# cold basement, hot upper floor



## Ben1491

I live in a 2 storey house with basement. In the summer with air conditioner on, main floor feels comfortable, upper floor feels warm. but the basement feels downright cold. I sealed all the outlets in the basement and it does not make any difference. Just wondering if there is a way to pump the cold air up to the main and 2nd floor.


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## Zipper

If you have a laundry chute to the basement, open it and put a turbo fan at the bottom.

The fan will circulate the cold air to the upper levels.


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## wendi1

If you have forced air, and vents and returns in the basement, just leave your furnace fan on.


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## Mortgage u/w

Basements are always colder due to high levels of humidity. Sealing off all the outlets is not an ideal solution. You will find with time that your basement will start to develop a musty odor since there is no air circulation. You need air circulation in order to remove the dampness and humidity.....if not, it will create mold which gives you the odor.

1st, reduce humidity as much as possible. Ensure you have a good slope around the house directing water away from your foundation walls. Check/install gutters and make sure the rain water is also directed away from the house. Disconnect any underground gutter system. Next, ensure your french drain is functioning properly. See if water is being evacuated properly through a sump-pump. Finally, seal any foundation cracks. Once you waterproofed your foundation, you should feel your basement to be more dry. If you need a boost, use a dehumidifier which will remove any remaining humidity and dry up the air.
2nd, find the best way to circulate some air in the basement. Play with your air dampers to get the ideal balance. Avoid closing up rooms in the basement and ensure you have a good air gap under each door. Install air vents in walls between closed rooms if needed. 
3rd, if you have a cold room in the basement, ensure the door is insulated with a proper seal and is closed at all times. You don't want the cold-room and basement air to mix. This is also important for efficiency purposes.
4th, if your basement walls are not finished, you will need to insulated and vapor barrier them.

Now that your basement is taken care of, you can easily balance the air on the upper floors by again, playing with your air vent dampers. Fully open the 2nd floor vents and reduce the 1st floor vent dampers. In the summer, you want more cold air to go to the top floor since cold air drops naturally. In winter, you want the reverse since hot air rises. Also, ensure your air-exchanger is on. This also helps in keeping the air balanced and will help with your HVAC efficiency.
For good measure, ensure your HVAC sytem is maintained. Change all filters, clean vents and seal any leaks in the ductwork with aluminum tape. Make sure none of your vents and returns are blocked by furniture.

Hope this helps.


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## AltaRed

The single biggest issue with a finished cold basement and a hot upper floor (besides the ever present - hot air rises to the top physics of convection) is the volume of "cold air return" from the upper floor and the lower floor. Most HVAC contractors do not put in a damper in the basement cold air return - the one that is often less than 2 feet from the furnace on the other side of the wall itself. It does not take a genius to know that a lot more 'cold air' will be sucked into the furnace fan from this cold air return than the 2-3 cold air returns upstairs that are often furthest from the furnace. 

The solution is to either install a cold air return that has a built-in damper into the basement cold air return that can be kept approximately halfto-three-quarters closed, or to have one installed in the ducting between this wall grate and the furnace itself. As said upthread, you do NOT want to cut off 100% of the circulation in the basement.... air must circulate to keep humidity down.

The real solution is when buiding a new house is to put in a 2 zone ducting system (one for upper floor and one for lower floor) connected either to a single forced air furnace system or have dual forced air systems, one for upper floor, one for lower floor. If I ever built a house from scratch again, I would install a 2 zone 2 forced air systems to help keep both floors at the same temperature. For $10-15k, it will pay for itself many times over.


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## Ben1491

Thank you all. My house has force air system. The problem probably because it does not have cold air return in the basement. Right now I usually have the fan on with the basement door opened for few hours a day. That seems to be a bit better but it is a very slow process.....


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## RCB

You don't say how old your house is. While the lack of a cold air return in the basement is likely a good part of the problem, there could be others.

