LED vs HPS Greenhouse Lighting: 2026 Comparison & ROI Guide

TLDR

LED vs HPS greenhouse lighting is the core comparison commercial growers face when selecting supplemental lighting. LEDs produce more photons per watt and offer spectral control, making them the stronger long term choice for most new projects. HPS costs less upfront and contributes radiant heat that can benefit cold climate production. The real decision extends beyond the fixture to include crop response, greenhouse heat balance, dehumidification, light uniformity, canopy penetration, dynamic lighting strategies, and total return on investment.

• Upfront budget is limited

• Winter heating costs are significant

• Existing HPS infrastructure is already installed

• Growers want a phased lighting upgrade

The best choice depends on:

• Electricity cost

• Climate zone

• Crop type

• Target DLI

• Heating and cooling load calculations

• Payback expectations

In most new greenhouse builds, LED is now the default recommendation, while HPS is increasingly used only in retrofit or hybrid scenarios.

Key takeaway: LED usually wins on efficiency and long term ROI, while HPS can still win on initial cost and beneficial radiant heat.

What LED vs HPS Greenhouse Lighting Means

LED vs HPS greenhouse lighting compares two supplemental lighting technologies used to boost daily light integral (DLI) in commercial greenhouses.

LED (light emitting diode) grow lights use semiconductor diodes to produce plant usable photons. They can be built with specific spectral recipes, combining white, red, blue, and far red diodes, and are generally the more electrically efficient option. HPS (high pressure sodium) is a high intensity discharge lamp that has been the standard greenhouse supplemental light for decades. It produces a broad yellow orange and red heavy output along with significant radiant heat.

The practical difference between these technologies goes well beyond wattage. For greenhouse operators, LED vs HPS is really a question about how many photons reach the crop, how much electricity that requires, how the lighting system changes the greenhouse climate, and how long the investment takes to pay back. A comprehensive review in Horticulture Research notes that horticultural lighting efficacy should be measured in µmol/J (photons per joule), not lumens, because lumens weight light according to human vision, not plants.

If you are starting to scope a greenhouse lighting project, a free consultation with a lighting specialist is the fastest way to match fixture selection to your specific crop and facility.

Quick Answer: Which Is Better?

For most new commercial greenhouse lighting projects, LED is the better long term platform. Modern LED fixtures deliver more photons per joule of electricity, last longer, and give growers meaningful control over spectrum and intensity.

But that does not mean HPS is dead. HPS still makes sense where upfront budget is the main constraint, where winter radiant heat offsets separate heating costs, or where a hybrid lighting approach allows growers to phase their capital spending. The comparison between LED and HPS greenhouse lighting is not a simple “one is always better” answer. It is a facility level decision.

Greenhouse energy modeling from Wageningen University illustrates why. When researchers compared HPS at 1.8 µmol/J to LED at 3.0 µmol/J, LED cut lighting energy demand by about 40%. But total greenhouse energy savings dropped to just 10 to 25% because the LED greenhouses needed more heating to compensate for lost HPS radiant heat, according to the Wageningen greenhouse energy study. That gap between “lighting savings” and “total energy savings” is the single most important nuance in this comparison.

If you are evaluating a greenhouse LED project, start with a clear understanding of your crop DLI targets and facility constraints.

LED vs HPS at a Glance

LED vs HPS Greenhouse Lighting Comparison Table

Summary

LED wins in most categories related to efficiency, controllability, and long term operating cost. HPS primarily retains advantages in lower upfront cost and supplemental greenhouse heating.

How to Compare Grow Lights: PPF, PPFD, DLI, and PPE

Comparing LED and HPS greenhouse lighting by watts or lumens is a common mistake. Watts measure electricity consumption. Lumens measure brightness to the human eye. Neither tells you how many plant usable photons reach the crop canopy.

Here are the metrics that actually matter.

PPF (photosynthetic photon flux) is the total number of photosynthetically active photons a fixture emits per second, measured in µmol/s. It describes the fixture’s raw output before accounting for layout, mounting height, or reflection losses.

PPFD (photosynthetic photon flux density) is the number of photons landing on a surface per second per square meter, measured in µmol/m²/s. This is what the crop actually receives. A typical supplemental lighting installation might deliver 60 to 80 µmol/m²/s, with some vegetable crops receiving up to 200 µmol/m²/s. For more detail on how PPFD targets vary by crop and growth stage, see this greenhouse PPFD guide.

