Heating & Air Conditioning Tips from Vince
1. Design, installation, capacity
 QUESTION: My house is 3,000 square feet. All but a guest room
and bathroom are on the main floor. When we set the air
conditioning at 78 degrees on a hot day, it does not
cool the house and will only cool to 82 degrees
downstairs and will be 90-plus degrees upstairs. We have
a dual-control Lennox SEER-rated 12.45 air conditioner
but only one compressor. Would a second compressor help
pull the hot air out? If that is not feasible, what
would you suggest to at least cool the upstairs (other
than a window unit)?
C. Ogden, via
email
ANSWER: Vince McDonald of McDonald Plumbing, Heating and Air
Conditioning in Sacramento believes that your system
failure is due to one or more of the following:
The system needs repair;
The system was not properly designed;
The system was not properly installed; and/or
The system’s capacity is too small.
“My first suggestion is to have an air-conditioning
contractor check to make sure the system is operating
according to the manufacturer specifications,” he says.
“A good contractor will run a series of tests, including
one to monitor the system’s refrigerant charge. If the
charge is too high or too low, it can have a large
impact on its cooling capacity and efficiency.”
“The contractor also should make sure the filter and
indoor components are clean, he adds. “This has to be
the No.1 problem we find that affects the overall system
performance. Also, homeowners should regularly change or
clean their filters. Something as simple and easy to
rectify as a clogged filter can cause your problem.”
“The contractor should also inspect your air duct system
to make sure the ducts are free of leaks, are properly
supported and that any exposed metal is insulated.” If
you are still having problems after the checkup or they
discover the system is clean, airtight and operating
properly, McDonald suggests having the contractor
inspect the system for proper design, installation and
sizing.”
“Two-story homes are always a concern when designing and
installing a HVAC system simply because hot air rises,”
he says. “it sounds like you may have a zone system,
with on thermostat upstairs and one down, to direct
cooled air where needed according to the individual
thermostats. Zone systems should definitely help even
out temperatures, so have the contractor make sure your
system was properly designed and installed.”
“Finally, the problem may be an issue of capacity,
meaning there may be nothing wrong with your current
equipment. The largest single residential air
conditioning system is 5 tons. If you already have a
5-ton system, and you have taken steps to make your home
more energy efficient (such as by adding more
insulation), you will need to add another air
conditioning system.”
“One option would be to take the upstairs ductwork off
the current system and add another system that will
serve the upstairs only,” McDonald says. “You mentioned
that the upstairs consists of a guest bedroom and
bathroom. If you use this area only occasionally when
guests come over, this option would allow you to direct
the full capacity of the existing system to service the
downstairs only, and save energy by not cooling the
upstairs when it is not being used.” he says.
2. Contracts, Contractors State License Board, estimate, proposal
QUESTION: My home is a two-story, about 15 years old. I
recently had to have a thermostat replaced. After the
repairman was in the attic, he told me he noticed my
ducting was beginning to deteriorate because of sunlight
shining on it through the roof air vents. I asked for an
estimate and he called yesterday to say it would
cost$1150. No written estimate was provided. Shouldn’t
he provide a written proposal? Am I being overly
cautious?
H.J. Hender,
via email
ANSWER: “A verbal quote should be used only to give you a
quick idea of the cost to perform the work prior to
actually writing up a proposal,” says Vince McDonald of
McDonald Plumbing, Heating and Air Conditioning in
Sacramento. “The Contractors State License Board
requires contractors to provide you with a written and
approved proposal before they perform the work,” he
says. “It should specify exactly what they propose to
do, what kinds of materials they intend to use, and how
they are going to perform the work including clean-up.”
“Other details about what must be included in written
contracts are explained online at
www.cslb.ca.gov .”
“Any company that is operating within the law and
concerned with providing its customers with great
service would want to make sure you are comfortable with
the service it provides and address your concerns in
writing. As a consumer, you have a right to insist on
it,” he says. “Even if it were not required by law, a
written proposal is just plain smart and can help
everyone avoid a variety of misunderstanding.”
“It’s also important to understand that not all ducting
is alike. Since the average home leaks 30 percent of the
heated or cooled air that flows through the duct into
unconditioned space such the attic or crawl space,
having your ducts work as efficiently as possible could
help you save a lot on your energy bills.”
