Heating, cooling outbuildings can be tricky
Question: Our new home came with an outdoor shed with an electric wall heater. How much will our electric bill go up if we use this heater, or should we insulate the shed?—Lloyd
Answer: An uninsulated outbuilding can be quite expensive to heat (or cool) depending on where you live.
The cost to heat or cool your outdoor shed depends on your climate, the size of the outbuilding and the price you pay for electricity. But as an example, heating an uninsulated 6-by-8-foot shed could cost twice as much as heating an insulated 900-square-foot home.
Some outbuildings are heated with wood, which is a sound choice if you have a free source of firewood. Another strategy often seen in workshops is a radiant heater directed at the work area, perhaps in front of a workbench. But if you’re paying for your fuel and decide to keep an outbuilding heated, you should definitely insulate it.
An important consideration, unless you live in a desert-dry climate, is the effect moisture can have in an outbuilding. Moisture enables rot, insects and mold to wreak havoc on your structure, and rust to degrade tools and other metals. Heating and insulating an outbuilding, if done right, can reduce or eliminate a moisture problem. Installed incorrectly, it can trap moisture and foster mold growth.
Moisture in an outbuilding is usually caused by three things: leaks where water can get through, typically through the roof, windows and doorway; seepage through floors and walls; or condensation when nighttime temperatures drop.
To prevent moisture buildup, you need to eliminate moisture sources and prevent condensation.
Only you can decide if the value of heating and cooling your outbuilding is worth the cost and effort to properly insulate and seal. Even if your shed is not heated or insulated, it’s worth keeping an eye out for mold and mildew.
PAT KEEGAN and BRAD THIESSEN write on energy efficiency for the National Rural Electric Cooperative Association