Heating · frost cloth · not a kit

How to heat a high tunnel in winter: propane/electric heaters, frost protection, row cover inside, thermal mass (sourced)

Growers search how to heat a high tunnel, hoop house heater, high tunnel propane heater, and do I need a heater in a hoop house after the film is on. This page is the winter-heat sibling — inner row cover, soil as night heat, then vented unit heaters, electric mats, thermostats, min/max alarms, and a CO detector. Double-poly inflation — blower, outside air, lock channel — lives on high-tunnel double-poly inflation; this page names it only in passing. Crop scheduling stays on high-tunnel winter lettuce. Summer air exchange stays on high-tunnel ventilation fans. It is not a commercially manufactured high-tunnel kit and not a USDA payment schedule.

Extension quotes copied 12 October 2026, about 03:15 UTC from UVM Callahan 2015 / 2016, UMass Bartok, Alabama Extension, Johnny's, Penn State, MSU Biernbaum 2013, Purdue, UAEX, Cornell, UKY, and N.C. State. Featured Amazon prices copied the same night. A missing featured price stays an em dash. Ratings are not copied. EQIP language below is the structure-only and producer-expense wording already on what EQIP will not pay for. No USDA payment dollar is invented here. Confirm heaters or electrical components with your NRCS district conservationist.

Kit index: commercially manufactured kits. Replacement-parts directory: high-tunnel replacement parts. Size map: high-tunnel sizes. Film: 6-mil plastic replacement. Winter lettuce: high-tunnel winter lettuce. Ventilation: high-tunnel ventilation fans. Double-poly inflation: high-tunnel double-poly inflation. Insect / exclusion netting: high-tunnel insect netting. County inspection: EQIP checklist.

Practice 325 houses are season-extension, not greenhouses

Land-grant and seed-house pages describe a high tunnel as an unheated house that uses the sun. Conservation Practice Standard 325 excludes greenhouses. EQIP money stays on the structure. Heaters, fuel, and electrical are grower cost on the pages that name them. Confirm with your district conservationist. This page does not invent a national heater rule or a payment dollar.

The ultimate tool in protected cropping is a high tunnel (also called a hoophouse), which is an inexpensive, unheated greenhouse erected right in the field.

Source: Johnny's Selected Seeds — Protect Your Crops • Basic High & Low Tunnel Components (Byczynski / Johnny's Research Team).

Hoophouses don't need electricity or heating systems, although some growers do add them to extend the season even further. In general, though, roll-up or roll-down sides are used to ventilate a hoophouse, and the sun does the work of heating it.

Source: Johnny's Selected Seeds — Protect Your Crops • Basic High & Low Tunnel Components (Byczynski / Johnny's Research Team).

This publication primarily covers unheated high tunnels and the use of internal row covers. In the Midwest, cool-season crops are grown in these structures from about September through March. Crops include leafy greens such as kale, chard, lettuce, mustard, and spinach; head-forming brassicas such as bok choy; and root crops including radishes and turnips.

Source: Purdue Extension HO-297-W — Managing the Environment in High Tunnels for Cool Season Vegetable Production.

A high tunnel, or hoophouse, is basically an arched or hoop-shaped frame covered with clear plastic and high enough to stand in or drive a tractor through. Traditional high tunnels are completely solar-heated, without electricity for automated ventilation or heating systems.

Source: NC State Extension Growing Small Farms — Season Extension: Introduction and Basic Principles.

The practice does not include greenhouses or low tunnel systems.

Source: NRCS Conservation Practice Standard 325 High Tunnel System.

A grower who has received Natural Resources Conservation Service (NRCS) Environmental Quality Incentives Program (EQIP) funds to purchase a high tunnel should check his/her state’s NRCS High Tunnel System Conservation Practice Standard to make sure heaters are allowed.

Source: University of Kentucky Center for Crop Diversification CCD-SP-2 — High Tunnel Overview. One extension sentence — not a county letter.

Passive first: inner row cover, soil, double poly, closed sides

Close the roll-up sides and end walls before you buy a heater. Then add a second layer over the crop. Winter-lettuce crop notes stay on that page; the figures below are the heat and frost-protection sentences only.

A secondary cover, often called a row cover or frost blanket, is made from lightweight material and placed over a row (or multiple rows) of plants. Mimicking the high tunnel’s ability to capture heat, the air beneath a secondary cover can be a few degrees (~2-5°F) warmer than the ambient air inside the high tunnel.

