What is the purpose of a back up heat source?

A back up heat source serves a critical purpose in any home. Having a secondary heating system can prevent your home from losing heat and becoming uncomfortably cold or even dangerous in the event your primary heating system fails. This quick overview will examine the key reasons to have a backup heating source and provide recommendations on the best options to consider.

Provide Heat in an Emergency

The most obvious benefit of a backup heating source is the ability to provide heat in the event of an emergency or failure of your primary heating system. Depending on your climate and time of year, even a few hours without heat can cause temperatures inside a home to drop to unsafe levels. Hypothermia and frostbite are risks during extreme cold. Pipes may freeze and burst without sufficient heat. Having a secondary heating source serves as an essential safeguard against these dangers. It provides a temporary solution until your main heating system can be repaired or power is restored.

Maintain Temperature Consistency

A secondary heating system can also help maintain more consistent temperatures throughout the home even when your primary heating is operating normally. Most central heating systems are designed to shutoff once the target temperature is reached. But different rooms or areas of a home will heat up and cool down at different rates. Rooms farthest from the central heating unit or with less insulation may become noticeably cooler than others and fall below comfortable levels. Turning on a backup heating source in those specific rooms provides supplemental warmth to keep temperatures steady.

Lower Heating Bills

Operating a more compact, energy efficient secondary heating system can be less expensive than relying solely on a large central heating unit. This can lower your overall heating expenses during the cold weather season. Strategically heating only certain living spaces with the backup source while allowing other rooms to cool down can further reduce costs. The efficiency benefits are maximized if your secondary heat source uses a different fuel type than your primary system. For example, pairing electric space heaters with a gas furnace or wood pellet stove with an oil boiler.

Enhance Zoned Temperature Control

Installing small, individual heating units in different rooms provides greater flexibility and customization of temperatures based on how various spaces are used. Maybe you want the bedrooms cooler at night while ramping up the heat in the kitchen and bathrooms during morning routines. Zonal control with multiple backup heating sources allows for this type of precision not possible with central heating alone.

How Does a Backup Heating System Work?

The operation of secondary heating systems can vary based on the specific type and fuel source. But most provide standalone, dedicated heating for individual rooms or living spaces in your home. This allows them to supplement or temporarily replace the primary central heating system located in a single area like the basement or utility room. Here are some key ways they work:

Direct Heating Method

Also called point source heating, backup units apply heat directly to the space without ducts. The heating elements or fuel combustion generate thermal radiation that warms nearby persons, objects, and air. This contrasts central heating systems which must circulate hot air throughout a home using vents. Direct heating is more efficient and allows precise control of temperatures in different rooms.

Uses Separate Fuel Source

Most secondary heating systems run independently from the main fuel line or electrical supply used by the central heating unit. This isolates the backup to provide heat even during primary heating failures. Self-contained fuel sources include wood pellets for pellet stoves, oil for certain space heaters, natural gas for wall furnaces, and electricity for plug-in space heaters.

Thermostat or Manual Operation

Smaller, single room heating units typically have built-in thermostats to govern operation and maintain set temperatures. Higher end versions allow programming custom heating schedules. More basic models utilize manual dials or controls for on/off and adjusting heat output. This standalone operation with no reliance on a central system makes them ideal backups.

Multiple Backup Units Often Used

A single backup heat source may only heat a limited space. In many homes, several portable space heaters or multiple wall furnaces are deployed for full coverage. This provides flexibility in how various rooms are heated compared to central heating alone. The number of backup units depends on the size of your home, areas you want heated, and your budget.

Secondary System Only

In some cases, smaller homes utilize secondary style heating systems as the sole heat source with no central heating unit. This avoids the higher install costs of ductwork and centralized equipment. Dual fuel heat pumps that combine electric heating and air conditioning in one unit also operate similarly to backup systems providing zonal heating.

Recommended Backup Heating Options

Choosing the right backup heating equipment for your situation involves comparing some key factors like heating capacity, cost, efficiency, ease of use, safety and your available fuel sources. Here are some top options to consider:

Space Heaters

Type	Description
Portable electric	Most affordable option. Omnidirectional radiant heat warms skin and objects directly. Use up to 1500 watts. 120V standard plug-in.
Wall-mount electric	Hardwired 120/240V space heaters mount on wall. Up to 4400W. Heat rooms up to 400 sq ft.
Oil-filled electric	Filled with thermal oil that retains and radiates heat. Lower wattage around 600-1500W. Warmer convection heat.
Natural gas	Wall-mounted gas space heaters vented outside. Heat output around 18-42,000 BTU/hr. Provides zone heating.
Propane	Freestanding propane heaters. May require venting. High heat output up to 100,000 BTU/hr.

Pellet Stoves

• Burn compacted wood pellet fuel
• Hopper holds up to 130 lbs of pellets
• Thermostatically controlled for consistent temps
• Output from 8,000 to 90,000 BTU/hr
• Pellet feed and combustion regulated via auger system
• Exhaust vented outside through wall

Gas Wall Furnaces

• Vented natural gas or propane wall heaters
• Hang on wall within living spaces
• Heat output ranges from 10,000 – 30,000 BTU/hr
• Available with manual or thermostat controls
• Ideal for supplemental zone heating

Wood Stoves

• Burn wood fuel in high-efficiency firebox
• Radiant and convective heat warms rooms
• Output range 5,000 to 90,000 BTU/hr
• Advanced combustion controls available
• Requires chimney or other venting outside

Sizing Backup Heating Systems

Properly sizing your backup heating unit is important to ensure it can provide sufficient supplemental heat to the spaces you intend to warm. As a general rule of thumb, multiply the room’s area by 25-30 BTU/hr/sq ft to determine the minimum output needed. For example, a 200 sq ft bedroom would need at least a 5,000 BTU/hr heater. Also consider the unit’s heating capacity, heated area, and your insulation and climate. Aim to size back up heaters to around 30% of total home heating load. Oversizing wastes energy while undersizing won’t warm spaces adequately.

Comparing Efficiency of Heating Systems

The efficiency of a heating system measures the percentage of fuel converted to usable heat rather than being lost out the flue. Higher efficiency means greater cost-effectiveness. When selecting backup heating devices, consider both their heating efficiency and standalone energy costs.

Heater Type	Typical Efficiency
Portable space heater	95-100%
Pellet stove	50-90%
Gas furnace	60-97%
Oil furnace	55-83%
Wood stove	50-80%

Electric space heaters convert 100% of energy to heat so are most efficient. But electricity costs more than other fuel types. Gas, propane and wood heating can be cheaper to operate but have lower efficiency and greater heat losses. Evaluate both efficiency and fuel prices when selecting the most economical backup units.

Key Safety Tips

While very beneficial, backup heating systems also present certain safety considerations. Be sure to follow these tips to minimize risks:

• Carefully follow all manufacturer safety guidance
• Maintain adequate clearance from combustibles
• Do not leave portable heaters unattended
• Plug heaters directly into wall outlets, no extension cords
• Confirm units have auto shut-off if tipped over
• Place on flat, non-flammable surfaces
• Check for functioning carbon monoxide detectors
• Install wood stove/pellet stove to manufacturer specs
• Inspect and clean systems regularly

Conclusion

Installing reliable backup heating systems provides critical protection against primary heating failures. They allow you to maintain safe, consistent temperatures when you need it most. Choose units sized properly for the spaces you want to heat. Fuel type, efficiency, cost, ease of use and safety considerations also impact which options best meet your needs. Following manufacturer guidance and best practices will keep secondary heating systems operating safely and effectively as an indispensable part of your home’s heating solution.