple reasons: per-unit tenant control (each tenant manages their own thermostat and comfort setpoints independently); per-unit metering (each tenant’s electric usage tracked through existing per-unit electric meters, avoiding shared operating cost allocation complications); per-unit Mass Save Whole-Home rebate qualification (each unit qualifies independently for $10,000 rebate maximizing total rebate scope); per-unit warranty coverage (each unit’s Mitsubishi Diamond Contractor warranty applies to that unit’s equipment). Shared multi-unit configurations are technically feasible but create allocation complications for tenant control, metering, and rebate qualification that most landlords prefer to avoid. Rivic’s standard approach for triple-decker and multi-unit residential is per-unit independent systems unless specific circumstances favor shared configuration.

Can Rivic complete similar triple-decker conversion at my Dracut or Lawrence multi-family property?

Yes for triple-decker or multi-family properties with suitable configuration. Prerequisites: adequate per-unit electric service (typical 100-200A per unit for triple-decker properties — 100A adequate for typical unit heat pump specification with careful load coordination), roof space or side-yard/rear-yard area for outdoor condenser placement (typically one condenser per unit), existing ductwork per unit suitable for heat pump conversion or property configuration supporting multi-zone ductless configuration per unit. Rivic handles landlord coordination including portfolio verification for discount tier qualification and phased installation scheduling coordinated with tenant occupancy. Typical installation range for Dracut/Lawrence triple-decker per-unit conversion: $18,000-$28,000 per unit before landlord discount, $8,000-$16,000 net per unit after Mass Save Whole-Home rebate and IRA 25C credit.

How does phased installation actually maintain tenant occupancy?

Phased installation coordinates unit installation independently with each tenant. Approach: each unit’s installation scheduled independently (4-5 days per unit typical from equipment delivery through commissioning); coordination with tenant on specific days requiring in-unit access (tenant can be present or away based on preference); transitional heating/cooling coverage during specific unit installation days (space heaters or portable AC as needed for days when unit’s own equipment offline); 3-day gap between successive unit installations for team scheduling and tenant re-orientation. Total calendar time typically 14-21 days depending on unit count and specific scheduling coordination. Some tenants prefer to be present during their unit installation for direct communication; others prefer to be away during installation activity days. Rivic accommodates individual tenant preferences.

How does the landlord portfolio discount tier structure work?

Rivic’s landlord portfolio discount tier structure: 10% discount at 3-4 rental units, 15% discount at 5-9 rental units, 20% discount at 10+ rental units. Two tier calculation options: single-property tier (based on units at the specific property receiving installation) or portfolio tier (based on total portfolio units across all properties). Landlord can select either tier depending on which delivers larger absolute discount for the specific installation. Portfolio tier requires verification of ownership across the claimed portfolio — Kathleen Brennan handles portfolio verification through property records review. Discount applied to installation cost only (equipment and labor, not rebates or tax credits — those apply separately at their standard scope). Discount coordination handled as part of Rivic’s landlord scope project management.

Did the third-floor unit’s first-time whole-unit cooling substantially change tenant satisfaction?

Yes, according to P.O.’s follow-up conversation with the third-floor tenant. Third-floor units in Collinsville triple-deckers historically have limited cooling options: window AC on primary rooms only (typically living area and one bedroom), no whole-unit distribution, and often higher summer temperature challenge given roof exposure. New multi-zone ductless installation provides whole-unit consistent cooling with independent zone control across living/dining/kitchen, primary bedroom, and second bedroom. Third-floor tenant reported particular satisfaction with consistent cooling across the whole unit and independent bedroom zone control (previously the second bedroom had no cooling access). This kind of tenant satisfaction improvement contributes to landlord tenant retention economics, which is a common motivator for landlord HVAC modernization scope.

Contact Rivic Heating and Air Conditioning — Collinsville Dracut Triple-Decker HVAC

Collinsville Dracut and Merrimack Valley multi-family HVAC service including triple-decker per-unit heat pump conversion, phased installation scheduling to maintain tenant occupancy, landlord portfolio discount tier coordination, Mass Save Whole-Home Heat Pump rebate per-unit application, IRA 25C federal tax credit per-unit coordination, and per-unit Mitsubishi Diamond Contractor warranty administration all route through our 225 Broadway #306 office in downtown Methuen. This case study represents a specific installation completed for P.O.; individual property assessments determine equipment specification and installation scope.

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