Alternative Technology Assn Forums

1. 

   parawolf
   Member

   Hi all - short term reader and first time poster.

   I'm looking for a Melbourne based expert that can give and audit of thermal performance of my new home i've bought (1950's deco/mid century style cavity brick). The past few days of warm weather has meant it's quite warm in the house at ~26 degrees, and it has no active cooling techniques.

   I was hoping to find someone, and would prefer recommendations, of someone that can do a proper audit based on design but also with the use of technologies like infra-red cameras to show where we are gaining heat, and where we will likely lose it during winter (we have central gas heating, but prefer not to use it if possible). Make recommendations based on best technology for the job to fix the thermal problems and then re-audit afterwards to show the difference.

   Google-ing around I keep ending up at a multitude of practitioners, and resources around what to do. But without experience, what do I apply to my situation. I mean if I hire an insulation guy, it's just going to end up with insulation.... but right now is my problem roof, wall, floor, all of the above, air gaps (and where are they) window orientation, etc. I mean I could pay $10k or whatever and just tick all of the above, but will it truly fix my problem.

   Also, i'm fairly convinced that spray in closed cell foam can be very good - if it is moisture isolated, which i've kind of read is difficult with cavity brick? Also odours and more can be an issue if the installer gets it wrong. But then blow in fillers can settle (can be topped up) and how do you guarantee fills - this is why the 'audit' after insulation would be important i feel.

   If anyone can recommend me experts in this field in Melbourne, I'd be very grateful.

   Posted Tuesday 21 Nov 2017 @ 5:16:20 am from IP #
2. 

   axess
   Member

   parawolf

   You could try ecoMaster for a thorough audit.

   Posted Tuesday 21 Nov 2017 @ 10:00:44 am from IP #
3. 

   backward
   Member

   I'm looking at open cell insulation for a new build. I thought both open and the very expensive closed cell foams were resistant to moisture. Please let me know if this is incorrect.

   I was hoping to imitate a Passive House by having the spray foam as the airtight layer AND insulation. Adding a HRV (Heat recovery ventilation unit) should get me close. Has any one heard of this? Can you see anything going wrong ie moisture issues?

   Parawolf you should start with the air gaps. Take out the old plaster wall vents and get rubber seals to all the doors and windows. It's the most cost effective way to improve the efficiency of an old home.

   Posted Sunday 26 Nov 2017 @ 9:53:41 am from IP #
4. 

   Ruffy
   Member

   Hi Parawolf, actually you don't need thermal imaging cameras or pressure doors to do a thorough audit if you understand building physics. They can be helpful, but aren't necessary.

   I have conducted over 1000 home audits and would love to help you but unfortunately won't be in Melbourne until some time next year.

   Given the age of the building, your over-heating problem is probably multi-modal - that is, it's probably a combination of the factors you mentioned. I would recommend the following:

   1. check the ceiling insulation thickness (measure it with a ruler and look for coverage - are there gaps everywhere, etc?) and report back here. If you have minimal ceiling insulation a fair amount of heat could be conducting down through the ceiling as the ceiling cavity warms up each day. Note also that double brick walls will be an issue in summer as the bricks will hold onto the heat absorbed during the day and re-radiate it at night. If they are double brick, you could install blow-in insulation in the cavity, although given that you'd only be able to get about R1 in a 50mm cavity this may not be worthwhile.

   2. the house is pretty old so draught sealing will be an issue - on a windy day close everything up and use the smoke from an incense stick to track where the air is coming in and going out. Then use appropriate products (draught sealing tape around doors and windows, bottom door seals, caulking for cracks, draft stoppas on exhaust fans, etc) to seal as much as you can - this won't cost much and can be effective.

   3. the major reason a properly insulated and sealed house will overheat is sunlight coming in through the windows - go around the house at various times of day and see which windows are letting sunlight in (check all east-west-north windows at various times of day) - externally shade all these windows (tack up shade cloth, install awnings, etc - depends on your budget and aesthetics) so no sunlight comes in, or use a product like Renshade to reflect the sunlight. Unfortunately closing your curtains will do little to help - the shading needs to be external to the window (or reflective at the window surface) to help significantly.

   That's the best I can do on here, except to say that someone who knows what they are doing will not need to charge you exorbitantly to audit the house. I charge $300 for a 1.5-2hr audit and detailed report, and have proven to be extremely effective given the positive feedback I receive. It's all about understanding things like sun angles and the physics of heat transfer.

   Posted Tuesday 28 Nov 2017 @ 12:59:44 am from IP #
5. 

   parawolf
   Member

   Thanks for the post Ruffy - appreciated. So i've gotten myself one of those thermal spot temperature gauges. Point it at stuff and it tells you the surface temp.

