If you have any questions you want answered, feel free to drop me a note. If you’ve got a question, chances are, there are lots of others out there with the same question. So ask away!
Note: all comments are moderated unless I’ve approved one of your previous comments. Almost everybody gets thrown off by this, but I moderate comments to avoid spammers. The downside of this is that you won’t see your comments post until I’ve had a chance to review and approve them. Sometimes this can take days (sorry!) Thanks for your patience.
Ted's Energy Tips 
Ted…. I’d appreciate any leads you can provide to deal with the air leakage, ventilation (if necessary) and possibly insulation. I live in Malvern. Thank you!
Ted, I’ve got serious condensation in my attic despite a humidistat/thermostat-controlled exhaust fan and gable vents. The cause might be air leakage through 15 hi-hats and other sources. I’m looking for knowledgeable contractors who can deal with this problem and would appreciate your suggestions.
Thanks very much.
Bill
Hey Bill,
You probably nailed it – those 15 high-hats are like open windows as far as moisture is concerned. If you’ve got insulation near them, and it appears discolored, then air has been moving through them.
There’s a good chance that it’s going through any access hatch/pull-down ladder as well.
I see you’re in the area – what town are you in? I might have a couple people who I could refer you to. You can email me directly: ted at soleburymountain . com
Sounds logical to me! Thanks, Ted!
Ted,
I’m building a log home and want to plan a good roof. I would love exposed rafters on a cathedral ceiling, so a “built up” roof seems the way to go. How would you go about doing this if spray foam is too costly? Here’s my thought: rafters on a ridge pole, then I want to do plywood ceilings, so I would put 3/4″ plywood on the rafters. I would then spray foam fill everywhere plywood sheets meet. Then I would toenail 2×12’s ontop of the plywood. Use visqueen in all of the gaps I’ve created with the 2×12’s. Then fill the cavity with cellulose, but leave 1.5 inches for venting. build soffets on the overhang and install a ridge vent. This is in a high country arid climate, but it does rain and snow. Thanks!
Sounds like you’ve been doing your homework!
I’m not visualizing your proposed solution very well.
How about using one of the sheet-foam products like polyiso or blue-board? Use that for a couple layers, staggering the seams 50% between layers and taping seams. That can work really well to prevent air movement. Then you could use the cellulose for the rest of the cavity, with the air gap, giving you reasonably priced, high-R-value structure.
If you haven’t read through the roof material on the Building Science website, take a look there.They’ve got designs for a variety of climate zones and construction techniques.
Hi Ted, I just found your blog and I’m really impressed with all the information. We are building a 2700 s/f house in Massachusetts and are now in the process of getting quotes from insulation contractors. We were planning to go with the “flash and batt” method with an inch of spray foam topped by fiberglass batts. So far, one estimator has said that’s “a fine method” and another says it’s not recommended in the northeast because over time, temperature fluctuations could lead to cracks in the relatively small thickness of foam. What do you think? We are using 2 x 6 construction.
Hi Barbara,
Thanks for writing. Hope I can be of help. My folks live in MA (in Falmouth/Woods Hole) and I spent quite a few years there myself. Beautiful area of the world…
On to your question – Flash & Batt: Even worse than cracks, if done improperly, it can lead to severe moisture/mold/rot issues. Here’s why – typically it’s done by spraying that thin layer of foam on the outer wall sheathing from the inside of the house, then packing the rest with inexpensive insulation. The best analogy I can make is imagine wearing a sweater with a rubber raincoat over it.
To continue the analogy, when you sweat, what happens? That moisture goes right through the sweater then comes to the rubber barrier. Before you know it, you’re dripping wet! This exact same thing happens with flash and batt. The fiberglass allows the moisture to flow through and the foam traps it.
Having said that, you can do flash and batt correctly in cold climates like MA. If the foam is sprayed to the back of the sheetrock and the fiberglass is packed outside the foam. Then what happens is the moisture from inside the house stops at the foam and never gets into the cold cavity of the walls or ceilings. Here the sweater and rain slicker analogy doesn’t work because the physics are different.
However, almost nobody does flash and batt like this because it means you have to install the sheetrock before the outer walls and roof sheathing.
Another way you can do F&B correctly is to use thicker foam on the outer walls. In your climate, you typically need at a minimum of 2″ (and likely more) foam if you’re going to use fiberglass with the foam. I’d have to go into the physics of dew points and moisture to fully explain this, but it’s well documented. The research of the best building scientists in North America supports this.
