Can I run a Legalett air heated slab system during a power outage?
I'm considering the electric system with the solar booster setup for a home addition. I love the idea of running a collector pipe though a wood fireplace also. I'm just wondering if there are any creative ways to keep the fans running during a power outage that don't require a backup generator. Battery backup, thermoelectric generation from the fireplace, etc. Being able to still pull in heat from the solar or wood booster would be pretty awesome.
We would say that to keep a Legalett air heated floor slab operating during a power outage is probably unnecessary unless it's going to be for several days in very low temperatures - as otherwise the thermal mass within the concrete will keep the room at a stable temperature. Otherwise if it's in an off grid home then we would suggest that the most economical and sensible option is a full solar array for the house's power needs with battery backup - then everything stays running.
Regarding the "collector pipe though a wood fireplace" idea, speaking from experience, be careful to not remove too much heat (I've recovered heat going up a masonry chimney stack before) as it can cause issues with the flue draw and condensation.
It's also useful to read our guide on how to survive a power outage in cold weather .
Hope that helps!