Understanding where to buy the right heaters, glazing, and supplies is as important as selecting the greenhouse site. Idaho’s wide-ranging winters, high-elevation sun, and local building practices demand that equipment be appropriate for low temperatures, variable winds, snow loads, and safe fuel handling. This guide breaks down practical options for sourcing components, sizing equipment, meeting code and safety requirements, and making purchase decisions that match hobby, market, and production greenhouses across Idaho.
Idaho climate and greenhouse essentials
Idaho spans USDA zones roughly from 3 to 7 and includes cold inland valleys, mountain valleys, and milder river basins. Even within a single growing season you may experience frost nights and sudden temperature swings. That reality drives two priorities for greenhouse systems in Idaho:
- durable glazing that balances insulation and light transmission,
- reliable heating with safe combustion or electric systems and proper ventilation.
Before buying, define your objectives (overwintering, year-round production, seed starting, or season extension), expected temperature set points, and whether you will operate off-grid or have access to natural gas or propane.
Heat loss basics (how to estimate heating needs)
Calculate heat loss in simple terms by using: Q = U x A x DT, where:
- Q = heat loss (BTU per hour),
- U = overall heat transfer coefficient of the glazing (BTU/hrft2degF),
- A = area of the greenhouse envelope (ft2),
- DT = design temperature difference between inside and outside (degF).
Example (illustrative):
- Greenhouse glazing area A 800 ft2.
- Choose a conservative U for a common multiwall polycarbonate: U 0.7 BTU/hrft2degF (confirm with manufacturer).
- Winter design inside = 40degF for frost protection; outside design = -10degF – DT = 50degF.
- Q = 0.7 x 800 x 50 = 28,000 BTU/hr.
That suggests you would size heating capacity to at least cover that loss, plus some margin for drafts, infiltration, and occasional extreme cold. Always confirm U-values with manufacturers and consider insulating end walls and thermal curtains to reduce load.
Heaters: types, pros/cons, and where to source in Idaho
Selecting heater type depends on fuel access, desired control, greenhouse size, and ventilation needs. Common choices:
- Unit/forced-air heaters (propane, natural gas)
- Pros: high output, fast warm-up, good for large spaces.
- Cons: require venting or make-up air; combustible fuel handling and CO monitoring required.
- Sourcing: HVAC contractors, local heating suppliers, farm co-ops, propane companies, and national agricultural equipment retailers.
- Infrared (radiant) heaters (electric or gas)
- Pros: heat objects and plant canopy directly, efficient in drafty spaces, comfortable for plants.
- Cons: may require multiple units for even coverage; gas radiant needs proper venting/clearance.
- Sourcing: specialty greenhouse vendors, HVAC trade suppliers, electric heating specialists.
- Electric unit heaters and baseboard/electric radiant
- Pros: easy installation, no combustion gases, good for small greenhouses or where electricity is cheap.
- Cons: operationally expensive in cold winter climates unless on off-peak rates or renewable backup.
- Sourcing: electrical supply houses, building material retailers, greenhouse equipment vendors.
- Infrared catalytic heaters (low-oxygen)
- Pros: safer mid-efficiency combustion with lower exhaust temperature; often used in greenhouses.
- Cons: require good maintenance, less common; fuel logistics remain.
- Sourcing: propane companies, greenhouse specialty companies, and HVAC distributors.
- Wood or pellet stoves
- Pros: fuel independence in rural areas; strong heat output.
- Cons: labor, ash handling, smoke management and insurance/building code issues.
- Sourcing: local stove dealers, farm supply stores, and builders that specialize in wood heating systems.
- Soil or cable heating systems (supplemental)
- Pros: protect roots and seedlings with low energy; often electrically powered mats/cables.
- Cons: supplemental only–won’t heat greenhouse air for larger spaces.
- Sourcing: greenhouse suppliers, hydroponic shops, agricultural irrigation and electrical suppliers.
Where to buy in Idaho:
- Local farm supply stores and co-ops carry small to medium heaters and fuels.
- HVAC contractors and commercial heating suppliers will size and install larger combustion and natural gas systems; they can also secure required permits.
- Propane suppliers often sell or lease heaters and deliver fuel, and can advise on storage and safety rules.
- Specialty greenhouse manufacturers and dealers in the Pacific Northwest supply models designed for greenhouse conditions and offer warranty support.
- Online retailers and national ag-supply houses are useful for hard-to-find accessories, sensors, and electric heaters but confirm shipping costs and local installation support.
Safety and permitting for heaters
- Any combustion heater requires appropriate venting, make-up air, and carbon monoxide monitoring.
- Fuel storage (propane tanks, fuel oil) is regulated provincially/locally–contact your county building department.
- For larger installations, a licensed HVAC/combustion contractor is needed to meet code and warranty requirements.
- Install automatic controls and fail-safes (thermostats with lockouts, low-oxygen shutoffs, over-temperature cutouts).
Glazing: materials, tradeoffs, and Idaho-appropriate choices
Glazing choices greatly affect light levels, insulation, durability, and cost. Common materials:
- Polyethylene greenhouse film
- Pros: low initial cost, easy to replace, good light transmission.
