Double Glazed windows

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Oriphix

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Topic # 114518 22-Feb-2013 10:53

Hi,

We are thinking of getting double glazed windows for our house.

I have heard that Lossnay would be better. (link below) Installation for my house is $3000 with 3-4 vents in each room plus lounge.

http://www.mitsubishi-electric.co.nz/ventilation/benefits.aspx

I had double glazed windows prices and its come up with close to $1600 just for one room.....excluding installation costs so that will be roughly another $500 on top.

So my question is has anyone got the any of the above and can recommend what is better?

Thanks

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Reply # 767497 22-Feb-2013 11:03

What are you trying to achieve? Your post is mixed up with double glazing and ventilation.

Double glazing retains more heat than single glazing and reduces condensation a lot - not completely but by 95 - 98% for me. The damp air is still in the house, making it more difficult to heat.

Ventilation will reduce condensation by removing water from the air. The downside is even with a heat recovery ventilation system you will still lose some heat, but a heat pump will make up for it. It also makes a noise, though how much varies between systems.

I have both. I got retrofit double glazing, it's $3000 - $6000 for the whole house, but it's a bit ugly. As I do rooms I get PVC double glazing, which makes far more sense than aluminium, and is cheaper than aluminium with a thermal break. I went from wet windows and puddles on my window sills to a light mist on the windows. In the very middle of winter I might need to wipe the windows but it's very rare.

I also have a ventilation system, a cheap one a previous owner put in. It only has two outputs in the hall and kitchen, I run it 10am - 4pm in summer to ventilate and add heat, but I have a timer turn it off at night to prevent cooling and noise. During summer it runs 24/7, though it turns off above 20 degrees. I'd like to put in a quieter heat recovery ventilation system one day. I like the CleanAire system better than Lossnay

http://www.cleanaire.co.nz/

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Oriphix

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Reply # 767511 22-Feb-2013 11:16

Yes I see your point I did ask 2 different things there. I am planning on getting both as well but sort of wanted to know why way I should go first that will provide me more bang for my buck. The double glazed windows I am going for is PVC (link below)

http://homerit.co.nz/

The way I understood the difference below between HRV and Lossnay. (I could be wrong)

HRV:
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This heats the air inside the house and provides ventilation however in summer when its hot why would you use this? So this would only be used in winter. Also heard is uses a lot of electricity?

Lossnay:
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This works all year round. One of my work colleagues has it and said that it completed removed getting mould & mildew from the house and water puddles from windows.

So I really don't know what to go for...

timmmay

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Reply # 767523 22-Feb-2013 11:24

You still haven't said what your primary aim is. Without knowing what you're trying to achieve you won't get the best advice.

HRV (the company) isn't great IMHO, I don't like the look of their products, and their salesmen hard sell with little knowledge. I called one out then complained to the company. Built in heaters are a waste of money, it's just blowing it out through the cracks in your house. They say they heat your house cheaply, they do a bit in winter during the day, but they cool it at night. Their main benefit is pushing damp air out, dry air is cheaper to heat.

HRV (the technology - Heat Recovery Ventilation) is great. Lossnay does HRV, as does the place I linked to. In winter it avoids throwing away heat as air goes through a heat exchanger. In summer I don't know if it has a different mode, not really sure how it keeps things cool in summer and warm in winter, but they probably claim it does.

Double glazing retains heat and reduces condensation. The heat loss thing is irrelevant until you have great ceiling insulation, as you lose more heat up there than through windows.

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Oriphix

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Reply # 767526 22-Feb-2013 11:31

Yeah so I am trying to get a warm house and avoid having condensation on windows in winter months.
We do have a fireplace in the lounge but the heat doesn't reach the rooms. With Lossnay I thought the heat might also be distributed to the rooms via the vents etc
Our ceiling is does have insulation I just need to get something for under the house.

So I guess I will need to get both the products.

timmmay

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Reply # 767530 22-Feb-2013 11:39

Double glazing (proper or retrofit) will significantly reduce condensation. Neither will make a huge difference to the temperature inside the house. What kind of heating do you have, other than the fireplace?

Fireplaces are huge holes that massive amounts of heat out. Even the modern ones have gaps around pipes to prevent fires, and gaps in the insulation, and the heat is really difficult to distribute. I got rid of mine, just doing that made the house warmer. I replaced it with a heat pump (my second). Removing the fireplace was really a great move for my house. If you must have a fireplace then a ventilation system with an input above it will help distribute the heat quite well.

