Re: [GBlist] Gas-fired tankless water heaters?

["Mike Rogers" <rogers.mike@verizon.net>]

There are "sealed combustion" hot water heaters.  By sealed combustion, I
mean that that combustion air is completely isolated from the interior--thus
combustion air is drawn directly from outside and exhausted directly
outside.  No mixing with, or use of, interior air.

By direct venting, I mean only that the exhaust air takes the shortest way
out, usually horizontally through a side wall.  Direct venting may, or may
not, be sealed combustion.

Again, there are sealed combustion hot water heaters, but I'm only familiar
with tank models.  I have not found a tankless sealed combustion unit yet.
I haven't seen the Myson that Speireag mentioned, hence my question.

----- Original Message -----
From: RET John <retjohnd@home.com>
To: Mike Rogers <rogers.mike@verizon.net>; Green Builders Server list
<greenbuilding@crest.org>
Sent: Wednesday, February 21, 2001 11:54 PM
Subject: Re: [GBlist] Gas-fired tankless water heaters?


> on 2/21/01 21:16, Mike Rogers at rogers.mike@verizon.net wrote:
>
> Wednesday, February 21, 2001 21:48
>
> > Do you know if the direct vent model is sealed combustion?
> >
> > -Mike
>
> No it is not. No such thing as a "sealed combustion" direct vent hot water
> heater that I am aware of. ANY product that uses a gas fuel all have to
have
> oxygen to burn the fuel so therefore you really cannot have a "sealed"
> combustion area so to speak.
>
> If you do not want combustion then you can buy an electric direct vent
> hot water heater, but of course your cost per BTU will be around $26.00 or
> so depending on the cost of electric in your area. Now that natural gas
and
> propane have gone up so much an electric instantanious electric hot water
> heater may not be such a bad idea. One has to compare fuel costs on a cost
> per BTU basis!
>
> --
> Sincerely,
>
> John D'Angelo