The problem: Property managers and hotel operators need to validate energy savings claims before committing to a fleet rollout – and headline percentages are not enough without the underlying numbers.
What this paper covers: Four detailed buyer scenarios (Airbnb host, property manager, hotel, extreme-abuse case) with per-unit and fleet savings tables, sensitivity analysis for electricity price and climate, and a 30-day pilot protocol to verify results in your own units.
The punchline: A typical property manager with 20 units saves €3,800–9,000 per summer – and a fleet operator at 50 units saves up to €22,500, with payback measured in weeks rather than seasons.
This paper explains the physical principles, field evidence, and per-scenario calculations behind Narveo's savings claim. It is written for property managers, hotel operators, and technical buyers who want to validate the numbers before running a pilot.
Contents: two-lever savings model (temperature band lock + timed shutoff) · evidence anchors from government agencies, the IEA, and peer-reviewed studies · four buyer scenarios with detailed input and output tables · sensitivity analysis for electricity price, climate, and guest behaviour · 30-day pilot verification protocol.
Narveo saves €190–€450 per AC unit per summer in the typical case – and 50–70% more in extreme-abuse cases. Payback is measured in weeks to a few months, not seasons.
An air conditioner's electricity consumption is determined to first order by two things: the temperature difference it must maintain against outdoor conditions (the lift), and the number of hours it runs. Narveo addresses both.
For a fixed outdoor temperature, reducing the indoor setpoint by one degree increases the cooling load by roughly 8–10%. The effect is well-documented by public authorities and compounds when users cool two or three degrees below a reasonable comfort band.
Compounded across a 3–4°C range – typical guest behaviour at 16–20°C versus Narveo's cap at 22–25°C – this alone produces 25–40% savings in AC electricity consumption.
A typical rental unit has a guest in the room approximately 60–70% of a 24-hour day. The rest of the time, if the AC is running, it is cooling an empty space. Narveo introduces non-negotiable pause windows – for example 14:00–17:00 when guests are typically out, or 01:00–06:00 at night.
The two levers multiply rather than add. If setpoint enforcement saves 35% of the baseline, and timed shutoff saves 20% of what remains, total savings are: 1 − (1 − 0.35) × (1 − 0.20) = 48%. This is why the 30–50% band is achievable in realistic operating conditions rather than only in edge cases.
All scenario calculations build up from a single unit baseline. These assumptions are deliberately conservative and can be replaced with the buyer's own numbers during a pilot.
| Input | Value | Note |
|---|---|---|
| Average AC power draw (single-room split) | 1.2 kW | Electrical consumption. The unit's 3.5 kW rating is cooling capacity, not power drawn |
| Daily runtime, blended (unmanaged) | 14–15 h | Some guests switch the unit off; most leave it running while out |
| Cooling season length | 150 days | Coastal / summer-only baseline. Continental properties (e.g. Madrid) run the unit year-round, heating in winter and cooling in summer |
| Electricity price (incl. taxes) | €0.25/kWh | Real range €0.22–0.29; €0.25 is the base |
| Baseline kWh per unit per season | 2,520–2,700 kWh | = 1.2 × (14–15) × 150 (coastal); roughly double year-round |
| Baseline cost per unit per season | €630–€675 | Coastal, at €0.25/kWh; continental year-round roughly double |
| Recoverable share Narveo captures | 30–50% | The gap between needed cooling and actual runtime / extreme setpoints |
The gap between the reasonable-use baseline and the abuse uplift is what Narveo recovers. In realistic mixed-portfolio operation, 30–50% of that gap converts to savings.
Each scenario uses the baseline from Section 2. Savings percentages apply to the scenario-specific baseline – they represent the middle of the evidence band from Section 1, not a best case.
Single owner, self-managed properties. Absorbs the full electricity bill directly.
| Parameter | Value |
|---|---|
| Baseline consumption per unit | 2,520 kWh/season (14 h/day × 150 days) |
| Baseline cost per unit | €630/season at €0.25/kWh |
| Observed guest pattern | Setpoint 18–20°C; AC left on during check-out gaps |
| Narveo savings (combined levers) | 30–40% → 756–1,008 kWh saved per unit |
| € saved per unit per season | €190–€250 per unit |
| Fleet impact (2–6 units) | €380–€1,500 per season |
| Payback (€69 retail unit) | Well within one season |
Managing a mixed portfolio on behalf of owners. Utility cost competes with cleaning and commission.
| Parameter | Value |
|---|---|
| Baseline consumption per unit | 2,700 kWh/season (15 h/day × 150 days) |
| Baseline cost per unit | €675/season at €0.25/kWh |
| Observed guest pattern | Mixed profile; abuse (16–19°C, left running) on 20–30% of stays |
| Narveo savings (combined levers) | 35–45% → 945–1,215 kWh saved per unit |
| € saved per unit per season | €235–€305 per unit |
| Fleet impact (20 units) | €4,700–€6,100 per season |
| Fleet impact (50 units) | €11,750–€15,250 per season |
| Payback (€54 bulk unit) | ~1 month at 20 units; weeks at 50 |
Room-scale deployment. Utility bills are a line item the general manager watches monthly.
| Parameter | Value |
|---|---|
| Baseline consumption per room | ~4,900 kWh/year (year-round: cooling in summer + heating in winter, same unit) |
| Baseline cost per room | €1,225/year at €0.25/kWh |
| Observed guest pattern | Continental city (e.g. Madrid): guests over-cool in summer and over-heat in winter; rooms conditioned while empty |
| Narveo savings (combined levers) | 30–37% → 1,470–1,800 kWh saved per room |
| € saved per room per year | €370–€450 per room (top of the band: two waste seasons) |
| Fleet impact (40 rooms) | €14,800–€18,000 per year |
| Fleet impact (100 rooms) | €37,000–€45,000 per year |
| Payback (€48 fleet unit) | Days |
Summer peak, coastal location. Guests routinely run 16°C all day with windows open or while absent.
