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

Positive or Negative Houses

homedesign | Posted in General Discussion on August 21, 2007 06:28am

What is your climate zone? Is your house tight? How tight?

Does your house run positive,negative or almost nuetral?

How do you maintain the proper pressure for your house in your climate?

How does fresh air enter your home? How does it exit?

How do you humidify or dehumidify?

“Keep the rain out.Keep the outside air out.Keep the inside air in and let the moisture out in both directions” per Lstiburek
 

 

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

Replies

  1. rez | Sep 08, 2007 08:18pm | #1

    Greetings home,

    This post, in response to your question, will bump the thread through the 'recent discussion' listing again which will increase it's viewing.

    Perhaps it will catch someone's attention that can help you with advice.

    Cheers


    sobriety is the root cause of dementia.   

  2. rez | Sep 11, 2007 06:55pm | #2

    Let's try this one more time.

    bump


    sobriety is the root cause of dementia.   

  3. User avater
    McDesign | Sep 11, 2007 07:40pm | #3

    Old house.  Windows rattle when the wind blows.  hope to build one soon that's sealed and with a HRV.

    Forrest

    1. homedesign | Sep 11, 2007 08:56pm | #5

      Forrest,

      When I built the house where I live now...I could not answer those questions.

      I had never heard of EEBA and I thought I was building an Energy efficient house.

      I have come to learn how important it is to be able to answer all of the questions that I posted.  I don't have all the answers...but I have questions. I would like to know if I am the only one at this forum that thinks  about such things. I think a lot of people have figured out how to build a tight house...I am not so sure that ventilation is very well understood.

      I live in a mixed Humid Climate, I intend to build to 1/3 air changes per hour and I plan to have the "tightness" verified by blower door test. My goal is to keep my house at a nuetral or slightly positive pressure at all times. I am still working on the strategy. For my climate I believe I will need a dehumidifier in addtion to my AC.

      Tim and VATom and ShelterNerd can answer for their homes..can anyone else?

      John

  4. User avater
    aimless | Sep 11, 2007 08:56pm | #4

    What is your climate zone? Is your house tight? How tight?

    Zone 6. No. About as tight as an extra-extra-large.

    Does your house run positive,negative or almost nuetral?

    Dunno, I'm a homeowner. Without AC or heat my house is always 10degrees hotter than it is outside - summer or winter.

    How do you maintain the proper pressure for your house in your climate?

    I haven't been able to fit the cuff from the aneroid monitor around my house's arm to check.

    How does fresh air enter your home? How does it exit?

    Through the walls. Out the same way.

    How do you humidify or dehumidify?

    I live in the desert. I occasionally cook pasta which humidifies.

  5. Rebeccah | Sep 11, 2007 10:16pm | #6

    What is your climate zone? Is your house tight? How tight?

    SF Bay area. Not sure what zone that is. No, it's not tight. At all. 1919 bungalow with no insulation. Original double-hung single pane windows. Big gap under front door, partially bridged with nail-on garage door weatherstrip. No damper in the chimney. Mail slot through the wall. I can see the light in the basement between the boards in the bedroom floor.

    Does your house run positive,negative or almost nuetral?

    I'd guess pretty close to neutral.

    How do you maintain the proper pressure for your house in your climate?

    Don't know about "proper", the pressure is what it is.

    How does fresh air enter your home? How does it exit?

    Walls.
    Back door (open most of the time during the day).
    Front door (open a lot of the time).
    Bathroom windows (one is open a crack all of the time, the other is open sometimes).
    Chimney
    Other windows.
    Floor over ventilated crawl space.

    How do you humidify or dehumidify?

    Dehumidify:
    Open bathroom window or back door.
    Fix/replace sump pump in basement.
    Humidify:
    Turn on shower.
    Cook, especially tea or soup.
    Drink lots of water.

    Rebeccah

    1. homedesign | Sep 11, 2007 10:25pm | #7

      Oh you California people...you are fortunate

      Your climate is pretty mild.  Here in North Texas we pay a pretty high energy penalty when we open our windows.   Enjoy your weather.

       

  6. pboxx | Sep 11, 2007 11:29pm | #8

    Homedesign,

    What is your climate zone? Is your house tight? How tight?

