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Summary: Diy heating is a nearly impossible task. It is
foolish for even a serious diy'r to think he can install a heating system as
well as a professional. You need special tools and skills. Diy heating and air
conditioning is far and away the most complex task one can undertake in a
home.
Related Articles: heating
consulting, duct
airflow, payback
DEAR TIM: I need to replace my existing furnace, and am
convinced I can do it myself. I looked at how the furnace connects to the metal
ductwork, and I don't see any real challenges. Even the solder connections for
the air conditioning seem simple. What obstacles do you feel I will encounter?
Is it realistic for me to complete the job with no major problems? I am a
serious do-it-yourselfer (diy'r), and have tackled all of my past diy projects
with success. Patrick N., Laconia, NH
DEAR PATRICK: Your confident attitude reminds me of a real
estate developer who requested a zoning change in my village a few years ago. I
listened to him tell our planning commission how he got every other zoning
change he had ever asked for from other local government bodies. He was proud of
his 1.000 batting average. Unfortunately for him, my village spoiled his perfect
record. I predict you are about to strike out as well.
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| Installing a furnace requires great skill, specialized tools and experience. This ultra-high-efficiency York furnace with a gas modulating valve took Richard Anderson, the BEST HVAC craftsman in greater Cincinnati, OH, several days to install. PHOTO CREDIT: Tim Carter |
Diy heating is perhaps one of the most challenging tasks I
can think of when it comes to projects around a home. I can think of more
physically demanding ones, like placing and finishing 20 yards of concrete in
one day with just two helpers. If you want a formidable challenge, install a
traditional post-over handrail with newel posts, volutes and goose necks. This
master carpentry task is a photo-finish second place to heating, when it comes
to precision and technical difficulty.
The skill sets you need to professionally install a new furnace are many.
Furthermore, you need many specialized hand and power tools, especially when it
comes to connecting the new furnace to your central air conditioner. For
example, I doubt you have a set of refrigeration gauges sitting around to
measure the high-and-low-pressure sides of your air-conditioner refrigerant. You
will also need a two-stage vacuum pump to remove all air and moisture from the
inside of the copper tubing after it has been brazed, not soldered. Don't forget
to flow pure nitrogen through the copper tubing as you braze the copper
connections.
I will assume you are installing a high-efficiency furnace, as they will give
you a fantastic return on investment. The newer gas furnaces that sport
gas modulating valves are state of the art, but my guess is
that unless you have a heating and air conditioning contractor who will secretly
buy the equipment, you may not be able to get your hands on the furnace you
want. Heating equipment manufacturers often demand that their top-of-the-line
equipment be installed by factory-trained craftsmen. This policy is a good one,
as they do not want their furnaces and air conditioning equipment to become lab
rats for people who feel they know more than they really do.
Once you remove your old furnace, you may be surprised to discover the shape
and size of the new furnace and the interior air-conditioning coil that sits on
top of many furnaces is quite different from your existing one. Connecting the
ductwork above the existing furnace to the new one will require precision
modifications. If you have not worked with sheet metal before, you may be in for
a surprise. You need to learn all about s-hooks, drives and custom-offset
ductwork.
One of your most serious challenges will be reclaiming the existing
refrigerant that is in your system. Those of us who want to protect our planet's
fragile atmosphere would sincerely appreciate it if you would not vent the
high-pressure refrigerant into the air. Professional heating and cooling
contractors have specialized equipment that allows them to reclaim the gas so it
can be properly recycled.
If your existing furnace is fueled with natural gas, oil or propane, you will
need to conjure up your best diy plumbing skills. You may be working with black
iron pipe that needs to be custom cut and threaded. If you have all of the
needed pipe-threading dies, cutters and the pipe vise, I am duly impressed.
These expensive tools make sense for a plumber to own as he uses them
frequently.
Diy heating is one of those tasks that homeowners
need to
avoid. There are many things that can go wrong, and worst of all, you
may put yourself and your loved ones at risk. Furnaces and any fuel-burning
heating device generates deadly carbon monoxide. Installing heating equipment
improperly can be a recipe for disaster.
If you still think you want to tackle the project, absolutely take out the
required building permit. Call for timely inspections to ensure all of the
equipment is installed to code. You may need two different inspectors, as some
municipalities may have a separate electrical inspector who looks at all of the
electrical connections, fuses, switches and disconnect boxes.