My house is post-war. The second floor wall insulation (paper-backed, 2 inches thick), side attics, windows receiving sun, and roof style (1/2 storey) lead to an excess amount of second floor heat in the summer. Rather than put out the money to change this, we opted for two inexpensive window AC units for the two second floor bedrooms, instead of central air and renos. They do the job quite well.


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## Earl

You should be able to open the blower motor door on your furnace (tape a filter over the door), then turn the furnace fan on and this would result in your furnace blowing all the cool basement air throughout the house. But I think even this would have a limited effect. A simpler solution would be to just spend more time in the basement and less time upstairs


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## Ben1491

My house is 38 years old. Only my wife and I live here. Although the basement is fully finished, we hardly go down there at all. Most of the time we are at the main floor. Upper floor is just for sleeping except the study room that I read and surf internet. Right now I have a little fan going when I am in the study if it is too warm. I turn on the force air fan around supper time. Turn off when we are ready for bed. It seems to help that I do not need to set the temperature of the air conditioner too low. BUT, it is just kind of waste knowing the basement is cold and I still need to turn on the air conditioner to cool the upper floor. Anyway, I might get a contractor to take a look to see if there is a way to solve the problem.


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## OhGreatGuru

Many useful suggestions above.

The problem is that most furnace duct systems are designed and sized for heating mode, and the A/C is just stuck on afterwards. If your home is 38 years old that will certainly be the case. For efficient air conditioning, the supply ducts, especially to upper levels, need to be larger, and your air return intakes differently located than for heating. In all likelihood your return air intakes are undersized in the upper levels too. (It's pretty common for return air ducts to be undersized. When the A/C contractor installs a unit, they generally set the multi-speed fan to run at high to try to compensate, but it's still sucking and blowing through undersized pipes.)

Putting the fan on continuous circulation should help, but will not completely overcome deficiencies in the general distribution system.

Most homes don't have a return air inlet in the basement, for fear of creating a down-draft in fuel-fired appliance flues. Adding one that you open only in summer will help get that damp cool air out, but you have to be cautious if you have something like a gas water that is naturally-vented. Simply opening the fan compartment is overdoing it, as then the return air ducts from the upper part for the house are carrying no air at all.


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## cainvest

Earl said:


> You should be able to open the blower motor door on your furnace (tape a filter over the door), then turn the furnace fan on and this would result in your furnace blowing all the cool basement air throughout the house.


The above should work very well, at least for a test to see how much difference it makes. You could always have someone add in a cold air return to the basement at a later time, one you could close off (if needed) for the winter.


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## mrPPincer

simplest most inexpensive solution is the most obvious, not sure why nobody mentioned it, open the windows on the upper floor at night if you have screen windows. 

ofc this is maybe not as workable if you live in a densely-populated area where the air and noise pollution is bad.


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## Koogie

We have a 50 year old house with a similar cold basement. We have three window-well windows in the basement that are sealed glass units. Would it be worth it to open them up and add in bugscreens on them for the summer and have the basement "breath" ? Obviously not help with getting cold air to the upper levels but it should help with the damp cold basement air ?


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## OhGreatGuru

If you live in a high-humidity area like southern Ontario it may not be such a great idea. You will be letting in high-humidity air, which will be cooled down by the cold basement walls and floor slab, which will cause the moisture in the air to condense in the walls and on the floor, promoting mold growth. Instead you want the condensation to occur in a controlled fashion inside the air conditioning system, where it will be lead to a drain. Just improve the air circulation between basement and the rest of the house so more of it is dehumidified by the air conditioner. (Or put a dehumidifier in your basement.)

If you are in a drier climate like the prairies it would not be a bad idea. An exhaust fan in one of the windows would improve the efficiency of air exchange.


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## Ben1491

I have a hygrometer and a dehumidifier in the basement. Will turn it on if the humidity is high. It is usually on between June and September.
As for opening the windows to relieve the heat. Cannot do that in spring and summer because my wife is allergy to pollen.


