Dual fuel kits for HPs

[Mark_USA]

Dear old Mom is ready to replace her AC. I suggested spending a little more & going dual fuel with a single stage Heat Pump. She was happy when I told her that her current tstat aprilaire 8570 will do dual fuel & she doesn't have to learn a new thermostat.
Her contractor recommends Rheem & Goodman. My question is about the outdoor coils freezing up. What benefits do the rheem & goodman dual fuel kits offer in preventing freeze up ? Can they detect initial freezup or do they work on a timer basis to turn on auxillary heat ? Can they work with the aprilaire 8570 that mom understands or is it best to use the manufacturer's monitor tstat/screen. Is the functionalty of the 8570 sufficient to meet her needs ?

[beachtech]

a dual fuel kit and or thermostat has nothing to do with defrost of the outdoor unit :)

and if the thermostat is dual fuel capable, then a kit is not needed. the stat will take care of the duties :)

that is taken care of by the outdoor unit itself :)

the balance point that you set the system at has alot to do with how much efficiency and comfort you like to acheive from the system :)

[crmont]

Dear old Mom is ready to replace her AC. I suggested spending a little more & going dual fuel with a single stage Heat Pump. She was happy when I told her that her current tstat aprilaire 8570 will do dual fuel & she doesn't have to learn a new thermostat.
Her contractor recommends Rheem & Goodman. My question is about the outdoor coils freezing up. What benefits do the rheem & goodman dual fuel kits offer in preventing freeze up ? Can they detect initial freezup or do they work on a timer basis to turn on auxillary heat ? Can they work with the aprilaire 8570 that mom understands or is it best to use the manufacturer's monitor tstat/screen. Is the functionalty of the 8570 sufficient to meet her needs ?


As for the defrost cycle itself;

Please research "On demand" or "Demand" defrost Vs. "Time/temperature" defrost. Then compare that to the specifications of the unit you are looking to purchase. Here is one article that I found;

http://wayneshirley.wordpress.com/2008/02/15/troubleshooting-heat-pump-systemsdemand-defrost-vs-time-temperature/

Hope this helps.

[BaldLoonie]

Rheem has demand defrost, it defrosts only when needed. Goodman has time/temp. It defrosts on a timer if the coil is below freezing, frosted or not.

[crmont]

Rheem has demand defrost, it defrosts only when needed. Goodman has time/temp. It defrosts on a timer if the coil is below freezing, frosted or not.

Aw, you gave away the plot:rolleyes:

[Some Dude]

Rheem has demand defrost, it defrosts only when needed. Goodman has time/temp. It defrosts on a timer if the coil is below freezing, frosted or not.

Thats good info,thanks:)