    Climate zone 4 (Central Oklahoma),Zoning depends on who's graphing... houses constructed about as tight as you can get, up too caulking studs, plates, etc. exterior tyveck wrap, radiant barrier, proper blocking throughout the frame of the home.

    Does your house run positive,negative or almost nuetral?

    Prefer to control with positive pressure.

    How do you maintain the proper pressure for your house in your climate?

    Proper HVAC and ventilation throughout home, also being very informative to clients operation of the house.

    How does fresh air enter your home? How does it exit?

    Intake through HVAC, fresh air makeup, exhausted through various vented areas in the home.  (Kitchen, bathroom, dryer exhaust, etc)

    How do you humidify or dehumidify?

    Additional humidifyers attached to HVAC systems.

     

    Maintain a 40% or so relative humidity in the homes, average bills for a 3000 sq ft home is approx $150.00 monthly, granted I do pay approx. 70% more for the set-up process but it will pay for itself within 5 years of use. the rest is money (kept) in the bank!!!!!

  7. MtnBoy | Sep 13, 2007 05:28pm | #9

    I think all the questions can be answered for the new house I will be building. Not sure I can personally answer them, but maybe:

    Tight as you can get with the building envelope fully insulated with Icynene. Pultruded fiberglass framed thermal windows with coating to minimize heat gain (in GA).Slab on grade with infloor hydronic radiant heat, so best practices for that dictate 4000 psi slab, which is waterproof, insulated only around the perimeter here in zone 7, but we'll take it a little farther in. HRV to supply air exchanges and balanced pressure; HRV shares ductwork with traditional central A/C system and whole house air purification unit. Will need to add a dehumidifier to that here, I'm pretty sure.

    Now, I have a question for you. I understand that there has been less than overwhelming success with maintaining positive pressure in houses. Do you have some good info. about that? Or is neutral the best we can actually accomplish? And, if it's a tight house with windows always closed, balanced mechanical ventilation, no backdrafting issues, etc--do we WANT to shoot for positive pressure?

    1. homedesign | Sep 13, 2007 06:10pm | #10

      And, if it's a tight house with windows always closed, balanced mechanical ventilation, no backdrafting issues, etc--do we WANT to shoot for positive pressure?

      MntnBoy,

      I can't say how good my info is. Here is some folksy "hearsay"

      If you live in the North your house should suck and you must perfectly airseal your house from an attached garage DO NOT SUCK AIR FROM YOUR GARAGE

      If you live in the South your house should blow.

      John B

      1. MtnBoy | Sep 13, 2007 06:31pm | #11

        I think it should be neutral wherever you are and most of the time I read about problems with houses sucking too much. And it being virtually impossible for them to blow, despite the use of gadgets to try to create a slightly positive pressure.With all sealed combustion systems, no oversized exhaust/range hoods, a separate garage, the mechanical room isolated air tight slab through roof from the house airstream, Icynene insulation, fiberglass window frames, etc.--why in the world would I want to make my house here in the south blow? Even if it could be accomplished?Have you read anything much on ventilation? If not, a good place to start would be John Bower's book Understanding Ventilation. It's 400 pages or so of really good, basic info. on residential ventilation.

        1. homedesign | Sep 13, 2007 06:53pm | #12

          I am only talkin about the south here.

          If you are concerned about air quality..would it not be better to be in complete control of all air that enters your house? and not as concerned with a little bit escaping?  perfectly sealed is not practical

          When we dive into water we humans stay nuetral or we blow a little.

          We would never suck

        2. homedesign | Sep 14, 2007 07:10pm | #16

          MtnBoy,

          Thanks for the suggestion...I will track down that book

          My question for you: Why do you think it is better for a house in the south to be slightly negative? was it something in that book?

          John B

          1. MtnBoy | Sep 14, 2007 08:14pm | #17

            I didn't think I said that. I believe that neutral pressure is best in every situation. But from what I understand, the efforts some folks have made, regardless of climate, to achieve positive pressure (by use of blowers usually) have met with little success.I am certainly no expert on this. The folks who regularly post under the Green section here will know about it.Good luck with your learning.