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## twa2w

I believe the proper way to deal with your situation may be to install some venting from basement to upper floor. 
Essentially you overlay your floor plans to see if there is a spot that you can run flexible ducting from basement floor to near the ceiling of upper floor. If you can run this up through closets is ideal but I have seen it done by running it up in a corner or against a wall and then boxing it in with drywall. It will look a vertical ' box in' for a chimney. Install an intake vent near the basement floor with ducting running up to the top of the top floor and install another vent into that room. Install a multispeed reversible fan( quiet) in the ducting. You can, depending on season, run the fan in the direction that works best. Push cool air up to the upper floor ( summer) or suck hot air down to the basement (winter). 
The ducts in the upper floor, if on an interior wall, can be split to have a duct in two rooms or run up through the attic ( make sure well insulated and sealed) to serve a number of rooms.
Alternatively depending on where your furnace is you can install ducting from basement floor level into the furnaces cold air return and use a diverter to control cold air return flow. Then just run your fan on your furnace on low speed and use the controls on your vents to get the mix you want.
Either will cost you but if you are handy it can be done relatively cheaply.


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## OhGreatGuru

Ben1491 said:


> My house is 38 years old. ...


Also, check how much insulation you have in the attic. In 1978 it was probably no more than R20. If it hasn't been upgraded it should be. I know someone who found their upper floor cooling improved dramatically after they added insulation. (The attic gets so hot the upper floor ceiling is like a radiant heat source in summer.)


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## coptzr

Our house is open in the middle for 30ft+, I found recently if we close the basement stairs door when using that area for 1hr or more the room seems to be much warmer. We have 4 circular vents across the open area in basement which get opened and closed, but only make little difference.


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## Ben1491

OhGreatGuru said:


> Also, check how much insulation you have in the attic. In 1978 it was probably no more than R20. If it hasn't been upgraded it should be. I know someone who found their upper floor cooling improved dramatically after they added insulation. (The attic gets so hot the upper floor ceiling is like a radiant heat source in summer.)


Yes, we did added insulation in the attic when we replaced the roof shingles 20 some years ago. In addition, also installed 2 turbines. Together with a matured shade tree on the south-west corner I planted. It definitely helps to reduce the work load of air conditioner. But, heat built up eventually..... 
Last weekend I bought a used 21" fan from a local garage sale for $5. I placed it at the floor of opened basement door. Switched on for 1 hour and it slightly raised up the basement temperature, but not by much. Installing fan and vents as some of you suggested is good but bit too much of a headache as we won't be staying in this house long. Will let the future house owner solve this problem


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## agent99

Better late than never  Especially apt with current heatwave. Hopefully OP solved his problem back in 2016.

INTERESTING: There was a 2018 post right above mine, but it has now disappeared! 

Cold air does of course flow downwards and will collect in the basement. And heat input is largely on the roof and through windows. Solution is to run furnace fan (if house has a furnace) to circulate air. And put blinds on upper windows to reduce heat input. A ceiling fan in upper bedrooms can also help a bit. We have a window A/C in one upstairs bedroom that is used just when it gets really hot.


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## OrganicRain

-Furnace fan set to "on" PLUS set AC to a COOLER temp at night. (72-73F degrees I suggest) These 2 are a must. 

-Make sure basement door is closed at all times (if you have that option) as the stairs act as a giant siphon.

-Heavy window coverings upstairs left closed all day.

If this does not work than you have poor ductwork or an older fan motor in the furnace with not enough force. 
Solution = (1) adjust fan motor on furnace if possible (2) new system with better blower motor or (3) new ductless split AC system upstairs if poor ductwork.

_*People make the mistake of setting the stat to a warmer temp at night - wrong.*_



Source 20 year in HVAC career


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## Earl

OrganicRain said:


> -Make sure basement door is closed at all times (if you have that option) as the stairs act as a giant siphon.


If the basement is cold and the upstairs is too hot, why wouldn't you want that door open so that cold basement air can come upstairs?

And of course setting the temp lower at night will be better. But it will also be more expensive.

