Category Archives: weather stripping

Draughts or Drafts? Either Way, Reduce Them.

Windows and doors can account for up to 40% of the heat lost from a home. In many instances, more heat passes through windows and doors than through ceilings, which themselves can account for up to 35% of heat loss.

Of course all homes are different, and there can be ranges based on the number and quality to doors and windows, and the thickness of ceiling insulation. For example, there are differences between timber windows, aluminium windows, single-glazing, double-glazing, and the R-Value of insulation.

Additionally, it matters whether windows and glass doors face north or south on how much heat they lose during winter. For example, south-facing windows emit heat from a home to the outdoors nearly every minute from May through August. On the other hand, north-facing windows can gain heat during sunny winter days and only release heat at night.    Screen shot 2014-06-07 at 8.39.25 AM

The bottom line is that in many cases glazing accounts for more heat loss than ceilings. This is significant for a number of reasons:

1) The government subsidizes ceiling and floor insulation but appears stop there.

2) Even with government funds, insulation often costs thousands of dollars.

3) Many landlords have no intention of insulating their properties.

4) Dealing to doors and windows can be done at a fraction of the cost of insulating ceilings and floors.

When it comes to doors and windows, heat is lost from a home in two ways: free exchange of air (aka draughts) and heat radiating through glazing. I have written about insulating windows with window blankets and I will write in the future about options for DIY double-glazing. Today is all about draughts, and more specifically it is about plugging them.

During our renovation, we engaged in lots of high-end draught-proofing around new windows and doors as required by the New Zealand Building Code. This involved foam and spray foam and a bit of a mess. But it works very well. Screen shot 2014-06-07 at 8.33.49 AM

Additionally, we engaged in many low-end draught-proofing strategies on existing doors and windows that anyone can use, whether they are a renter, owner, Chiefs supporter or die-hard Hurricanes fan. Some of these strategies have essentially no associated costs while others may have price tags ranging from $4 to $20.

Approaches to draught-proofing take two basic forms. The first is using adhesive foam strips to seal narrow gaps around timber doors and windows. This product is usually cheaper than a flat white in a café, and comes in a number of colours to blend in with your paint choices.

The other strategy involves blocking the passage of air underneath doors. In my free-home-energy-audit travels with Project HEAT (Home Energy Awareness Training) I have seen gaps as large as 2 centimeters beneath front and back doors. On a breezy Whanganui winter day, that can mean a lot of air transfer!

Blocking such draughts are about as easy as ‘home improvement’ gets. A low-cost option is to buy a draught excluder and fix it to the bottom of the door. I recommend against buying the cheapest plastic models as I do not believe they are durable. The one pictured has an aluminium strip holding a thin foam barrier.

Screen shot 2014-06-07 at 8.33.32 AM

A free option is to find a piece of off-cut ‘two-by-two’ (4.5cm x 4.5 cm) and cut it to length as wide as your door. Wrap it in a towel and tie the ends like a Christmas crack. At the end of winter throw the towel in the wash and store the wood for next year. Screen shot 2014-06-07 at 8.33.41 AM

One final note: I have noticed on occasion cold air blowing in through power sockets on exterior walls. My suggestion in this case is to keep electric plugs in them at all times or use a baby safety plug.


Peace, Estwing

Draft Dodger

Editor’s note: Sorry about the misspelling of hongi on the last post. I have never seen the word spelled out, and to my untrained ear it sounds exactly like hangi. Dani knew the difference, but she is too busy to proofread my blogs, plus it would not have been much of a surprise for her had she edited for me, eh? If you are not familiar with te reo, google hangi and you will get a good laugh!
Anyway, the topic of this post is dodging drafts in an eco and thrifty manner.
From what I have heard, anyone who has ever lived in a NZ villa has commented on how cold and drafty they are. We have been working to change that, but unfortunately were a little late for the coldest week in recorded NZ weather history. Although we did not get the flue for our multi-fuel stove installed by a plumber in time, the week provided an excellent opportunity to collect data on our passive solar design. We reached indoor afternoon temperatures of 20 – 24.2 degrees Celsius all week long, although morning readings dropped to around 10 as overnight lows were in the 1 – 3 degree range. I reckon there are four main reasons for this: we have not yet insulated under the floor; the new concrete hearth is uninsulated; all of the pelmets are not up yet; and draft-proofing is not complete. One particular culprit in the case of the latter is the back door(s).
Could not track down a good old American aluminum storm door. Bought this wooden door on trade me for $40, including 2 locks and 6 keys.
Although the back door(s) is “double glazed” so to speak…

Replaced the original traditional rimu four-panel glass door (inner door) that had been smashed by vandals with an identical one from the Renovators Centre for $100.
… as of last week there remained significant gaps around the perimeter.
The hardware store had a sale on door seals, so I picked up a couple. I decided to test the cheapest one along with a mid-range one. The cheapest model was on sale for $10. I reckon that is a good price, but the durability and longevity may be low as it is intended to be applied only with an adhesive strip.
That seems like a recipe for planned obsolescence. Some times being cheap is expensive. So I decided to beef up this model by pre-drilling 5 holes along its length. I used the adhesive to set it in place…
… and then tapped into my supply of stainless steel screws, which will not react with the aluminuim strip.
The entire installation took about 10 minutes and cost maybe $11 including the screws.
For the outer door, I went with the slightly more expensive model which included its own screws and was pre-drilled in the factory. I think this one was $15. But the feature that appealed to me most was the brush seal instead of the foam seal. Our new aluminium French doors has brush seals, so I figured that was a sign that they will take more wear and tear over time. Someone correct me if I’m wrong on this.
This installation took only 5 minutes.
15 minutes for both doors. Why had I not done this sooner? Oh yeah, PhD thesis, new bathroom, new kitchen, new roof, etc. And, the other measures I had already taken on these doors were functioning ok. For example, foam strips along the door frame.
Remember to follow instructions to get all sides of the frame.
Additionally, I had already put up a pelmet above the inside door and hung a thermal curtain so that it nearly touched the floor. Then I took a pair of second hand blankets from the auction and “draft-not-quite-proofed” the bottom.
When we bought this house a year ago this door was smashed and poorly covered by a sheet of some pulp-like wood product and some roofing iron. Rain driven by northwestern winds (prevailing for us) pushed water inside.
Now, for a total of under $200 in materials, we have two draft-proofed, weather-sealed glass doors to let in sun but keep out rain and cold. And, some might say its more attractive than an aluminum storm door.
Peace, Estwing