Odd, it maybe called duct tape but its not actually for ducting. Infact its for just about every conceivable situation that needs sticking together. Apollo 13 even used to make a repair to get home safely but not for ducting – but here it is being used for ducting.
The problem…duct tape does not adequately seal the joints and has a short lifespan. Over a three-month period in 1998, Lawrence Berkeley National Laboratory (LBNL) researchers tested duct tape and 31 other sealants under accelerated laboratory conditions that mimicked long-term use in the home. They heated air to nearly 170 degrees and chilled it to below 55 degrees before blasting it through ducts. They baked ductwork at temperatures up to 187 degrees to simulate the oven-like conditions of a closed attic under a hot summer sun.
Of all the things they tested, only duct tape failed – and they reported it failed reliably and often quite catastrophically.
Eventually it will dry up and fall off.
Did You Know?
Proper duct sealing can reduce home heating and air-conditioning costs by $60 to $120 a year.
According to the Energy Performance of Buildings Group at LBNL, each year, U.S. residential duct leakage costs consumers $5 billion. This energy loss is equivalent to:
The annual oil production from the Arctic National Wildlife Refuge
The annual energy consumption of 13 million cars
The carbon dioxide uptake of 7 billion trees is needed to offset the global warming impacts of this energy waste.
You may also spot in the picture above how certain elements of the venting system for the hood fan are not even attached – and that’s how we found them. Everything really does work better if they are air tight.
An articulating 90 degree elbow made from glavanised steel may have been more appropriate in this situation……and the correct tape is a HVAC foil tape.
In part one I showed you some pics of the ‘space’ we were creating after a handy man had previously helped us take the wall out and leave minimal structural support. You can see in the pics below we have removed the 2-2×4’s that were the only support under the floor joists and also removed the upstairs toilets waste pipe. During the whole process we supported the joists in various places and relieved the pressure uniformly with a variety of 4×4 posts on 2×10’s and 2/8 tonne jacks. We then in one location put in a double 2×10 beam and in our problem spot put in a triple 2×12 beam. All seems to have gone pretty well so far and we were able to take alot of the belly in the joists out of the ceiling without incurring any damage to the walls up stairs.
The beam also has a dual function, one is obviously support, the other is to carry the new plumbing and ducting (the ducting previously terminated and thus rendering a bedroom without heat). The plumbing and ducting will run alongside the beam and then down the wall – this is all then encased within the trim.
As you can see from the above picture things have changed quite drastically – yes, the kitchen has gone. In part I the vertical plumbing and electrical was still in place. Now, obviously it has gone and our load bearing beam is in place. Within the plywood (which is giving our final dimensions) is the heating ducting and toilet waste pipe.
Looking in reverse in the picture below you can see another beam. This is a load bearing steel I beam. We also wanted to remove this so we have a continuous ceiling with no visual breaks. The only way to do this was to remove the beam (keeping everything supported of course) cut the joists so as to accomodate a laminate beam and give a flush ceiling. The final result is below.
Just a quick update on the furnace project. We found (after quite an intrusive investigation) a complete lack of logic in the way the existing ducting was run. Some obvious ones were dampers completely closed (and no way to open them – they were drywalled in) and some supply ducts terminated because of alterations upstairs leaving some rooms without heating completely. There’s no easy way to do it – so we pulled the basement apart to accomodate a new ducting plan. Whilst we were at it we decided to do some layout alterations to the basement suite – but that’s another story.
The basement before
and now the fun begins
there is no avoiding it, if you want to do it right just like Mike says ‘bring it all down’! This also allows us to eliminate all asbestos taping and insulation. We found that the basement was inadequately heated aswell and we found alot of supply vents located at ceiling level contradicting the basic rule of heating – hot air rises! During the assessment we were (well the funace/ducting subcontractors) vigilante to incorporate adequate return air.
We called in our plumbing/heating/gas fitting self proclaimed god for our present renovation. Upon his expert inspection it came apparent that the furnace was original – 1941 vintage, and apparently back in those days the home owner could fit them. The furnace was probably running at 40% efficiency. Couple that with 3mm single pane windows and some poor insulation you’ve got yourself a hell of a hydro bill. We also brought in a ducting subcontractor and well to put it mildly he’s mystified. He’s going to have to spend some time figuring it all out, what is supply and what is cold air return by playing a radio at one end and hopefully hearing it at the other end. There could be a chance that in the present set up there isn’t enough cold air return points in the system. We’ll come back to this post when we know more.