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Comments
Randy
29 Nov 2007, 00:09
While I see the risks in giving advice in this DIY situation, many...... I
do mean, MANY, DIYers can do a better job than the "average" professional.
In my own line of work, I see many retired individuals with engineering or
other trade based backgrounds ding some very nice work, and doing a lot of
reserch as to the issue at hand.
This particular individual's confidence seems to be worthy of further
questioning rather than giving a blunt put down, not knowing his
experiences or DIY abilities.
That said, I also see the liabilities to the owner of this website for
continuing the conversation. So take my comments for what they are.
As for heating systems and DIYers, I just made two, 250 watt "clones" of
the infrared system promoted by Paul Harvey. (Edenpure, I recall)
They do a fantastic job in my older mobile home .......both are installed
at the far ends of it.
I no longer have a forced air furnace to keep the air circulating in the
farthest corners of the home, so I made up two heating units using 250 watt
infrared hight bulbs, a ceramic socket, a piece of black stove pipe and a
stove pipe cap.......... basicly, it's ventilated can with a light source
inside it.
No parts of the unit get over 278 degrees.
They work on convection only, so unlike space heaters, there are no
elements to blow out, not thermostats to go bad............ these put out
very little heat, but serve their purpose much safer than a commercially
built space heater.
I did this for additional comfort, plus to keep moisture and mold issues
at bay.
Just a tad bit of heat plus some air movement.
The units I made require no fan, no thermostat, nor does any surface on the
units reach temps above 275 degrees. ........... pretty much the same as
leaving a light on.
I did a lot of testing over a few days using my infrared thermometer to
test different configurations.
What is the worst case scenario with 250 watt infrared lighting
considering the nearest combustible surface is 3 feet away and the infrared
lighting source is 90% enclosed? ................ Yup, just as I
thought...... the light bulb might need to be replaced at some point I
suppose.
I agree heating can be quite dangerous, so you may be correct to say what
you did.
I would have loved to see a resoponse from the initiator as to his
experience and abilities.
Randy
29 Nov 2007, 00:16
To my embarassment, I didn't see the topic's content to it's finality......
oooops! I missed the last parts.
I agree with your comments and recomendations.
Maxx Stryker
12 Dec 2007, 22:37
Tim, I was not surprised to read the shut-down, inhibiting response to
Patrick regarding his desire to install his own High-Efficiency furnace.
Living in a northern climate, I know many homeowners who decline an A/C
install entirely. A lot of the connections of the furnace heating system
are a one for one swap of component connections. Yes, I too work with many
engineer-types (Auto Industry) who have plenty of on-the-job work skills
that will enable them to competently complete this install. Thanks, Tim
for your marvelous advertising for the IBEW, plumbing & HVAC unionized
skilled trades. Remember - Unionization sometimes equals Exclusionism....I
am not predicting a reply to this, nor the publishing of my subjective
comments.
Randy
13 Dec 2007, 00:30
My thoughts after reading the initial question that the homeowner was going
to do a relatively simple swap of systems as Maxx mentioned.
Now that said, going from an electric forced air furnace to a heat pump
would require considerable knowldege. Myself, being a man "in the trades",
I do know quite a lot. I have never in my 50 years hired any so called
"professional" work, with the exception of having me engine block machined
so I could rebuild it.
I rea a lot, understand a lot, and that said.......... I simply gotta know
what makes things tick. I"m naturally inquisitive.
Since a little kid, I have torn apart everything from a wind up alarm
clock to fixing my brown and blueish colored TV's 3 main color transistors.
I got my color back and it didn't cost me a dime........... I also didn't
touch that nasty capacitior....... hence, I'm still here. :)
OK, "DIYer" bragging aside, there are mega thousands of people like me and
much, much more educated. There is more than one grade of DIYer. I will
simply set myself in the above average catagory somewhere.
I also know guys in the heating trade that could assist me with any
questions I might have on installing a new system. I do virtually nothing
without researching the subject.
Going from an old forced air system to a heat pump would most likely
require new duct work to make the air flow work properly. I don't believe
an "advanced homeowner DIYer" could tackle a replacement like that. Too
much knowlege on the system and air flow distribution than a DIRer would be
required in my opinion.