Source: University of Arkansas System Division of Agriculture — High Tunnel Production Guide for Arkansas and the Southeast (MP586).

Row covers can come in different thicknesses (0.5 – 2.0 oz/sq. yd), with thicker covers offering more frost protection than a thinner fabric. Row covers are often suspended above the plants using hoops or other means, but they can also be placed directly on the plants.

Source: University of Arkansas System Division of Agriculture — High Tunnel Production Guide for Arkansas and the Southeast (MP586).

A common approach to growing cold-tolerant crops in unheated high tunnels during the fall-spring in Northern climates is to plant beds in the late summer/early fall so that plants are mature by end of November, at the latest, at which point plant growth slows considerably until early February. Crops can then be harvested from November-February, using the tunnel as a “living refrigerator” and picking as needed.

Source: Purdue Extension HO-330-W — High Tunnels: Scheduling Fall and Winter Vegetable Production (Maynard and Hilfinger).

All harvest ranges assume that the grower would use at least medium-weight row cover over beds within the tunnel when nighttime temperatures drop below 25°F and double layer cover if nighttime temperatures drop below 10°F.

Source: Purdue Extension HO-330-W — High Tunnels: Scheduling Fall and Winter Vegetable Production (Maynard and Hilfinger). Single-layer tunnel schedule.

Row covers come in different weights: heavier ones provide more insulation but block more light if they are left on during the day.

Source: Purdue Extension HO-297-W — Managing the Environment in High Tunnels for Cool Season Vegetable Production.

Medium-weight row cover supported on hoops gives 5-10 F warmth, more on colder nights. But those covers must be removed during the day for light transmission.

Source: Cornell High Tunnels — Greens (structures, cultural practices, winter hardiness).

Row covers can also be used inside high tunnels for an added layer of protection for overwintered crops. For example, we use a layer of Agribon+ AG-70 over many of our overwintering high tunnel flower crops.

Source: Johnny's Selected Seeds — Protect Your Crops • Basic High & Low Tunnel Components (Byczynski / Johnny's Research Team).

Johnny's 2021 vendor chart — not a field measurement: Agribon+ AG-19: 2–4° frost protection; 0.55 oz per sq. yd.; 85% light transmission. Agribon+ AG-30: 4–6° frost protection; 0.9 oz per sq. yd.; 70% light transmission. Agribon+ AG-50: 6–8° frost protection; 1.5 oz per sq. yd.; 50% light transmission. Agribon+ AG-70: 8+° frost protection; 2.0 oz per sq. yd.; 30% light transmission.

Source: Johnny's Selected Seeds — Row Covers Comparison Charts (copyright 2021; opened 12 October 2026).

High-tunnel growers often use a tunnel-within-a-tunnel method to get plants off to a fast start or to maintain production of cold-weather crops such as spinach and greens throughout the winter. The use of floating row covers or low tunnels can greatly improve cool-season crop production by trapping heat directly in the crop canopy versus having the heat escape into the full tunnel.

Source: Penn State Extension — High Tunnel Production (updated 13 March 2023).

Soil is the night heat. Water barrels are not sized here.

Growers sometimes park drums of water in a hoop house. No extension page opened tonight printed a barrel count or a °F gain from those drums. MSU Biernbaum treats the soil itself as the heat store and uses a half-full five-gallon bucket as a frost diagnostic. Those sentences stay qualitative.

The warmer the soil, the more energy (heat) is radiated back out into the surrounding air at night so the soil becomes a source of heat.

Source: Michigan State University — John Biernbaum, Passive Solar Greenhouse Growing: Winter Light and Temperature Management (2013).

Heat is lost either by conduction (heat movement through a solid), convection (heat movement by air movement) or by radiation. In a heated greenhouse, conductive loss is most important, followed by convective leaking of warm air, and radiant heat loss is considered very small.

Source: Michigan State University — John Biernbaum, Passive Solar Greenhouse Growing: Winter Light and Temperature Management (2013). The following sentence on unheated-tunnel radiant loss was truncated in the PDF extract opened tonight — that gap stays blank.

When the air temperature decreases, moisture from the air condenses on the fabric. As explained previously, the moisture helps to trap long wave radiant energy emitted by the soil or plants. Ice forming on the covers and the plastic helps trap heat. We call this the cloud or igloo effect. We have examples of temperature outside being from 0 to -20F while temperatures under the cover inside the greenhouse have rarely gone below 12-15F.

