I’ve been working on an old house in the Adirondacks (my own). Outside is done, new Marvin windows, doors. clapboards ,roof etc. Inside is getting close… Its 1400 sq. ft., two stories. Upstairs, I had someone spray urethane insulation into Cathedral ceilings and knee walls, downstairs I added a second wall inside existing aged framing so I now have fiberglass in 8″ of wall with 6 mil plastic. Downstairs is now rocked. Place seems to be pretty tight , stayed warm (above freezing)all winter with just a small electric heater on low during the week when we were gone. There were some moisture issues (condensation), I believe that the basement/crawl space floor being bedrock contributed as did the new floor/wall framing. I’m addressing that by placing plastic down and running a dehumidifier.
Now for the question…….. I’m thinking that I’ll need a ventilation system. I had thought about just relying on the bathroom fans as the house is basically two rooms and a bath on each floor. Seems that I could put them on timers to do the job. What I can’t figure out is how to provide the makeup air. Do I have to do a blower door? Don’t know who does that around there. I guess an HRV would be most desireable, but I don’t know if I need one. Also, would like to do this myself if possible. I imagine a fresh air port that would work under the negative pressure that the fans would provide when active. Ideally, this would help the crawlspace moisture as well. I’m a cabinet guy by trade and this is one of my shortcomings………any help.
by the way…I’m a longtime lurker and want to thank you all for the immense help you have provided me along the way.
Thanks
Replies
The last issue of FHB has a great article on tight homes and venting.
Frost, there is plenty of info. here in the archives as well.
Thanks guys,
I have tried the advanced search function here and found stuff from long ago, nothing real pertinent. Am I doing something wrong when searching?? Actually felt I was not searching the right way. Will seek out the FHB issue.
thanks again
Hi frost,
Here's one thread on the subject: 68805.1
If you decide you want a system to pre-condition incoming air, I followed an old Popular Science article about building one. Changed it a little when I built mine, but it works great. I pressurize our place.
Your bath exhausts will work fine, but won't do anything except increase leaks for makeup air. My makeup air is filtered and conditioned, much more comfortable. Ductwork is generally the biggest problem.PAHS Designer/Builder- Bury it!
Thanks Tom and Dave,
I investigated the Lifebreath system last summer. The Co. provides dealers names and I called them all within northern N.Y. and not one returned my calls or e-mails. Even hunted one down and dropped off plans and called him for a few months untill I just gave up. Really this is the reason I'm looking for simple ways out, this is an area where its hard to get someone to do things or return calls. Decided to go with radiant heat as I could do it myself, still left with ventilation issues though.
I have thought about a few of those Fresh Air 80's. I know they are basically holes in the wall of a well insulated home, no contradiction there huh.... But in a small home with just 2 adults and with radiant heat , Iwonder if they would be just as cost effective as a full blown system. We already sleep with windows open from March to November. Or should I just accept the fact that I need an HRV and get on with it.
thanks again
Unless your outside air is what you want inside, you want an exchanger. Here's the PS article in case you want to DIY. I used a sheet of corrugated aluminum roofing for my core.
PAHS Designer/Builder- Bury it!
Edit: Two is better than one? Don't know how that happened.
Edited 4/25/2006 8:22 pm ET by VaTom
Tom,
I guess that I have no issue with outside air becoming inside air, but then again I don't know much about this ....The outside air quality concerns (and the makeup air questions) are mostly about exhaust, i.e. clothes dryer, cook stove, on demand gas water heater for hot water and radiant, direct vent gas parlor stove for ambiance and supplemental heat. and bathroom fans. Again, I'm really just concerned with 4 months or so as we enjoy cool evenings and open the bedroom windows the rest of the year. I know that a window needs to be cracked when the dryer is on and when the cookstove fan is activated. The house has lots of solar gain and the air in the adirondacks is cool and dry during the winter. Are those fresh air ports worthwhile? Do they really work according to pressure and demand or are they just holes in the wall that cost in the end? I'm wondering if radiant systems and their conductive nature would make it better (ok)to use these fresh air ports in conjunction with bath fans as opposed to a hot air system where most of the heat would dissipate. OR....... am I just being a real idiot who should just suck it up and do the proper ventilation thing? Again, I'm a cabinet guy by trade and I just venture into other trades by necessity.
