FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

Power Vent v Direct Vent Water Heaters

timc | Posted in Construction Techniques on March 25, 2007 06:54am

Could someone explain when you might use a power vent water heater rather than a direct vent one (and vise versa) and what are the advantages/disadvantages of each. While you’re at it could you explain the requirements (combustion air and venting) for each. It seems that one disadvantage of power vents is that they are extremeley noisy, how do direct vents compare?

I have tried to find info on the web about each but I can’t seem to find anything that breaks it down in laymans terms, any suggested further reading?

thanks

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. Abm | Mar 25, 2007 10:53am | #1

    Here in Michigan power vents are now required in a basement, not sure why but the plumbers enjoy the added markup dollars that it brings.

    1. Stilletto | Mar 25, 2007 02:15pm | #3

      I haven't heard that Power Vents were required in Michigan.  Must be a fairly new code. 

      I built a house a few weeks ago that had a direct vent in the basement, the house passed inspection for occupancy with it.  Thoughts determine what you want,Action determines what you get

  2. steve | Mar 25, 2007 01:34pm | #2

    i've sen lots of both i older and new homes, a power vent doesnt require a chimney o course just a abs vent pipe to the outside wall. however the heater wont work during a power outage whereas regular vented pilotlight equipped heaters will

  3. Brian | Mar 25, 2007 02:28pm | #4

    The no chimney needed (just a sidewall pvc vent) can save installation problems and labor, sometimes enough savings to make them make economic sense.

    The powervent heaters I have seen have higher efficiency ratings too.

     

    Treat every person you meet like you will know them the rest of your life - you just might!
  4. User avater
    BossHog | Mar 25, 2007 02:50pm | #5

    I always thought the power vent models were safer - Less chance that they could backdraft.

    I'm also under the impression that they're generally higher in efficiency than the kind with the metal chimney. But I don't know that for a fact.

    If athletes get athlete's foot, do astronauts get mistletoe?
    1. User avater
      Matt | Mar 25, 2007 03:52pm | #7

      I don't know much about this - just discussing...

      I thought direct vent HWHs didn't have the problem of backdrafting?

      1. User avater
        Matt | Mar 25, 2007 03:53pm | #8

        What do you know about this?

  5. BoJangles | Mar 25, 2007 03:38pm | #6

    Power vent models usually have higher efficiency ratings because you don't have as much heat loss from natural draft passing through your heater.

    Better yet is power vent with sealed combustion, where the combustion air is drawn from outside through a pipe ( like a high efficiency furnace).

    These are also more suitable for more hazardous areas where volatile vapors may be present.

    Of course, the elimination of a regular chimney is a huge advantage.

  6. CardiacPaul | Mar 25, 2007 04:07pm | #9

    Some negatives on the power vents, 1- The up front  & replacement cost of the units, Life on a power vent & standard unit are the same, 9-12 years.  2-Location for installation, the units normally vent though a side wall not the roof, with the side wall venting you have to avoid & stay away from windows, doors, overhangs, gas meters, fresh air intakes, the neighbors wife, oh wait a minute, that last one is a biblical thing.  I've talked to the plumbers & they say with all the opening in todays homes, the vent location can be a challenge.  I have a power vent unit in my house at my request, I wish I would have spec a standard unit. 

    Paul

    1. User avater
      BillHartmann | Mar 25, 2007 04:43pm | #10

      I see no one has mentioned Direct Vent.Direct vent uses a coxial pipe with combustion air around the outside and flue dischage in the center.The water heater is seal combustion. No problem with back drafting or getting combustion air in tight hosues.They are much like direct vent gas fireplaces.IIRC the venting is very limited on distance but can be side vented..
      .
      A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

      1. CardiacPaul | Mar 25, 2007 05:43pm | #11

        I did'nt realize there was a direct vent like fireplaces, I thought there was only B-vent/chimney type & power vents

        1. roger g | Mar 25, 2007 06:04pm | #12

          Diect vent, natural vent, power vent, sealed combustion chamber, automatic vent dampers etc etc etc. All have their pluses and minus' depending on if you have enough combustion air, whether it is "good" combustion air, difficulty in venting, efficiency, size, location(can't put a natural vent in a bedroom etc).

          Lots of choices and probably more than I know.

