standard vent vs. direct vent

[karter56]

Can I replace a direct vent water heater with a standard vent model. The water heater is located in my crawl space, which is 10 feet tall.

[hj]

IT depends on WHY the direct vent was used, because it would normally NOT be the :first choice" if there were not an overriding reason for it.

[jimbo]

A standard vent must go mostly up, and all the way to the roof. The direct vent was probably used because it was a lot easier, given the location.

[Little Tim]

IT depends on WHY the direct vent was used, because it would normally NOT be the :first choice" if there were not an overriding reason for it.

I'm curious as to why you emphasize that a direct vent would normally not be the first choice unless there's an overriding reason. After all the research I've done I'm surprised direct vent isn't used more often. No need for electricity, no noisy power vent, no need for chimney (most people have high efficiency furnaces these days and wood burning fireplaces are becoming increasingly rare). Except for it being a little more expensive I see only benefits.

I've just booked an installation for a Bradford White 50 gallon direct vent to replace our 18-year old Rheem atmospheric vent. Didn't want power vent because we have bedrooms in the basement and I've heard about a lot of noise issues with power vents. Also, our current water heater is the only appliance venting up the chimney, so this switch allows us to get rid of the chimney. Less penetrations through the roof, less chance of a leak. The chimney is not in the best of shape either, so spending thousands of dollars restoring it made no sense when we could just spend a few hundred dollars more on a direct vent water heater instead.

I realize that in our case there are what could be called "overriding reasons", but I would assume any one of these reasons could apply to the majority of people, so I'm still wondering why direct vent isn't more popular.

[jadnashua]

The non-powered direct vent is limited on how far it can be from an outside wall. The flue pipe is expensive, too. A powered direct vent can often use PVC pipe and go further. Both pull combustion air from outside, which can be a big energy saver in itself. So, some of it is convenience, but a lot of it is initial cost. Most people don't think running costs, they think of initial installed costs, even though there's often a reasonable payback.