Heat pumps leave customers cold
Nelson's cold snap is putting the heat on modern technology, but if you find yourself shivering as the heat pump defrosts too frequently, you might have to turn it down a notch, or shut a few doors.
Glenn Roberts of Nelson Heating & Cooling said they had started getting calls from people concerned their heat pumps were not working properly, but it was likely that homeowners were turning up the heat too much as temperatures dropped to freezing and below. This meant they were likely to be driving heat pumps too hard, which was switching them to "defrost" mode too frequently.
"It's a bit like towing a huge trailer with a mini," he said.
"A heat pump works like your fridge, and that's why they're economical to run, but a fridge has auto defrost and so do these," Roberts said.
He said even he was affected during Saturday's cold, damp conditions when the heat pump at his home was stricken by the icy conditions.
"Once there's too much ice [on the outside unit], it has to go into the reverse cycle," Roberts said.
The defrost function removed ice built up on the outdoor unit heat exchanger. It usually happens depending on how cold or damp the air is around the outdoor unit, how much work it has to do - if a home is uninsulated or the heat pump is heating spaces bigger than it can handle, or there are mechanical defects with the unit.
Roberts said if the unit was defrosting too often, the first thing to do was to check and clean the air intake filters on the indoor unit.
Heat pumps defrost less and use less energy in well insulated rooms.
- © Fairfax NZ News