TURTLE wrote:

"jessica" wrote in message
roups.com...


We have decided to go with a 14 seer heat pump with back up propane.
Now the question is what size? Different contractors have said
anywhere from 3 ton to 4 ton. Only one contractor actually did a
Manual J. He determinded we need 41,000 BTU for cooling and 75,000 BTU
for heating. He recommends we go wtih a 4 ton unit. There are actual
BTU's and sensible BTU's, and given our area, we should size to 4 ton
to match the "sensible BTU's" Does this make sense? This contractor
has come with very good reviews. We just want to oversize the unit.

I live in southern maryland about 35 miles south of D.C. We have very
hot and humid summers.

Thank you!

Jessica



This is Turtle.

Go with the contractor that did the Manual J and go along with the 4 ton 14 seer
/ propane back up because some contractor have dought about the Manual J reading
and will up a 1/2 ton in there recommendations to remove errors.

i just can't picture Southern Maryland being a hot area of the country but could
see a humid area.

TURTLE


Turtle, we know that they should size for the latent humidity load as
well as the sensible load.
That is especially true in a high humidity area like he lives in.
The latent load is a major critical factor toward efficiently achieving
the human comfort zone.

When the humidity is high the latent load will take a lot of BTUs away
from the sensible capacity of the evaporator; which will also provide
more needed run-time.
However, they should be careful not to oversize, --because it takes
adequate run-time to get the humidity percentage down.

If they have the blower speeds to do it,-- they could use a relay
operated by a dehumidistat to go to 350-cfm per ton airflow for a colder
coil, when needed until the dehumidistat is satisfied.
- udarrell

--

What is the most Affordable Path to the "Human Comfort Zone" Goal?
http://www.udarrell.com/air-conditio...tent-heat.html