Source: Michigan State University — John Biernbaum, Passive Solar Greenhouse Growing: Winter Light and Temperature Management (2013). 2013 Michigan examples, not a current energy audit.

Under very cold conditions, some growers will apply a second layer of fabric at night.

Source: Michigan State University — John Biernbaum, Passive Solar Greenhouse Growing: Winter Light and Temperature Management (2013).

One way to estimate the effect of night time low temperatures is to use buckets of water placed in strategic locations. In my experience, a five gallon bucket half full with water will form ice if in the greenhouse but not under the interior tent while a bucket under the interior tent will not form ice.

Source: Michigan State University — John Biernbaum, Passive Solar Greenhouse Growing: Winter Light and Temperature Management (2013). Diagnostic, not a thermal-mass shopping list.

Double-poly inflation if you add any heat

This heading is the passing mention. The method — why two layers, outside air versus inside air, lock channel, Bartok ¼-inch pressure, light loss, and power — is on high-tunnel double-poly inflation.

High tunnels are generally covered with a single layer of greenhouse-grade polyethylene film (six mil) instead of the air-inflated double polyethylene layer found in greenhouses.

Source: Penn State Extension — High Tunnel Production (updated 13 March 2023).

With heated greenhouse, the second inflated layer is generally reported to decrease heating requirement by 40%. If any heating at all will be used in the structure, even if only minimal heat on very cold nights, a double inflated layer is necessary.

Source: Michigan State University — John Biernbaum, High Tunnel / Hoophouse / Solar Greenhouse notes (2013). The 40 percent figure is 2013 Biernbaum copy, not a current energy audit.

Where we have such a large emphasis on winter production, we have decided to go with the second layer in most cases. We have two greenhouses with the double layer. The plastic does not blow and flap under windy conditions and there is an approximately 4F advantage or increase on average under cold and freezing conditions.

Source: Michigan State University — John Biernbaum, High Tunnel / Hoophouse / Solar Greenhouse notes (2013). Approximately 4°F is that 2013 note's double-layer observation.

Active heat: vented gas, electric mats, thermostats, alarms

Penn State treats a portable clean-burning heater as a cold-snap tool and a thermostatted greenhouse heater as optional. Electric heat mats stay on the propagation bench. Combustion heaters need a flue, makeup air, a thermostat, a min/max thermometer, and a CO alarm.

If unusually cold night temperatures occur several days to weeks after planting the vegetable crop in the high tunnel, a portable, clean-burning heater can be placed in the high tunnel until more seasonal temperatures return to the location. Many growers choose to permanently install greenhouse-type heaters that are controlled by thermostats to ensure an early, damage-free crop.

Source: Penn State Extension — High Tunnel Production (updated 13 March 2023).

Most crops in high tunnels can be damaged if air temperatures drop below 45°F.

Source: Penn State Extension — High Tunnel Production (updated 13 March 2023). Warm-season crop note, not a winter-lettuce setpoint.

The budgets assume the production in a 25-foot by 128-foot-high tunnel without heaters.

Source: Penn State Extension — High Tunnel Production (updated 13 March 2023). Budget assumption, not an EQIP dollar.

Unvented heaters dump CO, ethylene, and water

An unvented heater is one that is designed without a flue connection so that the heat and products of combustion are exhausted into the greenhouse. Dumping these flue gases into the greenhouse may improve the overall efficiency rating as compared to a conventional heater but the pollutants and added moisture from combustion may put your plants in jeopardy.

Source: UMass Extension Greenhouse & Floriculture — John W. Bartok, Jr., Problems With Using Unvented Greenhouse Heaters.

Ethylene gas is another pollutant formed during combustion. It can also be formed from ripening or rotting plant materials. Levels as low as 0.01 ppm can create symptoms such as malformed leaves and flowers, stunted growth, bud abcission, epinasty and flower senescence.

Source: UMass Extension Greenhouse & Floriculture — John W. Bartok, Jr., Problems With Using Unvented Greenhouse Heaters.

If we take a 30' x 100' double poly greenhouse and maintain inside temperature at 60 ° F on a 0 ° F night for a 12 hour period, heating with unvented propane or kerosene heaters would add about 22 gallons of moisture to the air and heating with natural gas would add about 16 gallons.

