1 Symptoms are due to the effects of excess acetylcholine on nicotinic and muscarinic acetylcholine receptors in the CNS, at neuromuscular junctions, and in the sympathetic, and parasympathetic nervous systems. 2  Nicotinic and muscarinic receptors have different. 3  Functions.
We're taking here about mains voltage (say 120 V or 230 V AC) power supplies with power ranging from a few Watts to several hundred Watts. Switch mode power supplies are everywhere; here are some pictures of their guts. The big high power components and small heat sinks are typical of SMPS. These devices are incredibly reliable, but being very often left powered all the time (even when their load is switched off), they still are the weak link.
Even at 20 degrees, your heat pump will be approximately twice as efficient as your electric furnace. Look at the outside unit to see if it has an outdoor thermostat. If it does, and it is set at 30 degrees, that is your culprit. Turn it down to 0 degrees. Get as much heat from that heat pump as you can. If it does not have an outdoor thermostat, you could have a bad defrost board. Get a good technician who is well versed in heat pumps. I recommend a NATE technician who is certified for heat pumps.