An all-in-one heat pump ERV combines space heating, cooling, balanced fresh-air ventilation and energy recovery in one indoor system. For multifamily buildings, it can reduce the number of separate apartment-level HVAC components while supporting a concealed ducted layout.
However, an all-in-one heat pump ERV should not be selected by nominal capacity alone. Engineers must also check low-temperature heating performance, ventilation airflow, indoor circulation airflow, available external static pressure, duct resistance, outdoor-air connections, ceiling space, drainage and service access.
What Does an All-in-One Heat Pump ERV Combine?
A conventional apartment HVAC design may use separate equipment for heating and cooling, outdoor-air ventilation, exhaust and energy recovery.
A heat pump ERV coordinates these functions in one system:
- Heat-pump heating
- Heat-pump cooling
- Filtered outdoor-air supply
- Exhaust-air removal
- Energy recovery between the outdoor and exhaust air streams
- Ducted indoor-air distribution
- Apartment-level control
The system can be installed above a ceiling, but it still requires engineered ductwork, outdoor intake and exhaust openings, condensate drainage, electrical connections and maintenance access.
Start with the Apartment Heating and Cooling Load
The first step is to calculate the heating and cooling load for each apartment and room.
The calculation should consider:
- Outdoor summer and winter design temperatures
- Apartment orientation
- Window area and solar exposure
- Building-envelope performance
- Occupancy and internal heat gains
- Required outdoor-air volume
- Sensible and latent cooling loads
- Room-by-room airflow requirements
Heating capacity must be checked at the project’s winter design temperature. Nominal capacity at 47°F does not represent the heating output available at 17°F or 5°F.
The current North American EXINDA AURA configuration has the following published performance:
| Mode | Outdoor-air condition | Capacity | Input power | Efficiency |
|---|---|---|---|---|
| Cooling | 95°F DB / 75°F WB | 12,000 Btu/h | 1,090 W | EER 11.0 |
| Heating | 47°F DB / 43°F WB | 14,000 Btu/h | 1,687 W | COP 2.43 |
| Heating | 17°F DB / 13°F WB | 7,800 Btu/h | 1,230 W | COP 1.86 |
| Heating | 5°F DB / 3°F WB | 7,165 Btu/h | 1,400 W | COP 1.50 |
These figures are rated values at the stated indoor and outdoor conditions. The applicable low-temperature capacity should be compared with the calculated project load before equipment is selected.
More detailed data are available in the EXINDA AURA performance article.
Ventilation Airflow Is Not the Same as Indoor Airflow
An all-in-one heat pump ERV has different airflow paths for ventilation and space conditioning.
Ventilation airflow represents the outdoor air supplied to the apartment and the exhaust air removed from it. Indoor airflow represents the recirculated air used to distribute heating and cooling through the rooms.
For the current AURA configuration:
| Airflow function | Published data |
|---|---|
| ERV outdoor airflow at 32°F | 42–135 CFM |
| Cooling indoor airflow | 400 CFM |
| Heating indoor airflow | 430 CFM |
The required ventilation airflow must be calculated according to the applicable code, occupancy and project design. The ERV airflow should not be treated as the total heating or cooling airflow.
This distinction is especially important in multifamily projects where one unit may need to ventilate the apartment while distributing conditioned air to several rooms.
How Does External Static Pressure Affect the Duct Layout?
Available external static pressure determines how much resistance the indoor fan can overcome while maintaining its rated airflow.
The complete pressure-loss calculation should include:
- Supply and return ducts
- Elbows and transitions
- Branch fittings
- Filters
- Dampers
- Supply diffusers
- Return grilles
- Outdoor intake and exhaust ducts
- Exterior louvers
- Acoustic components
The current AURA configuration publishes the following indoor airflow data:
| Operating mode | Rated indoor airflow | Available external static pressure |
|---|---|---|
| Cooling | 400 CFM | 75 Pa / 0.30 in. w.g. |
| Heating | 430 CFM | 75 Pa / 0.30 in. w.g. |
A multi-room duct system can be designed when its calculated resistance remains within the available external static pressure at the required airflow.
The 0.30 in. w.g. value does not automatically approve every long or multi-branch duct layout. The longest and most restrictive air path should be calculated before the final unit location and duct sizes are confirmed.
Can One Heat Pump ERV Serve Multiple Rooms?
A ceiling-ducted heat pump ERV can be evaluated for multiple rooms when the airflow distribution is properly designed.
The design should establish:
- Required airflow for each room
- Duct size for each branch
- Resistance of the longest duct route
- Balancing-damper locations
- Diffuser selection and throw
- Return-air location
- Transfer-air paths
- Occupied-room acoustic requirements
The return grille should not be installed too close to a supply outlet. Otherwise, conditioned air may be drawn back into the unit before reaching the occupied area, creating a short air path and uneven room temperatures.
For apartments with distant bedrooms or living areas, the duct layout should deliver the required airflow to the furthest room rather than concentrating supply air close to the unit.
Does a Heat Pump ERV Need Outdoor Connections?
Yes. “No conventional outdoor condenser” does not mean that the equipment operates without outdoor connections.