Source: UMass Extension Greenhouse & Floriculture — John W. Bartok, Jr., Problems With Using Unvented Greenhouse Heaters.

A free air inlet of at least 1 sq in/1000 Btu/hr input is needed. Each winter there are several instances of tight greenhouses that have frozen up when the heaters were starved for air and the heat output decreased.

Source: UMass Extension Greenhouse & Floriculture — John W. Bartok, Jr., Problems With Using Unvented Greenhouse Heaters. One square inch per 1,000 Btu/hr input.

If you are using a heater that burns propane, natural gas, or oil, it is critical that these fumes from combustion of fossil fuels be vented to the outside of the house.

Source: Alabama Cooperative Extension — Joe Kemble and Jeremy Pickens, Greenhouse Vegetables and Ethylene Damage (31 January 2019).

Unvented gas burners should not be used when growing greenhouse vegetables.

Source: Alabama Cooperative Extension — Joe Kemble and Jeremy Pickens, Greenhouse Vegetables and Ethylene Damage (31 January 2019).

There should be 14 cubic feet of air for each cubic foot of gas burned or 1 square inch of vent cross-sectional area of opening from outside air should be provided for every 2,500 BTU capacity of the heater.

Source: Alabama Cooperative Extension — Joe Kemble and Jeremy Pickens, Greenhouse Vegetables and Ethylene Damage (31 January 2019). One square inch per 2,500 BTU — a different makeup-air rule from UMass. Both stay labeled. This page does not invent a third number.

Plants are 5,000 times less sensitive to carbon monoxide than to ethylene, but humans are highly sensitive to carbon monoxide poisoning.

Source: Alabama Cooperative Extension — Joe Kemble and Jeremy Pickens, Greenhouse Vegetables and Ethylene Damage (31 January 2019). Hang a CO detector if any combustion heater runs.

BTU sizing — 2016 workshop example, labeled as an example

Callahan's 2015 blog points to an online calculator and to NRAES-33 pages 65–71. It does not print a BTU-per-square-foot rule in the body. The 2016 VTC / UVM Day-2 slides do. Those 2016 figures stay labeled. Dayton heater list prices and the $2/gal propane line from that workshop are 2016 copy — this page does not treat them as today's fuel or hardware prices.

I am often asked by growers to help estimate what size heater is needed for a greenhouse or what minimum temperature their high tunnel will reach at a certain outside temperature.

Source: UVM Extension Ag Engineering — Chris Callahan, Calculating Greenhouse and High Tunnel Heat Loss (1 April 2015).

SIMPLEST – Use our online high tunnel and greenhouse heat load calculator. This online calculator allows you to enter the dimensions, construction material and location you are interested in and it estimates the heater sizing required, determines overall heat load and fuel use, and provides ventilation and circulation sizing information using historical weather information.

Source: UVM Extension Ag Engineering — Chris Callahan, Calculating Greenhouse and High Tunnel Heat Loss (1 April 2015).

HEAVY LIFTING, but FULFILLING – Do the calculations yourself! The formulae behind all of the tools above are well described in “Greenhouse Engineering, NRAES-33” by R. A. Aldrich and J. W. Bartok. Available here as a PDF: http://blog.uvm.edu/cwcallah/files/2021/03/NRAES-33_Web.pdf. See p. 65-71 specifically.

Source: UVM Extension Ag Engineering — Chris Callahan, Calculating Greenhouse and High Tunnel Heat Loss (1 April 2015).

Generally 50-60 BTU/hr/ft2 of ground area

Source: Vermont Technical College / UVM Extension — Winter Greenhouse Growing in Cold Climates, Day 2 workshop slides (2016; Callahan). 2016 workshop rule of thumb.

30’x96’ = 2,880 ft2 --> 144,000-173,000 BTU/hr – Most growers would install 200,000-250,000 BTU/hr

Source: Vermont Technical College / UVM Extension — Winter Greenhouse Growing in Cold Climates, Day 2 workshop slides (2016; Callahan). Worked example for a 30×96 house — not a shopping list for a specific Amazon heater.

Q'rate = UADT → Qsum = UA*GDD

Source: Vermont Technical College / UVM Extension — Winter Greenhouse Growing in Cold Climates, Day 2 workshop slides (2016; Callahan). Slide notation.