If I were you, rather than using 1″ of foam and the rest fiberglass, I’d go with 3+” of foam and forget the fiberglass. High density spray foam gives you R6.5 to R7 per inch, so with around 3″, you hit the requirements for building code and you don’t have to worry about condensation, mold and moisture like you would with F&B. And of course, the thicker foam the better, but you’re trying to get the best bang for your buck, so there’s going to be an optimal thickness for you based on what is cost effective vs. the R-value.
I am the author of the McGraw-Hill textbook “Retrofitting for Energy Conservation.” I have a free energy audit spreadsheet on my website at http://whclark.com as well as excerpts from the book. The book is now out of print, but McGraw-Hill has now transferred the copyright back to me. You can now order the book in a handy spiral bound form for a fraction of the original cost.
Thanks,
Bill Clark
Hi Bill,
Thanks for the contribution! I’ll check it out and hope it proves to be a valuable resource for my readers.
Cheers!
thanks for your quick reply and advice !
hi Ted – i’ve read your comments regarding the Energy Kinetics system 2000 and i’m wondering if you might offer me some advice – i live in northern NJ in a 2700′ sq house that i bought in 2007 – the house has EK 2000 system with water tank (previous owner installed). I want to convert the house to natural gas from oil and have been told that i can convert the burner to a gas burner (without replacing the EK 2000 system which has been good to me)- i’ve also read that EK 2000 is really meant “for oil” – but in my situation since i already have the system in my house i want to avoid scrapping it and buying an entire new gas boiler. How easy is the conversion and how do i find a compnay with experience doing it ? all the EK 2000 dealers seem to be oil companies around NJ. How long is the job to convert and what would you estimate the cost for conversion parts? If you were in my situation would use also go for the conversion vs. an entire new system? is it ‘really true’ that the EK 2000 works just as well with NG compared to oil ? thanks in advance for you help !
Mike,
First, I’ll give you a disclaimer – I’m not an HVAC tech/installer, so I can’t give you any real-life numbers or comments based on experience with this type of conversion.
As I understand it, you should just be able to replace the burner with a natural gas burner that has been designed for oil to gas conversions. These type of conversion products, which should cost a few hundred dollars, should work fine because their designed for the purpose, and the flame they produce should be cleaner and less corrosive than an oil flame (which can produce sulfuric acid). So in theory, you shouldn’t have any problems.
Here’s a link to one such device: http://www.waynecombustion.com/news.aspx/oil-to-gas-conversion-burners
I suggest you call EK since they’re based in NJ. They should be able to give you a lead on someone in your area to do the conversion. However, if they don’t know, any competent gas HVAC tech should be able to swap out burners for you since they design these things to be “plug and play”
As for your other questions – I would absolutely go this route if I had NG in my area. The EK2000 is a fine unit, so I’d keep using it as long as possible.
Good luck! Let me know how it works out for you.
Hi Tted,
How noisy are the Fujitsu heat pumps? Are they like a hotel unit?
Thanks,
Bob
Mpls
Bob – they’re much better than most hotel units which I find to be very noisy. However, if you turn them on “high”, they’re moving a lot of air, so they definitely make a fair amount of fan noise. If you run it on any of the lower speeds (quiet, low, medium), they are very quiet indeed.
Cheers,
-Ted
ok, thanks again!
Mia
Thanks Ted, we’ll try those suggestions. Any suggestions for insulating materials for that problem area roof to prevent heat loss, assuming we are up to re-roofing? We did have someone come in with an IR camera a while back that said we were losing heat through the ceiling, but don’t know if it’s enough loss to warrant investing in ripping off shingles and insulating $$!
– Mia
It’s difficult to comment on insulation without knowing the ceiling construction. You noted that it’s tongue and groove. Is there anything above that or are the boards just nailed to the rafters? That would be the typical (incorrect) construction method. If you’re lucky, then they attached sheet rock to the rafters first, which acts as a good air barrier. So my answer will vary considerably depending upon that.
The big problem is, if they just attached the tongue & groove ceiling to the rafters, you can’t really properly insulate above it without ripping off the roof sheathing as well as shingles, and you really don’t want to go through that unless absolutely necessary!
If you don’t have moisture problems (other than the existing leak) then I wouldn’t mess with the roof insulation. But if there are signs that the roof sheathing has been moisture damaged and they are going to rip off the roof, then you have a once-in-a-lifetime opportunity to redo the roof “correctly.”
In the case that all the roof is going to be replaced, the best solution is to coordinate a spray foam insulator to come in right after the roofers rip off the sheathing. They can then spray the foam right in to the back side of the tongue and groove ceiling material. This will air and moisture seal it better than anything else. To keep costs down, you could do an inch of closed-cell foam and then have the rest of the space filled with damp applied cellulose, leaving 1″ of air space between the top of the cellulose and the roof sheathing. This is a ventilation channel allowing air to rise up through the soffit, go up the channels and out the ridge vent.
