PTAC air conditioner/heater

[Joe1]

I live in a condo that has Hotel type heater/AC units. My 3 GE units are 30+ years old and one is shot, one works iffy and one is serviceable. I'm thinking about replacing them before the colder weather arrives in NJ this winter. My research indicates that for heating, some use a heat pump while others use electric heat. The heat pump models are a bit more expensive and more energy efficient, but the electric heat models heat better and are quiter. Can l expect gains in efficiency compared to my ancient GE models? Are heat pump models more or less reliable than electric heater models? The major brands seem to be Amana, Friedrich,GE, Frigidaire, and LG. Should any be avoided? I'm interested in hearing feedback from those that have some knowledge about these things.

 

[Nick1994]

From what I've read on hvac-talk.com, brand of equipment doesn't matter that much, the installation is the most important role. That includes correct sizing.

 

[mk378]

You can compute the efficiency of the old units from the nameplate cooling BTU divided by cooling watts. It's going to be remarkably low. Since a heat pump runs the compressor to heat, it will be about as loud in the winter as it is in the summer. Heat pump will fall back to electric heat when outdoor temperature is too low for the heat pumping to keep up. Converting to mini-splits is the way to go, if the building allows them.

 

[SZR48207]

Electric heat (like with strips) is 100% efficient.. all of the energy consumed turns into heat. However, the amount of electricity consumed to create enough BTUs to heat a home is often quite large. Using 120V for an example, a 1500W portable electric heater creates around 5100 BTUs of heat. However, a 120V heat pump that consumes 1500W can create 11,000 BTUs of heat (under ideal conditions) because it extracts any heat in the air outside via the refrigeration cycle and dumps it into the living space. The drawback with a heat pump, though, is that there is an ideal temperature point for it to run.. and if the outside air is any colder then you may not be able to extract enough heat to make the operation worthwhile. If you replace your 30 year old units, yes there is very likely to be a gain in efficiency, largely because the government has mandated minimum efficiency standards for new systems.

 

[WyrTwister]

If it were me , I would replace the worst of the units with a heat pump & see how you like it . Then go from there . If your existing equipment is that old , I would expect to see some reduction in electric cost .

 

[Joe1]

My old models have an EER rating of about 8. Newer models go up to 13+ EER. If my electric bill is 100 a month with old units, what would cost be with new units with a 13 EER? Thanks for the info.

 

[WyrTwister]

I am accustomed to seeing efficiency ratings in SEER numbers . Check out http://ingramswaterandair.com/eertoseerconversion.php But a wild guess would be something like $ 100 x 8 / 13 = $ 61.54 . That may not be very accurate . Hopefully some one more knowledgeable than I can answer . However , it the old equipment is not operating well / correctly ( low on refrigerant , for instance ) , it will be running longer than necessary & using more energy than necessary . So , I would think , in that case , the numbers could be better than that ? Best of luck , :-)