We recently completed a multi-zone heat pump installation in downtown Portsmouth, New Hampshire, for a condominium located within a mixed-use residential and commercial building. The goal of this project was to install a ductless heat pump system capable of providing efficient primary heating and cooling, while keeping all equipment discreet and fully serviceable.
Because of the building’s layout and shared spaces, this installation required careful planning, concealed line-set routing, and non-standard equipment placement.
Project Overview: Heat Pump Installation in a Mixed-Use Building
This Portsmouth, NH, condominium required a two-zone ductless mini-split system to condition both the living area and the bedroom. The system design included:
- One outdoor Fujitsu heat pump
- Two wall-mounted indoor units
- Concealed refrigerant line sets
- Basement routing for piping and wiring
- Pumped condensate drainage
Downtown condominium installations often involve tighter access, aesthetic concerns, and shared infrastructure—all of which were factors on this project.
Outdoor Heat Pump Placement & Underground Line-Set Routing
Selecting the outdoor unit location was one of the most important parts of this heat pump installation. The unit needed to be:
- Hidden from public view
- Accessible for long-term service and maintenance
- Positioned to allow the owner to install a future privacy fence
The Fujitsu R-32 outdoor unit was installed on a 20-inch elevated equipment stand mounted on a pad. Because the outdoor unit was located opposite the living space, the installation required underground routing of refrigerant line sets and electrical wiring beneath the building’s entrance walkway.
To accomplish this:
- The existing paver walkway was dismantled.
- A trench was excavated for refrigerant lines, electrical, and condensate piping.
- Lines were protected in an underground conduit.
- The trench was backfilled, compacted, and the pavers were reinstalled to closely match the original layout.
Cold-climate note: For optimal heating performance, snow and ice must be kept clear of the outdoor unit to maintain proper airflow.
Indoor Mini Split Installation & Concealment
Each indoor unit required a different approach to maintain a clean appearance while preserving future service access.
Living Area – 12,000 BTU Wall-Mounted Unit
The living area heat pump was installed inside an existing built-in cabinet. Refrigerant lines, condensate piping, and electrical wiring were routed tightly into the cabinet corner and kept exposed only where necessary to minimize visual impact.
Bedroom – 9,000 BTU Wall-Mounted Unit
The bedroom mini split was installed on the interior wall of a closet. To conceal the line sets, we opened the closet wall, routed the piping internally, and reconstructed the wall to a ready-for-patch-and-paint condition.
All line sets were routed through the building’s basement, allowing clean transitions to each indoor unit without disturbing finished living areas.
Condensate Drainage for Condominium Heat Pump Systems
Because gravity drainage was not feasible, all condensate lines were routed to the basement and connected to a condensate pump, which safely discharges water to the exterior of the building. This approach ensures reliable operation during both heating and cooling seasons while protecting interior finishes.
System Commissioning & Final Setup
Once installation was complete, we performed full system commissioning, including:
- Evacuation of refrigerant lines
- Refrigerant charging within factory specifications
- Functional testing in heating and cooling modes
- Customer walkthrough and system operation overview
The complete multi-zone heat pump installation was completed in three days, including trenching, wall access, restoration, and system startup.
Why Professional Heat Pump Installation Matters in Downtown Portsmouth
Installing a ductless heat pump system in a downtown Portsmouth, NH, condominium presents challenges not found in typical residential projects:
- Shared building spaces
- Limited routing options
- Noise and visual considerations
- Long-term service access requirements
This project highlights the importance of proper system design, equipment placement, and line-set routing—especially in urban and mixed-use buildings.
When installed correctly, a multi-zone ductless heat pump can provide quiet, efficient, year-round comfort without compromising the appearance or functionality of the space.