Key ways to have a warm, dry, comfortable house, off the top of my head:
- Good ceiling insulation, well fitted with no holes (holes include downlights which are truely awful for heating, fireplaces)
- Wall, under floor, and double glazing helps, but not as much as ceiling insulation
- A plastic ground sheet taped to piles helps a lot to reduce smells and dampness if it's at all damp under your house
- Make sure the house is well sealed (but remember ventilation is required)
- Ventilate during the day, to remove hard to heat damp air
- Heat pumps are a very efficient form of heating, unless you leave them on 25 degrees 24/7. They're most effective in a well insulated, well ventilated house - though I ventilate when it's not on, a low level of ventilation through a heat recovery system will keep the air fresh and dry
- Heavy drapes that seal the window can help a lot. Most drapes aren't much good, they need to seal the window frame and touch either the floor or the ceiling - ideally the floor I think.

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Jaxson

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Reply # 767531 22-Feb-2013 11:40

Condensation forms when moisture in the air touches something cold. Double glazing helps by keeping the inside pane of glass warm. You haven't removed the moisture in the air, you've just removed the cold object it would be touching.

Ventilation aims to reduce the amount of moisture in the air by pumping 'fresh' air (ie air with less moisture in it to start with) into your home, pushing the 'used' moisture laden air out. (This can only really work if you provide a path for the air to leave your home by...) Outside air will be cold in winter, so you'll have to spend more on heating, but the air should be dryer so the heating process should be more efficient.

So really they are completely two different things, but each have an impact on condensation issues in their own ways.

Oriphix

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Reply # 767545 22-Feb-2013 11:54

I also have the plastic sheet under the house it covers the whole area.

Okay that gives me a much better idea.

Thanks for all the feedback :)

Goosey

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Reply # 767582 22-Feb-2013 12:42

For underfloor you should consider EXPOL
"A plastic building sheet wont be doing much"

timmmay

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Reply # 767586 22-Feb-2013 12:44

A plastic sheet stops water coming up through the ground, it made a HUGE difference to the dampness and smell in my house. I put in under floor insulation at the same time, not expol, it was semi rigid sheets of something like polyester - similar to a blanket.

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Goosey

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Reply # 767594 22-Feb-2013 12:57

ok, its just that you said in an earlier post you will need to get somthing for your floor !

stuzzo

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Reply # 767637 22-Feb-2013 13:36

I don't think you should look at a mechanical heat recovery ventilation system (MHRV) like Lossnay as something which saves you heat, rather something that minimises losses when you have mechanical ventilation. They work best to minimise the heat losses when very air-tight houses are ventilated.

Such a system, almost certainly, won't make your house any warmer. The HRV system (confusing in NZ because of the brand name) takes air(hopefully warm) from the ceiling but is likely to be not very effective in those coldest months when you need it most.

To have a warm house the goal is airtightness, effective insulation, and a heat source as appropriate. My advice is get a full understanding of the area first. Good sites are greenbuildingadvisor.com, greenbuildingpress.co.uk., buildingscience.com

Unfortunately retrofit double-glazing is likely to be expensive but shop around if that's the way you want to go or look at cheaper options such as perspex or polycarbonate or plastic film for temporary use.

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Reply # 767641 22-Feb-2013 13:39

timmmay: Double glazing (proper or retrofit) will significantly reduce condensation. Neither will make a huge difference to the temperature inside the house. .

what's the difference between proper and retrofit?

timmmay

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Reply # 767643 22-Feb-2013 13:42

joker97:
timmmay: Double glazing (proper or retrofit) will significantly reduce condensation. Neither will make a huge difference to the temperature inside the house. .

what's the difference between proper and retrofit?

Retrofit is a sheet of 2-5mm thick plastic that's attached to your windows somehow - magnets, screws, etc. It usually has a frame of some kind which is visible inside your main frame. It's easy to install, easy to remove. You can put one over each sheet of glass if your windows are multi pane (ie one part opens), or you can put it across the whole window. Whole window is better for insulation but then you can't open your window easily. Performance is about 80% as good as proper double glazing at about 20% the price (very approximately).

Proper double glazing removes the whole window frame and replaces it with a unit that's aluminium (bad) or PVC (good), with two panes of glass with an inert gas between them. They're usually well made, heavy weight, with good rubber seals.

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Batman

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Reply # 767650 22-Feb-2013 13:49

ah i see thanks

wazzab

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Reply # 767665 22-Feb-2013 14:01

We double-glazed and insulated an old bring bungalow and it made a huge difference. I decided to do the windows and insulation first to see what my heating were requirements once I got the house a lot warmer. And to be honest, the house is really warm and needs minimal heating. I put in new windows and went from about 2mm thickness to doubleglazed which is 21mm total thickness. The warmth, sound reduction and less moisture were instant. I went for Alu Windows - I think the PVC ones are fairly ugly and you can't get decent profiles on them. Alu windows you can get now with Thermal Break which is great. Like a previous poster said, do good insulation also. I put new stuff in the roof, walls, and underfloor and we are toasty all year round (with minimal heating in winter from a gas fire)

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