Terry Beck
07-13-2010, 06:01 AM
I don't see many air source heat pumps in this part of the country, though do inspect a fair number of A/C units in newer homes. Yesterday's house had a Lennox XP15 heat pump combined with a class IV Lennox propane furnace.
Question #1: similar to prior thread, "How do you check an ac unit?"
Should I expect to find the same temperature difference between a return vent and supply register (i.e. preferrably 10-20 degrees diff) with a heat pump as I would for a standard electric A/C? Or, are heat pumps not as dramatic, or slower to show a significant difference? I can't find the owner's manual on the Lennox web site.
The house was already pretty cool inside, 65-70 degrees at the return vent, and I couldn't get any major difference at a supply register. I didn't really test heat mode (I forced the system into emergency heat mode in order to make the Lennox furnace fire up).
Question #2: This system has two zones (two thermostats), running through a Lennox controller (see Pic - sorry, no model #). I have only seen one other of these Lennox controllers before. What happens if someone set one thermostat to Heat mode, and the other to Cool mode? Is the logic in the controller smart enough to not try and do both?
Terry
Question #1: similar to prior thread, "How do you check an ac unit?"
Should I expect to find the same temperature difference between a return vent and supply register (i.e. preferrably 10-20 degrees diff) with a heat pump as I would for a standard electric A/C? Or, are heat pumps not as dramatic, or slower to show a significant difference? I can't find the owner's manual on the Lennox web site.
The house was already pretty cool inside, 65-70 degrees at the return vent, and I couldn't get any major difference at a supply register. I didn't really test heat mode (I forced the system into emergency heat mode in order to make the Lennox furnace fire up).
Question #2: This system has two zones (two thermostats), running through a Lennox controller (see Pic - sorry, no model #). I have only seen one other of these Lennox controllers before. What happens if someone set one thermostat to Heat mode, and the other to Cool mode? Is the logic in the controller smart enough to not try and do both?
Terry