Plus, does it pay off to work so hard to make an exhaust piping system
for something that may not be likely to live long.
I changed my exhaust to a 3/4" copper ell and tubing 8" in length.
Slotted the end of the ell and used a SS hose clamp it to the steel
Just friction tween the ell and the tube.
The other end goes through a 3/4" hole in a little 1/8" thick rectangle
of sheet of asbestos board (from a kiln) attached to a 6" high x 36"
wide sheet of plywood that seals the single hung window.
I ran it for 30 minutes today and I could not detect any leaks or
Not a lot of work.
BTW The generator ran for 30 minutes and nobody in my house even
noticed it running.
Nonono. Never use a generator outdoors. That wastes about 80% of the fuel's
heating value. You might run the exhaust from a $900 1500 W Honda generator
with a $2K grid-tie inverter into the top of a $200 gas water heater that
preheats water for the usual water heater, then outdoors, all inside a small
plastic film room in the basement, depressurized by the combustion airflow,
with a CO detector outside the room.
Actually a small exhaust-to-water heat exhanger would provide quite a
bit of hot water.
I considered it but I am concerned about the steam flash problem and
the other complexities involved.
My system is up and running fine in my garage. We can't hear it
running in the house nor can our neighbors.
Here's how I connected the 220 VAC generator cable to the W/H.
220 to 220.
Open one wire of the W/H to the center of a SPDT swtich. One throw to
A/C from panel, the other to a SPST switch.
The other end of the SPST switch to Neutral.
(The prongs of the generator plug are of course energized and an
plastic insulator cover was fabricated for safety - no touch.)
With grid power, everything normal.
No power, flip off Main Breaker, throw the SPDT switch away from panel
to lessen the load on my 3,000 watt generator.
I also flip off all other 220 breakers. Generator is used only for 120
devices and the small breakers.
Plug in cable, start generator. Generator feeds house through W/H
Hot water needed? Throw the SPST switch to neutral and the H/W heater
is using 1/4 the power (~850 Watts) on 120 VAC than it uses at 220.
Simple, efficient, and for me, quite safe.
For photos, email me.
Thanks for your thoughtful reply.
I meant CO detector, but couldn't be give thethe benfit of the doubt.
If you lived therough Francism Jeanne, and wilma, you would understand
what we are attempting to accomplish in SE FL.
I want the quickest, , quietest, cheapest, longest running, genrator
hookup for standy for minimum power and which requires minimum effort
to get running.
First the generator garage issue: My welds are strong enough to trust
my life on when I ride my recumbent trikes and other vehicles that I
have built over the years. Also, my $100 elevator in daily use for
over 3 years was also condemned by the usual Google lurkers who never
seem to trust their own abilities to build anything that their life
would depend upon. What happened to the pioneer spirit? "Leave it to
the professionals" is their motto. True in many cases but not in all
cases. Why have a Forum on Home repair? Just use the Yellow pages and
hire a pro.
There are 2 closed interior doors separating the garage from the
house. The Garage door will be partially open for ventillation and
for oxygen for the generator.
The genertator is a 3000-3500 watt 6.5 hp model. Modest output,
enough for a refridge and a few lights etc.
Complication is not the case. Just the opposite. A short 3 wire cable
from the generator to a junction box and 2 switches.
Throw one switch for generator power to the entire house.
Throw the other switch for 120 VAC hot water.
What could be simpler with fewer wires or switches?
The 4th crooked lead in the generator receptacle does not measure
'short' to the generator case not to any other terminal.
I'd feel better about it if you have a flexible section near the generator.
If your construction is entirely rigid then forget it, it will eventually
break no matter how good your welds are unless it's *extremely* short. Is
it a threaded connection into the engine? That's a good place for a break
if the vibrating engine is rigidly connected to a lengthy pipe. That condo
emergency genset you mention...if it was indoors it surely had some sort of
flexible pipe connection. Does your engine vent the crankcase back to the
intake? Finally, a decent ventilation fan either bringing in fresh air or
exhausting inside air, with either a vent or window that will be open
during generator runs to allow for circulation is a bare minimum. Then
Is this gasoline or NG? Where is the tank vented? What about spills on
refueling? So much simpler and safer just to take the thing outside. Then
you can tell everyone about how you will hook it up via the A/C disconnect
The same switch that connects generator to water heater must
also disconnect AC mains from water heater. Switch must be
'break before make' type. It does not matter how many times
you say "it is off". Humans have a bad tendency to always
make the exception occur. A design must be human proof.
Design must be 'not mechanically possible' to ever connect
generator until heater has been disconnected from AC mains.
Switching equipment is simple to obtain which is just another
reason why the heater must always disconnect from AC mains
before generator makes a connection. Any residential
procedure that calls for human knowledge is unnecessarily and
If anyone ever makes a mistake (connects AC mains and
generator together), then 100% blame belongs on the human who
built that mistake. If anyone can make a mistake, that human
who installed the dangerous system should be hung by his balls
- this last sentence only my opinion. All other sentences are
required by both code and common sense.
Where does generator connect to safety ground? For example,
assume the generator has a circuit breaker. Assume one side
of 240 volts shorts inside heater. Now heater frame is
electrically hot. Where is the conductive circuit that goes
out of generator, through short to water heater frame, then
(and this is the missing part) back to generator on either
safety ground or other side of 240? Without that direct
circuit, then circuit breaker / fuse may not trip/blow.
Demonstrated is why all building safety grounds (ie one in
breaker box) must connect to safety ground on generator by a
dedicated safety ground wire of sufficient gauge.
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