Riga greenhouses are among the best-insulated hobby models available, so they generally require less supplemental heat than thinner polycarbonate or poly-film structures. Still, most owners in cold climates add some form of heat for true four-season growing or for warmer crops.
Electric Heaters (Most Common & Recommended)
Electric heaters are the most common and recommended heating solution for Riga greenhouses. They stand out as the safest and easiest option for the majority of owners, offering simple installation, reliable performance, and straightforward operation without the complications of fuel storage or venting.
For the narrow Riga ‘S’ model, a portable milkhouse-style or fan heater rated at about 1,500 watts (roughly 5,000 BTU) is typically sufficient. These units are plug-and-play and work best when equipped with a thermostat for consistent temperature control.
Owners of the Riga Standard or Black models generally choose milkhouse heaters, units such as the Bio Green Palma, or comparable models in the 1,500–3,000 watt range. Proper air circulation becomes especially important at this size to distribute heat evenly throughout the greenhouse.
Larger Riga XL structures (14 feet wide) call for more substantial electric heaters delivering 13,000–17,500 BTU. These often require a 220-volt circuit and are frequently included as part of Pro Kits, providing a ready-made solution matched to the greater volume of the greenhouse.
Propane and Gas Heaters
Propane and gas heaters serve as a practical alternative for larger Riga XL models or for sites that lack reliable electricity. Portable units, such as those in the Mr. Heater Buddy style, work well for smaller Rigas as a backup heat source or in milder climates. In XL greenhouses, some owners turn to larger propane or natural-gas heaters and even small furnaces when greater capacity is needed.
Any combustion heater must be paired with continuous fresh-air ventilation. Without it, carbon monoxide can accumulate and excess humidity can build up inside the greenhouse. Many Riga owners simply run a small exhaust fan or crack a roof or side vent whenever the heater is operating.
A few practical points apply specifically to Riga structures. Most owners target nighttime temperatures of 50–55°F (10–13°C) for cool-season crops; pushing the temperature higher increases both heater runtime and operating cost. A thermostat is essential—it prevents overheating and keeps energy use under control. A small circulating fan improves heat distribution and eliminates cold spots. Adding thermal mass, such as water barrels or large containers of water, stores daytime warmth and releases it slowly at night, further reducing the hours the heater must run. Finally, Riga’s glazing itself is a major advantage: the 8 mm or 10 mm twin-wall panels used on the Standard, S, and Black models, and especially the 16 mm triple-wall panels on the XL, cut heat loss far more effectively than the thinner 4–6 mm polycarbonate found on many ordinary hobby greenhouses.
Choosing the right approach depends on the grower’s goals. For occasional frost protection or cool-season crops, a small electric milkhouse heater paired with a thermostat is usually sufficient. Growers aiming for serious winter production of heat-loving crops such as tomatoes or peppers benefit from a properly sized electric heater, good air circulation, and the addition of thermal mass. In a Riga XL located in a cold climate, a larger 220-volt electric unit or a carefully ventilated propane system becomes the more reliable choice.