This probably came up beforebut I still am not sure of the answer.
My AC condenser is exposed to the sun for a good part of the day.
I have often thought that by making some sort of a covering to ward off the
sun the unit would cool better and perhaps not work as hard.Any ideas?
I have just moved into a house about 40 years old. Very nice condition and
was a good buy. There anyway to modify the fan motor so when heat or air is
required will torque up to a higher RPM.
I had this in my previous house and it was great. I admit I have not done
too much research on the motor, so this question is just for feelers and
There are a couple of nice HVAC guys in this group and several who are not.
I am not one of either group.
It may be possible if you have a multi-speed motor. For anyone to help you
is going to require more information. I suggest you post again with the
brand name and model number of the furnace. A guy with the nick of Turtle is
one of the nice guys.
Yes, there is, but ... you have to do so with knowledge
of what you're doing. The pulley sizes can be modified
(assuming it's not a direct drive type) to increase the
speed of the fan, but the motor must be able to handle
the added load.
It's also possible that the belts, assuming there
are belts, are too worn or even the wrong width to ride
properly in the pulleys.
Some pulleys are even adjustable in size.
But, add too much load and you'll be looking for
another motor, so step carefully and listen to any
experts that may chime in here.
The standard air flow rate is 400 CFM / ton for cooling and whatever the
heating (furnace or resistive heat) manufacturer recommends for heating.
Don't go messing with this unless you know what you are doing.
Your question is a bit confusing. Most of us are assuming that
you are asking if you can have two different fan speeds - one lower
speed for heating and a higher speed for AC. If so, then the answer
is "usually." Many fan motors have multiple taps for multiple
speeds and it is pretty easy to determine how to change those
taps IF you know what you are doing. If not, then get some advice
from somebody who has done this many times or integrate this
simple modification with a routine service call for HVAC maintenance.
The pro shouldn't charge you too much extra to "rewire" the motor
as long as he is already out to your home for the annual maintenance
Also, many tract home developments built around 40 years ago
had the same furnace, AC and ductwork in most of the homes. If
you locate a neighbor with the same setup as yours, then you can
check out which taps are being used on his fan. This isn't 100%
guaranteed, but it is usually safe. Many of us could make a good
educated guess on which taps and fan speeds should be used, but
I'm not going to make that blind suggestion over a newsgroup.
Final comment: Be certain that whoever pulls out that fan/blower
assembly cleans the squirrel cage if needed and lubes the motor.
Fins on the squirrel cage can get clogged with dust, especially if
the home has every had an electronic air filter which was neglected.
Also, some motors are difficult to lube and some HVAC guys skip
one or both oil ports on the motor.
You can adversely affect your system's performance as well as indoor
comfort by injudiciously changing the blower speed.
Motors that have multiple speed taps are designed to allow for
maximizing performance and/or to allow the same motor to be used for
multiple applications. Increased blower speed will result in less
effective air filtration and greater air noise.
I admit I have not done
Since you mention AC, I should guess that the furnace system has both heat
In this case, typically the AC is set to the highest blower power. But not
always. You do have a local HVAC guy who services your system?
The cost of any cover will be more than any return you will see in
efficiency. Plus you want the AC to be in the open as much as possible to
get good air flow around and above the unit. Good chance a roof over it
would block the air flow enough to be counter productive!
Leave it alone!
No ideas off the top of my head, but ... yes, getting
the sun off an air conditioner will make it work better
and more effieicntly. The trick though is not to block
any air flow.
It varies from unit to unit, but it can be done. I
had some noticeable luck and a measured increse in the
cooled air temp of a few degrees just by putting
mirror-film on the case of one of mine, a 10k btu unit.
Since the western sun hits it both from the top and the
west-side directly it was hard to figure any way to get
the sun off it without stopping some air flow.
The tree I finally planted does a great job now,
after only a few years.
BTW, it only took the film idea a few weeks to get
so dirty it didn't reflect anymore so it's not a good
I suppose there are ways to do it with properly
positioned louvres but that's beyond my abilities <g>.
The tree worked best in the long run, for me at least.
Also shades part of the hosue of course.
No...wont make any difference you will ever see.
Want proof? Just look at the millions of units in CA, NV etc that are
installed on rooftops....and yes, I started working in the deserts of CA in
HVAC, and I can promise you, the units are designed to be outside, in the
This is Turtle
This question has been ask at least a 100 times that i know of and here is what
was said just about everytime.
The HVAC People and some manufactors say it makes very little difference as to
sun hitting it or not. Now when they say that it is on the thought that it will
run just fine but at a little higher head pressure which will cost a little bit
more to operate the system. This will come from the ground, unit, and area
around the unit will be heated up and will be putting off heat to be sucked into
the condenser coil which will be a little higher temperature than if it was
setting in the shade. Now this small amount of added heat is small but may not
justify any cost to build a shade cover for it but shading may not be cost
effective but it does save a little money to shade it.
I researched it over the internet and came up with a few good sights that said
it saved money but none said how much. Now here is one from the Florida Public
Service Commision on 101 ways to save on your electric bill. Check out Artical
number 53 to see about condenser in the sun.
You don't need any research.
Just put your clamp-on ammeter on the compressor, and hold up a big sheet
of something lightweight to turn the shade on and off. Does it register
anything on the meter when you do so?
Would like to hear your results.
Instantaneous current mesurement isn't the answer. When the compressor
is running, it always requires the same power. But maybe it will run
less often to keep the set point...
Watt hour meter is the required device to compare for example, two
similar weeks temperature.
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