          2. User avater
            SamT | Sep 15, 2007 03:07pm | #18

            Positive and negative do not refer to any measurable difference in inside and outside pressure. They refer to whether the main vent fan blows in or out.The house my father built was as airtight as a screen door, but because we used a swamp cooler, it was a positive house.If you use exhaust fans for air exchange, you have a negative house. Air tightness doesn't matter.In this context, neutral implies no mechanical air exchange.SamT

          3. homedesign | Sep 15, 2007 07:41pm | #19

             Air tightness doesn't matter.

            SamT,Air tightness does matter. Before we can control air we must first enclose air.If  exhaust air is greater than makeup air then the house will become negative.Which can be a good thing in the North.Negative is a bad thing in the South because we do not want to suck warm humid air into our walls.

            Exhaust fans do present challenges, but as long as we can introduce slightly more makeup air.... then we can maintain a positive pressure.

            It can be done....we have the technology.

             

  8. User avater
    CloudHidden | Sep 13, 2007 07:11pm | #13

    For the house I sold in January...

    >What is your climate zone? Is your house tight? How tight?

    Zone 4. Yes. Similar client house measured 0.035 ACH

    >Does your house run positive,negative or almost nuetral?

    Slightly positive

    >How do you maintain the proper pressure for your house in your climate?

    HVAC contractor set up system with filtered intake, dehumidifier, etc.

    >How do you humidify or dehumidify?

    Dehumidifier. 35%-45% RH year-round.

    1. homedesign | Sep 13, 2007 07:15pm | #14

      CloudHidden, thank you

      can you imagine building a house without thinking about this stuff?

      1. User avater
        CloudHidden | Sep 13, 2007 07:50pm | #15

        Since I really only design in one genre, it's an automatic byproduct of the design. The merit of what we built was brought home (pun intended) when we bought a 3 yo house upon moving. Normal new frame house for the area, but the difference from the other in performance is huuuuuuuuge. Temp change is felt immediately. Humidity fluctuations are constant and large, and there's no hope for controlling them. Wind makes the house creak. <sigh> I look forward to someday being in one of my houses again.

  9. frenchy | Sep 15, 2007 09:46pm | #20

    HomeDesign.

      I'm not finished yet but am attempting to get neutral pressure For Minnesota's cold climate.  To achieve that the standby furnace is one of the high efficency designs which take outside air in and exhaust flue gases sideways..  I've eliminated other  air consumers such as gas fired water heaters and fireplaces.. When I do put a fireplace in I will ensure that it draws combustion air from outside.   The Boilers for in floor radiant heat are electrically powered and operated so no air will be consumed.  I will not have a stove hood so that consumer of air is not in place.. The sole remaining aplliance which uses air will be the clothes dryer.. which while it's in regular use now will quickly decrease isage.. However I've given serious thought to even replacing that item .

     How tight is my home, again it's not complete yet so I don't have blower door test results.. however I took extreme care using SIP's as an insulation media and taking great pains to ensure that the joints are tight and well sealed..  all windows and doors are sealed with sprayed in foam. and care was taken to ensure good quaility windows/doors  were used..

     



    Edited 9/15/2007 2:49 pm ET by frenchy

  10. User avater
    JeffBuck | Sep 16, 2007 02:57am | #21

    house was build in 1902 ...

    so U figure it out!

     

    at least we don't have to worry about radon, mold or excess moisture ...

    it all just leaks out!

     

    sometimes blows out ...

    depends on the wind.

    Jeff

        Buck Construction

     Artistry In Carpentry

         Pittsburgh Pa

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

Picture-Perfect Pergola

Built from locally sawn hemlock, this functional outdoor feature uses structural screws and metal connectors for fast, sturdy construction.

Featured Video

Builder’s Advocate: An Interview With Viewrail

Learn more about affordable, modern floating stairs, from design to manufacturing to installation.

Related Stories

  • Podcast Episode 692: Introduction to Trade Work, Embodied Carbon, and Envelope Improvements
  • FHB Podcast Segment: Embodied Greenhouse Gas Emissions and the Building Codes
  • Old Boots Learn New Tricks
  • Install Denim Insulation Like a Pro

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 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • 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 2025
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers

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 70%

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