           

           

          roger

        2. User avater
          Matt | Mar 25, 2007 06:49pm | #13

          On the houses I have been building lately I have been having direct vent HWHs installed.  I think I'm doing the future HO a service by providing a safer gas appliance that has faster recovery time than electric, and is hopefully a little less costly to operate than electric.   The direct vent HWHs are a little more expensive than a standard vent or an electric HWH.  I've also been going with direct vent gas fireplaces.  To me, on any gas appliance, it's just wrong to draw combustion air from the interior of the home - with the probable exception of a cook top.  Unvented gas fireplaces are WAY wrong - regardless of what the mfg says.

          Edited 3/25/2007 11:53 am ET by Matt

          1. User avater
            BillHartmann | Mar 25, 2007 06:56pm | #14

            "Unvented gas fireplaces are WAY wrong - "There is no such thing as an unvented gas fireplace.It is just a question of where the vent is..
            .
            A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

          2. davidmeiland | Mar 25, 2007 07:27pm | #15

            Matt is probably referring to this type of appliance:

            http://hearth.com/what/gaslogs.html#anchor160143

          3. User avater
            Matt | Mar 25, 2007 07:38pm | #16

            Oh - come on Bill!  :-)  I was hoping there was at least one little item that we might all agree on :-)

            How about this one:  Wood is a natural product... :-)  Can I make that statement?  Ever since Clinton said "I did not have SEX with that woman".  things have been so blurry :-)

          4. User avater
            BillHartmann | Mar 25, 2007 09:39pm | #17

            "Oh - come on Bill! :-) I was hoping there was at least one little item that we might all agree on :-)"You day dreaming again ;)No, there is no such thing as a ventless gas fireplace.Ones with external vents, vent to the outside.Ones without another vent, then vent into the house."How about this one: Wood is a natural product... :-) "No. Except for the support for a tree house wood used in building a house is a processed product.No more or less than cement is a processed producted gotten from the ground."To me, on any gas appliance, it's just wrong to draw combustion air from the interior of the home - with the probable exception of a cook top. "I do agree with that.When I built my house in 79 I tried to isolated the furnaces and WH in a closet with external vents for combustion air.But for several reason it did not work out and the area communicates with the rest of the house.I hope to update it with a direct vent WH and high eff (external combustion) furnace and/or heat pump.The get rid of the combustion air vents..
            .
            A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

            Edited 3/25/2007 2:51 pm by BillHartmann

          5. roger g | Mar 26, 2007 06:35am | #18

            If I remember, our code would have worked in your instance if you brought in combustion air to within I think 12inches of the combustion and so many inches from the floor. The part of the code where all this is in took some reading and a lot depends if the house is "air tight construction" and other stuff.Because your situation wasn't completly enclosed it would have been deemed to be drawing from the whole house which was good. Most of my work in recent years involved high effiency stuff and direct vent stuff so I never had to venture into the part of the code involving combustion air air and venting.

             I was told years ago that eventually only direct appliances would be allowed though it hasn't happened yet.

             I've always wondered why we can have a gas range capable of burning 80,000BTU into an unvented kitchen with flames impinging on cold sauspans which causes carbon monoxide and sooting. Yet a leak in the venting of a 38ooo btu water heater or furnace creates a major stir.

            Such is life.

             

            roger

      2. jrnbj | Mar 27, 2007 11:07pm | #19

        I was perusing those the other day....looks pretty cool if it fits your layout....no stack effect, no electric, and hot water during power outages....what's not to like!

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Ducted vs. Ductless Heat Pumps

Choosing the right heating and cooling system means finding the best fit for your home's size, layout, and climate—and balancing trade-offs in efficiency, comfort, and cost.

Featured Video

How to Install Exterior Window Trim

Learn how to measure, cut, and build window casing made of cellular PVC, solid wood, poly-ash boards, or any common molding material. Plus, get tips for a clean and solid installation.

Related Stories

  • Podcast Episode 684: Masonry Heaters, Whole-House Ventilation, and Porch Flooring
  • FHB Podcast Segment: Repairing an Old Home While Maintaining Its Integrity
  • Tools and Gear for the Moms Who Get it Done
  • An Easier Method for Mitered Head Casings

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 81%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data