Greenhouse Heating  

Greenhouse Heating Systems

Delta T Solutions designs, manufactures and integrates commercial greenhouse heating systems for growers of horticulture, agriculture and MMJ crops. The right heating system can dramatically reduce fuel costs, increase greenhouse productivity and eliminate condensation problems.

Commercial Greenhouse Heating Systems include:



Radiant Heating for Greenhouses

On the bench or on the greenhouse floor, Delta T’s radiant heating systems offer the grower distinct advantages, including accelerated rooting and plant growth, as well as 20-30% fuel savings over conventional forced air heating. Maximum soil and plant temperature control combine with the ability to create different temperature zones for the ultimate in flexible growing. And because radiant systems heat objects first and air last, people stay warmer and more comfortable, and in the case of floor heat, happier with warm feet!

Delta T’s engineered radiant heating systems can meet the needs of any grower. Packages include heating system components (heat source, controls, and radiation) as well as performance engineered drawings (pipe layouts and electrical diagrams), installation supervision, or installation itself, as required.

How do you know how much heat is needed for your greenhouse? Our heat loss calculator can determine how much heat is being lost on a per house basis.


DELTA-TUBE™ EPDM SD rubber tube bench heating

DELTA-TUBE™ EPDM SD rubber tube in-ground heating for greenhousesThis bench system heats the greenhouse starting at the soil level. Heat rising from the bench warms the soil and the plant roots. Tubing spaced 2 to 3 inches apart provides even soil temperatures, which prove extremely beneficial to propagators. Seed germinators and plug producers have found that by heating the soil, they achieve a higher germination rate and quicker production time. Growers have found a reduction in rooting cuts by heating the soil directly.

The DELTA-TUBE EPDM rubber tubing used in this hot-water heating system offers superior heat transfer capabilities as well as excellent resistance to temperature degradation and chemicals. The SD system’s small tube design reduces water volume, enabling the system to respond quickly and efficiently.

The DELTA-TUBE manifolds use a unique plastic fitting that creates a watertight connection to the tubing guaranteed not to leak. Tubing is easily installed into the manifold, and each manifold is custom manufactured for each system. Cut to the bench width for ease of installation, tubing spacers secure the Delta T tubing at optimum intervals.


“I had some experience using hot water, bench-top heating (for my organic crops) so I wanted to use that system in the new greenhouse.  Delta T designed a system around our operation.  Now, we can shut off heat to various benches, or just heat some of them.  Instead of heating the whole house, we can heat individual benches.  The hot water heat also has really improved the quality of our plants. In mid-winter, the house is dry and warm, and the plants love it. The leaves are dry and the roots stay warm.  Even though we added a new greenhouse, we’re still saving nearly $5,000 in energy costs.  When you’re planning a new heating system, look beyond the first year’s payback and think long-term.  A hot-water system will cost you more initially, but it will give you payback within a few years and also improve your environment.”

— Howard Prussack, Owner, High Meadows Farm, Putney, VT

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Howard Prussack



DELTA-TUBE™ EPDM LD rubber tube ground (sand, soil or gravel) heating

Greenhouse Radiant Heat: DELTA-TUBE™ EPDM LDSimilar in concept to the DELTA-TUBE EPDM SD system, with the same productivity and fuel saving advantages, this hot water heating system with its 4 to 6 inch tube spacing is the system of choice for starter houses. It also excels in the nursery industry for general growing. Growers using this system for heating soil or nutrient bags of tomatoes and cucumbers have shown a 50% increase in yield. Grape growers have found a quicker and more even callusing pattern by using bottom heat to callus grade stock.



“I knew I would grow a better crop and that it would be energy efficient, but I didn’t realize how much better of a crop it would be (after using Delta T’s LD ground rubber tube heating system).  Plants don’t seem to stretch as much because they are getting heat from the roots, which form faster and better, making a sturdier plant on top…We have (the greenhouse) zoned so if we only have a crop in one zone, we only have heat there and don’t have to heat the whole house. We zone it off, curtain it off, and can have a mix of different crops in there with different climate needs too.”

— Pam Snodgrass, President, P&D Nursery, Tualatin, OR

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Pam Snodgrass



DELTA-TUBE PEX tube floor heating

Greenhouse Radiant Heat DELTA-TUBE PEX tube floor heating The DELTA-TUBE PEX heating system heats the greenhouse from the floor by running hot water through a grid of durable, cross-linked high-density polyethylene polymer tubing installed in the concrete. Using the concrete floor as a radiant surface, heat radiates from the floor into the greenhouse and directly to the plants. The direct contact between the root zone and the warm floor provides for maximum soil and plant temperature control, resulting in consistent temperatures and even crop growth. Compatible with any type of heat source, the DELTA-TUBE PEX floor system allows for different temperature zones, increasing grower flexibility. Because it eliminates the need for loud and unsightly unit and infrared heaters, it is an excellent choice for a retail area. In fact, retail garden centers report that customers stay longer and buy more because this silent and comfortable heating system makes for a great shopping environment. 


