Two ventilation strategies can deliver different airflows, controls and indoor conditions, so comparing equipment price or rated power alone gives an incomplete cost picture. Define equivalent service and operating assumptions first. See Feathers Hospitality’s approach, review the hotel management platform, or contact the team about aligning building decisions with hotel operations.
Compare ventilation options on equal service conditions, including fan energy, heating and cooling effects, controls, maintenance and commissioning.
In brief
- Compare opções com o mesmo caudal e condições de qualidade interior.
- Inclua eletricidade dos ventiladores, efeitos térmicos, manutenção e controlos.
- Modele custos do edifício e verifique a instalação após comissionamento.
Specify the indoor service to be maintained
Write down the required spaces, operating hours, occupancy assumptions, airflow and indoor-environment constraints for each option. Have a competent building professional confirm applicable requirements for the property. A cheaper option that delivers less air or different comfort is not a like-for-like alternative. Include guest rooms, kitchens or other special spaces only where relevant, and distinguish continuous operation from demand-based schedules. The comparison begins with service equivalence, not with equipment labels.
Set the system boundary
Map fans, ducts, filters, controls, heat recovery, heating and cooling plant, and any interactions with building automation. State whether the analysis covers one unit, a floor or the whole property. A change can shift energy use between systems: fan electricity may fall while heating or cooling demand changes. If meters cover multiple areas, note the allocation method. A transparent boundary prevents a narrow equipment figure from being mistaken for whole-building savings.
Calculate fan electricity under real schedules
Collect model-specific power or performance data at the relevant airflow and pressure, then estimate operating hours by season and occupancy. Use local tariffs and distinguish rated from expected operation. Filters, dirty ducts and control settings may change fan demand over time, so include maintenance assumptions. The European Commission’s ventilation-unit information covers product-specific requirements and energy indicators; it cannot substitute for a site design or confirm actual annual consumption.
Model heating and cooling interactions
Where a strategy includes heat recovery, model the useful recovered energy under the expected climate, schedules and system configuration. Consider bypass, frost protection, summer conditions and control logic where applicable. Demand control may reduce operation during low occupancy, but only if sensors, commissioning and operating rules work as intended. The US Department of Energy describes retrofit measures such as heat recovery and demand control; this is technical context, not proof of savings for a Portuguese hotel.
Include maintenance and availability costs
Compare filter replacement, cleaning, inspections, calibration, repairs, access requirements and expected downtime. Ask suppliers to specify consumables, service intervals and warranty exclusions. A system that is difficult to maintain can drift from its design performance or interrupt guest areas. Cost labour and call-outs using the property’s own assumptions. Avoid assigning a generic maintenance percentage when quotes or maintenance records can support a more grounded estimate.
Account for building performance obligations
The recast EU Energy Performance of Buildings Directive establishes a building-performance framework, but applicability and implementation depend on building characteristics and national transposition. Confirm current Portuguese requirements with a qualified professional. Treat regulatory compliance and indoor environmental constraints as conditions of the comparison, not optional benefits. The presence of an energy label or a compliant product does not automatically show that a particular system design is suitable for this building.
Compare scenarios over a common horizon
Use the same analysis period, occupancy patterns, energy prices, replacement assumptions and discounting method for both options. Show base, low-use and high-use scenarios. Include capital and installation costs as well as energy, maintenance, controls and replacement. A result sensitive to one uncertain input should be labelled accordingly. The output should reveal which assumptions drive cost rather than create a false impression of precision through a single total.
Plan commissioning and measurement
Before procurement, define who will test airflow, control sequences, alarms and handover documentation. Record baseline energy and operating conditions where feasible. After installation, verify the system under representative conditions and investigate deviations before claiming savings. Use a measurement approach proportionate to the decision; the US federal measurement guidance is a methodological reference, not a Portuguese requirement. Preserve settings and records so maintenance teams can detect later drift.
Frequently asked questions
Is heat recovery always cheaper to run?
No. Its performance depends on design, operating hours, climate, controls, maintenance and the connected heating or cooling system.
Can a product energy rating decide between strategies?
Not by itself. Compare equivalent airflow and indoor conditions, whole-system energy effects, installation, maintenance and site-specific tariffs.