the walls in my house aare all spray foam insulated. the exterior is sheathed with 1 1/2 styrofoam. there is poly on the inside , not sure why tho. found some really rotted boards when i opened a wall for some patio doors. the original walls were 2×4, and whomever did the reno, framed 2×6 walls inside the 2×4! yes, the walls are that thick. the attic is 16 inches of blown fibreglass, yet this house still feels cold in the winter. part of the basement is unfinished, but shoudnt all that insulation account for something?
Replies
Wow ... they really put 2x6 inside the 2x4?? Then foamed the whole thing? How odd. But that may be a clue ... the renovators were a bit clueless (as opposed to clewless:) ). If so, maybe there is a major leak lurking somewhere. Maybe e.g. a fireplace flue chase or a major gap in the floors? What type of heating? Central forced air gas? Ducts in the floor? Single story?
Maybe you have major leaks e.g. around windows due to the funky new framing. Maybe you ended up w/ a 'leak' where exterior walls are intersected w/ interior walls (although I've no specific idea of what may have happened there ... it would be a potential point of 'detail failure' of unknown issues. (boy was that just about the most unclear statement!!).
Anyway ... some questions and thoughts to get you thinking about possible weaknesses.
Many might argue that the 16" of blown fiberglass in the attic is marginally effective.
I trust the basement is 'tight' and cool, but not cold (like outside). Time for a reality check. Might consider a blower door check after you check the 'obvious' (which may not be so obvious).
Hopefully others will chime in, too. They always lend another point of view that may be worthwile.
Any energy auditors around who can come and do a blower door test and IR camera scan?
Is the whole house cold?--or just certain rooms?
Do you have ducted forced-air heat, or what?
What is the BTU rating of your heat source?
i guess more info would be helpful, thanks all for your input. heat source is gas, forced air furnace 95 % eff. 5 years old
entire house is heated, block foundation, i am in southern ontario, there are three windows whose seals have failed., the basement floor and block has not been sealed or painted. i want to seal it with a product that is sprayed on the concrete and it crystallizes in the block hoping it might keep out the damp?? i have considered the blower test, i think that would be prudent
.
You only answered a few of the questions ... More answers might help us help you more.
Failed window seals (between panes) are a non issue, really ... primarily an aesthetic thing (although if it had e.g. argon gas, it does affect the insulating value a little).
Don't forget that it could also be you. Not being a smart aleck but certain medical conditions wacky thyroid in particular and poor circulation can cause people to perceive heat and cold differently than others. There is a gal in our office who keeps her door shut because she is cold and its 80+ in her space. Others, particularly the large marges of the world break out in a sweat at anything over 69. Get some cheap thermometers and place them around the house. If they all read reasonably close to the temp you set your furnace at and that temp would be considered normal by most people say 68-72 then you might consider if it could be a medical condition.
Just confirming the temps around the house with multiple thermometers will help diagnose the problem. You might need to adjust registers in parts of the house to get the temp to balance. We have to completely close registers in some rooms to get our house to balance out. We have particular trouble with registers really close to the thermostat. If someone leaves them open, you'll get short cycles and never get comfortable.
The other issue could be that with the extreme modifications, you now have a furnace that is way oversized. If it is constantly short cyclying, you are going to spend a lot greater % of time in the beginning of the cycle when the air is not yet up to temp and at the end of the cycle when the blower is still running without the burner to squeeze that last little bit of efficiency out of the furnance.
Inspect for demons from the depth of Hell.
How is it heated, and is the heat well distributed?
Is the whole house cold or just certain areas or rooms?
ok the furnace detail is familiar. there is a lot of short cycling in the winter, and the thermostat would read 68 but you never reallly get a feel of warmth. i will try monkeying around with the registers, and i would like to have the fan run constantly for circulation but the wiring in the wall doesnt jive with the number of receptors on the thermostat. how many wires should be in the cable running from the furnace?
You need a minimum of 3 wires to the thermostat to support fan operation, generally 4 for heat/fan/cool support.
You can get a manual switch wired directly on the furnace to turn the fan on. Used to be known as a "summer switch".
And keep in mind that thermostats are not always very accurate. Usually the thermostat is in some "central location", meaning the warmest spot in the house, and if you're doubly lucky it's actually installed on a wall with a heating duct behind it.
To Ki:
Just in case it flew past your head, Dan is being quite factitious.
It sounds to me like you've got a thermostat issue. The main clue is the short cycling. This could be a defective unit, or as Dan implies, a location which gets warm quickly before the rest of the house thereby causing the thermo to open prematurely.
Another reason for short cycling is an oversized furnace. In an over-insulated house (especially if the furnace predates the insulation) the furnace may simply not run long enough to stir up the air everywhere.
It is likely that the furnace is grossly oversized, as others have noted.
Also, if the duct system is starving the furnace for air, the heat exchanger will overheat, causing the high temperature limit switch to shut down the system for a few minutes until the temp drops enough to let it restart.
One of the most common causes of insuffient airflow is undersized return air, and previous remodelling may have reduced the return path, or the original installation was deficient for return air.
As I noted, our problem came the need to balance the system. Out thermo is located next to our stairs to the second floor. The second floor is not on its own zone which would be ideal. Instead, its either hotter or colder than the rest of the house IF you don't do something to balance out the system.
In winter, cold air droppng down the stairs would trigger the thermo but with a register in the dining room, foyer and two in the living room close by it would soon shut down and the process would start again shortly. The solution was to force more hot air upstairs by closing/adjusting downstairs registers which also meant the downstairs stayed colder longer and forced even more heat up. Additionally, the extra heat being sent up forced more cold air down the stairs so in the end the thermo calls for longer run times and better balance.
Balancing is big--even if the equipment is right-sized for the load, and the duct system, supply and return, is sized to handle the airflow, an unbalanced system won't be satisfactory. It's sort of like buying the best satellite dish and TV, but then never bothering to aim the dish.
On top of that, the airflow needed for the heating season will be different from what's needed in the cooling season--basements need high airflow in the winter, but very little in summer, with the opposite problem for a bonus room over the garage.
And closing off registers can be bad for efficiency as well as messing with the balance between supply and return. Severe cases of pressure imbalance can lead to backdrafting of gravity vent appliances, like water heaters. And restricted airflow can cause a 3-ton A/C unit to perform like a 2-ton because low airflow across the coil won't adequately unload the coil.
Realistically, a single duct system just won't deliver whole-house comfort and efficiency year-round in mixed climates for a house with incompatible spaces, like basements and 2nd floors.
One thing to observe is that with this house apparently the previous occupants could never get warm either, and hence the multiple layers of insulation. I'd kinda suspect some fundamental problem, like major air leaks through the baseboards, cold air pouring down a flue chase from the attic, or something similar.
more
i pulled the thermostat off the wall again, there are 5 wires in the sheath, 4 are hooked up, but down at the furnace only three are hooked to the motor., also did some exploratory digging in the walls. the rims joists are all sprayed with foam, except in one small unfinished area in the basement near the panel, the exterior of the 11/2 styrofoam has roofing felt as a house wrap, and the joints on the styrofoam are not taped, soooooo, i guess that doesnt help! i am getting in a friend of a friend who sells/designs hvac and present him with the questions everyone has posed here, i will contact the city to see if there was any permits for the work done on the property, it may help with tracking down some answers keep u posted
From the way you've described it I'm betting it was all unpermitted.