Interested in wall insulation options?
Someone who contacted the Home Energy Advice Centre recently told me about Paul Kennetts website, www.myonlinediary.com
Paul is a Lower Hutt resident and an energy efficiency enthusiast. His site details several of his projects which include building a solar oven and insulating the walls of his 1927 Moera home himself using blown-in polystyrene beads.
I contacted Paul to ask him whether he had noticed using less power after installing the beads, and he commented that the beads had definitely reduced their power usage (prior to the arrival of their new baby). His site is well worth a look. Note however, that Paul has highlighted the danger of the danger of polystyrene beads coming in contact with electrical wiring. Also we advise caution when placing any material into the building cavity which may impact on airflow and/or drainage. Our advice is that the most proven method is still to remove the gibboard and install wall batts.
Have you any experiences with installing wall insulation, including foam, beads or batts? We are very interested in collecting more information on this topic.
Sarah Free ( Energy Advisor, Wellington Home Energy Advice Centre)
April 2nd, 2009 at 1:06 am
Hi. I too am interested in the option of blowing in loose fill insulation.
There is an interesting article here http://www.azobuild.com/news.asp?newsID=6005 referring to particle foam beads made from Neopor (by BASF).
I haven’t found anyone in NZ who can install this or a similar product. However it seems a much better option than pulling back the plasterboard from every external wall to install pink batts.
Does anyone know if this loose fill foam bead insulation meets the NZ building standards for insulation?
Matt.
May 15th, 2009 at 3:10 am
Hi, I have recently been going thru the “insulation exercise” and I stumbled across a company call Airfoam - http://www.airfoam.co.nz. Their website is quite informative. You may find it useful. What I have found is essentially the only way to get insulation into pre existing walls is to either take the walls off - i.e. the gib/scotia and skirting, install batts and put new walls/scotia/skirting back or punch holes in the walls and fill up each noggin cavity. I think if you really want to retrofit insulation in walls, do it gradually, if you are going to redecorate each room do it then. Regarding the govt grant and insulation - I was told by the underfloor insulation installer your ceiling insulation had to be up to code. Fair enough, but if it wasn’t then that was the first place you had to insulate and you would get the govt grant to spend on that first. He also mentioned there is talk of making underfloor insulation mandatory too. Would that be right? Or is he just saying that to make a sale? I also wonder - does anyone have any experiences - good or adverse with an HRV unit? I feel a bit hoodwinked because the roof temp in the summer reaches 45°C and cannot ever cool the house down and in the winter the room temp rarely exceeds the house temp and so cannot ever heat the house up. If I wanted to pay an extra $2500 I could have a summer kit and another fan installed. What experience do other people have. Thanks
July 20th, 2009 at 8:20 am
With wall insulation you will have to be prepared to pay for building. If you don’t want to be one the early adopters of the blown in insulation and want to take the chill out of your home, then prepare to pay for building costs of lining removal and plaster and painting. Or you can pay for external wall lining building and create an external block without changing your internal walls. These processes use principles which are common within building practices and are building code compliant as they use batts for insulation. Also there is a system where you don’t need to remove scotia and skirting so if someone has scared you with that
For an HRV/DVS it is an air movement device which moves air using a fan system. You can add as much sales talk as the advantages of it but it still is a fan system taking air from your roof cavity and pushing air into the house. So if the thermal gains (Free warm air)from the roof is what you think will keep you warm then you will only get this advantage of thermal gain if your home during sunlight hours. This means you need to have a night shift job to make sure your home. Also the thermal gains will can be effective from the roof if the roof cavity is air tight stopping the colder temperature air from mixing and cooling the warm radiant heat from the roof.
Best bet would be a moisture master which uses a true heat recovery system taking air from the outside rather than from your roof cavity through a sock.
July 23rd, 2009 at 8:14 pm
What a load of claptrap. Efficiency Dude is pushing the moisture master product and the page isn’t about whose is biggest.
Some facts:
Any home ventilation system is good.
Not because it heats but because it changes the air inside the home. That is to say, stale air is a problem in buildings that are virtually air tight. If the air is not cycled then contaminates build. Contaminates arise from cooking, smoking breathing and so on, which can cause serious harm.
In the old days when homes weren’t particularly well sealed and almost every home had an open fireplace there was plenty of circulation. That changed after it was found that we could reduce draughts in homes. So reducing draughts created an air circulation problem, which is resolved using a powered ventilation system.
Insulation is good.
For insulation to be effective, the passage of air from inside the building envelope to the outside must approach zero litres per hour. That’s why all government funded insulation programs include door and window draught stopping measures. Ceiling extractor fans, chimney pass-through openings and unsealed down lights are among the things that allow the passage of air from inside the envelope into the ceiling space. These things create conditions so bad the effect of insulation overall is reduced to practically nothing. This is by virtue of the fact the envelope becomes negatively pressurised due to the updraughts. IE there is a lower pressure inside the home than on the outside creating inflows from cracks and crevices from all manner pf places.
{If when you open your fire door smoke comes into the room then your home is negatively pressurised and that’s a whole other can of worms}
I digress;
Can you see where this is going? You guessed it. Now we need to increase the insulation rating to reduce the transference of energy across the whole envelope surface to an acceptable level to compensate for the holes we punched in the ceiling, And yes, that includes the holes for the ventilation system.
Clean heating is good.
Knowing that hot air is rising and causing updraughts we need to compensate by introducing heat into the envelope. The next step is to consider the size of the heater and type we’ll use.
The higher the temperature wanted; the greater the updraught flow losses; the bigger the heater required and the more energy it will use.
In other words we need to control the temperature to the LOWEST comfortable temperature for the occupants and that’s a subjective quality.
You’ll also want an appliance that can cope with the conditions inside your home.
A heater inside a ventilation system sort of works providing there aren’t too many other exits for draughts. The biggest plus can be that the home is positively pressurised while being heated, meaning that air is escaping from the inside to the outside via door and window leakage rather than being sucked in to compensate for updraughts. Updraughts will still occur but you’ve probably got some recycling going on.
You could opt for a heat pump and that works as long as it’s big enough to cope with the various losses, including the ventilation system openings.
A fire is good too, gas or solid fuel, but be prepared to suck a lot of air into the envelope in the process, causing cold draughts at floor level. Also, consider the replenishment task and weigh that against an electrical where hardship that might be caused in the event of a power problem.
Consider too if you opt to put in a fire that you might also benefit from a wetback as well.
There is no substitute for good advice…
I hope I’ve shown that there is no easy answer, call your experts – all of them, slice through the BS and make decisions based on facts.
August 7th, 2009 at 3:05 am
Here here … with any advice for your home, remember it is your home and you can experiment with it. You can have experts in systems and theory but every home will perform differently, you will find many things will work for you it is a case of choosing which one will do it and for the best price. Subsidies for window seals will be covered by EECA? Not sure about that one myself but you can always ask as I know that Doors were covered before the 1st of July it may be different with the new scheme.
July 28th, 2010 at 9:33 pm
We have a 1960’s home and are sorting out our insulation. Can someone please tell me which is cheaper from a wall point of view. Removing the outside cladding to put the batts in or removing the gib on the inside. Each seems to have its downside but cost really is a factor for us.