DLI (daily light integral) is the total photosynthetic light received per square meter per day, expressed in mol/m²/day. In northern U.S. winters, greenhouse DLI can fall below 10 mol/m²/day, making supplemental lighting essential for quality and scheduling. A quick formula: DLI = PPFD × hours × 0.0036. For example, 100 µmol/m²/s for 16 hours adds about 5.76 mol/m²/day.

PPE (photosynthetic photon efficacy) is the number of plant usable photons produced per joule of electrical input, measured in µmol/J. This is the core efficiency metric. A fixture rated at 3.0 µmol/J produces roughly 67% more photons per watt than one rated at 1.8 µmol/J.

Biomass efficacy goes a step further: how much edible crop weight is produced per kWh of electricity. Cornell researchers argue that fixture efficacy alone does not account for plant performance and that biomass efficacy is a better measure of real growing efficiency.

When evaluating any lighting proposal, ask for average PPFD across the full growing area, not just a peak reading directly under one fixture.

LED vs HPS by Greenhouse Type

Different greenhouse operations benefit differently from each lighting technology.

Vegetable Greenhouses

LED is typically preferred for tomatoes, cucumbers, peppers, and lettuce. Benefits include higher efficiency, better crop steering, and lower electricity consumption. For crop specific DLI and PPFD targets, guides on tomato lighting and lettuce lighting requirements break down the numbers by growth stage.

Cannabis Greenhouses

LED provides spectrum control, dimming capability, and better integration with environmental controls. However, growers must carefully manage humidity and VPD after transitioning from HPS.

Ornamental and Bedding Plants

Research shows both technologies can perform well, making ROI and energy cost major decision factors.

High Latitude Winter Production

Hybrid systems often perform best because HPS contributes useful radiant heat while LED reduces electrical consumption.

Energy Efficiency: Lighting Electricity vs Total Greenhouse Energy

This is the single biggest misconception in the LED vs HPS greenhouse lighting debate: the difference between lighting energy savings and total facility energy savings.

LED fixtures use significantly less electricity to produce the same number of photons. That part is straightforward. In the Wageningen modeling study, LED at 3.0 µmol/J required about 40% less lighting electricity than HPS at 1.8 µmol/J to deliver equivalent photon levels. Earlier experimental results cited in the same paper showed fixture level electricity reductions of 37% to 60%.

But here is where most comparison articles stop, and where growers get burned.

HPS lamps dump a large amount of heat into the greenhouse. In cold months, that heat partially offsets the boiler or heating system. When LEDs replace HPS, the lighting electricity drops, but the heating bill rises. The Wageningen study found total greenhouse energy savings were only 10 to 25% across the modeled scenarios, not the 40 to 60% that fixture only comparisons suggest.

This distinction matters enormously. A grower in the Netherlands or northern Canada will see different total savings than one in southern California. Anyone evaluating LED vs HPS for a greenhouse project should model the whole energy balance, not just the lighting circuit. For a broader look at where energy savings come from in a greenhouse, this energy savings guide covers LED, HVAC, and rebate strategies together.

Heating and Cooling Load Calculation for LED vs HPS

One of the most overlooked steps in an LED vs HPS decision is running a proper heating and cooling load calculation that accounts for the lighting system. Growers who skip this step tend to underestimate the climate impact of switching technologies.

Why Lighting Changes the Load Calculation

Every watt of electricity consumed by a grow light eventually becomes heat. The difference is where that heat ends up. An HPS fixture converts roughly 60 to 65% of its input power to heat, most of it as infrared radiation directed at the canopy. An LED fixture at 3.0 µmol/J converts a higher share of input power into photons, but the remaining heat exits primarily through convection at the fixture and driver, not as radiant heat on the leaf surface.

This means switching from HPS to LED changes three things simultaneously:

• Sensible heat load in the growing zone drops. Less radiant energy warms the air and canopy.

• Heating demand in cold months increases. The greenhouse loses a “free” heat source and must compensate with boiler or heat pump output.

• Cooling demand in warm months decreases. Less waste heat means less mechanical cooling or vent time.

A Simplified Approach

A practical heating and cooling load estimate for a lighting retrofit starts with the current system’s total wattage, then calculates the BTU contribution. One watt equals approximately 3.41 BTU/hr. A greenhouse running 500 kW of HPS contributes about 1.7 million BTU/hr of heat to the facility. Replace that with 300 kW of LED (delivering equivalent photons), and the heat contribution drops to roughly 1.02 million BTU/hr, a gap of about 680,000 BTU/hr that the heating system must cover during cold periods.