If you go this route, check out the excellent Cor-a-vent product for soffit and ridge venting. It’s the best I’ve seen (used it on my own house).
-Ted
Hi Ted,
We have an expanded log cabin in Northern New Jersey with too many addition mistakes to mention, but we have an urgent one right now that I’d appreciate any input on:
We had our vaulted/cathedral tongue and groove original (about 60 years old) pine ceiling (which used to be “A” frame but we made a loft above, so now only half an A frame) re-roofed about 4 years ago. Unfortunately was not advised on insulation, (we had no GC for this addition, just a “project mgr” who wasn’t very knowledgeable in construction, as it turns out. Anyway, we know we are losing some heat out of there and now we have a leak but can’t pin point it. We were thinking of insulating on the inside with foam then sheetrock. We haven’t done anything because we didn’t know what to do about moisture issues, vapor barrier, etc., and it’s a good thing we didn’t because now we have a leak! We also have two skylights fit within log beams in that area that we put in 10 years ago. So, we don’t know how to go about re-roofing this area as far as insulation and correct roof system for this type of vaulted wood ceiling with skylights. We are getting ice cicles in that roof area but not sure if due to heat factor or need wider gutter due to pitch, etc. We believe the last roofer put a layer of ice shield, but who knows.
On another note, we have to replace our gas water heater soon which is in a low ceiling basement. Current water heater is 50 gallon and it really doesn’t have enough ventilation area due to low clearance, so we’ve been told. We have 2 CO readers and haven’t had a problem in 10 years here. We run out of water if two people take a shower at same time. Seems by looking online, that the lower profile tanks only come in electric or are only up to 40 gallons and since we are already running out of hot water at 50 gal, I’d hate to go to 40!. So we don’t know whether to try a tankless or what. Also we have hot water lobster in upstairs bathroom because takes for ever to get water warm up there (probably bad insulation below!) The lobster definitely helps but isn’t really compatible with tankless.
Any recommendations there?? I could go on and on, but will stop with those two pressing issues!
Thanks,
Mia
Hi Mia, Thanks for visiting. Sounds like some real issues going on there!
Leaks can be tricky to find because sometimes water will behave “strangely.” However, most of the time, it’s fairly predictable when there’s a large enough quantity that gravity is the main force on it. In general, it will run down hill, with a little side-to-side movement if it hits a barrier that redirects it. The tongue and groove ceiling, I’m assuming runs parallel with the roof’s width – i.e. not from ridge to soffit but from side-to-side. What can happen is that the water can run in the grooves and go sideways a bit. But, for the most, your water will leak into your house pretty much downhill from where the water leaks into the roof.
So the first question is – is the leak downhill from the skylights, maybe off to the side by a foot or two, but still pretty much downhill from the skylight?
If not, might the leak be somewhere downhill from a chimney?
Unless you have really bad shingles, the probability is vastly higher that the leak is occurring at the flashing for the skylight or chimney. With either of those, it should be relatively easy to fix for someone who knows what they’re doing.
So that should get you started troubleshooting the roof leak. You can also verify this problem using the high-tech testing called “the hose test.” Seriously, if you methodically spray the hose at your roof, you can pretty well pin down where the leak is. There’s definitely a technique to it, because it can take a real soaking and 5-10 minutes for the water to soak in and drip down to where it’s coming into the house. But the first thing I would do is a detailed visual inspection in the vicinity of the leak and up the slope, all the way to the peak.
Regarding your water heater – that lobster sounds interesting. I’ve never heard of it. But looking at the description, it’s probably doing the opposite of what they say. It’s not saving you energy because it’s constantly re-heating the water in the pipes every time they cool down. This is great for supplying instant hot water, but it’s bad for efficiency. The “chilli pepper” is a much better idea. You push a button and it circulates water in your pipes until it gets warm. So you still have to wait, but at least you’re not flushing tons of water down the drain. It’s the best compromise between a circulator and nothing.
With something like the Chili Pepper, you could use a tankless. Given your situation, that’s the route I’d go. You’ll just have to get a big capacity tankless system if you want to take two showers at once. Or, maybe consider using a lower flow shower head. You might have read my article on these…
Hope that helps. Post again with your leak troubleshooting findings.
-Ted
I should have been more clear- we’re running ductwork anyways, b/c getting enough cooling to all the rooms we need in our upstairs (6- 2 of which are rooms off of rooms off of the hallway) would require it anyways to work with our architecture and the minisplits. And we are also tired of the ups/downs of the oil market and trying to budget around that. If our boiler were newer, we would probably just do the minisplit upgrade for cooling but since it’s such a dinosaur (38 years old) we’re gonna scrap it.