“I worked with Delta T, which helped me figure out what we needed to fit our size and growing zones.  We added thin pipe under benches, then heat retention curtains, then in-floor heating.  The natural gas boiler controls four different zones covering 30,000 square feet….Our plants are healthier and we could speed up our crop times by as much as three weeks. Compared to the costs of forced air, we’re now saving between 40% and 50% on our heating costs.”

— John Urbanowicz, Owner, Urban Growers, Burton, OH

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John Urbanowicz



DELTA-FIN™ TF under-bench heating system

The DELTA-FIN™ aluminum under-bench heating system heats the greenhouse by running hot water at temperatures of up to 230°F through the fin tube system. The fin tube then heats the air around it, distributing heat to the soil, roots and foliage of the plants through a combination of natural convection and radiation. Because of the superior transfer capabilities of the DELTA-FIN TF, even temperatures are maintained throughout the system and the growing media. The end result is an envelope of warmth around the entire crop which the grower controls.


Delta-Fin TF under-bench greenhouse heating system Delta-Fin TF under-bench greenhouse heating system Delta-Fin TF under-bench greenhouse heating system


Two fin sizes allow for targeted applications:

  • TF1 two-fin aluminum with 3/8" fins is ideal for climates that have low heat requirements or need closer temperature control, like plug production
  • TF2 two-fin aluminum with 1" fins has the added surface area for more heat transfer to meet high heat requirements

Other advantages:

  • Lightweight aluminum construction allows for hanging material from benches without special support
  • Rugged construction can be supported on 12-foot OC hangers
  • External coupling technology for easy installation
  • Requires NO special tools for installation
  • Does not restrict flows like internal couplers
  • Does NOT require Tek screws to hold material together
  • All-aluminum return loops make installation rigid. No rubber hose required for loops.
  • Special barb connection to main lines using a minimal hose connection
  • Low water volume allows for quick response time



DELTA-FIN™ SF high-output heating system

The DELTA-FIN SF high-output heating system includes several specially engineered components that work in conjunction with one another to create a durable, cohesive system. Using water temperatures up to 230°F, the all-aluminum fin tubes heat the greenhouse via natural convection. Placed around the perimeter or under the gutter, the DELTA-FIN SF heating system puts out enough energy to heat a greenhouse range, melt snow from the gutters or supplement an under-bench heating system.


Delta-Fin SF greenhouse heating Delta-Fin SF Greenhouse Heating System Delta-Fin SF greenhouse heat


The finned pipe is made of schedule 40 aluminum pipe. The industrial-strength aluminum fin can be run in long lengths up to 13 feet, allowing for application flexibility. The system’s heavy-duty construction resists oxidation, guaranteeing a long life in a harsh environment.

The system includes the following components:

  • Fin – Available in two sizes (1.25-inch and 2-inch) for multiple spacings and configurations; Lightweight aluminum construction allows for hanging material from columns or posts without special support.
  • Couplings – The cast-aluminum couplings have EPDM rubber gaskets with pressure ratings of up to 300 psi. The grooved coupling technology absorbs expansion from the heated aluminum.
  • Elbows – Cast-aluminum elbows have special outputs for venting and draining the system.
  • Hanger Brackets – For sidewall and column and post installation, the all-aluminum hanger brackets allow for expansion and contraction.  Truss brackets are also available.
  • Cover System – Utilizing flattened, expanded-aluminum, the heavy-duty cover system protects and enhances the DELTA-FIN system.

Typical fin spacing:

48/24 fins per foot for 1.25-inch size

24 fins per foot for 2-inch size



Greenhouse Heat Sources

Centralized or localized? Together, that’s the first question we need to answer when it comes to heating your greenhouse.

Centralized systems typically use a boiler to generate heat in one spot. Piping is then used to distribute the heat throughout the greenhouse. Centralized systems are often more efficient for large operations. However, the cost of installing and maintaining one can be high, and difficult to justify for smaller operations. These systems generally distribute heat as either steam or hot water of varying temperatures. Hot water systems require more complicated plumbing and circulating pumps. In addition, they require large volumes of water to achieve heat levels. Steam systems require less plumbing, and no circulating pumps. They provide more BTUs and allow for more rapid temperature adjustments. However, they do not provide heat reservoirs.

Localized systems are situated in the section of the greenhouse they are responsible for heating. There are many types of localized heating systems, ranging from gas fired and hot water unit heaters to radiant bench, under–bench, and floor systems, often the systems of choice for propagation and germination.



RBI boilers

RBIHigh quality construction, quiet operation, and energy efficiency as high as 82% make our RBI boilers the perfect choice for hydronic heating. Integral, 2-pass heat exchanger and standard bronze headers ensure long life and years of worry-free service. In fact, our RBI boilers virtually eliminate standby losses and condensation problems.IE2


Greenhouse Heater: Multi-Stage Boiler Control
Multi-Stage Boiler Control

Greenhouse Heater: RBI Dominator Power Draft Boiler
RBI Dominator Power Draft Boiler


The Infinite Energy 2 (IE2) condensing boiler uses a radial variable circulation stainless steel heat exchanger for maximum heat transfer, resulting in up to 98% efficiency. These durable heat exchangers are easily serviceable and ASME certified. The unit’s modular design and easy-to-set-up integrated controls provide flexibility and non-stop functionality.

