Dear Jim: I enjoy using my deck and patio in the chilly fall weather, but my electric space heater does not eliminate the chill. What type of heater is best to provide several more months of deck use? – Jeri R.

Dear Jeri: Heating an entire patio or deck is not a good use of our limited energy supplies and it adds to greenhouse gas and air pollution problems. Try to get by with jackets and sweaters and only use auxiliary heat as a last resort. Adding a windbreak wall or fence will often help tremendously.

If you find you still need some heat, use a spot heater that warms only the small area where you are sitting. There are many attractive and effective models designed specifically for residential patio-deck use. These use natural gas, propane, wood, or alcohol-gel as the fuel source.

All of the effective patio-deck heaters use a radiant heat design. Instead of trying to heat the air around the deck, radiant heaters warm people and objects, similar to how the sun feels warm on a clear cold winter day.

For quick heat, a natural gas or propane heater is best. If you know ahead of time you will be outdoors, a wood-burning heater is fine. Burning wood produces no net greenhouse gases (trees use carbon dioxide as they grow).

Propane and natural gas patio-deck heaters are not expensive to operate. Natural gas models are the least expensive to operate, but propane models provide better portability. Depending on the heat-output level you set, a standard grill-type propane tank can provide 10 to 12 hours of heat.

For heating a large area (when entertaining), a tall umbrella-style heater with a push-button starter is effective. These are mounted on an 8-foot column with a reflector on top and a tank (propane models) in the base.

If your deck has a cover or partial roof, you can select an umbrella model that hangs from it. This allows you to locate the propane tank or gas line in an out-of-the-way location. They are often white, also available in custom colors and stainless steel. Mini-tabletop models are also available.

Small unidirectional propane heaters are very effective for heating just one or two people sitting together. The radiant heater burner is mounted directly on top of the propane tank. These are also ideal for camping. Alcohol-gel (made from corn) models light quickly and burn very cleanly.

Wood-burning models are the least expensive to buy and operate. Potbellied chimeneas (wood or gas) are effective, but require a while to warm up. Collapsible models, with screen sides, provide fairly quick heat and can easily be moved on its rollers. To extinguish the wood fire, you lower the top.

Write for (instantly download – www.dulley.com) Update Bulletin No. 775 – buyer’s guide of 14 gas, propane and firewood deck-patio heater manufacturers listing heat outputs, features, prices, cost-to-use and location-spacing charts. Include $3 and a business-size SASE, and send to James Dulley, 6906 Royalgreen Drive, Cincinnati, OH 45244.