Long term plan is to rip out the hydronic system as we renovate each room over the years.
Back to the geothermal: do you have a favorite brand and/or setup?
Thanks again,
Josh
Ah sorry. Well it was a useful discussion anyway!
For that, usually it turns out that your best luck is with the best installer in the area. Get someone really experienced who has done dozens or hundreds of installs and talk to references. Every Joe is jumping in the business because of the incentives so there are a lot of hacks out there.
Internally, most of the systems are very similar, so I wouldn’t worry about brand A vs. Brand B.
Hi Ted,
We got a quote for minisplits and then, in light of the age of our boiler and the price of oil as well as the tax credit that runs until 2016, we’re considering upgrading our hydronic system to geothermal heat pump instead of getting the minisplits and then later replacing our old boiler. Do you have any thoughts about this and/or a favorite brand?
Josh,
The geothermal incentives are indeed attractive. The trick is, they’re not very friendly with conventional hydronic systems, unless you just have radiant underfloor heating.
Here’s the problem – I should probably write an article about this because it’s a common question…
Conventional boilers run at very high temperatures. By default, most are set up to run at 180F. When you run water that hot through radiators and baseboard fin-tube convectors, they throw off a lot of heat!
Geothermals are very efficient at making hot water at temperatures up to about 120-130F. Some can push this a little, but in general, physics stands in the way, so you’re very unlikely to get a geothermal thats producing hot water much above 130F with any reasonable efficiency.
So you have two things working against you. First, if you try to generate water hot enough for the radiators or baseboard convectors, you lose the efficiency. Second, if you run at a lower temperature where the geothermal is still somewhat efficient, the radiators won’t throw off enough heat to keep you warm.
If you have proper underfloor radiant (by proper, I mean tubes embedded in concrete and a tile floor), you can run at much lower temperatures, like 90F. At that temperature, geothermal is very efficient. So if you have that type of radiant of this sort, you can get very good results.
Feel free to ask if you have more questions!
-Ted
sorry for the typo’s on the previous post. That’s supposed be “a small duct” and “upstairs in a loft…”
Thanks Ted
That’s been my experience also although the blowers seem to have the same consistent output. The outdoor unit slows WAY down! These are the same units as yours except meant be roof or ceiling mounts. We adapted them for our particular utilization. I’ll check and see if the blowers are on auto mode and if they slow as well but overall these things work like a champ! I think they even use less or equivalent energy of an attic fan. Thanks again JIm
Interesting. My indoor unit has a number of setting – auto, low, medium, high, quiet. I usually run it on medium or high during the afternoon then switch it to auto for other times when demands are lower. At those times, the fan varies considerably on ours. Maybe the ceiling version behaves a bit differently?
Hi Ted,
Hope you’re enjoying your holiday weekend and you don’t answer this until Tuesday. Back to these minisplits again! I’m wondering about two things. The unit is locked when I try to set the thermostat at the remote as opposed to the unit. I’m concerned because the units sit in an attic space where it is hot so I’m not sure where the temperature is actually measured. I’d rather have it at the remote so I’m wondering if I can unlock this factory setting. I’m also having trouble getting the controllers to allow me to set the set back time and temperature. I also can’t get it to set in timer mode. In both functions I can get to the setting program but once I select a day, single day or all nothing else sets like time or temp. i keep going back to the instructions to see if I’m missing anything but no luck. Any ideas? thanks, jim
Hi Jim,
I’m always on my email. Don’t feel bad because I don’t have to put too much thought into this answer – “I don’t know!”
Seriously, I have no idea how that works. The only recommendation I have is to call the installer and see if they can help. Sorry I can’t be more helpful than that.
When you find an answer, let me know. I’m sure others will be interested in what you learn.
Cheers!
-Ted
Hi Ted, You’ve written extensievly about heat pumps and particularly the Fujitsu. I happen to have the AOU24RML1+ARU12RML x2-Concealed Ceiling Heat Pump Dual-Zone Mini Split.
I mounted the units behind a wall and did a small dust into the room which hides them nicely. I love the performance, we mounted them upstair sin a loft room and they basically keep 3200 sq feet cool most of the time. My question is whether or not you can have them shut off like traditional HVAC units? Once I turn them on they run constantly and of course the inverter unit varies its speed greatly. I’d just like the to shut down at night sometime and can’t figure out if you can set them to do that. Thanks jim
Hmm, I’m not familiar with the specifics of those units but my units (12RLS) behave the same way. The blowers one them are very efficient and when I run on “auto” mode, they slow down to a whisper.
I do notice that the outdoor units do shut down even when the blowers are running and when I monitor their power draw, it drops down very low.
Otherwise, when I want it “off” I actually have to use the remote and turn the unit fully off.
-Ted
Hi Ted,
How do you think the Fujitsu split units will work out in NM? We have radiant floor heat in the new house, but no cooling system at this time. I would like to keep the floor temp down a little in the winter and have some back up heat provided by a heat pump for the rooms we spend most of our time in, but don’t know if these units would work for us here due to the sometimes cold nights. Can the heat pump also be used to provide some hot water as well? I really don’t know much at all about these units, so look forward to your input.
Hope you are well,
Stephen
Hi Steve, thanks for asking!
The units should work quite well for supplemental heat even down to some of those chilly SF nights. It won’t blast out the heat at 5F, but it will still be much more efficient and throw off more heat than a typical space heater. And of course, the air conditioning will be welcome in the summer.
Because of the dry air out there, you’ll have less to worry about the heat pump frosting up as well.
No luck on the hot water though. There are some interesting units that will do hot water. See: the Daiken website for more info on these. I haven’t had any experience with them unfortunately, but they do sound like good tech. Note: I just checked their website and it looks like they’re for heating only because they’re all hydronic so that’s probably no good for you.
Well, Ted,
We had 2 Fujitsu tri-zone mini-split units installed in July, and they are great! Our house is very comfortable now, and our first utility bill was a very pleasant surprise. Thanks for the good advice!
Your brother Stephen in Santa Fe
Hey, that’s great news! That’s a great system with all those independent zones. Glad it’s working out for you.
Cheers,
-Ted
Hi, Ted-san,
Love your blog. I am looking into getting mini-splits for cooling in my home in Montgomery County PA and from some reading I’ve done I’m guessing the right system might also be used to replace our 37-year old boiler and hydronic heating system for heat as well. I appreciate any thoughts you have on the efficiency of these systems for heat. I also welcome any recommendations you might have for an HVAC outfit that installs either the Fujitsu or Mitsubishi systems since they seem to be the most efficient due to the variable speed/inverter technology.
Thanks,
Josh
Thanks Josh. You’re close by – I’m just in New Hope.
I use my mini-splits to supplement heating/cooling year round. I wouldn’t necessarily use it as my only system however, since the output drops as it gets cold. However, you might consider just getting some electric baseboards put in as supplemental backup which you’d only use when it gets too cold for the heat pumps. Electric baseboards are dirt cheap (less than $100 each) though the electrical work will of course drive up the cost.
As for efficiency (speaking for the Fujitsu Halcyon units I use), in our climate, they are at least equal my geothermal system and they’re better than any central system for air conditioning.
A lot depends on the size and layout of your home. With all these things, you want to start with a house that is well insulated and tight. This will help keep things more comfortable and efficient regardless of your heating system, but it’s especially important for heat pumps. Also, with the mini-splits, you really need one for each area. They’re great for us because it’s just my wife and I so we have one in our master bedroom and one in the living room. But if you had several used bedrooms, I’d want one for each bedroom. That really starts adding up!
If you do stick with a boiler, I’d strongly suggest looking into the Energy Kinetics System 2000. It’s less expensive than the high end one I got but more efficient overall due to a better design.
As for installers, for the Fujitsu units, I used TCS Heaing and Air Conditioning out of Philly. The owner lives in Bucks and they do a lot of work in Bucks and Montgomery County.
For the Energy Kinetics boiler, talk to Hannabery, based out of Quakertown. I believe they also do the Mitsubishi mini-split.
-Ted
Continued: On the other hand if rot/moisture is found then you are recommending the cellulose be removed and foam insulation be applied. Would that foam be closed as opposed to open and how many inches would you recommend?
Thanks again for your assistance!
It it were my house, that’s the approach I’d take – spray foam, closed cell.
I’d fill the cavity minus ~2″ to leave the air gap between the foam and the roof deck. Then use full soffit-ridge vent combination.
There may be some areas where you can’t get air flow due to obstructions (chimneys, etc.) With the closed cell foam filling the cavities, I wouldn’t worry about those areas. There’s not much you can do and if the foam job is done right, minimal moisture is getting through.
Let me know what you find when you start deconstruction. I’ll be very interested in seeing what happened. We can all learn from your misfortune!
Maybe take pictures and send them along. They’d be a great educational resource especially if you can trace the path of the moisture.