Practitioners on Reddit consistently flag this as the surprise cost of LED conversion. One grower in an r/macrogrowery discussion described discovering a $15,000/year increase in heating costs after switching an entire facility to LED, partially offsetting the electricity savings. The lesson: model the net energy balance, not just the lighting circuit.

For facilities where the HVAC math gets complex, understanding latent vs sensible heat is essential. Radiant heat from HPS disproportionately affects sensible heat, while LED conversions tend to shift the balance toward latent heat (moisture) as a bigger proportion of the remaining load.

When to Bring in Engineering Support

Any facility over 10,000 sq ft should consider a formal HVAC audit before a full LED retrofit. Smaller projects can often get by with the simplified BTU approach, but larger operations need to model boiler capacity, dehumidification requirements, and air exchange rates against the new lighting load.

Heat, Humidity, and VPD: Why LED Is Not a Drop In HPS Replacement

When an HPS lamp runs, a substantial portion of its energy output reaches the crop as radiant heat. That infrared radiation warms leaf surfaces directly, increases leaf temperature, drives transpiration, and helps manage vapor pressure deficit (VPD). LED fixtures convert more energy into photons and less into radiant heat. That sounds like a pure advantage. In practice, it creates a different greenhouse.

Practitioners on Reddit report this consistently. In one r/macrogrowery thread, growers warned that switching from HPS to LED often leaves facilities with too much AC capacity and not enough dehumidification. Another thread focused on how LEDs do not warm the leaf surface the way HID fixtures do, meaning ambient temperature targets often need to increase by several degrees to maintain the same VPD range.

Svensson, a major climate screen manufacturer, made the same point on LinkedIn: LED efficiency changes greenhouse climate and requires new humidity strategies, especially when energy screens are deployed. Grodan’s full LED tomato trial confirmed that stable production under LEDs with closed screens depended on active air dehumidification and increased air movement to support transpiration.

What Changes When You Switch to LED

• Leaf temperature drops. Growers may need to raise air temperature setpoints to compensate.

• Transpiration decreases. Lower leaf temperature means less water vapor leaving the plant, which can slow nutrient uptake and calcium transport.

• Humidity rises. Less radiant heat plus reduced AC runtime means less passive dehumidification. Active systems or adjusted ventilation become necessary.

• VPD targets change. The crop’s microclimate is different even when the same number of photons arrive. Irrigation, fertigation, and climate recipes all need revisiting.

For sealed indoor cannabis facilities, the dynamics are similar but more intense. The enclosed environment amplifies any change in heat load. Growers considering an LED switch for indoor cultivation face the same VPD and dehumidification challenges, often at higher PPFD levels. Understanding HVAC sizing for LED lights prevents the most common engineering mistakes.

One clear message from practitioner forums: do not switch lighting technology mid crop cycle. Multiple r/macrogrowery threads advise waiting until the next cycle rather than hard switching during flower. Test in one zone first.

Dynamic LED Lighting in Greenhouse Production

One of LED’s most significant advantages over HPS has nothing to do with raw efficiency. It is programmability.

Dynamic LED lighting refers to the ability to adjust light intensity, spectrum, and photoperiod in real time based on crop stage, ambient sunlight levels, or energy pricing. HPS fixtures are essentially binary: on or off. Some ballasts allow limited dimming, but the spectrum cannot change and dimming below about 50% causes lamp instability and accelerated degradation.

LED fixtures, by contrast, can dim smoothly from 100% down to 10% or lower without affecting spectrum or fixture lifespan. More advanced systems allow spectral shifts, adding far red during end of day treatments to promote flowering or increasing blue wavelengths during vegetative stages to control stretch.

How Growers Use Dynamic Lighting

Sunlight compensation. On bright days, LED fixtures dim or turn off entirely when ambient DLI is sufficient. On overcast days, they ramp up. This strategy delivers a consistent DLI target with minimal electricity waste. One YouTube walkthrough by a Dutch tomato grower showed a 15 to 20% reduction in lighting hours per year simply by integrating PAR sensors with automated dimming.

Spectral recipes by crop stage. Propagation might use a higher blue ratio for compact growth, while flowering stages shift toward red and far red. This kind of crop steering is impossible with HPS.