I'm not sure if there's even any point in running the air overnight, because the outside air is pretty cool at night so you could cool your house by simply opening the windows. Of course that wouldn't work the last few days we've had here in southern ontario, I think the temps stayed in the mid 20s overnight.


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## like_to_retire

OrganicRain said:


> -Make sure basement door is closed at all times (if you have that option) as the stairs act as a giant siphon.


I always thought that leaving the basement door open allowed warm air from the house to be funneled down the stairs into the basement, then it would be picked up by the cold air return in the basement. I know it does this in my home because when I leave my basement door open six inches or so it will be pulled shut by the air flowing down those stairs.

Why isn't this a good thing?

ltr


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## OrganicRain

Earl said:


> If the basement is cold and the upstairs is too hot, why wouldn't you want that door open so that cold basement air can come upstairs?
> 
> And of course setting the temp lower at night will be better. But it will also be more expensive.
> 
> I'm not sure if there's even any point in running the air overnight, because the outside air is pretty cool at night so you could cool your house by simply opening the windows. Of course that wouldn't work the last few days we've had here in southern ontario, I think the temps stayed in the mid 20s overnight.


Hot air rises. Cold air drops. While running the AC, keeping the basement stairs door open will continue to contribute to the problem of a colder basement and warmer upstairs.

Running the air at night is inexpensive relative to running it during the day because lower hydro rates, and cooler temps at night so it won't run as long. If your house was hot all day, it will also be hot at night unless you do something different. Set stat at 77-78F (25C) during the day, and about 73F (22C) at night. PLUS have the furnace blower ON.

If the temperature drops enough to warrant opening the windows, then thats a different story. However, here is Ontario, opening windows at night this past week of heat wave would have had done nothing in terms of lowering temperature and indoor humidity. Would have made the indoor humidity levels worse, in fact. 

The AC's 2 main functions is to (1) cool the indoor air relative to outside by removing heat and (2) remove humidity relative to outside. The unit has to run to get the humidity out of the house.


Yes the AC costs to run, but if the issue is hot upstairs, this will fix it, while keeping hydro costs under control due to more nighttime use vs daytime use - assuming ductwork and equipment are functional.


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## Earl

OrganicRain said:


> Hot air rises. Cold air drops. While running the AC, keeping the basement stairs door open will continue to contribute to the problem of a colder basement and warmer upstairs.


That makes sense. I"ve been keeping my basement door open, but I will close it and see if I notice any difference.



> Running the air at night is inexpensive relative to running it during the day because lower hydro rates, and cooler temps at night so it won't run as long. If your house was hot all day, it will also be hot at night unless you do something different. Set stat at 77-78F (25C) during the day, and about 73F (22C) at night. PLUS have the furnace blower ON.


That just seems very wasteful. I'm usually not home during the day so I can't bring myself to run the a/c for an empty house. And even when I am home during the day, I just tolerate the heat instead of running the a/c. On very hot days I turn on the a/c in the evening so that it cools the house down before I go to sleep, let it run for about 2 hours which is enough to bring the temp down from 80+ to about 76, then turn it off again before I go to sleep. I don't see the point of setting it on 73 overnight, because the outside air is cooler than 73 overnight so you could simply open your bedroom window, which is free. Doing it your way would probably result in a cooler house than what I do, but the cheapskate within me just can't bring myself to do it. Growing up, we did not have a/c because my parents refused to spend the money. Even now, I only turn on my a/c on the very hottest days. As soon as this heat wave is over I will not turn on my a/c anymore at all. Mid-70's is a comfortable indoor temperature and does not justify wasting money on a/c as far as I'm concerned, unfortunately for the past week or so my house has been in the 80's.


