27 degrees does seem very cold but I can't think of any reason its not just the cooled air being recirculated. You definitely need some backup heat strips installed. Your installer should be able to calculate the necessary wattage. You might also have him/her check the defrost cycle time and possible increase it.

For your location, I can't understand why a 7-10 KW heat strip was not installed at time of installation. At one time Carrier offered a prewired 9 KW heat strip already staged in 3 KW increments which would be my choice if available. Too bad Carrier/Bryant don't offer demand defrost for their HPs. Current method is just a jazzed up time defrost with software algorithm. Keep in mind that heat strips serve 3 functions, supplemental heat, to temper air on a defrost call, and emergency heat if outside condenser has a malfunction.

IMO

Was the installation done by a Bryant dealer?

You have the question the ability of a HVAC contractor who installs a heat pump in Massachusetts without a backup heat strip.

I agree with tiger and mike,the installer is either incompetent or simple doesn't care. We use back-up in Texas so Ma is a no brainer.

Before we bash the installer, could it be the homeowner requested no heat strip? Maybe his electric panel needed updating before it could accept the heat strip. Regardless, the heat strip should be on separate circuit as should the outside condenser and inside air handler.

IMO

"The installer thought it might be because my ducts are in the attic and as soon as the air is no longer being heated it instantly gets cold from the attic air."

It doesn't look good for the installer if he actually said this.

Dadoes is correct. Your heat pump acts as a cooling unit during defrost. That far north, I would expect 10 KW electric heat just to partially overcome the effect of the defrost cycle. How in the world do you ever stay warm anyway without heat strips. I'm in Tennessee and wouldn't even consider installing a heat pump with no backup heat. The good news is that heat strips are usually an inexpensive add-on to your heat pump, assuming your electrical service has the capacity. I would consider finding a reputable service provider to add this in for you. In Tennessee we would just pitch a hissy fit until the installing contractor came back and did it for free, since he should have in the beginning.

I have more information on heat pump operation and service on my website at Air and Energy Solutions

@dadoes, @Air and Energy Solutions -
I wasn’t sure that I did understand how the defrost cycle works. Thank you for the correction, that helps.

Now I’m wondering why we can send a man to the moon but
not invent a heat pump that can defrost without blowing cold air into my home -
forcing me to throw more electricity at
it to solve the problem. Sorry I just
had to vent (pun intended).

Regarding the question of whether I was offered electric
backup, the answer is no. My previous 15
year old heat pump did have it, but I was told the Bryant Extreme could handle
the low temperatures I would experience in my location. It actually does seem to work ok when it’s
heating, although I can’t be 100% sure because of the ongoing battle between
heat mode and defrost mode. But I am
getting air as warm as the low 90’s when it’s in heat mode. It’s the defrost that’s killing me.

So it seems clear that I need to have the heat strip
installed to deal with the defrost issue.
But now that I know it goes in A/C mode during defrost I’m wondering if
mine is going overboard. The air during defrost
is consistently going as low as the 30’s and 40’s, with 27 being the coldest I’ve
seen. A few of my neighbors (we’re all
on the same top floor of a condo building) also just bought the same heat
pump. The only difference is their
condos are bigger than mine so they bought the 3 ton. I’m gathering temperature info from them
also. So far I only have data from one
unit for one day, but the lowest temperature I saw from his vent was 50
degrees. That’s not nearly as bad as
mine. Could his defrost cycle be working
better because he has the 3 ton? The heat
pumps are installed on the roof and the sun is going to hit each one slightly
differently. Would that make a
difference in how much defrosting it needed and how cold the air will be during
the defrost cycle?

I will ask my question again. Was the installation done by a Bryant dealer? If it was then he needs to go for more training.

Is the thermostat a Bryant controller? If not then you should get one.

You have a variable speed heat pump that can run from 40-100% of capacity. I am not an expert on how the Bryant Extreme runs its defrost cycle, but it could be that yours is running at 100% capacity, while your neighbor's operates at a lower capacity. The capacity might be determined by the controller and the outside temperature sensor. This assumes the installer has done the installation correctly, which is big assumption here since your installer didn't think you needed a heat strip.

You should question the installer/contractor as to what is his explanation for why he doesn't include heat strips on his installations since the neighbors you mention also apparently don't have them.

Lack of heat strips obviously causes issues with comfort during defrost cycles.

The heat strips also serve as emergency heat if the compressor or any system component related to it fails. You currently have no heat if/when that happens.

" Could his defrost cycle be working
better because he has the 3 ton?"

No.

"The heat
pumps are installed on the roof and the sun is going to hit each one slightly
differently. Would that make a
difference in how much defrosting it needed and how cold the air will be during
the defrost cycle?"

Not really.

Have you opened their units to see if heat strips were installed? Else, how would you know?