Assume that we are building “tight”.
How/where/when does fresh air enter YOUR home and how/where/when is it exhausted?
How do YOU regulate it?
I have found some examples(ERV’s, fan-cyclers, etc) on a BSC (Lstiburek) site, an article in FHB and I think ShelterNerd has a nice strategy. I would like to hear strategies from others.
If we over-ventilate we are wasting energy. If we under-ventilate we get sick.
Replies
.5 ACH, 20k cu ft: filter, dehumidifier (seasonal use), exchanger, duct everywhere (including closets). Different sized fans in the exchanger ensure that leaks go out.
Excellent air, minimal cost. Guests often notice. Breathing's pretty basic. Radon issues, non-existent. Only problem: putting up with the air elsewhere.
PAHS Designer/Builder- Bury it!
VaTom,
Where is the intake, the exhust and how do you regulate?
How do different size fans make sure leaks go out?
Where? Outside wall. The dehumidifier lives out there too, on a covered shelf. A little sheet metal allowed me to bring the dehumidified output inside, leaving most of the compressor heat outside. Filter lives on the input to the dehumidifier. Clean incoming air means the coils stay clean.
We constantly monitor indoor rh, switch on the dehumidifier when needed (wall switch inside). Here, everybody needs dehumidification. Most get it with ac, which we don't need. I spend $50-100 on a dehumidifier (50 pint), keep a spare on hand.
Regulate? I just let the fans run. Non-stop ventilation, though I could switch or time them if I chose. Penalty for over-ventilating isn't an issue here. DIY exchanger turned out to be upwards of 90% efficient. Plan published by Pop Science if you're interested.
With the larger fan bringing in outside air, the house is slightly pressurized. Leaks go out. Noticeable when we open our large doors (48"x88"). Was not suggested by the Pop Science article, read about it elsewhere and it made sense.
My advice, for those planning, is to forgo operable windows (except for egress) and use the savings on a tiny (<200 cfm for us) air system. Better air, costs less. PAHS Designer/Builder- Bury it!
Va Tom,
Your house concept(from the link in your profile) is very fascinating.
Do you have any intentional exhaust openings/flaps or just go with what you got?
Did you make a an effort to build tight? Is the dehumidifier noisy? What brand?
Why have a backup? are they unreliable?
It's a bent box. Original plan was to be a future furniture shop. Replacement house is started, very similar but with features this one lacks.
Like a utility room, so I won't have to listen to the exchanger fans. Sounds like a refrigerator running, nonstop. I'd also like to have easier access for the (infrequent) fan replacement. Currently listening to the heat pump water heater, housed in the bathroom near the tank heater. The HPWH provides better than 50% of our required dehumidification, as a free byproduct.
Openings/flaps? I've got a pair of wall penetrations, 15' apart. Dehumidifier sits just outside the inlet. Outlet has an elbow pointed down, usually a bird's nest on top. As there's always air moving through, just open ducts. Inlet filtered, exhaust has a bug screen.
I'm cheap, built on a very short shoestring. Didn't consider anything but cast-in-place concrete. Tight by it's nature. Windows are almost all fixed, gasketed by Danish EPDM from Resource Conservation Technology. Best seals I've found, and inexpensive. Doors also got seals from there, silicone tubes. You saw the doors, not exactly homecenter pre-hungs. If you're putting in an air system, might as well help it do its job.
"Whole house" dehumidifiers are available for $1200 and up. I've been buying used portables, mostly from Sears. The fan's the weak point. For 50 bucks I've gotten good service, same rating as the expensive ones, lasted the last 4 heavy-use summers.
The cheaper ones aren't quiet, don't know about the $$$$.
We're very rural so I notice noise more than if we were urban/suburban. Much rather listen to the forest critters. With a passively heated/cooled house, active systems go against my grain. Unfortunately I've yet to find a satisfactory passive dehumidification and ventilation system for this climate.
I'm partial to having spare parts on hand for the active systems. When I can stock a spare dehumidifier for 50 bucks, that's preferable to having to drive to town to Sears for a new one, if they had one in stock. I also keep a spare pair of exchanger fans to avoid shutting down the system until UPS brings me a new fan. $20 investment for peace of mind.
Well pump too. We've got a small bore, standard submersible doesn't fit. Couple of years ago I realized we'd gotten 15 yrs out of the pump. Got an incredible price quoted for stainless and ordered 2. 1 will go into the next well, 1 for a spare.
Surely north Texas isn't much different. Just gotta decide how you want to live. PAHS Designer/Builder- Bury it!
Tom, where on the well pumps?
I have a 3" Grundfos, thinking a spare at the right price would be a better investment than the "Gotta have it today after it fails"
Haven't found any fantastic deals on the net, they all seem about the same or close.
Joe H
You actually read all that? LOL
Same pump. Why do you need a skinny?
My well bore's 4", which works with a standard 3 7/8" pump until the bore gets the least bit crooked. Far as I know only Grundfos has a 3" pump (2 3/4" if memory serves). At least they seem to be excellent quality. I've run a lot of grit through mine.
Anyhow, Grundfos no longer manufactures the non-stainless 3" I've got in my well. Makes replacement pricey. My preferred driller supply dropped Grundfos so I called to ask who else had the line. Turned out a local plumbing supplier had just picked it up. Why they quoted me half what I'd seen on ebay, I have no idea, other than I bought the first 2 pumps they'd sold. My high head model isn't something they intended to stock.
Got a model #? I can call them tomorrow, probably get it drop-shipped to you if the price is still exceptional. Little worse than putting up with whatever you can find for whatever price, just 'cause you've got a system down. Uh, you do know the warranty's apt to expire before you install it? I buy hardware, not warranties.
