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
The Fine Homebuilding Podcast

Podcast 623: Condensation on Windows, HVAC Registers, and Water Heating

Listeners write in about the value of FHB and ask questions about basement flooring, condensation on windows, HVAC register locations, and heat-pump water heaters

By Patrick McCombe, Brian Pontolilo, Mike Guertin, Andres Samaniego
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles
Video Player is loading.
Current Time 0:00
/
Duration 0:00
Loaded: 0%
Stream Type LIVE
Remaining Time -0:00
 
1x
    • Chapters
    • descriptions off, selected
    • captions settings, opens captions settings dialog
    • captions off, selected

      This is a modal window.

      Beginning of dialog window. Escape will cancel and close the window.

      Text
      Background
      Window
      Font Size
      Text Edge Style
      Font Family

      End of dialog window.

      This is a modal window. This modal can be closed by pressing the Escape key or activating the close button.

      This is a modal window. This modal can be closed by pressing the Escape key or activating the close button.


      Follow the Fine Homebuilding Podcast on your favorite app. Subscribe now and don’t miss an episode:

      Watch on YouTube

      Campbell says FHB helped him remodel his kitchen. Jonathan has an update on his basement. Ben’s windows are steamy. Tricia asks about HVAC registers. Zeo Geo is considering a switch from gas to a heat-pump water heater.

      Editor Updates:

      • Mike: Backyard re-sculpting, backhoe rental, electric breaker hammer
      Mike's re-sculpting backyard
      Mike's re-sculpting backyard
      Mike's re-sculpting backyard
      Mike's re-sculpting backyard
      Mike's re-sculpting backyard
      Mike's breaker hammer

       


      Listener Feedback 1:

      Courtesy of ©2024 Asterisk Magazine and illustrator, Dalbert B. Vilarino
      Courtesy of ©2024 Asterisk Magazine and illustrator, Dalbert B. Vilarino

      Cambell writes: 

      First, let’s talk about this article. Lies, Damned Lies, and Manometer Readings: America’s HVAC labor force is plagued by dishonesty and frequently incapable of meeting industry standards. Interventions in indoor air quality are the next frontier in pandemic prevention — but are they up to the task?

      Also, every now and then, you folks read an email from someone who expresses their appreciation for giving them the wherewithal to tackle DIY jobs. I’m not sure I’ve ever explicitly said so, but as an FHB subscriber for about 15 years, I owe you that. The photos show a job I did in 2018 that I couldn’t have taken on without the truly expert advice from the magazine.

      Also, yes, that is a softwood (Douglas fir) floor in the kitchen. It matches what was there originally, matches the rest of the floor in the house, and could be installed to accommodate the lack of flatness inherent to the 130-year-old subfloor (to fix that would have been a job). Yes, it’s slowly getting a little dinged up, but that’s fine—it’s character.

      Campbell's kitchen
      Campbell's kitchen
      Campbell's kitchen

      Related Links:

      • HVAC and Indoor-Air Quality
      • Rise of the IAQ Monitor
      • GBA.com: Indoor Air Quality and Building Diagnostics

      Question 1: What is this white stuff and what do I do about it?

      Jonathan writes: FHB crew, you discussed in Episode 587 my hardwood floor in my basement.

      Patrick asked: If it’s not a big deal. I would tape a piece of plastic sheeting (about 1 ft. sq.) to the slab near the exterior wall subject to rain and see if/how bad it fogs up. Let me know what happens. A more conclusive test is with a moisture meter, but most are terrible, so you have to get the right thing, which costs several hundred dollars. An in-between option is a calcium-chloride test. Thanks again for listening Jonathan.

      Campbell's fungus
      Jonathan replied: I haven’t noticed any fogging when I tried this, but it’s hard to know in winter in Minnesota.

      The asbestos tiles are one problem. The other is some pretty white fungus above the patio door in the same room. I noticed some sad drywall and peeled it back to reveal this scene (see photo). This is the ledger/support beam above a sliding patio door that is directly beneath a sliding patio door above that walks out to a deck.

      I thought there might be a mold/rot issue, but poking the boards yields solid sounding boards and the fungus doesn’t seem to be damaging the wood. I cut back the ceiling above and poked through the insulation to find solid sheathing on the outside.

      The gap between the boards leaks a substantial amount of air, so the only thing I can think of is that due to the air leakage, with most air leaving, this fungus can grow. Although who knows if this grew and halted years ago.

      I would love any and all feedback on this issue, since it seems to be the most pressing one. I’ll respond with any more pictures and info that I have.

      Related Links:

      • How it Works: Wood Rot
      • In-Wood Rot Preventer
      • The No-Mold Finished Basement

      Question 2: What’s the best plan to stop window condensation?

      Ben writes on GBA (Condensation issues in house):

      Hi All,

      I am looking for some advice for a condensation problem I have in my house. The house is ’90s construction in Northern California, located about 10 miles from the coast. I have lots of condensation on some of the older (original dual-pane) windows on the west and north sides of the house during the winter months. If I don’t mop it up every day, it pools and has caused some surface mold. I originally thought it was just the windows that were old and needed replacing. However, I looked at the problem in some more detail. Relative humidity is between 45% and 65+% through the year; I think being close to the coast and having misty mornings is contributing. I purchased a standalone 50-pint dehumidifier that runs 24 hours a day and has 100% stopped the condensation and brought the RH down. There are close-fitting honeycomb shades on all of the windows, which has not helped the condensation issue. The crawlspace does not have a vapor barrier, but luckily the house is on the top of a hill so water drains away very well. Originally, I was going to replace 5+ windows, but now I thinking there is a better plan:

      • Windows: Don’t replace now
      • Crawlspace: Install vapor barrier
      • Install a whole-house dehumidifier

      I welcome any thoughts on this. I have not had to deal with condensation before.

      Thanks Ben

      Related Links:

      • Why are my windows wet?
      • Dealing with fogged windows
      • GBA.com: Indoor Relative Humidity and Window Condensation
      • Do I need a Vapor Retarder?
      • Dedicated Dehumidification

      Question 3: Are there rules for locating HVAC registers?

      Tricia writes: Hey podcast,

      First, thanks for putting together such an informative show. I’ve learned so much from the podcast. One valuable tip I have learned from the show is to call the support line to ask questions. I recently finished renovating a bathroom. I wasn’t sure how to handle the new shower connection to the old cast-iron drain line. So, I called the Schluter support line, and the very kind customer service rep helped me find an even better solution.

      Second, my question. The air handler and furnace are in the attic of my 75-year-old house in Savannah, Georgia, with a hot and humid climate zone. The ducts to the bedrooms have a short run to registers at the top of the bedroom walls. The ducts to the living room, kitchen, and dining room run down to the crawlspace then out to the rooms with registers on the floors. I had the attic spray-foamed two years ago so the air handler and attic ducts would be in conditioned space, which has helped a lot, especially in the summer. In the winter, the bedrooms get very warm, but the living room, dining room, and kitchen are almost 10 degrees cooler thanks to the long duct run through the unconditioned crawlspace. I’m thinking of running new ducts to the living room, dining room, and kitchen through the attic. These ducts would be in conditioned space and have shorter lengths, and, I expect, less of a temperature loss from the bedrooms. My question is about the registers. Is there any reason I should not put the registers in the ceiling or high up on the walls other than aesthetics? It would also be nice to put furniture anywhere without blocking a vent and to never fish another Lego or kids toy out of a floor duct, but there could be a building science factor to consider on unintended consequence to avoid.

      Thanks for any advice.

      Tricia

      Related Links:

      • 8 Strategies for Effective Ductwork
      • Building Codes for Insulation and HVAC in Attics
      • Ducting HRVs and ERVs

      Question 4: Does a heat-pump water heater retrofit make sense for Chicago?

      Zeo Geo writes on GBA (Heat pump water heater in a Chicago townhome):

      We live in Chicago in a four-story townhome. Our top floor is a small bedroom that has a louvered-door utility closet with a gas furnace and gas water heater.

      The gas water heater is showing its age and probably needs to be replaced soon. I’d like to put in a heat-pump water heater instead of replacing it with another gas heater. I had one company come out to give a quote, and the estimator basically told me a heat-pump water heater doesn’t make sense in Chicago, full stop.

      Everything I’ve read about heat-pump water heaters says you should put them in a room with excess heat. Our top floor definitely fits that description due to stack effect, especially in the summer. That location actually seems to me like an ideal place for a heat-pump water heater. I would love to hear your opinions on whether I’m thinking about this the right way.

      Oh, and one more thing: If a heat-pump water heater does makes sense, should we vent it to the outside? I’m thinking we shouldn’t, since we’d likely have to change damper configurations with the seasons (which I very well may forget to do), and I’d like to avoid as many wall penetrations as possible.

      Looking forward to hearing your thoughts!

      Related Links:

      • Furnace to Heat Pump Retrofit
      • Air-to-Water Heat Pump Retrofit
      • Heat Pumps and Cold-Climate Applications: Designing for Comfort and Resiliency

      This episode of The Fine Homebuilding Podcast is brought to you by TiteGrab Plus Construction Adhesive

      Titebond

      You may know them for their wood glues, but did you know Titebond also has a complete selection of construction adhesives? Designed for a variety of applications, Titebond’s adhesives make any building or home improvement project a breeze with their high-performing and durable formulas. These adhesives are trusted by the professional, providing squeak free subfloor installations, long lasting retaining walls and even fastener free feature walls.