- Cons: low insulation, 1-4 year lifespan (shorter in UV and wind-exposed areas), more susceptible to snow and wind damage.
- Best for: seasonal tunnels, low-cost hoop houses, or double-layer inflated systems.
- Multiwall polycarbonate (twin-wall or triple-wall)
- Pros: excellent impact resistance, better R-values than single glass, diffuses light, long service life (8-20 years depending on grade).
- Cons: higher upfront cost; panels require careful installation to prevent condensation and dust accumulation in channels.
- Best for: year-round greenhouses in Idaho, where insulation and snow/wind resistance matter.
- Tempered greenhouse glass or insulating glass units (IGUs)
- Pros: excellent light transmission and longevity; IGUs provide better insulation than single panes.
- Cons: heavy, breakable, higher cost, may require stronger framing; snow load and wind considerations.
- Best for: high-end production houses where clarity matters (nurseries with flowering crops, show greenhouses).
- Acrylic and rigid PVC panels
- Pros: good clarity and impact resistance.
- Cons: variable UV resistance and thermal properties; check manufacturer specs.
Where to buy glazing in Idaho:
- Regional greenhouse manufacturers and authorized polycarbonate distributors stock panels cut to length and can provide installation advice.
- Local glazing contractors and large glass shops can supply tempered glass and insulating units, and advise on structural framing and snow load requirements.
- Agricultural suppliers and plastic distributors offer polyethylene film rolls and repair kits.
- Building material retailers often stock smaller quantities for hobbyists but may not carry commercial-grade multiwall panels.
Choosing glazing for Idaho:
- For winter production or low-temp protection, prioritize multiwall polycarbonate or insulated glass over single-layer film.
- Consider diffusion to prevent sunscald in high-elevation bright sun; matte or micro-structured polycarbonate diffuses light.
- Ensure materials are rated for snow and wind loads for your locality and properly flash, seal, and tape multiwall channels to avoid moisture intrusion.
Supplies and accessories: what to buy and where
A greenhouse needs more than heaters and glazing. Common supplies and where to get them:
- Benches, shelving, and staging: local metal fabricators, nursery supply houses, and used equipment dealers.
- Fans, louvers, and ventilation controls: HVAC suppliers, greenhouse equipment dealers, and electrical wholesalers.
- Environmental controllers, thermostats, and sensors: greenhouse controllers from specialty suppliers provide sequencing for fans, heaters, vents, and irrigation.
- Irrigation systems (drip lines, misters, timers): irrigation dealers, hydroponic stores, and agricultural suppliers.
- Shading cloth and screens: greenhouse suppliers and textile distributors.
- CO and temperature/humidity monitors: safety equipment from electrical or safety-supply stores.
- Spare parts and maintenance supplies: fasteners, sealants, panels, and replacement motors via greenhouse vendors and building suppliers.
Sourcing strategies:
- For one-off items, big-box or local hardware stores are convenient.
- For integrated systems and warranty support (controllers, fans, specialized heaters), use greenhouse specialists or suppliers with local representation.
- Consider used equipment from local nurseries, auctions, and marketplaces for low-cost benches, fans, and benches–inspect motors and electrical components carefully.
Local resources and contractors in Idaho
- County extension services and the University of Idaho Extension are excellent first stops for localized advice, cultivar selection, and sometimes lists of trusted contractors and suppliers.
- Local HVAC contractors experienced with greenhouse combustion systems can size heaters, handle permits, and ensure safe ventilation.
- Propane distributors and fuel suppliers often provide guidance, delivery schedules, and can assist with leasing heaters and tanks.
- Local fabricators and construction contractors familiar with snow-load framing will help retrofit or build conservatively for your location.
Practical purchasing checklist
- Know your design temperatures and compute a preliminary heat loss estimate (Q = U x A x DT).
- Confirm actual U-values and light transmission with glazing manufacturers.
- Prioritize safety: CO detectors, ventilation, and licensed installation for combustion appliances.
- Get multiple quotes that include installation, venting/make-up air, and electrical work.
- Ask about warranties and local service, especially for heaters and electronic controllers.
- Buy critical spares (thermostats, fan motors, fuses) when installing equipment–downtime in winter costs plants.
- Check local building and fuel storage codes before purchasing tanks, stoves, or permanent fuel lines.
Final practical takeaways
- In Idaho, favor insulation and durability: multiwall polycarbonate or insulated glass for year-round use, and robust heater systems sized with a conservative margin for extreme cold.
- Use local expertise (extension services, HVAC contractors, fuel suppliers) for code compliance and safe combustion heating installations.
- Balance upfront cost with operating cost–electric heat can be convenient but expensive in prolonged cold; propane and natural gas offer heat density but require safe exhaust and fuel logistics.
- Buy from suppliers who will support service and replacement parts–local or regional greenhouse vendors often provide the best long-term value despite slightly higher initial prices.
Planning and sourcing carefully will save money, reduce crop losses, and keep your greenhouse safe and productive through Idaho’s challenging winters.