Is a heat pump less efficient in cooling mode?

[pines]

Am I better off with a heat pump or a unit with resistance heat?

The obvious answer is "heat pump" but now I am not sure because of the EER ratings.

I am considering:

Amana... PTC153B35A…...... Resistance heat.........9.5 EER
Amana... PTH153B35A…...... Heat pump ..............9.3 EER

Project in Tucson Arizona 9 months of cooling.

I welcome efficient heat but not if it means less efficiant cooling.

[mark beiser]

The deal is that the extra 0.2 EER will save you less than $100, likely less than $50 over the entire cooling season.

A heat pump will likely save you more than $100, over straight electric heat, in just one month in the winter.

[pines]

What I want to know is:

Is the cooling efficiency basically the same on both units?

And if the cooling efficiency is about the same then why is the improved heating efficiency not reflected in the EER rating?

[beenthere]

Because the EER is a cooling rating, not a heat rating.

Heat ratings are COP, and HSPF

that .2 EER equals less then 30 watts per ton per hour more electric to use the heat pump for cooling.

About 840 watts more for 24 hours of constant run time.

An electric strip heater will use far more then that in 1 hour of run time.



So they are close enough in cooling to justify the heat pump over the A/C.

[Mstrav]

a heat pump looses performance as outdoor temps drop, especially under 55 degrees. This is why we use strip heaters to off set this loss, you also need to think of the combined use of the heat pump and the strip heater when in heat mode, could get expensive.

matt

[allstar08]

A heat pump will be more efficient then strip all the way down below freezing. Your strip heat will be used in defrost mode more then it will be used to augment the heat pumps heating cycle.

[Mstrav]

A heat pump will be more efficient then strip all the way down below freezing. Your strip heat will be used in defrost mode more then it will be used to augment the heat pumps heating cycle.



yes as far as power draw, but keep in mind a heat pump that is 5 ton a/c output, but when in heat mode may put out 60k btu at 62* and then at 47* maybe down to 53k btu ouptut and keeps droping as outdoor temp goes down, so the strip is there not just for "defrost" to keep from cold air blowing, but is there to act as a second stage or "suplimental" heat to off-set the loss as outdoor temp drops and the heat pump performance in btu's drops.


matt

[jackpiner]

[QUOTE=pines;1557823]What I want to know is:Is the cooling efficiency basically the same on both units?



Yes

[Mstrav]

is this a window or "ptac" unit?

electric heat in az is not legal as a primary means of heat is it?(meaning strip heat) the H.P. is fine just cant use cooling only with a strip heater can you?


BUT,

Is this a window / wall unit? then never mind, If this is a pack unit, where are you finding cooling only? most dont stock in the package type, better off with a H.P.


matt

[allstar08]

a heat pump looses performance as outdoor temps drop, especially under 55 degrees. This is why we use strip heaters to off set this loss, you also need to think of the combined use of the heat pump and the strip heater when in heat mode, could get expensive.

matt

Arizona is alot different then Boise.;) I wonder if he would even see a defrost cycle?

[mark beiser]

is this a window or "ptac" unit?

electric heat in az is not legal as a primary means of heat is it?(meaning strip heat) the H.P. is fine just cant use cooling only with a strip heater can you?


BUT,

Is this a window / wall unit? then never mind, If this is a pack unit, where are you finding cooling only? most dont stock in the package type, better off with a H.P.


matt

Straight cooling package units with strip heat are common in my area, as are split systems with electric strip heat as the only source of heat.

[Mstrav]

Arizona is alot different then Boise.;) I wonder if he would even see a defrost cycle?


just as a reminder I am from las vegas, and have mucho experience in lauglin and bullhead Az. People have no idea that it does get cold there, very cold in fact and in bullhead az. they would not let us use straight cools, we had to use H.P. units, every city and region is different, and I just moved to Idaho thank you, to get away from all the B.S.!!!!

[pines]

The unit will be installed through the wall.

The type often used in hotels. Standard 16 x 42

The unit will be the primary heat sores.

[mark beiser]

The unit will be the primary heat sores.

Sounds painful! :eek: