Heat pumps just keep getting hotter. The über-efficient, emissions-free appliance looks almost certain to have outsold gas furnaces in 2024 — and by a bigger margin than ever. To be sure, the data ...

paraffin will release heat as temperatures drop and then stay solid until they rise again. “If you’re designing for Philly, it’s not going to be working 100% of the time,” he said. But the Drexel team ...