My insulation contractor Ned Reynolds of Newport, RI, is bullish on packed cellulose and says he’s be installing if for years with never a call-back. My contractor interrogated him for about an hour about vents and condensation. Ned said these days, with AC, the condensation is as likely to come in from the outside as the traditional route from the inside out and having cellulose with no vapor barrier allows the whole wall (or roof) to breathe, even without vents. The final factor in deciding was when we talked about mice. Mine is an 1850 farm house with a dry-laid stone foundation and hybrid framing (mix of post and beam and balloon frame) and it is very mousy. According to everyone we talked to, and my own experience, mice LOVE fiberglass insulation and HATE packed cellulose. Apparently the borate is an irritant to the mice and you can guarantee mice will stay out of walls/roofs that are stuffed with it. My finished attic has blown in cellulose and my cathedral ceiling-ed sunroom has 3″ of closed cell spray-in foam against the underside of the sheathing and then cellulose in the rest of the space and there’s narry a soffit vent or ridge vent in any of it. Fingers crossed it was the right decision.
I did my own cathedral ceiling this way as well. The Building Science article warns that many roofs are vapor impermeable to the top which can lead to problems. Between tar-paper, rubber membranes and whatever else is under the shingles, they note that the moisture can in fact migrate up to the underside of the roof sheathing and get trapped there. So I’m being a bit more conservative in my recommendations on dense packing cathedral ceilings. Doing what you did with 3″ closed cell spray foam would be great because the inner surface of the foam shouldn’t drop to a low enough temperature to allow condensation. So that’s safe. That construction dries to the inside. The only potential issue with that is when you have a roof leak, that saturates the roof sheathing and works its way down the topside of the foam. That would likely rot out your sheathing because it couldn’t dry out.
My preferred method for Bruce would be to pull off the rotten roof sheathing and check for any signs of moisture/rot. If there are, then you know there’s a problem. Unfortunately, my recommendation then would be to vacuum out all the cellulose and fill most of the cavity with foam to the back side of the ceiling – the part exposed when you pull the roof off. This will air/moisture seal the ceiling. I’d then leave a gap so that you could install soffit and ridge vents to allow ventilation under the roof deck which would both help any moisture in there dry out and keep the sheathing cold in the winter which will dramatically reduce the possibility of ice dams. If I were building a new house, I’d do it that way. Actually, I’d also add a couple inches of polyiso inside to reduce thermal bridging. I did the walls of my addition that way. Worked great! But I definitely take these things to the extreme…
Hi Ted:
When I have the rotten roof sheathing removed and a check reveals no moisture/rot, would you remove some of the cellulose to leave a 2″ gap for airflow and then have soffit vents installed. If the answer is to leave the cellulose as is; would you then close off the ridge vent?
Bruce – if you have rotten roof sheathing, it’s almost has to be due to interior moisture unless you had a bad roofing job and it’s been dripping for a long time.
An approach that I would consider is to create the air channel between the roof deck and the cellulose as you note. However, to avoid wind-washing the cellulose I would be inclined to use 2″ polyiso board foam pressed down into the cellulose and affixed in place with 1×2 nailers. It’s a little hard to describe.
_____________________ roof sheathing
| |I <– nailer I| | <—- rafters
| |==================| | 2" Poly-iso rigid board foam
| | ********************| | cellulose
| | ********************| |
| | ********************| |
——————————– interior sheet rock
I had a home energy audit 2 years ago and among the many things done as a result wad dense packing of cathedral ceiling with cellulose. I have no soffit vents. I have been talking to roofing contractors who all seem to be of the opinion that I need to add soffit ventilation. I have a ridge vent when my previous roof was applied approx, 17 years ago. I live near Albany, NY.
I read your article entitled “Cathedral Ceilings – Problems and Solutions where you state “I have no problem with ridge vents IF they’re implemented along with a proper amount of soffit vents. I have huge problems with ridge vents when installed without soffit vents.”
As I am going to have a new roof installed, this is the time for me to handle the cathedral ceiling properly.
What do you suggest?
If you had the roof dense packed, then adding soffit vents isn’t going to do anything for you. A dense-packed ceiling is supposed to be sealed because the cellulose dense packed should be stopping air movement.
However, you have to be really careful. It depends on the interior construction of your ceiling also.
When you say you’re having a new roof installed, are you actually removing all the roof sheathing? Are you having moisture or issues with your roof making it need a new roof? This is definitely the time to handle it “properly”.
Thanks for the reply! I’ve had problems with ice dams in the past and again this year (which was an especially bad year in our area (Albany, NY). I probably will have to replace some roof sheathing. The underside of the ceiling (sheetrock) has peeling paint and you can see dark spots where the rafters are. However, this problem existed prior to the dense packing. The gentleman who performed the home energy audit suggested the possibility of installing 3″ of polyiscyanurate to the underside of the ceiling for additional insulation properties which I would then cover with some kind of wooden ceiling. Should the ridge vent be closed or is that even possible? At this time I will consider any solutions you may offer. Thanks for your time and help!!