Funny to see the Amazon ad on this page for a book titled:
" Complete Construction
Forced Hot Air Furnaces, Troubleshooting and Repair"
A little contradiction is good for the soul. :)
AsktheBuilder
15 Dec 2007, 10:14
Maxx,
Maybe it is still early in the day, but I am not sure I understand your
point. All I can tell you is that of all the people I have worked for and
met in my life's journey, there is not 1 in 5,000 that could successfully
complete the above replacement.
Randy
15 Dec 2007, 21:20
I wish the original poster would have provided more details as to what he
was actually pondering. A replacement with the same type and size of unit,
or a totally different type of system?
I am going to guess since he hasn't responded, that he realized it was way
over his head after reading the initial advice.
That's my story and I'm stickin' to it.
James
07 Feb 2008, 00:43
I replaced my furnace and it was no problem...well it onlt took me 1/2 a
day. To start with I have no A/C and I installed a 80% unit, it would take
me 13.5 years to pay off the extra cost. The firt thing I did was was find
a furnace that had the same orentation for the fittings. After taking out
the old one there were 8 things to hook up. 1) gas line, I used a flexable
one, 2) 5" vent stack, I used the old one. 3) thermostat, 2 wires. 4)
110volt power, one connection 5) cold air return, I had to extend the
flashing 6) hot air duct, I made a template out cardboard and duck tape, a
local shop made me a sheet metal one for $50, I supplied the sheet metal.
7) installed flexable duct for fire box 8) added a flexable line to add
freash air to the cold air return, one way flapper valve on this item, no
power required. I used themost basic of hand tools, sheet metal screws and
a cordless drill. Where I live it was $40 to pull a permit and you can do
it over the phone. The inspector was great and there were no problems.It
has been running fine for the past 4 years. My final cost was around $700
installed. The furnace was $550.Good luck
Garry
03 Mar 2008, 18:34
While I applaud some people's success in replacing a furnace themselves, I
don't believe that most DIYers should even attempt it. I work in the HVAC
field and there are certain things that most homeowners do not have the
tools, equipment, knowledge, or experience with. Unfortunately, buying a
furnace with the same dimensions and connections is no substitute for
buying the furnace you want. Swapping an 80 for 80 is relatively simple.
Swapping an 80 for a 90+ is another story. When changing to a 90 from an
80, you will be running anywhere from 2" to 3" PVC pipe, depending on the
BTU rating, which must be pitched correctly to drain back to the furnace,
the chimney where the 80 was vented must be resized if using a natural
draft water heater (does not apply to power-vented water heaters). The
mechanical connections are generally fairly straightforward, but to
properly set up the furnace, you should check inlet gas pressure and adjust
the outlet gas pressure to the manufacturers specs (which most people DON'T
do, believe it or not). Using the right kind of thermostat is also
important, especially if you are considering a dual fuel system, which can
also be a way to save some money on energy bills. But installing a dual
fuel system or simply doing a changeout with A/C requires special tools,
which are not available to the public, as well as the fact that you must
have an EPA Type 2 or higher certification to handle, pump-down, recover
refrigerant. If someone is caught releasing refrigerant into the
atmosphere, the fine is very steep (I believe $50.000). Bottom line is
that this is generally not a job for do-it-yourself types. The other
option however is to have an EPA certified technician help you with the
brazing, recovery, recharging, etc. Besides, if you don't have the gauges
and know how to properly set a refrigerant charge (which BTW is different
depending on the type of refrigerant being used, as well as the method for
calculating the charge is also dependent on the refrigerant metering
device) Most homeowners don't have this knowledge or information and an
incorrect guess on a refrigerant charge can lead to no cooling. freezing,
compressor slugging/failure, as well as the A/C generally not working
correctly. Some things are better left to professionals.
AsktheBuilder
08 Mar 2008, 13:15
Garry,
I agree 100% and basically said many of the things you said in the column
above. I was trying to paint a picture of all of the challenges.
Bob Linville
12 Apr 2008, 14:57
My mistake...I thought the site was DIY (DO it yourself. According to this
page, it's DDIY (DON'T do it yourself). I wasn't looking for someone to
tell me I can't do something. I was looking for information to help insure
I did it properly.
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