OR....... am I just being a real idiot who should just suck it up and do the proper ventilation thing? Again, I'm a cabinet guy by trade and I just venture into other trades by necessity.
Frost, I hope you've seen what "experienced" posted in the other ventilation thread. I've no claim to substantial experience and simply followed what Canadian code was (at the time) for air changes. What we have is indoor air that is often noticed (and admired) by guests.
My vocation is furniture building, not contracting- certainly not HVAC. What I've learned is what I needed to know to make a house for me and mine. We're also in a moderate risk radon area. You might (should) be reading the current radon thread if it's relative to your area. My general assumption is that more fresh air is better. Unfortunately, our outside air is often too cold or too hot or too allergen-filled for our comfort. We filter and condition our incoming air.
Didn't strike me as much of a deal to install a ventilation system in our 20k cu ft. Had no idea how well it would work, but ventilation systems are all but unheard of here, even now. Had to be better than nothing, was my assumption. Turned out to work extremely well.
Breathing's pretty basic. I want the best air I can get, so long as the cost isn't prohibitive. Our house had easy access for ducts, so I ran them everywhere, including closets. My system's total material outlay was less than a normal HRV unit, inexpensive. Due to our house design (requiring neither heat nor ac), the heat penalty of ventilation is negligible.
Only you can decide how far you should go. For us, I traded operable windows for an air system. Saved thousands with our 400 sq ft of glass. Have a replacement house out of the ground. Guess what? Same design, ventilation included. PAHS Designer/Builder- Bury it!
Our timber-framer / builder had a HRV installed since the house is so "tight" with SIPs on most exterior walls and roofing. We've been very happy with the Lifebreath model he installed. It has options for running periodically (i.e. x minutes / hour)and variable speed. The hardest part for him was running the ducts and balancing the suystem when first installed. He used 6" Sch 40 PVC in the house and insulated, specialized flexible ducts for the intake and exhaust air. The unit "back-vents" in the winter to prevent frost build-up.
If you're sitting on intact ledge, maybe you should grout/waterstop the foundation perimeter? Be advised that it does NOT exchange any cellar air though. We run a dehumidifier down in the cellar. The product website is:
http://www.lifebreath.com/
Have you done a tightness test? From there you will know if your house is so leaky that it already changes air rapidly, or is drum tight and needs an active air exchange system. Before that it's just guess work, and finger crossing.
Good luck, Glen in Canada
No, I haven't done a tightness test. I'm fairly sure that the home would qualify as "tight" though. I've worked on homes in Vermont, my home state, that were 5 star rated that did not feel as stale (air wise) during construction, pre HRV stage. Again, the whole second floor is foamed and the ground floor is R23 or better, albeit fiberglass with two 2x4 walls staggered. I tried hard to air seal before insulating down, lots of minimal expanding foam etc.
I really want to thank you all for your responses. None of you has advocated for fresh air ports, so I'm forgetting about those although I'm still curious. I've always known that an HRV was my best option. I was just getting a little tired of learning new trades and doing what I want to hire out, just can't find someone to do it. I'm ready to put down wood floors, trim windows, make cabinets and built ins and do the stuff I'm best at. Guess that will wait untill I've piped and installed the HRV. It will be over before I know it and I'll wonder why I ever fussed about it.
Thanks again, I feel that I know some of you now and will not be so shy about chiming in from time to time.
It will be over before I know it and I'll wonder why I ever fussed about it.
There you go... The first step's always the hardest. Afterwards, you just enjoy. Make sure you place the unit where you can get to it for fan replacement. Don't ask...PAHS Designer/Builder- Bury it!