Bruce – Definitely problems! Did your auditor find signs of heat leakage from the house where the the ice damming occurred? Did you happen to notice the snow melt pattern on the roof? I have some posts with pictures of exactly this that you can check out. There’s an article on ice dams as well with a pointer to a Building Science article that goes over this in gruesome detail.
I like the idea of a few inches of polyiso on the inside and then using a nice facade inside that. I’ve recommended that before (in fact I want to do it to my house but my better half won’t let me…).
But before I did anything drastic (and potentially expensive), I would want to know why it is happening in the first place. There’s got to be some major heat leaks, maybe up through the wall and into the soffit area. If that’s the case, then even the polyiso treatment wouldn’t work.
If you can get your auditor out with their thermal camera, I would try scanning the roof from the outside on the coldest morning possible (hard this time of year) before the sun rises. That should show any hot spots on the roof which can give more clues as to the sources of the problems.
The other thing you can do, though it’s destructive, is to cut out the sheetrock in those areas where it’s damaged already and examine the roof sheathing and the construction in that area. That can be invaluable in tracking down these issues. I wouldn’t be surprised to find that the dense packing wasn’t done properly and perhaps left areas un-insulated.
Have you heard of Hunter Cool-Vent panels? They are made of polyisocyanate rigid foam with built-in venting. Foam, then 1″ cube wooden spacers about 1′ apart, attached to 3/4″ flakeboard, onto which your roofing material is attached. It was recommended for my vaulted, plank & beam ceilings, and is the cat’s meow. It replaced 1″ of old fashioned beaver board. Needless to say, I went from having icicles as big as my arm and the front door being frozen shut, to icicles only sometimes as big as my little pinkie. Big energy savings!
Thanks,I’ll have to look into those. I haven’t seen them but they sound like a great idea.
Isn’t cellulose flammable? I know of at least one instance where the fireproofing compound on cellulose was washed away because of water damage and an electrical fire started from wires damaged by the same water damage. What about fiber metal insulation, I saw it on How It’s Made?
I’ll have to look into the cellulose flammability issue. I do know the green building community has wholeheartedly adopted it for many projects so perhaps it was a shortcoming of an older version of the fireproofing. Much cellulose is installed using a “damp spray” method these days, so I can’t imagine that the borates would come off however it’s manufactured today.
The last research report I saw showed that the house have a vastly improved fireproofing capacity, but much of that was because the fire couldn’t more through wall cavities, since it typically travels along air currents and it would just snuff out in the cellulose. However, if exposed to enough heat, they say it will burn. It has fire retardant properties, not fire proof.
Check into Roxsul- discovered it when our cabin was done 3 years ago and the stuff is incredible. For our home to be done in roxsul, it was only a 25% increase in insulation cost, but the non-flamability and r-value together were the drving factor. Around here, many of the trades use it for fireproofing at required spaces. Additionally, the wood stove and chimmney penetrations can be insulated right to the object- no need for the air space as with fiberglass or other insulations. Just cant put tight to can lights or other devices that air space to dispurse heat. Hope this helps…
Roxul is great stuff! Most of the Green builders I know love it as a replacement for fiberglass. It can be hard to get, but if you’re persistent, you can usually find a supplier to special order it for you.
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Ted, I have oil fired forced hot water heat and indirect domestic hot water. In the basement and on the first floor I also have two chest freezers, a refrigerator/freezer, a dehumidifier, and two window air conditioners. Although I currently get domestic water from a main in the street, I also have two dug wells piped into the cellar (i.e. a lot of cool water) and a good site for solar thermal panels (i.e. a source of hot water). It seems to me that with a little plumbing there ought to be a clever way to make all the things that are hot but trying to be cold and all the things that are cold but trying to be hot work together to reduce my energy bill. My first thought was pipe cool water to the radiators of the freezers and dehumidifier, but would cooling their radiators make the compressors any more efficiently? My second thought was why not a sterling engine to generate electricity and preheat the domestic hot water. The WhisperGen system burns natural gas, and low hot-end temperatures are said to increase the size of a sterling engine, but in my cellar space isn’t an issue. Thoughts? Too bad you don’t live closer, we could tinker.
Ah tinkering. That would be fun!
