Gifts Not to Give a Building Scientist
We have all received stuff for Christmas, and other celebrations, which wasn’t appreciated. There is a special set of items which aren’t going to please the building scientist in your life. We decided to just come out and tell you what we don’t want and why in this article.
Stuff that is sold as good but is actually bad for indoor air quality
- Scented candles. Many an indoor air quality field study in the eighties was thrown off by the very high emission of pollutants from scented candles. There are lots of things from the eighties we would love to bring back but scented candles aren’t one of them. Don’t even get me started on “air purifier” candles.
![candle-px]()
- Ozone generators. Ozone in stratosphere good, ozone in troposphere (ground level) makes smog. Do you really need to be exposed to more smog?
- Whole house humidifiers. If your house is too dry, you should do some air sealing. Whole house humidification runs too big of a risk of causing condensation on cold surfaces.
Stuff that is sold with false energy savings claims
- Space age “insulating” paint. The general trick with over-claiming insulation values is to claim effective performance based on unrealistic conditions. If you are designing a house intended for the deep cold of outer space, the hot burn of atmosphere re-entry, and the full exposure of the sun then go to town with all the space age stuff you want.
- Bubble wrap with radiant barrier insulation. Radiant barriers work well when radiant heat transfer is a significant part of the heat loss. When radiant barriers are in direct contact with any solid material – say, for example, dirt or concrete – the heat flows by conduction and not radiation. Hence, ignore the R-whatever claims from foil-faced bubble wraps.
- Efficient electric space heaters. Sure, some space heaters come with timers, thermostats and so on to reduce the amount of electricity they use. But that just means they are producing less heat. Electric resistance heaters are already 100% efficient (i.e., all the incoming electric energy is converted to heat). Radiant, even flow, jet, ceramic, blah, blah, blah. All 100%. If you want to go above 100% you have to use heat pump technologies. If you need a little extra heat in a room then put in an electric space heater, just don’t brag about it – at least, not to an engineer. Next you’ll be telling me that 100 calorie chocolate bar is the same size as the regular one…
Stuff that might wreck the house
- Christmas sweaters that get stuffed in floor vents. Ugly sweaters wind up in all kinds of places…and anything stuffed in a floor vent will decrease air flow. Most houses have single speed furnace fans. They need a minimum amount of air flowing through them to avoid problems in both the winter and summer. So don’t give ugly Christmas sweaters except to people who will wear them with pride.
- Red and green paint for exterior brick. Okay, so more likely the colors are grey or black. You know all those brick houses painted baby blue back in the day – any color is the same bad choice. Once you paint you can never go back. Furthermore, when the paint cracks water gets into the brick, which can no longer dry out, putting the brick at risk from freeze-thaw decay. It is not worth the risk – for aesthetics or durability.
So what can you buy? My personal recommendation is a fancy thermostat (like NEST, Ecobee, Honeywell Lyric Round). Most of the energy savings claims for fancy thermostats are overstated because they are actually replacing thermostats carefully programmed by us nerds (the same people who buy the fancy ones). However, they do allow geeks to look at their smart phones more, and download and play with data, and if you are lucky you may get them at a discount from your utility for taking part in a peak saving program. For the non-geeks they are prettier than normal thermostats. Everybody wins!
The post Gifts Not to Give a Building Scientist appeared first on RDH Building Science Laboratories.