“Consider spending a little extra for flex duct made
with a metalized polyester vapor barrier. The flex duct
with the plastic outside vapor barrier is not the best
product to use, especially in your situation, because
the plastic breaks down over time, especially when
exposed to sunlight. Ask about ducts with better
insulation in the jacket. The standard insulation has an
R rating of 4.2, but for a little more money you can buy
R6 or R8 insulation duct. Make sure all the metal duct
joints are sealed with duct mastic.”
“Ask your contractor if he has the equipment to test the
ducts for leaks before and after the work is performed.
Since you are changing the ducts anyway, this is the
time to make sure the ducts are properly sized for
individual rooms,” he says.
3. Odor, air conditioner
QUESTION: When we turn on our air conditioner, I get a strong
odor of stale air that I think that it is coming from
the attic, though my husband doesn't agree. It has been
happening for a year or so. Any ideas?
D.R. Gregory, Roseville, CA
ANSWER: “It sounds like you may have a problem with your heat
and air duct system,” according to Vince McDonald of
McDonald Plumbing, Heating and Air Conditioning in
Sacramento. “The duct system of course transports the
conditioned air into your home. The same air that comes
out of the ducts (supply air), eventually flows back to
the furnace or air handler and becomes the return air.
This process continues over and over as long as the
system is running. It is considered a closed system.
"If the ducts are in good condition, the pressures
within your home are equal to the outside of the home,"
he explains. "But If the ducts are not in good condition
and leak, then there is going to be any number of
problems."
”What you describe is possibly a failure in your duct
system. This can cause negative pressures in your home
when the system is running. The stale air from the attic
can now enter the house through the leaky or
disconnected ducts. The average existing home in the
Sacramento area has approximately 25 percent duct
leakage into unconditioned space, such as attics and
under the home, according to SMUD.”
"My suggestion is to have a licensed HVAC contractor at
least provide a visual inspection of your duct system,"
says McDonald. "Better yet, have one perform a 'blower
door test' with an instrument that enables the
technician to accurately test and gauge your system for
duct leakage. For best results, I suggest having the
ducts tested again after the repairs to accurately
monitor the work. Considering how much expensive
conditioned air is wasted through leaky ductwork, I am
sure you can appreciate that duct sealing is money well
spent."
4. Ventilation
QUESTION: We had some settling of our foundation along one wall
of our house and had a foundation engineer evaluate the
situation. One of his suggestions was to put in a
ventilation fan under our house crawl space to keep the
moisture out. We have no water runoff underneath
just a large deck right next to this area that stays
damp underneath. He suggested we call a Heating
and AC company for this type of fan or go to Home Depot
and get a large fan.
Needless to say, the two Heating and AC companies I
called never heard of such a thing and I would have no
clue as to what kind of fan or even where to put it if I
just went to Home Depot. Besides that, running a
fan whenever it was damp underneath our deck would mean
that it would always be on. Our SMUD bill would be
out of sight. Can you help me out as far as where to go
next?
M. Terra, Sacramento
ANSWER: “The fans are a good option for an occasional dry-out
but they certainly don't sound like a good permanent
fix.” says Vince McDonald of McDonald Plumbing, Heating
and Air Conditioning in Sacramento. “It sounds like you
need to go after the cause of the water rather than
treating the symptoms,” he says. “My suggestion is to
consult with a general building contractor, landscaper
and or civil engineer.”
“What is the saying, ‘an ounce of prevention is worth a
pound of cure’? If you prevent the water from going into
the area then you won't need the fans. If you have no
leaks under the house I would suggest that you inspect
and evaluate how the water from rain and irrigation runs
away from the house. Pay particular attention to the
downspouts and water that is shed off the roof. We
commonly see downspouts terminating at a point next to
the foundation and the slope of the surrounding ground
prevents this water from running away from the house. If
water is trapped and cannot naturally run away from the
house due to the landscaping and lay of the land, then
consult with a landscaping contractor to design and
install a storm drain system to do the job. If it is
fairly complicated, it may be best to also consult with
a civil engineering firm.”
Call (916) 233-4194
|
Tips and advice from Sacramento's heating and air
conditioning
experts for over 50 years!
|