An indoor all-in-one heat pump ERV still requires:
- Outdoor-air intake duct
- Exhaust or discharge duct
- Exterior intake and discharge louvers
- Suitable separation between intake and discharge
- Weather protection
- Condensate drainage
- Electrical and service access
The exterior openings and louvers must be selected according to the design airflow and acceptable pressure loss. Their resistance must be included in the complete external static-pressure calculation.
Outdoor intake and discharge locations should also be coordinated to reduce the possibility of exhausted air returning through the fresh-air intake.
What Ceiling and Service Space Is Required?
The ceiling design must allow space for both the equipment and everything connected to it.
The coordinated layout should include:
- Unit dimensions
- Supply and return ducts
- Outdoor intake and discharge ducts
- Duct transitions
- Condensate piping and drainage slope
- Filter removal space
- Electrical service access
- Internal inspection access
- Vibration isolation
- Required acoustic treatment
A unit may physically fit above the ceiling but still be unserviceable if the access opening is too small or positioned away from the main service panels.
Equipment location should therefore be reviewed together with the ceiling plan, duct layout and maintenance path.
Is an All-in-One Heat Pump ERV Suitable for Retrofit Projects?
It can be evaluated for selected retrofit projects, but the existing building must have suitable installation conditions.
Before selecting the system, confirm that the building can provide:
- Adequate ceiling space
- Supply and return duct routes
- Outdoor intake and exhaust routes
- Suitable exterior openings
- Condensate drainage
- Required electrical supply
- Maintenance access
- Acceptable sound and vibration control
If the building cannot provide these conditions, another HVAC arrangement may be more practical.
For new construction and modular projects, these requirements can be coordinated earlier with the architectural, mechanical and production layouts.
EXINDA AURA Heat Pump ERV Application
EXINDA AURA is a ceiling-ducted all-in-one heat pump ERV developed for apartment and multifamily applications.
The current North American configuration combines:
- 12,000 Btu/h rated cooling
- 14,000 Btu/h rated heating at 47°F
- Balanced outdoor-air ventilation
- Exhaust-air removal
- Energy recovery
- Ducted indoor-air distribution
- 208–240 V / 1 Ph / 60 Hz electrical supply
- R32 refrigerant
For modular and prefabricated apartment layouts, AURA can be evaluated as part of the coordinated ceiling design. The unit position, supply branches, return-air path, outdoor ducts, drainage, electrical supply and service opening can be planned together before site installation.
Suitability still depends on the actual apartment load, ventilation requirement, duct resistance, design temperature and available installation space.
Review the EXINDA AURA 12,000 Btu/h Heat Pump ERV product page for current model information and technical downloads.
When May a Heat Pump ERV Not Be the Right Fit?
An all-in-one heat pump ERV may not be suitable when:
- The apartment load exceeds the available capacity at the design temperature
- Required ventilation airflow cannot be provided
- Duct resistance exceeds the available external static pressure
- Outdoor intake or discharge openings cannot be installed
- Intake and discharge separation is insufficient
- Ceiling or maintenance space is inadequate
- Condensate cannot be drained correctly
- One unit cannot distribute air effectively to all required rooms
A supplementary system, a different unit location or another equipment configuration may be required when these conditions cannot be resolved.
Information Needed for AURA Project Selection
To evaluate AURA for a multifamily project, provide:
- Project location
- Building and apartment type
- Floor plans
- Room-by-room heating and cooling loads
- Summer and winter design temperatures
- Required ventilation airflow
- Proposed duct layout
- Estimated external pressure loss
- Available ceiling space
- Outdoor intake and exhaust locations
- Electrical supply
- Project quantity
- Required certifications and technical documents
EXINDA can review these inputs against the current model data and identify a suitable next step for the project.
Frequently Asked Questions
What is an all-in-one heat pump ERV?
It is an indoor system that combines heat-pump heating and cooling with balanced fresh-air ventilation, exhaust and energy recovery.
Can a heat pump ERV heat and cool an entire apartment?
It can be evaluated for an apartment when its capacity at the project design conditions matches the calculated load and its airflow can be distributed correctly to each room.
Is ERV airflow the same as heating and cooling airflow?
No. ERV airflow measures outdoor and exhaust air, while heating and cooling airflow measures conditioned indoor air distributed through the apartment.
Can one heat pump ERV supply several rooms?
Yes, subject to room loads, required branch airflow, total duct resistance, diffuser selection and return-air design.
Does AURA require an outdoor condenser?
AURA does not require a conventional separate outdoor condensing unit beside the apartment. It still requires engineered outdoor intake and exhaust connections, exterior louvers and condensate drainage.
Can a heat pump ERV be installed in an existing building?
It can be considered for selected retrofit projects with sufficient ceiling space, outdoor-air routes, drainage, electrical capacity and maintenance access.
Request an AURA Project Review
Planning an apartment, multifamily, modular or high-rise project?
Send EXINDA your floor plan, room loads, design temperatures, required ventilation airflow, proposed duct layout, available ceiling space and electrical supply.
EXINDA can review the application against the current AURA model data and technical documentation.
Contact: info@exindagroup.com
