David Meiland

How could a skylight NOT be a net energy loser? You take your well-insulated roof, let's say U-.026, and you put a couple of big holes in it--I haven't looked at Velux NFRC ratings in a while, but let's say you really ring the bell and get a unit U-factor of U-.25. An area-weighted U-factor calc will show significant decrease in the overall U-factor unless the roof is huge and the skylights are tiny. Snow on top as an insulator is a bonus, and I agree they don't leak, although I have observed plenty with broken seals and that's when the owner always wants something done.

I've read comments from several flat roof IR guys and the timeframe seems to be at least a few hours after sundown, when the day was warm and sunny and the night is clear. They go up in the dark, hopefully with someone to help keep them safe, since walking around looking at the screen will make you blind when you try to see where you're placing your feet. Of course, if you're really cool you just do an aerial survey and never even land in the state where the building is located. http://www.aitscan.com/roofmoisturefindir.php

A halogen work lamp on a stand can be quite useful for this. Point it at a suspected surface for a while, then turn it off and look with the camera. The main thing I use is a 4000W electric heater. Close the doors to a room with the heater inside and the temp usually goes up several degrees in half an hour or so. I like to go right after dawn, when it has been cold all night and the house is heated. If I am looking at walls, I set the camera to a narrow span, anywhere from 6-10 degrees, and keep it there. Going back and forth fairly often between manual and auto is usually necessary.

What is the roof pitch, and how were the shingles installed?

If I'm not mistaken those are Simpson Duravent high-wind rain caps, not B-vent caps.

Marathon heaters have an "as long as you own your house" warranty on the tank, but cost more than twice as much as a conventional type. http://www.marathonheaters.com/

I bought a Ridgid a couple of years ago, and think it's a mistake to get one that doesn't take digital pics and/or have a video out.

I've read a number of pieces on this issue and have yet to see anything conclusive on the offending glass. Factors mentioned are low-e glass, thin glass, temperature effects on the airspace between the glass, time of year, and argon depletion. I've read of at least one case where newly installed replacement windows caused the problem fairly quickly, which would appear to rule out argon depletion as a necessary cause, but it sure is an interesting phenomenon anyway.

At least you're aware that gas pipe has to be sized! There are charts and other means available for sizing. They take into account the BTU input of each appliance, and how many feet of pipe there are. It can get a little complicated when you are T'ing off this way and that to different appliances at different points. Are you actually doing the piping yourself? 87K BTU is a fairly small tankless. Which model is that?

I'm in the market for a combustion analyzer. There are a number of models in the $500-1500 range, and one of the apparent differences is whether the unit filters nitrogen oxides before the gas reaches the CO sensor, and/or whether the unit displays an NOx reading. From what little I've read the presence of NOx can lead to an erroneous CO reading if there's no filter.... but many of the available tools do not do the filtering, although you can buy an inline filter and add it to your instrument if you want. I'm not an HVAC tech and don't plan to become one, but as part of energy audits I need accurate CO readings in ambient air and in the flue, as well as combustion efficiency. I don't want to buy an $1100 tool if a $500 tool will do. Can someone break this down for me?

I think a quicker approach would be to talk to a couple of paint manufacturers about the vapor permeability of different sheens, as well as oil vs. latex. I've had a couple of conversations over the years with tech people at Benjamin Moore, and they are quite able to answer questions like that.

The wall surface is cold, so vapor turns to liquid when it comes in contact, and I bet a very large percentage of the vapor turns to liquid with a tiny percentage diffusing into and thru the drywall. Changing the paint sheen will not change this appreciably. We have two bathrooms, they are both about 60 square feet and the same cubic volume. The one I built is served by a 120CFM Panasonic inline fan that moves about 95 CFM with the door and window closed, as measured by an Energy Conservatory device suggested to me by someone here at TIJ. The showerhead is low flow but does not produce a mist, it produces droplets. The inlet to the fan is in the ceiling directly above the shower. You can't steam that room up much at all. The other bathroom has an older 50CFM fan that moves about 35 CFM, and you can make it foggy in there. In building new homes and remodeling baths I have been able to get pretty much every bathroom to vent well. The keys are to oversize the fan, run a clean duct, and undercut the door.

Mike, you could probably arrange a loaner camera for a week or two by calling the Fluke thermography sales department in Everett. Coincidentally, there is very good training coming up shortly in Olympia. It sounds to me like Kurt is endorsing a 320x240 camera, and I agree.

Lots of bath fans make lots of noise. The trick is to test it with the door closed. If the door is not undercut enough that can restrict fan flow. If the installer used 50 feet of pipe and 8 elbows to get out, that can restrict fan flow. The pipe could be blocked, etc.

First thing to do might be to measure the fan flow with the door closed. Changing the wall paint so that the drywall can absorb and give off moisture seems highly improbable. Is the showerhead one of the watersavers that atomizes the water into a fine mist? If so that doesn't help. Anyway, get the ventilation right, including a timer that keeps it running after you leave the room.

The installer that does those here connects them to the internet for remote monitoring. If your client has that setup he should be able to monitor the system himself or get reports from the installer, which will tell him if it's being overworked.

http://www.thesnellgroup.com/Content/In ... ining.aspx

Manufacturer's list and street price are definitely two different things. Fluke lists the Ti32 at $8995 but it can be had for $7500-8000, possibly lower, depending on where you go. I think most or all of Fluke's cameras, even the cheapest, come with SmartView software, which is definitely pretty basic. Dunno about Flir, I believe you have to buy software.

I've done the BPI and RESNET training and think it was very well worthwhile. An earlier poster is correct in that BPI has standards and a procedure for testing combustion appliances and the area(s) they're installed in for CO issues, and I would not recommend or perform air sealing without following this. In houses with sealed combustion appliances or nothing burning gas it's a non-issue. There are a lot of organizations out there training energy auditors and my expectation is that a lot of the trainees will not find much work performing audits as independent operators. In general, someone coming into "the booming business of energy auditing and weatherization" is going to face a steep climb. There are plenty of auditors who work for community agencies doing WAP work, and they are busy as long as the funding keeps coming. Increasingly, builders and remodelers are tooling up and adding an energy angle to their projects, and I think this is viable (it has proven so for me). The Home Star program died in the Senate a few weeks ago and may or may not reappear after recess. If it does, it might create some work for auditors, as one level of the program was set to require BPI audits to qualify for incentives. A few municipalities are starting to require audits when properties are sold, at least in some circumstances. If that catches on, watch out, the market will open up nicely. Other than that, make your business plans very carefully.

Will the software not make larger JPG images?

Great photos all around. Thanks for posting them.

If the typical HO could find a good HI for this, then I'd agree with you, but I wonder if the ranks of HIs aren't similarly sketchy, present company excluded.

I was snooping around an older commercial building today that has a concrete slab floor, painted in some places and carpeted in others. Out of idle curiously I scanned around with my MEP. Is there any way this meter is useful for an application like this? On the plaster/brick scale it seemed to read in the middle of the relative range a lot, with some lows or highs. Some of the carpet was shag laid over pad, some was indoor/outdoor glued down, and this had quite an effect. I know that Tramex makes a meter specifically for concrete slabs but there are only a few times a year when I could really use it. Any thoughts on this?

Interesting and scary. I took a look at the Gastite web page, and all it says is "Type 300 stainless". Not real helpful.

I have one that bangs on the metal roof of my shop. A client who is a birder explained that this is how he announces his virulent bird-ness to the females. It must work because it lasts for a short time and then he's gone.