Property: Late 19th-century mill worker housing, Machine Shop Village North Andover National Register Historic District
Owner: M.R. (property owner alias)
Scope: Whole-home cold-climate heat pump installation replacing aging gas furnace and window AC units; multi-zone ductless configuration selected for property configuration; HDC coordination for outdoor condenser placement
Timeline: Diagnostic and design 3 weeks, Machine Shop Village HDC coordination 5 weeks (parallel to installation planning), installation 6 days
Investment: $26,800 installed, $10,000 Mass Save Whole-Home Heat Pump rebate, $2,000 IRA 25C federal tax credit, net $14,800
M.R. owns a late 19th-century mill worker housing property in the Machine Shop Village Historic District, one of North Andover’s designated Local Historic Districts and listed on the National Register of Historic Places. Machine Shop Village developed as industrial-era mill worker housing in the late 19th century adjacent to former textile mill operations that were part of North Andover’s industrial history. The district retains substantial architectural integrity from its 1870s-1890s original development period.
Machine Shop Village architectural character differs substantially from Old Center’s earlier Federal and Greek Revival residential styles. Machine Shop Village properties are typically smaller-scale worker housing with distinctive late 19th-century mill-era detailing: modest single-family or two-family residential configurations, cross-gable or simple side-gable rooflines, small front porches with turned posts, clapboard siding, and coordinated neighborhood streetscape reflecting the mill worker housing development pattern.
M.R.’s property retains original architectural elements: original clapboard siding (recently repainted in period-appropriate colors), original wood windows with true divided lights (some replaced but with period-appropriate replacements), small front porch with turned post details, and coordinated exterior character with the surrounding Machine Shop Village streetscape.
Original heating: mid-life gas furnace with existing ducted distribution serving the compact two-story property. Original cooling: window AC units on primary rooms during summer months. Property size approximately 1,800 sq ft two-story (compact mill worker housing scale).
M.R. requested Rivic assess replacement options with priorities: (1) preserve Machine Shop Village Historic District character — outdoor condenser placement coordinated with HDC review, (2) fossil-fuel elimination through heat pump conversion for Mass Save Whole-Home Heat Pump rebate, (3) coordinated whole-home cooling replacing window AC operation (window AC units impact the property’s exterior character during summer months), (4) property-appropriate scope and cost given the compact mill worker housing scale (not requiring larger-property premium equipment specifications).
Andrew Samples conducted the initial diagnostic assessment. Kathleen Brennan initiated Machine Shop Village HDC coordination in parallel — reviewing HDC guidelines for both outdoor condenser placement and window AC removal (some HDC districts specifically address window AC unit visibility as an exterior character consideration).
Key findings: (1) mid-life gas furnace with declining efficiency, functional but approaching end-of-life range for coordinated replacement, (2) window AC units impacting the property’s exterior character during summer months — replacement with heat pump provides both cooling improvement and exterior character improvement, (3) existing ductwork in acceptable condition but sized for the compact property with limited zone flexibility, (4) 100A National Grid electric service — adequate for heat pump installation with capacity margin but at the lower end of Rivic’s typical minimum, requiring careful load coordination, (5) property configuration favored multi-zone ductless configuration over ducted retrofit given the compact two-story scale and the desire for zone-level control across the small property, (6) outdoor condenser placement options: side-yard location required for typical Machine Shop Village property configuration (rear-yard often shared with adjacent properties in the mill worker housing development pattern).
ACCA Manual J load calculation determined property heating load at 4°F winter design of approximately 32,000 BTU/hr and cooling load at 88°F summer design of approximately 22,000 BTU/hr (both loads modest reflecting the compact property size).
Rivic recommended Mitsubishi Hyper-Heat MXZ 3-zone multi-zone ductless configuration matched to property configuration: (1) first-floor living/dining/kitchen 15,000 BTU/hr concealed ceiling cassette (compact property first floor configuration), (2) master bedroom 9,000 BTU/hr wall-mount cassette, (3) second bedroom 9,000 BTU/hr wall-mount cassette. Total outdoor unit capacity 30,000 BTU/hr matched to Manual J loads.
Outdoor condenser placement: side-yard location with landscape screening from public rights-of-way as required by Machine Shop Village HDC. Placement coordinated with adjacent property owner acknowledgment (Machine Shop Village mill worker housing properties have narrow side-yards typical of the development pattern). Refrigerant line-set routing through existing utility chase.
Window AC unit removal: all three window AC units removed as part of installation scope, restoring the property’s exterior character during summer months. Window trim inspection and any needed touch-up completed as part of scope.
Gas furnace decommissioning: existing furnace removed with proper handling; gas piping capped at previous furnace location.
Kathleen Brennan handled Machine Shop Village HDC coordination throughout the project. Application package included: property drawings showing existing conditions and proposed installation scope, side-yard outdoor condenser placement details with landscape screening, window AC removal scope with exterior character restoration, and adjacent property owner acknowledgment for side-yard placement (Machine Shop Village HDC values coordinated neighborhood streetscape given the mill worker housing development pattern).
HDC review completed in 5 weeks (application submission to Certificate of Appropriateness issuance). Certificate confirmed the installation approach preserved the Machine Shop Village Historic District character. The window AC removal was specifically noted in the Certificate as an exterior character improvement.
Both Old Center and Machine Shop Village are North Andover Local Historic Districts listed on the National Register of Historic Places, and both HDCs coordinate through the same North Andover municipal process. Similarities: 4-6 week typical review timeline, similar Certificate of Appropriateness scope, similar handling by Kathleen Brennan. Practical differences reflecting district character:
Installation completed over 6 days including outdoor condenser side-yard placement, indoor cassette installations (concealed ceiling in first-floor main area, wall-mount in second-floor bedrooms), refrigerant line-set routing, window AC unit removal, gas furnace decommissioning, and commissioning.
Post-installation first-year operational verification: heat pump operated reliably through the first winter including cold-snap periods. Property exterior character improved substantially from previous summer configuration (three window AC units removed). M.R. reported particular satisfaction with the coordinated heating and cooling improvement plus the exterior character restoration.
Post-installation first-year utility monitoring: total electric operating cost approximately $980 for combined heating and cooling. Previous year utility costs: gas heating approximately $1,140, electric window AC approximately $340, combined approximately $1,480/year. Annual operating cost reduction approximately $500/year.
Machine Shop Village North Andover mill worker housing HVAC service including multi-zone ductless heat pump installation, Machine Shop Village HDC Certificate of Appropriateness coordination, window AC unit removal with exterior character restoration, National Grid electric service coordination and Eversource Gas of Massachusetts coordination for North Andover utility framework, and Mass Save Whole-Home Heat Pump rebate coordination all route through our 225 Broadway #306 office in downtown Methuen. This case study represents a specific installation completed for M.R.; individual property assessments determine equipment specification and installation scope.