E.g.: 30’x96’, single layer, 45 F, Burlington Q = 1.2 BTU/hr/F/ft2 x 5200 ft2 x 1100 F-day x 24 hr/day = 164 million BTU or 2240 gal propane (@80% eff) = $4,400 @ $2/gal

Source: Vermont Technical College / UVM Extension — Winter Greenhouse Growing in Cold Climates, Day 2 workshop slides (2016; Callahan). 2016 Burlington seasonal example, including a 2016 $2/gal propane line. Not a current fuel price.

EQIP pays for the structure, not the heater

Practice Standard 325 High Tunnel System language on electricity, venting, and heating is already collected on what EQIP will not pay for. Heater eligibility and any payment dollar stay with the county. Confirm with your NRCS district conservationist. Tunnel Spec does not invent either.

Under the High Tunnel System Initiative, financial assistance is provided only for the structure itself. Electricity, venting systems, lighting, etc. can be installed providing the additions meets manufacturer’s designs and specifications. However, the grower is responsible for those costs.

Source: USDA NRCS High Tunnel System Initiative FAQ (Updated November 2024; Oregon-branded).

Producers can install heating, ventilation, or electrical systems at their own expense.

Source: USDA NRCS Pennsylvania — Seasonal High Tunnel System for Crops. One state office page, not a national heater payment.

Rules vary; call your county NRCS office.

Sourced Amazon heating parts

Titles and featured prices were copied from live amazon.com product pages 12 October 2026, about 03:15 UTC. Kit frames stay on manufacturer product pages. Winter-lettuce row-cover crop notes stay on winter lettuce. Fans stay on ventilation fans.

What these parts are for

• Frost cloth. Agfabric 0.55 oz 5×25 (B01BU13PJK) is a pack-size blanket. UAEX names 0.5–2.0 oz/sq. yd.; Purdue HO-297 used 0.55 oz./sq.yd. This listing is not a 30×96 takeoff.
• Wire hoops. Gardener's Supply Super Hoops (B00IHKFA9Q) are 58-inch supports for fabric over a bed. UAEX and Cornell want the cover off the leaves. They are not house bows.
• Min/max thermometer. TempPro TP50 (B01H1R0K68) records high and low temperature and humidity. Hang one at crop height, including under the inner cover.
• Plug-in thermostat. Inkbird ITC-308 (B011296704) is a 2-stage 1100W outlet controller. Heating outlet for a plug-in heater or heat mat; cooling outlet if you already have a fan. It is not a hardwired two-stage house controller.
• Seedling heat mat. Hydrofarm Jump Start MT10006 (B01C90GNAY) is a 17 W, 8.875×19.5-inch propagation mat. Callahan's 2015 note sends root-zone sizing to a different paper. This mat is not a tunnel heater.
• CO detector. First Alert CO400 (B000N8OYXI) is a battery carbon monoxide alarm. ACES: humans are highly sensitive to CO. It does not detect ethylene.
• Inflation blower. Farm Plastic Supply 12 W (B097HT6P4Q) is titled as a greenhouse inflation fan. MSU 2013 says a double inflated layer is necessary if any heat will be used. Needs electricity at the site. Full method on high-tunnel double-poly inflation.

FAQ

Do NRCS Practice 325 high tunnels need a heater?

Extension pages treat a high tunnel as an unheated season-extension house. Johnny's calls it an inexpensive, unheated greenhouse and says hoophouses don't need electricity or heating systems, although some growers add them. Purdue HO-297-W primarily covers unheated high tunnels and internal row covers. N.C. State Extension Growing Small Farms says traditional high tunnels are completely solar-heated, without electricity for automated ventilation or heating systems. NRCS Conservation Practice Standard 325 says the practice does not include greenhouses or low tunnel systems. The High Tunnel System Initiative FAQ (Updated November 2024) says financial assistance is provided only for the structure itself. The Pennsylvania seasonal high tunnel page says producers can install heating, ventilation, or electrical systems at their own expense. UKY CCD-SP-2 says an EQIP grower should check that state's High Tunnel System standard to make sure heaters are allowed. Confirm with your NRCS district conservationist. Tunnel Spec does not invent eligibility.

How much frost protection does inner row cover add?