| Parameter | Value |
|---|---|
| Baseline consumption per unit | 3,200–3,600 kWh/season (near-continuous runtime, long season) |
| Baseline cost per unit | €800–€900/season at €0.25/kWh |
| Observed guest pattern | 16°C setpoint; near-24/7 runtime; windows open; AC on during absences |
| Narveo savings (combined levers) | 40–48% → 1,300–1,730 kWh saved per unit |
| € saved per unit per season | up to €450 per unit (top of the €190–450 band) |
| Fleet impact (20 units) | up to €9,000 per season |
| Payback (€54 bulk unit) | Weeks – often a single abuse-pattern guest stay |
Three variables shift the numbers meaningfully: electricity price, climate severity, and guest behaviour. The table below shows how the Property Manager scenario (B) responds to electricity price.
Savings are denominated in kWh first, euros second. When electricity prices rise, payback accelerates.
| Price €/kWh | Baseline / unit | Saved / unit | Fleet 20 units | Fleet 50 units |
|---|---|---|---|---|
| €0.22 (lower EU range) | €594 | €167–€396 | €3,340–€7,920 | €8,350–€19,800 |
| €0.25 (base) | €675 | €190–€450 | €3,800–€9,000 | €9,500–€22,500 |
| €0.29 (Spanish peak / islands) | €783 | €220–€522 | €4,400–€10,440 | €11,000–€26,100 |
A 90-day season (northern coasts) scales savings down approximately 25%. A 150-day season (islands, southern coasts) scales them up approximately 25%. The per-unit number stays proportional – percentage savings are largely climate-independent.
The methodology above is defensible, but for any serious buyer the right question is not "do we believe the numbers" but "does it work in our units." The protocol below answers that in 30 days.
¹ Agencia Andaluza de la Energía – AC setpoint guidance: ~8% additional energy per °C below the reference setpoint.
² European Commission and International Energy Agency – "Playing My Part" report (2022): raising AC setpoint by 1°C cuts electricity consumption by up to ~10%.
³ IEA – Singapore Green Building Council field data: raising office AC setpoint from 24°C to 26°C delivered ~30% electricity reduction across the cooling season.
⁴ Peer-reviewed experimental study on R32 residential mini-split ACs: 13.5% energy reduction at 21→22°C, 10.7% at 23→24°C, confirming the 8–10% per °C elasticity under laboratory conditions.
Narveo. CEE ratings vs real energy use: why efficiency labels mislead rental operators. White paper, April 2026. Available at narveo.eu/whitepapers/cee-ratings-vs-real-energy-use.html
Narveo. Reducing AC energy costs in rental properties: the hidden impact of temperature settings and guest behaviour. White paper, April 2026. Available at narveo.eu/whitepapers/rental-property-energy-costs.html
Narveo in one sentence: Narveo is a plug-and-play AC control device for holiday rental properties and hotels that reduces electricity costs by enforcing temperature limits and automated runtime shutoff – no WiFi, no app, and no changes to existing AC equipment required.
This savings model is calibrated for Mediterranean and continental Spain with electricity tariffs in the €0.22–0.29/kWh range (€0.25 base) and 1.2 kW (electrical draw) residential split units of the kind common in vacation rentals across Spain, Italy, Greece, and Portugal. Coastal properties run a ~150-day cooling season; continental properties (e.g. Madrid) run the same unit year-round, heating in winter and cooling in summer, which roughly doubles the per-unit figure. Properties in cooler northern climates, regulated low-tariff markets, or with centralised hotel chiller systems will see results outside the headline 30–50% range. The Andaluza, EU/IEA, and IEA Singapore evidence cited above is robust within those parameters; outside them, the methodology should be re-modelled before relying on it.
The savings range assumes a typical guest behaviour mix – a meaningful proportion of guests setting setpoints below 22°C and leaving units running while away from the property. Properties whose guest profile is predominantly disciplined repeat customers, long-stay business travellers, or operators who already manage AC by hand will see lower per-unit savings. Conversely, properties with high turnover, price-insensitive holiday guests, and unsupervised teenage occupants (the IEA-defined extreme-abuse scenario) regularly exceed the upper bound.
Narveo enforces temperature and runtime limits at the remote-control level. It does not meter electricity consumption, report telemetry, or integrate with energy management systems. The savings figures in this paper are model-based estimates calibrated against published evidence and field data; verification at a specific property requires direct comparison of metered electricity bills before and after deployment, or installation of additional sub-metering infrastructure. The 30-day pilot protocol described above is the operator-friendly approximation, not a substitute for utility-bill comparison.
The 8–10% per °C setpoint elasticity is established under controlled laboratory conditions. Real-world results vary with unit age, refrigerant charge, building thermal envelope, and outdoor temperature. Older units, units overdue for refrigerant service, and units in poorly insulated buildings tend to overperform the elasticity – baseline waste is higher, so each restored degree releases more energy. New, well-maintained units in well-insulated buildings underperform the elasticity. Use the central estimate; expect a ±20% range around it depending on these factors.
For pilots run near season edges (May or September in the Mediterranean), scale the observed savings up to the full 150–180 day season before drawing conclusions. A 30-day pilot in late September will systematically understate annualised savings because cooling demand falls in shoulder months. The verification protocol above accounts for this; informal pilots should adjust accordingly.
From €69 per unit. No Wi-Fi. No app. No installation. Typical payback: weeks to a few months.
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