Time of use energy management. In regions with variable electricity pricing, growers can dim or shift lighting hours to avoid peak rate periods while still hitting daily DLI targets. This is especially valuable for operations running 16 to 18 hour photoperiods in winter.

End of day far red treatments. A pulse of far red light at the end of the photoperiod accelerates phytochrome conversion and can shorten time to flower in long day sensitive crops. Some LED greenhouse fixtures include dedicated far red channels for exactly this purpose.

Dynamic lighting is not just a feature. It changes the economics. A greenhouse that can dim its LED array by 30% on sunny winter afternoons uses 30% less electricity during those hours. Over a season, the cumulative savings can meaningfully accelerate payback. For growers interested in optimizing supplemental lighting strategy, dynamic dimming is the first capability to implement.

Canopy Penetration and Fixture Spacing

When comparing LED vs HPS greenhouse lighting, most discussions focus on efficiency, spectrum, and heat. Canopy penetration and fixture spacing get far less attention, but they directly affect yield uniformity and crop quality.

The Physics of Light Distribution

HPS fixtures produce light from a single, intensely bright point source (the arc tube). That concentrated output, combined with a large parabolic reflector, creates a deep cone of light that penetrates relatively well into tall, dense canopies. The downside is that PPFD is highest directly below the fixture and drops off sharply toward the edges.

LED fixtures spread their output across many diodes on a bar, panel, or multi bar array. This creates a wider, more even footprint at canopy level but with lower peak intensity at any single point. The result is better uniformity across the horizontal plane but potentially less penetration into the lower canopy layers of tall crops like tomatoes, peppers, or cannabis.

Why Fixture Spacing Matters More Than You Think

Uniformity is measured as the ratio of minimum to maximum PPFD across a defined area. A ratio above 0.7 is generally considered acceptable for most greenhouse crops. Below that, you get hot spots under fixtures and dim spots between them, leading to uneven growth, variable fruit size, or inconsistent flower quality.

LED fixtures often require tighter spacing or different mounting heights than HPS to achieve equivalent uniformity, especially in greenhouses with low gutter heights. Practitioners on Reddit regularly note that a 1:1 fixture swap (replacing each HPS with one LED at the same location) frequently produces dark spots between fixtures. A proper lighting layout simulation, run before purchase, prevents this problem.

Addressing Lower Canopy Light

For crops with dense upper canopies (cannabis is the obvious example, but tall vine crops also qualify), upper fixture light alone often cannot reach lower leaves and developing fruit. This is true regardless of whether the top light is HPS or LED.

Under canopy or interlighting fixtures solve this by positioning supplemental light bars within or below the canopy. Research and grower trials consistently show yield improvements of 20 to 30% in lower bud sites when under canopy lighting is added to cannabis production. The same principle applies to greenhouse tomato interlighting, where supplemental light at fruit cluster height improves color development and sugar content.

For greenhouse top lighting projects that need high output and wide, uniform coverage, commercial fixtures in the 800W to 1050W range are purpose built for this application.

See greenhouse top lights

Crop Response: What the Research Actually Shows

“LED yields more” is not a universal truth. Crop response depends on species, cultivar, spectrum, light intensity, climate management, and grower SOPs. The research paints a nuanced picture.

Lettuce. Cornell researchers studying hydroponic greenhouse lettuce found that LED arrays used less than half as much electricity as HPS while producing similar sized lettuce. Electrical biomass efficacy was two to three times higher under LEDs. However, in one trial phase, HPS actually produced larger height or diameter for certain cultivars.

Water use. A separate greenhouse lettuce study found 15% lower water consumption under LED compared to HPS with no yield loss, likely tied to lower transpiration from reduced radiant heat.

Bedding plants. A Purdue/USDA/MSU study on commercial greenhouse bedding plants found seedlings grown under HPS or LED supplemental lighting were comparable in quality. When both systems produced similar results, the researchers concluded growers could prioritize energy savings, fixture price, and lifespan.

Cannabis. The picture is more complicated. Some cannabis growers on Reddit still prefer HPS for specific legacy genetics, flower structure, or perceived terpene outcomes. Others report that LEDs produce equal or better quality once the climate recipe is dialed in. One commercial operator quoted on LinkedIn described transitioning from 64 1000W DE HPS fixtures and said plant quality justified the change. The evidence suggests cannabis can perform well under either technology, but the transition demands cultivar validation and adjusted SOPs.

