krisman Solar Expert Posts: 57 ✭✭✭✭
i have the enery star windows. the ones that can be opened and flipped out, or the top half or bottom half opened. anyway i was noticing that right in the middle, where the window latches are and the two halves meet, you can feel some air all the way across the center and center corners. it is that way with about all the windows in the house. what should i do to insulate this better while assuring that they will still work properly?
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check the "felt/vinyl strip between the 2 window sashes and see if they are still good, some times they look good but they are not? Not only that, check 2 see if their is a minor adjustment can be made at the latches. (but highly unlikely). but sometimes you can loosen the latch screws and put put a little pressure against the latch ( the direction needed ) and re-snug the screws. ????????
thats kind of where it felt like it was coming from, the felt in behind the window frame. would i need to get some kind of special insulation from the hardware store to replace the felt with or what?
A decent window will have a "meeting rail" that has a fuzzy of felt or rubber gasket to seal. The seal come from the latch squeezing the two halves together, compressing the weather stripping.
If you can't adjust the latch, contact the manufacturer and complain. "Energy star" rated windows should have a infiltration rating, and if you are feeling the draft they aren't meeting it I would guess! In the real world, over the winter, a strip of clear package sealing tape will cut down on a lot of window leaks without looking like hell!.
thats really hard to say....the mileage will vary from window type and/or manufacture. but a lot of time you can get replacments from your local DIY store. How old are the windows????? are they still under warranty????, if so have the installer/manufacture repair them????
i'm not speaking from experience, but i was told long ago by someone that pella windows are notorious for leaking seals. of course the older a window gets the more that can go wrong too.
My new home has large sliding glass windows (would not qualify for energy star) and İ was worried about air infiltration this first winter. Wanted these windows for the view of the bay.
İ was quite pleased that there really are no drafts coming in around them - the 'fuzzy' strips are working well.
Ok, this is a dumb question, and I live near the beach in California, so almost never heat and never air condition, but...
What are you supposed to do to get some fresh air? You don't really want your house absolutely perfectly sealed up do you?
solution- don't have any windows.
people don't buy them to have built-in leaks. when you want fresh air you can open the windows.
The typical solution is a Heat Recovery Ventilator... Designed for when there is a large temperature difference between the inside and outside air. Works well for both Heated and Air Conditioned spaces.
Not sure that it does anything useful when inside temp ~ outside temp... Then you have the issue of salt air and humidity and an active dehumidifier (i.e., heat pump) / filter is probably needed.
As İ understand it you want approximately 0.35 air changes per hour to control mold, mildew and other contaminant build up. A properly sealed home that passes a blower test will not meet that requirement.
The HRV is an excellent choice - especially in a new home - can be rather difficult to retrofit. They do use power - mine takes about 4 kWh per day.
A typical HRV is designed to control humidity as well as act as a heat exchanger.
Wow! -- That would increase my average power usage for my home by 50%.
One more thing to strike off the system (temperate climate).
Depends on the amount of air flow - this is a 6000 sq ft home
There are many different sizes but the 0.35 air changes per hour is important.
Our home is 1/4 that size--so that make it a bit better... I have sealed up several homes now (mostly double pane vinyl windows and doors--although added fiberglass insulation in this last home)--and my wife always complains about not enough fresh air afterwords.
Sealing up the windows is a big help to reduce infiltration. The other help was to seal up the central heat inlet ducts--the 70 year old home was not that weather tight and the ducts pulled in most/stale air from the crawl space.
Adding drain pipe to roof drains, perf pipe and drain rock around the perimeter of the property plus a sump pump got rid of the wet crawl space once and for all.
The important aspect of this is "controlled" ventilation. One other solution, if you don'e use a heat exchanger is a whole house exhaust fan, couple with an damper controlled intake, usually on the cold air return of the HVAC. A timer can control the amount of time these two run, regulating air changes. At the very least you can cut off the vent ait if it is very cold for part of the day.
Like I say, the key is being able to control the intake air.
Hmmm... How much heat is lost in a 6,000 sq.ft. building with 0.35 air changes per hour and 20F (11C) temprature difference:
- 6,000 sq.ft.
- 8 foot ceilings
- Say 20F (11F) change between inside/outside air temp
- 0.35 change per hour
- 0.018 BTU per cu.ft.
- 1 watt = 3.41214 BTU/h
That is a fair amount of heat/cooling load... Vs 4kW for a heat recovery ventilator...
- 6,000 cuft * 8 ft * 0.35 per hour * 0.018 btu/cft * 20F change = 6,048 BTU/Hr
- 6,048 BTU/H / 3.41214 BTH/H = 1,772 watts
- 1.772 kW * 24 hours = 42.5 kWhrs per day (assuming heating 20F differential air)
An "average" home may have:
Sort of makes heating/cooling the "average home" an energy impossibility.
My old 1,000 sqft home with the old windows probably "leaked" more air than a 6,000 sq.ft. modern home...
Now I don't feel nearly as bad about the Federal Weather stripping program:
Obama's federal government can weatherize your home for only $57,362 each
In must be a job done really well (yea--those are 5 month old numbers--but what the heck--its just statistics).