Month: August 2015

My parents and I stopped by the construction site today after stopping off at the Transfer Station and dropping off the recycling and trash.  Great day, great weather!

Paul and his team are going along great – hopefully soon NStar will show up and run electrical power up to the house so they can stop using a generator for power.  They are doing a fantastic job and the house is really taking shape – my Mom said that it is just “floating there” (when looking at it from across the mill pond) and I think she is right.  With the complex roof lines, I was really hoping for something that was open, airy and uplifting – not a hulk squatting on the lot.  Nothing is done till its done, but it is looking good!

Speaking of Rumford style fireplaces – what is a Rumford anyway?  In short it is fireplace that is designed to maximize the infrared radiation (aka – the actual heat from a fire) out to a room.  The way it does this is by having flat sides and a very shallow and open hearth.  To keep the fire drawing well and not smoking up the room, the chimney/flue design is much like a smooth wind-tunnel.  The top-front of the fireplace (below where the mantel is normally) is a smooth internal airfoil.  As the hot air rises, the airflow is smoothly accelerated there and keeps the smoke flowing up the chimney.  There are other effects like induced turbulence in the flu to increase burning of gases etc… – but that is basically it.  Measurements on some fireplaces have the temperature at the front top of the fireplace at 72 degrees while it is hundreds of degrees hotter only a foot deeper in the hearth.

Here is a classic photo of the design

and more technical details on how it works

So who thought this all up?  A native son of Massachusetts – Count Rumford.  He started writing up his ideas and plans for this type of fireplace in 1796.  Count Rumford was born Benjamin Thompson in Woburn MA in 1753 and was given his title in Bavaria where he spent the Revolutionary period (he was a Loyalist and Woburn is only a few miles from the Lexington and Concord revolutionary battle fields).  His writings are very interesting, even today.

While I have probably seen a Rumford design in older houses before, I have not ever been able to build a fire in one.  I heard about the design from the This Old House 25th anniversary show, which rebuilt a house about a mile from my parents place in Carlisle – they put one in.  Programs 2410 and 2411

So – this fall should be fun to experiment with different fire building strategies to see what works best

http://www.rumford.com/index.htm

http://superiorclay.com/fireplace-firebox-design/rumford-fireplaces/

A brief gap in the updates on the construction front while I had some business travel to California and Paul awaited delivery of some of the roof trusses.  Paul however made progress with getting NStar/Eversource rolling for running electrical power to the house – that should be happening “soon”.  The contact and initial jousting over schedules has happened – so hopefully not too long for that.

The trusses arrived and they are very interesting.  Part of the plan for this house was to not do a Deck roof throughout the entire space of the house and garage.  A Deck roof is a very specialized structure – adapted as the name implies – from house decks, and performed by only some special roofers newcastle.  Without going deeply into the details, most of which I am not expert in, what you see from the inside is a cathedral ceiling with massive beams and tongue and groove cedar planking.  This allows for really open spaces and lots of wood to be shown.  For a different feel (and lower cost) Deck also has a truss based roof system.  I chose to utilize that for the mechanical and private areas of the house – I am hoping that this will give the public and private parts of the house two very different feelings or vibe.  (note – there is also a different truss system for the floor shown in some of the earlier photos here – allowing for very easy wiring.)

The construction of the trusses themselves is interesting.  They are nailed together with standard carpentry nails through galvanized metal plates – gang nail systems.  I had not seen these before and I did a little digging – they seem VERY strong and apparently houses in south Florida that were constructed with them survived hurricane Andrew much better than those which were not.

The plates are pierced and form lots and lots of “nails” – so you get a flat surface that has connection to the wood below – across its whole face.  Then you use a half dozen carpentry nails for that deep connection.  It seems like both a very strong and fast way to build a truss

In some of the earlier photos, you may have noticed the big orange machine in the background – that is Paul Heberts’ Lull Telescopic Lift machine – a key piece of equipment on a Deck House building project from the looks of it.  It handles the majority of the heavy work related to taking the flat pack materials from the factory and placing them around the site and for final assembly.  My dad happened to capture a series of shots placing a truss.

The trusses are now all in place I believe – or really, really close to being done – so some interior shots below – you can really start to see how it is coming together now.  Fantastic progress since June when it was just a hole in the ground waiting for a foundation.

Some design thoughts : 

From what I can tell, the house tends to get a fair amount of breeze from the south due to the lay of the land. The south facing glass has more sections that open – so the house is asymmetric in terms of volume and location of openings – my thinking during the design phase is that this might induce a venturi effect when the wind is not blowing strongly – in other words, it will act like a wind sock in low wind speed conditions – the large opening moving to a small. This should generate a compression acceleration of the air speed, creating a proverbial “ahhh – a nice breeze” on day that would normally be considered low wind or even stuffy.

I am starting to think about a post that ties together the design thought process I went through and how it is turning out in reality – maybe even a series of posts with a separate category from “construction”….  hmmm….  🙂