Wednesday, April 10, 2019

Improving Energy Efficiency In an Old Home

One of the things we take great pride in, is dramatically improving the energy efficiency in each home we renovate.  This is primarily behind the walls stuff,  that you can’t really see.  But I thought it might be helpful to point out what we look for and do – it may give you some ideas for your own home.

First, you need to consider the ceiling and the basement.  Much like our bodies feel warmer with a hat and warm boots, your home needs to be warm at the top and bottom. 

How do you do that?  Well, let's start at the roof.  I love creating cathedral ceilings to maximize the volume in a room, but that usually means rafters that don’t provide a lot of space for traditional insulation.  We like to use closed cell foam insulation for these spaces. It has an R value of a little over 6 per inch of foam, it’s structural because it’s so rigid, and it creates a vapor barrier as well.   The guys come out in their bunny suits and get it done in a day.
Foam insulation in basement sill stops all air leaks!
Purple areas are cold and show where there are voids in insulation

We also like foam under open living spaces, like this porch that we are enclosing.  The new porch has foam insulation under the floor (in the crawl space) and in the roof.  That will keep the new office and foyer nice and warm, minimizing heat loss.  But it will also help it stay cooler in the summer.

Foam is also great around the sills in your basement.  This is an area that many people don’t think to insulate, but it can be a big source of cold air infiltration.   Foam is perfect for this application, because it fills every little nook and cranny. (The only caution here is I don’t use it on really old homes with massive timbers for a sill.  These timbers have been 'breathing' for a century or more and the foam can change the way they function – and there are horror stories about how moisture has been trapped in them, creating rot.) Your local big box store carries kits that you can use to foam your own basement sills – this is a DIY project that is really worth the effort!! We recently foamed the sills on own house and reduced the monthly heating expense by 10%.  That’s a nice ROI!  
In this house, we were especially lucky, because the sills between the 1stand 2nd floor were exposed because of all the construction we are doing.  We went ahead and foamed them as well!  This is an area that you can't always reach.

For the rest of the house, I knew that the house had been insulated with blown in cellulose at some point and thought we were in good shape.  But as a precaution, I did a scan with my infrared camera.  My happiness quickly turned to dismay as I discovered a lot of gaps in the insulation.  Sort of like swiss cheese with lots of BIG holes.
Hash marks are areas with no insulation - holes were drilled to blow it in
Here you can see the cold air gaps in purple - we filled them with foam and dense pack cellulose 

Some of that probably came from settling over the years.  But some areas just seem to have been forgotten.  I drew big hash marks over the bad areas and the cellulose insulation team came out to drill new holes, filling those areas with new insulation.  Now it’s much  better!
Next, we look at the windows.  This house had the windows replaced at some point, but the seals between the dual panes of glass had separated in about 40% of them.  Their energy properties were useless!  So we ended up replacing all the windows with new low-E, argon filled windows that will help this place warm during our cold Maine winters.  And as an added bonus, the windows will be easy to open and shut (so often in an old house, the windows have been painted so many times, you can't get them to budge).
We found chunks of coal!
New 95% high efficiency gas boiler

But that’s not all. The boiler appeared to be really old. Evidently it burned coal at some point, we even found some chunks of coal in the back of the basement.  At best, it was running at 75% efficiency. To improve this, we had the house connected to natural gas and switched to a wall hung (aka we could get rid of the old chimney), high efficiency gas boiler.  This takes us to 95% efficiency – a huge improvement!!
We’ll also install all energy savings appliances and lots of LED lightbulbs, which will dramatically decrease the electrical usage.

And don’t forget water usage!!  We’ll install low flow toilets, showers and faucets.

So while this is a 1930’s house, it will have the energy footprint of a brand new home!!! The result of all these efforts will give the new homeowners lower fuel bills - and also help the environment by using less of our natural resources.  A win win!!

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1 comment:

  1. Great information to know. I'm getting ready to renovate my grandparents 1936 farm house. What infrared camera do you use?


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