Only the figures the pages printed. UAEX MP586: air beneath a secondary cover can be a few degrees (~2–5°F) warmer than the ambient air inside the high tunnel; covers 0.5–2.0 oz/sq. yd.; suspend on hoops or rest on the crop. Cornell High Tunnels greens: medium-weight row cover supported on hoops gives 5–10 F warmth, more on colder nights, and must be removed during the day. Purdue HO-330-W: at least medium-weight cover below 25°F and a double layer below 10°F on a single-layer tunnel. MSU Biernbaum 2013: moisture or ice on fabric (the cloud or igloo effect); examples of outside 0 to −20°F with under-cover temperatures rarely below 12–15°F; a second fabric layer on very cold nights. Johnny's 2021 row-cover chart (vendor table, not a field trial): Agribon+ AG-19 2–4° / 0.55 oz / 85% light; AG-30 4–6° / 0.9 oz / 70%; AG-50 6–8° / 1.5 oz / 50%; AG-70 8+° / 2.0 oz / 30%. Those numbers stay labeled. This page does not invent a barrel-count or a °F from water barrels.

How do I size a heater for a high tunnel?

UVM Callahan (1 April 2015) points growers to an online heat-load calculator and to Aldrich & Bartok, Greenhouse Engineering (NRAES-33), pages 65–71 — the 2015 blog does not print Q=UAΔT in the body. The 2016 VTC / UVM winter-growing Day-2 slides print a rule of thumb and a worked 30×96 example: generally 50–60 BTU/hr/ft² of ground area; 30′×96′ = 2,880 ft² → 144,000–173,000 BTU/hr; most growers would install 200,000–250,000 BTU/hr. The same slides write Q'rate = UADT and a 2016 Burlington seasonal example (1.2 BTU/hr/F/ft² × 5,200 ft² × 1,100 F-day × 24 = 164 million BTU / 2,240 gal propane at 80%). Those 2016 workshop figures and the 2016 $2/gal fuel line stay labeled as 2016 copy — this page does not invent a current fuel dollar or a Dayton list price. Work the calculator for your house; the 30×96 numbers are an example.

Why not an unvented propane heater?

UMass (Bartok) defines an unvented heater as one without a flue, so heat and combustion products dump into the house. Ethylene as low as 0.01 ppm can malform leaves and flowers; a 30×100 double-poly house held at 60°F on a 0°F night for 12 hours adds about 22 gallons of moisture from unvented propane or kerosene (about 16 gallons from natural gas); makeup air of at least 1 sq in per 1,000 Btu/hr input. Alabama Extension (Kemble and Pickens, 2019) says combustion fumes must be vented outside, that unvented gas burners should not be used when growing greenhouse vegetables, and that plants are 5,000 times less sensitive to carbon monoxide than to ethylene while humans are highly sensitive to CO. Their makeup-air rule is 1 square inch per 2,500 BTU of heater capacity — a different number from UMass. Both stay labeled; this page does not invent a third. Hang a CO detector if any combustion heater runs.

Does EQIP pay for heaters, fuel, or electrical parts?

Tunnel Spec does not invent eligibility or dollars. The High Tunnel System Initiative FAQ says financial assistance is provided only for the structure itself, and that electricity, venting systems, lighting, etc. can be installed if they meet manufacturer designs — the grower is responsible for those costs. The Pennsylvania seasonal high tunnel page says producers can install heating, ventilation, or electrical systems at their own expense. Confirm heater, fuel, thermostat, or electrical-component eligibility with your NRCS district conservationist. See what EQIP will not pay for.

Which Amazon heating parts are on this page?

Seven live listings fetched 12 October 2026, about 03:15 UTC: Agfabric 0.55 oz 5×25 frost cloth (B01BU13PJK, $11.99), Gardener's Supply Super Hoops 58-inch set of 6 (B00IHKFA9Q, $44.99), TempPro TP50 min/max hygrometer (B01H1R0K68, $10.99), Inkbird ITC-308 1100W plug-in thermostat (B011296704, $35.99), Hydrofarm Jump Start MT10006 17 W seedling heat mat (B01C90GNAY, $30.33), First Alert CO400 battery CO alarm (B000N8OYXI, $22.49), and Farm Plastic Supply 12 W inflation blower (B097HT6P4Q, $139.98). A missing featured price stays an em dash. Ratings are not copied. Kit frames stay on manufacturer pages.

Rules vary; call your county NRCS office. Tunnel Spec does not determine eligibility, payment rates, or inspection outcomes. Confirm heaters or electrical components with your NRCS district conservationist. As an Amazon Associate, we earn from qualifying purchases.