   Well internal walls yesterday were 27.4 degrees (all walls and ceiling), and the metal frame of our art deco/modern windows was reporting outdoor ambient temp (south facing, no direct sunlight) of 33 degrees. So yeah, our window frames are definitely leaking substantial heat in there.

   I haven't had a chance to get into the ceiling to have a solid look yet. But i'd hazard a guess that it's probably blow in insulation if any, that has settled. Also i'm going to bet that there is no reflective sheeting against the tiles either on the roof. So the Tiles on a Melbourne day like yesterday and today probably have a external surface temp in the 80's, and radiating back into the roof cavity. Probably wouldn't be a bad idea to contemplate some kind of forced air flow exhaust fan out of the ceiling when it's temp reaches say 45-50 degrees.

   Drafts haven't been too bad. You gave a great idea about using an incense stick, All the windows that are drafty (not super windy yesterday but could get an idea) i've already marked out for requiring new seals/insulation strips based on noise transference. Front door, and one of the rear doors could be better and will be done shortly.

   We only have one set of windows that are directly hit by the north facing sun, and those are in a Sun room, which is then sealed off from the rest of the house by doors, walls and windows. So not bad, but again, sub-optimal.

   So my big ticket items are:
   * Windows - go to double glazed, low-e with thermally broken structures. Benefit both summer and winter.
   * Insulation - get it all done, floor (easy access under the house), roof, and then consider in-fill between the walls for cavity brick
   * Draft Sealing - continue and extend.
   * External Window Shades

   My only concern with all of this, is then what do to about air quality? I mean once the house is sealed up and snug-as-a-bug-in-a-rug, how do you keep air freshness?

   Posted Wednesday 29 Nov 2017 @ 11:38:05 pm from IP #
6. 

   Ruffy
   Member

   Air quality won't be an issue - there will still be plenty of gaps and cracks you can't see letting air in and out. If you did a pressure door test you'd be shocked how leaky all buildings are in Aus. Many new 6-star houses actually perform as 4 stars or less because they are so leaky and there is no requirement for pressure testing before completion.

   As for the ceiling, don't worry about the reflective insulation under the roof - difficult and annoying to retrofit. Concentrate on getting the bulk ceiling insulation right (R5, total coverage across the ceiling), and it won't really matter how hot it gets up there because not much heat will conduct through R5. Don't forget to deal with protrusions through the ceiling properly BEFORE the installing the insulation: exhaust fans should have draftstoppas, downlights should be removed (replaced with in-room lighting) or replaced with LEDs with in-built fire-retardant covers (or covered with after-market fire-retardant DL covers like these: http://efficiencymatrix.com.au/downlight-cover-products-for-energy-efficiency/). Do that first, then the insulation can go right up to the covers.

   If you don't want to pay for double glazing, you could install insulated internal window coverings instead: honeycomb blinds installed in the window reveal and bracketed to seal properly, or multi-layered curtains (including an internal layer of wadding) sealed to the architrave with velcro tabs and topped with some kind of pelmet.

   Posted Thursday 30 Nov 2017 @ 3:51:27 am from IP #
7. 

   Ruffy
   Member

   PS Benefit from double glazing accrues most from reducing conduction of heat, so although it will help a little in summer (mostly on very hot days), it'll do a lot more to keep heat in during winter.

   In summer the majority of the heat gain through windows is radiant (ie. sunlight), so double glazing won't do much to stop that (two panes of glass doesn't reduce the sunlight coming through much more than one pane). And if you go with a reflective tint you lose the radiant heat gain through the windows in winter, which is undesirable. Thus I recommend shading or renshade for addressing summer heat issues, and insulated internal window coverings (or double glazing if you can afford it) for winter.

   Darn physics, huh?

   Posted Thursday 30 Nov 2017 @ 3:59:15 am from IP #
8. 

   parawolf
   Member

   Yup - so all the down lights we have are LED's, otherwise we have in-room lighting. I'll be getting up in the ceiling this weekend when it's a bit cooler. But also check for roofing leaks.

   Posted Thursday 30 Nov 2017 @ 6:04:35 am from IP #
9. 

   Ruffy
   Member

   Definitely check out those fire retardant DL covers I recommended then - depending on your LEDs' warranty you may need the ventilated or un-ventilated version, but they a great idea to install if the LEDs don't already have fire resistant covers so that you can fit the insulation close to them without leaving gaps everywhere.

   Posted Thursday 30 Nov 2017 @ 11:48:08 pm from IP #

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