On Monday, April 20, 2020 at 5:53:03 PM UTC-4, Ralph Mowery wrote:
In article ,
says...
Have heat pumps improved much in the last 30 years, wrt to heating a
home in Baltimore?

I was under the impresssion that the limiting factor is often the
outside temperature, and if it's not over 45 or 40 or 35 or 30 (I forget
which), that it's hard to extract enough heat to keep a place warm.

And that since it's colder than that a lot here, the supplemental
electric heat will go on and that's much more expensive.

The salesman today, called by them a saleman, tells me that things have
improved a lot in 30 years and it can heat the house. But I don't see
how you can change the laws of physics.




Over the years the heat pumps have became more efficent. I have not
checked it out, but maybe things like larger outside units to collect
more heat from the air. Look at the HPSF ratings for the heat pumps.
The units that operate in the open air usually work well to about 30 deg
F. From around 25 to 30 deg F they are ok. Much below 25 deg they go
down hill fast, or should say the operating cost go way up .

They also have a SEER rating for the air condition cooling.

They have improved, just like today a 14 SEER AC is the lowest you can
buy where 30 years ago, 10 was common. How cost effective they are as
always depends on the cost of electricity, cost of alternative fuels
and climate. I can tell you I've never seen an air sourced system here
in coastal NJ, which isn't all that cold. I have heard of ground sourced,
which Dean mentioned, but I think when you look at the cost of the install,
that's a losing proposition if you have nat gas available.