The bottom line: LED can match or exceed HPS yield with much less electricity, but only when fixture, spectrum, layout, and climate are designed for the specific crop. For dense cannabis canopies where upper fixture light struggles to penetrate, under canopy lighting can supplement the main system and improve lower bud development regardless of top light technology.

How Much Can LED Save Compared to HPS?

The actual savings depend on climate, operating hours, and utility rates.

Hybrid LED and HPS Lighting ROI

The LED vs HPS conversation often gets framed as either/or. In practice, many commercial greenhouses run hybrid systems, and the ROI math for this approach deserves its own analysis.

Why Hybrid Makes Financial Sense

A full LED conversion for a 5 acre greenhouse can require $1 million or more in capital, depending on fixture density and electrical upgrades. A hybrid approach lets growers capture meaningful efficiency gains while spreading capital expenditure across multiple budget cycles.

The typical hybrid strategy works like this: retain functional HPS fixtures in zones where radiant heat is beneficial (propagation houses in cold climates, for example), and install LED in zones where cooling load is a problem or where spectrum control adds crop value (flowering zones, research bays, or areas with long photoperiods).

Modeling Hybrid ROI

A hybrid ROI model needs to account for the fact that LED and HPS zones will have different operating costs, different climate loads, and potentially different yields. The key variables:

• Electricity cost per zone. LED zones consume less power per photon. Calculate annual kWh savings for each LED zone relative to the HPS baseline.

• Heating offset value. In HPS zones that benefit from radiant heat, calculate the avoided heating cost and credit it against the HPS operating expense.

• Maintenance differential. LED zones have near zero relamping cost. HPS zones require lamp replacement every 8,000 to 12,000 hours, plus reflector cleaning.

• Rebate eligibility. DLC listed LED fixtures may qualify for utility rebates that do not apply to HPS. This can reduce the effective LED capital cost by 20 to 40% in some utility territories.

• Phased capex timeline. Spreading LED investment over 2 to 3 years reduces the annual cash impact and aligns spending with crop revenue cycles.

Practitioners report that hybrid systems typically achieve 3 to 5 year payback on the LED portion, while the retained HPS fixtures continue operating at their known cost structure until they reach end of life.

When Hybrid Becomes Full LED

Most hybrid systems are transitional. As HPS lamps reach replacement age (typically every 2 to 3 years of heavy use), growers can convert those zones to LED incrementally. This natural replacement cycle means the facility reaches full LED without ever taking a single large capital hit.

Cost and ROI: The Variables That Matter

LED fixtures carry higher upfront cost per unit. That is still true, though the gap has narrowed. The question is whether lower operating cost, longer fixture life, and available incentives close the payback gap within a reasonable timeframe.

A fair LED vs HPS greenhouse lighting ROI comparison should account for:

• Fixture and installation cost, including electrical service, mounting, and controls.

• Electricity price and operating hours. A greenhouse running 16 hour supplemental lighting at $0.15/kWh will see very different payback than one running 8 hours at $0.06/kWh.

• Maintenance. HPS lamps degrade over time and need periodic replacement. Reflectors lose efficiency. LED fixtures avoid relamping but are not maintenance free.

• HVAC, heating, and dehumidification changes. If LEDs reduce cooling load but add heating or dehumidification cost, those numbers belong in the model.

• Crop value. Higher value crops justify faster payback timelines.

• Utility rebates. The DesignLights Consortium (DLC) released its Horticultural Lighting Technical Requirements V4.0 in March 2025, with applications accepted starting April 2025. DLC listed LED fixtures can qualify for utility rebates that meaningfully reduce net capex.

There is no true one for one replacement of HPS by LED. LEDs are directional and create different light distributions, so comparisons should evaluate the entire growing area, not just fixture output directly under the luminaire.

For large scale projects, power architecture also affects total cost. Moving LED drivers out of the grow space through a centralized power system can simplify electrical distribution, reduce heat in the canopy zone, and lower installation complexity.

When to Choose LED, HPS, or Hybrid

The LED vs HPS greenhouse lighting decision maps to specific facility and business situations. Here is a practical starting framework.

Hybrid lighting (combining LED and HPS in the same facility) is a real world compromise that many growers adopt. It captures some LED efficiency and control while retaining HPS radiant heat where it benefits the crop or the energy balance. Practitioners on Reddit mention hybrid systems as a practical bridge strategy, and it lets facilities spread capex over time.