RBI natural draft boilers are the workhorses of the industry, using surrounding air to provide the required heat. Available in sizes from 100,000 to 400,000 BTU/hr, these boilers offer fast response, smooth heat transfer, load matching and up to 82% energy efficiency. Integral, 2-pass heat exchanger and standard bronze headers ensure long-life performance and years of worry-free service.

Greenhouse Heater: RBI BoilerRBI sealed combustion boilers. Looking for superior performance and serviceability in a high-efficiency, multi-stage boiler? Look to our RBI sealed boilers. Their sealed combustionchamber offers the flexibility of using outside air or mechanical room air, and provides a low NOx rating that meets the strictest air-quality standards. Plus their fan-assisted, multi-speed blowers and advanced staging control create high-efficiency stage firing in a compact package.

Delta T oil fired boilers are available for capacities up to 15,000,000 BTU/hr and working pressures up to 125 psi. They come completely assembled, wired, and fire-tested for quality assurance. There is full access to the water sections and combustion chamber, and the easily removable tube bundle makes the boiler easy to maintain.

Our electronic boiler control is an add-on microprocessor-based energy management control that regulates water temperature by sequencing up to 12 stages on a single multiple-boiler installation. With on-board diagnostics for easy troubleshooting, our electronic boiler control not only ensures lower operating costs; it can maximize crop turnovers, creating savings that can pay back your initial investment quickly.



Greenhouse Heating: Heat ExchangerHeat exchangers

Our steam-to-water and water-to-water heat exchangers represent the latest technology in performance.  All are designed for superb efficiency, low maintenance, long life and fitting into tight spaces. Understanding how important growing space is, Delta T’s heat transfer units use up to 80% less floor space than shell and tube models, and weigh up to 10 times less. That means they are easy to ship and handle, and don’t use up precious growing space.


Greenhouse Heater: Gas-fired Shield unit heaters

Gas-fired Shield unit heaters

With their 5-year warranty, our Shield gas-fired heaters have 2-1/2 times the warranty of the competition. Which makes them a longer lasting, more durable, and more reliable source of safe, efficient, and economical heating for you. The GF Heater offers you stainless steel construction to withstand moisture and chemicals, a tubular heat exchanger for significantly longer life, 80% thermal (combustion) efficiency, and the highest BTU output of any gas-fired heater.


Sterling hot water unit heaters

Sterling greenhouse heaters Sterling model “HS” horizontal unit heaters are available in both serpentine and header designs. Serpentine units offer outputs from 8030 to 35,900 BTUs and are ideal for hot water installations with limited clearances. Header type horizontal units range from 18,000 to 360,000 BTUs, and can operate with either hot water or steam. Both units come standard with totally enclosed motors. Explosion-proof motors are also available.


Piping for Greenhouse Heating

How heat is delivered in a greenhouse is critical. Even distribution of heat, without hot or cold spots, is the goal. It is a goal that Delta T takes seriously. In our experience, uneven temperatures can result in uneven crop growth rates, as well as inconsistent maturation times. That's why at Delta T, we offer a range of piping options to optimize the heating in every greenhouse. How do you know how much heat is needed for your greenhouse? Our heat loss calculator can determine how much heat is being lost on a per house basis.


“We’re always looking for more efficient systems, and Delta T sells one of the most efficient heat delivery systems that you can find — under the root zone hot water heating.  We’ve always enjoyed dealing with Delta T and have taken advantage of Russ Zabel’s expertise and sharp troubleshooting skills over the years in designing new systems and in repairing old ones.”

— Grace Dinsdale, Owner, Blooming Nursery Inc., Cornelius, OR

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Grace Dinsdale


Greenhouse heating supplies: Piping Centralized greenhouse system piping

When a central heating system is used to produce hot water or steam, grooved steel, copper, or PVC pipes can be used to distribute the heat energy throughout the greenhouse. Hot water systems typically require more piping and circulating pumps; steam systems require fewer pipes because steam provides more BTUs per linear foot of pipe than hot water. Steam also offers less movement resistance, which means smaller pipes can be used.

Grooved steel pipe and fittings for greenhouse heating

Delta T heating systems that use high temperatures (140° to 230°F) can use steel piping as the main lines to the radiation material. Although some companies use welded steel pipe for this, our grooved steel piping is just as good and reduces labor costs by as much as 50%.


Copper pipe and fittings are an excellent choice for both low and high temperature greenhouse heating systems that require exceptional corrosion resistance.


PVC pipe and fittings for greenhouse heating

Delta T also offers low temperature/low pressure heating systems. These provide growers the ability to use less expensive PVC piping and fittings to distribute the heat from the heat source to the radiating materials. Care in designing the PVC piping system is required, but the advantages are numerous:

  • PVC can be direct buried as there is no problem with rusting
  • PVC is easy and quick to install; Just cut, primer and glue
  • PVC piping is inexpensive compared to other materials

Also see Delta-Temp™ warm water irrigation systems.

Delta T Solutions
27711 Diaz Rd, Suite B, Temecula, CA 92590 • 800.552.5058 • 760.682.0428 (fax) •