You’ve got a lot going on there and your thoughts about using systems together instead of opposing one another makes a lot of sense. I’ve always wondered about utilizing waste heat from refrigerators to pre-heat water, for example. You’d have to be a bit clever about it to optimize the operation. For example, turn on the compressor to pre-heat the water at the same time as you’re taking a shower so that cold water is coming through the heat exchanger. Otherwise, you’d actually be less efficient than normal because it would be trying to extract heat into hot water. So there are definitely some nuances that would have to be considered.
The Stirling engine idea is always intriguing. My issue is that, for residential applications, the “waste heat” issue is much lower than in industrial apps where it’s a huge problem. Because of that, the benefit of reclaiming the waste heat in residences is reduced. I would probably just go solar-thermal since that’s well developed and highly efficient. Anything with off-the-shelf parts is going to make your life easier in the long run.
Have you looked into the wastewater heat recovery systems? I would have installed one of these but my drain line isn’t far enough below the bathroom and you really need the drain to be going out down low in the house. http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13040
Hey Ted,
Can you talk about the pros and cons of different insulation materials?
Hi Ted
Hope your well. Thanks for including me on your e-mail list. I like your blog and could of used it years ago.
On my 16 seer heat pump I can’t stand the fan revving up and down constantly. If I knew this I would of never got a 2 stage variable speed unit. It’s loud enough to wake you up at night. Starts at high, slows down for 30 seconds then high again. Was told it may be the thermostat and may have to upgrade. They say it is all about comfort but really feel it is defective. They said if I upgrade to $500 thermostat it may help?
Thanks
Steve
Thanks Steve,
That sounds defective to me. These systems typically ramp up slowly so that they’re unobtrusive. Not to say that they’re silent, but they should be much “smoother” sounding than a conventional single speed unit.
The ramping cycle is handled by the controller electronics in the unit, so that should be independent of the thermostat. However, it is possible that the thermostat is doing something odd with the multiple stages. Normally, they’ll turn on stage one, let it run a bit and then if it can’t satisfy the call for heat, it will ramp up to stage 2. If that doesn’t work, it will turn on the auxiliary heat strips. But this should all be very smooth.
One thing that could be making it run less than optimally is if you program your thermostat to use setbacks of more than a couple degrees. Heat pumps like to be run at a constant temperature with only changes of one or two degrees. If you have it programmed to, for example, set the temperature to 65 during the day when you’re not home, then up to 70 for bedtime, then it will most likely force it to high speed or auxiliary heat, making it run inefficiently.
You could also have an issue with how the refrigerant lines run through the wall. I have this problem – my lines are strapped to the wall outside my bedroom so that when the system comes on, there’s a loud buzzing as the vibrations are transmitted right into the wall. Very annoying.
One question – is the noise coming from the outside unit or the air handler?
Thank for the message. I appreciate the feedback!
First, good for you doing your research. If you’ve done the calculations and they don’t make sense, keep being skeptical of the contractors! Every time, and I mean every, that I took a contractor’s advice over my own calculations and best practices, I’ve sorely regretted it!!!
I’ve had great luck and misery with mini-splits. In general, I love them. Having spot heating and cooling is wonderful and the system level efficiency trounces central systems for all the reasons you mentioned, especially the elimination of ductwork. Though I guess you’ll have some for the furnace, but you’ll be installing that fresh and can “do it right”
Definitely go with heat pumps over “air conditioning only” units. The simplicity of having the units at point-of-use is great. You’ll find that you almost never need the furnace.
The misery I”ve experienced with both Mitsubishi and Fujitsu relate to the indoor units developing leaks in the coils. I think the first generations of super high efficiency units had extremely thin copper which didn’t stand up to the high pressures of the newer refrigerants over time. They also had crappy warranty periods so I had to pay way too much for repairs.
That said, Fujitsu now has a really long warranty period (something like 10/5 year parts / labor). The key thing is using a contractor who has installed many of these systems and is factory certified. Apparently the charge is so sensitive that they don’t want you putting gauges on them unless the system is non-functional. Additionally, they have electronic pressure control valves, so even if the unit is low on refrigerant, you can’t tell with gauges. If you’ve got a tech who doesn’t understand this, they’ll ruin it and you’ll experience the misery I did!
Hope that helps. Good luck with the project!
Thanks! I have spoken to one guy who is certified to deal with the line carried under Trans/American Standard – but the product data is not publicly available. He is one I trust but he recommends I go with central. We have discussed the issues with the ductwork and he knows the dilemma. I think he is more in the “we will make it work” camp. I go with ductless, I don’t mind sticking to him and going with the Trane line, I just dont know which line they carry (its clearly rebranded) and I don’t have access to product data.
The coil info is great help! Reminds me of some Luxaire units I had installed at an apartment complex many years ago. They leak right at the warranty expiration like clockwork. Great efficiencies come at a cost of reliability I suppose.