LED Retrofit Checklist

Before replacing HPS with LED in a greenhouse, work through these steps.

1. Measure current HPS PPFD across the canopy at multiple points, not just directly under fixtures.

2. Calculate seasonal natural DLI inside the greenhouse after accounting for glazing, shade structures, and latitude.

3. Define crop target DLI by growth stage.

4. Model the LED layout for average PPFD and uniformity across the full growing area, paying close attention to fixture spacing and mounting height.

5. Estimate fixture shading and mounting constraints. LED fixtures have different profiles than HPS and may block or pass sunlight differently.

6. Run a heating and cooling load calculation. This is the step most growers skip, and it is the most expensive mistake. Use the BTU approach described above or bring in HVAC engineering for larger facilities.

7. Adjust temperature and VPD targets for the new heat balance.

8. Review irrigation and nutrient strategy. Lower transpiration rates under LED may require changes to fertigation timing and EC management. This nutrient strategy guide covers the adjustments.

9. Check DLC listing, rebates, and local regulations if applicable, especially for cannabis projects in regulated states.

10. Trial one bay or one cultivar group before committing to a full facility conversion.

For deeper technical planning, LED lighting white papers can help bridge the gap between this overview and a formal project design.

Frequently Asked Questions

Is LED better than HPS for greenhouse lighting?

For most new projects, yes. LED delivers more photons per joule, lasts longer, and offers more control. But “better” depends on the specific facility, climate, crop, and budget. HPS remains rational in some cold climate or budget constrained scenarios. Hybrid systems split the difference.

Do LED grow lights produce less heat than HPS?

LEDs produce less radiant heat toward the crop and convert more electricity into photons. But all electrical equipment eventually becomes heat somewhere in the building. The difference is where that heat goes. LED greenhouses often need more active heating and dehumidification than HPS greenhouses do.

Can LED replace 1000W HPS one for one?

Not reliably. LED and HPS distribute photons differently. A fixture that matches HPS output directly underneath it may deliver less uniform light across a full bay. Any replacement should be designed around target DLI, average PPFD, and canopy uniformity rather than fixture wattage.

Do LEDs improve yield?

They can, but yield depends on delivered DLI, cultivar, spectrum, climate management, and grower SOPs. Research shows LED can match HPS yield with significantly less electricity in lettuce, bedding plants, and other crops. In some trials, HPS produced larger plants for specific cultivars. Results are crop specific.

Why do LED greenhouses need more dehumidification?

Lower radiant heat from LEDs means cooler leaf surfaces, reduced transpiration, and less moisture removal by cooling systems. The net effect is higher relative humidity in the growing environment. Without active dehumidification or adjusted ventilation, this creates disease risk and poor VPD conditions.

What is hybrid greenhouse lighting?

A lighting strategy that combines LED and HPS fixtures in the same facility. Hybrid systems let growers capture LED efficiency and spectrum control while retaining some HPS radiant heat. It is also a practical way to phase a full LED conversion over multiple budget cycles.

Should I compare grow lights by watts or lumens?

Neither. Watts measure electricity consumption, and lumens measure brightness as perceived by humans. For plant lighting, compare PPF (total photon output), PPFD (photons reaching the canopy), PPE (photons per joule), and DLI (total daily photons). These metrics describe what the crop actually receives.

What is the biggest mistake when switching from HPS to LED?

Treating the switch as a fixture replacement instead of a system change. Successful LED transitions require new lighting layouts, updated climate recipes, adjusted VPD and temperature targets, potentially different irrigation strategies, and a trial period before full facility conversion.

How does dynamic LED lighting save energy?

By dimming fixtures when ambient sunlight is sufficient and ramping up only when DLI falls short of crop targets. Automated dimming based on PAR sensor feedback can reduce annual lighting hours by 15 to 20% in many greenhouse locations, compounding the per watt efficiency advantage LED already holds over HPS.

How do I calculate the heating load change when switching to LED?

Multiply the total wattage difference between your current HPS system and the proposed LED system by 3.41 BTU/hr per watt. That gives you the approximate additional heating load your boiler or heat pump must cover during cold months. Factor this into your ROI model alongside electricity savings.

Ready to evaluate LED greenhouse lighting for your facility? Talk to a lighting specialist about fixture selection, layout design, and project planning.