PAHS Designer/Builder- Bury it!
Edited 8/5/2007 11:50 am ET by VaTom
Tom, I have a 15SQ/SQE10C-250. 230V 1 1/4" outlet.
I think I could get away with a larger diameter pump, well is a 6" case but that's what the driller was pushing when he did my well.
We irrigate a lot of trees + Rubys' garden so it gets a good workout. A spare would leave me to figure out how to build an A frame and get it out. It is on PVC pipe with joints, not a single length of poly so I'll have to pull it & take the sections apart as it comes out. There's no cable either, just the pipe so it's going to be harder than it should be to pull.
It's not going back together that way, I'll hang it on a cable & replace the pipe too I'm thinking. For easy replacement for the next guy?
Uh, you do know the warranty's apt to expire before you install it?
No problem, I've got a lot of expired warranty stuff in stock too. Better old stock on hand than having to pay the local Banditos prices.
Joe H
I'll call tomorrow and let you know. 6" casing is standard here. My small rig only can handle a 4" hammer.
I'm sure you have an extension ladder. Last pull I did, on Easter Sunday for a friend, that's what we used. Split the halves and tied the top together. That well had old steel pipe that had to be clamped and unscrewed every 20', for 360'. Used a lever-handled chain hoist for the lift (pulling on a nylon sling), were pleasantly surprised when we actually got the dead pump out. Often something breaks and down it goes. Poor sap had 2 commercial greenhouses to keep alive and an Ohio funeral to attend that Tues. Talk about bad timing. He'd been turned down by every well service when he called me, in tears. Told him he should have called me first.
Jointed PVC is a new one on me, but I'm not very experienced. You know what you want to put back in there. Make sure you have help. I like to bleach the well after I go in.PAHS Designer/Builder- Bury it!
Don't know what that pump is, but they thought it an odd one. Not in their system. Anyhow, available (from Grundfos) for $670.80 plus freight. Drop ship, no problem. Guy thought it was a lot of money, but the best they could/would do.
Probably, I'd be looking for a different pump. You don't have much of any head I don't guess, big volume? For my edification, is that price about the going rate? About what I paid for 2.
Turns out they'd been dealing with Grundfos circulators forever, just new to well pumps when I bought my pair. PAHS Designer/Builder- Bury it!
Tom, Grundfos are expensive. Also damned hard to find any prices for them on line. It was about $500 7 years ago.
Head is 260' at well, + uphill to house. I think that pump is rated up to 20GPM depending on install depth. I have another 100' of hole if the water table drops.
Probably changing brands is a better answer than $700 for another of these unless one comes by at a good price. Ebay occasionally has the same or similar pump.
Thanks for checking, Joe H
Tom, Thanks for the details. You really have a great philosophy. Simple,Simple,Simple.
Unfortunately, we can not all live on an acre plus or we will run out of land.
How would you construct a house if you were limited to living in the city? With a meager size lot and traditional type deed restrictions and politics? Would you build ICF or SIP like Frenchy? What can the rest of us do? What strategies can we employ?
LMAO... yeah, I'd have trouble with an acre. Couldn't turn my truck around on it. And I've got 2 of those 10 wheeled things. You know, one's a spare...
Now tell that "simple, simple, simple" to my wife- who lives in mortal fear I'll predecease her and she'll get stuck with all my stuff. I keep telling her to keep in touch with JoeH. He likes old junk. That'd make his DW real pleased...
Slightly more seriously, the best thing I ever did was leave Denver. There really is still a lot of "country" out there. Real pricey around here now, but not everywhere.
However, somebody's gotta live in cities so... I saw an undergound house in Saginaw, Mich. Flat-as-a-pancake land where they'd imported enough dirt to bury a house. Nobody home when I was there, but I'm pretty sure it wasn't PAHS. Just the best performer in the neighborhood.
We had a 1911 (structural brick) commercial building in Denver, pretty much no way to make it very efficient. Take something designed for cheap heat and you've got a problem when that runs out. Malcolm Wells made good use out of infill lots, particularly ones that weren't attractive for conventional housing. Noise issues for instance? Good time for underground.
We have set-back and zoning requirements out here, just not as tight as in a city. When I first applied for an underground house permit I had to jump through hoops. Now the building dept mostly yawns and stamps the plan. Even when they change plan approvers. Follow the zoning, give 'em the engineering, everybody's happy. Except for the inspectors, who generally have no clue. But that's not bad.
I'm not a SIP fan, except for overhead, where underground is far better. Even frenchy generally suggests concrete for walls. ICFs are less efficient than a concrete wall with insulation only on the outside. This was long ago been hashed out here. I suggest ICFs only to those unwilling to do traditional concrete forming, then it's the next best thing.
You have infill lots or is demolition required? Either way, it's a financial question. Would your zoning dept allow you to pile dirt on the set-back? If so, you could build the same size house as conventional on a tiny lot. Other issues such as depth of drains could get interesting, but without specifics not worth contemplating. Basements are all but unknown there? Your profile doesn't say which city. Tornados?
Take a look at annualized geo solar (AGS). Details are lacking, at least to those who haven't employed the originator. Similar to PAHS (which Don incorrectly disparages) but it's a high temp dirt (usually) heat storage. Higher temps allow you to store the same btus in a smaller package. Watch out, as Don has no interest in planning for differing climates, particularly hot summers. When I climate-adjusted his shining example, my not-stellar PAHS out-performed his AGS. But both would be extremely comfortable.
I did a lot of reading and dreaming while I awaited a sale in our crummy Denver neighborhood (now gentrified). Let your mind roam around every possibility you can find. When something strikes a chord, you'll hear it. You've seen what affected me. Nothing here I invented. PAHS Designer/Builder- Bury it!