      Check out Titebond’s construction adhesives at Titebond.com, including their newest award-winning adhesive—TiteGrab Plus!


      Check out one of our latest Project Guides: Energy Retrofit!

       

      NEW! FHB Project Guides

       

      Check out our FHB Houses:

      FHB Houses 2023

      Visit the Taunton Store  •  Magazine Index  •  Online Archive   •  Our First Issues   •  All Access

       

      Fine Homebuilding All Access

      FHB Podcast sticker

      If you have any questions you would like us to dig into for a future show, shoot an email our way: [email protected].
      If we use your question we’ll send you a FHB Podcast sticker!


      FHB Podcast T-shirts!

      Represent your favorite podcast! Available in several styles and colors. Made from 100% cotton. Find the Podcast t-shirt and more cool products in the Fine Homebuilding Store.

      Podcast t-shirt and more cool products


      Fine Homebuilding podcast listeners can now get 20% off anything in the Taunton store, including Pretty Good House.

      Use the discount code FHBPODCAST to take advantage of this special offer.

      Pretty Good House “Finally, knowledgeable people talking about building reasonably-sized, high-performance houses for normal people with real budgets!”
      — DanD, VA, 8/19/22, Amazon.com review

       


       

      We hope you will take advantage of a great offer for our podcast listeners: A special 20% off the discounted rate to subscribe to the Fine Homebuilding print magazine. That link goes to finehomebuilding.com/podoffer.

      The show is driven by our listeners, so please subscribe and rate us on iTunes or Google Play, and if you have any questions you would like us to dig into for a future show, shoot an email our way: [email protected]. Also, be sure to follow Fine Homebuilding on Instagram, and “like” us on Facebook. Note that you can watch the show above, or on YouTube at the Fine Homebuilding YouTube Channel.

      The Fine Homebuilding Podcast embodies Fine Homebuilding magazine’s commitment to the preservation of craftsmanship and the advancement of home performance in residential construction. The show is an informal but vigorous conversation about the techniques and principles that allow listeners to master their design and building challenges.

      Other related links

        • All FHB podcast show notes: FineHomebuilding.com/podcast.
        • #KeepCraftAlive T-shirts and hats support scholarships for building trades students. So order some gear at KeepCraftAlive.org.
        • The direct link to the online store is here.

       

      Sign up to get the Fine Homebuilding Podcast newsletter and special offers delivered to 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
      ×

      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

      New Feature

      Fine Homebuilding Forums

      Ask questions, offer advice, and share your work

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

      Log in or create an account to post a comment.

      Sign up Log in

      Become a member and get full access to FineHomebuilding.com

      More The Fine Homebuilding Podcast

      View All
      • Podcast Episode 694: Bath Fans, Too Many Minisplits, and Second-Story Additions
      • FHB Podcast Segment: Can You Have Too Many Minisplits?
      • Podcast Episode 693: Old-House Hazards, Building Larsen Trusses, AI in Construction
      • FHB Podcast Segment: Finding Hazardous Materials in a Fixer-Upper
      View All

      Up Next

      Video Shorts

      Featured Story

      Two Ways to Test Windows

      New devices showcased at the Builders' Show make it easy to measure glass performance, u-factor, SHGC, window thickness, and more.

      Featured Video

      A Modern California Home Wrapped in Rockwool Insulation for Energy Efficiency and Fire Resistance

      The designer and builder of the 2018 Fine Homebuilding House detail why they chose mineral-wool batts and high-density boards for all of their insulation needs.

      Related Stories

      • Get a Grip
      • Two Ways to Test Windows
      • Seating and Storage for Any Space
      • Clear the Air

      Discussion Forum

      Recent Posts and Replies

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

      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

      Video

      View All Videos
      • FHB Podcast Segment: A Homemade Radiant Heat Floor Assembly
      • FHB Podcast Segment: Drywall-Free Half Wall Finish
      • FHB Podcast Segment: Old Home Insulation Troubles - How to Find the Right Contractor
      • FHB Podcast Segment: XPS Insulation on Basement Walls
      View All

      Water Heaters

      View All Water Heaters Articles
      • One-System Wonder
      • FAQs on HPWHs
      • High-Demand Heat-Pump Water Heater
      View All Water Heaters Articles

      Fine Homebuilding Magazine

      • Issue 333 - August/September 2025
        • A Practical Perfect Wall
        • Landscape Lighting Essentials
        • Repairing a Modern Window Sash
      • 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

      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