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## Emjay85

Earl said:


> That makes sense. I"ve been keeping my basement door open, but I will close it and see if I notice any difference.
> 
> 
> That just seems very wasteful. I'm usually not home during the day so I can't bring myself to run the a/c for an empty house. And even when I am home during the day, I just tolerate the heat instead of running the a/c. On very hot days I turn on the a/c in the evening so that it cools the house down before I go to sleep, let it run for about 2 hours which is enough to bring the temp down from 80+ to about 76, then turn it off again before I go to sleep. I don't see the point of setting it on 73 overnight, because the outside air is cooler than 73 overnight so you could simply open your bedroom window, which is free. Doing it your way would probably result in a cooler house than what I do, but the cheapskate within me just can't bring myself to do it. Growing up, we did not have a/c because my parents refused to spend the money. Even now, I only turn on my a/c on the very hottest days. As soon as this heat wave is over I will not turn on my a/c anymore at all. Mid-70's is a comfortable indoor temperature and does not justify wasting money on a/c as far as I'm concerned, unfortunately for the past week or so my house has been in the 80's.


Different strokes for different folks.

But on nights where it is warmer than 73 (an arbitrary number anyhow, used for the purpose of the example) and/or when there is high humidity, the previously posted example sounds like a pretty good idea.

There are all sorts of different ways to look at the whole AC process. Some will even argue that keeping it the same temp setting all day and night is the right way to go with the argument being once the house is cooled and dehumidified it is easier on the system to simply maintain that rather then work really hard for a good few hours to get the temp and humidity down to a suitable level a couple times in the day.

Whichever way you look at it, the one that works best for you is the one to stick with in my eyes.


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## like_to_retire

Emjay85 said:


> There are all sorts of different ways to look at the whole AC process. Some will even argue that keeping it the same temp setting all day and night is the right way to go with the argument being once the house is cooled and dehumidified it is easier on the system to simply maintain that rather then work really hard for a good few hours to get the temp and humidity down to a suitable level a couple times in the day.


I'm in the camp that believes you should just select your temperature (mine is 26 degrees) and leave it on hold for the entire summer. If you try and set up a winter style program for different temperatures at different times it just makes it uncomfortable and the system works a lot harder. It takes a long time to get that humidity down, and so shutting the AC off lets the humidity rise and it takes forever to get back to where you started.



Earl said:


> That makes sense. I've been keeping my basement door open, but I will close it and see if I notice any difference.


For my house, I shut down the dampers on the basement feeds. This creates a higher pressure upstairs. I leave the basement door open and the hot air is pushed from the upstairs down to the cool basement and then returns to the furnace coils through the basement cold air return. Works for me.

ltr


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## andrewf

I chill my house overnight and leave the ac off during the day. I almost never use anything other than off-peak TOU hydro rates for AC. I think only 2% of my hydro consumption is on peak rates.


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## OrganicRain

andrewf said:


> I chill my house overnight and leave the ac off during the day. I almost never use anything other than off-peak TOU hydro rates for AC. I think only 2% of my hydro consumption is on peak rates.


 Not a bad idea either, the key is to run it at night when you need it most....different temp settings for different people (whatever floats your boat)


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## Userkare

I also try to use the colder basement air to cool the whole house. The furnace cold-air returns are blocked upstairs so that it draws from only the basement. I have de-humidiers working in the basement as well.
I have set up the thermostat as the temperature rises above 22C to first use the circulating fan at 30% duty cycle, then if the temp keeps rising, 50% duty cycle, and finally continuous on if the temperature doesn't level. At 26C the A/C cuts in.

This works well for the first few days of a heat-wave, but after that, the basement isn't so much cooler than the rest of the house that it can make any significant difference pumping the air upstairs. It usually goes quickly through the fan-only mode into active A/C.


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## OhGreatGuru

Blocking the upstairs air return ducts is counterproductive. The furnace is having a hard enough time pushing cool air upstairs through the under sized ducts. If you block the air returns you are increasing the resistance to air flow from the supply ducts - so you get less air circulation upstairs, not more. Sucking in cold air from the basement isn't a solution. The basement is cold because it is below ground, and has practically no heat gain. If you close the basement supply ducts in summer, you will still get leakage plus the cold supply plenum will chill the air around it. Putting a cold air return in the basement will allow the air conditioner to pump more air, by reaching the friction loss in the system, but most of it will still go to the first floor. Which will get cold quicker, thereby shutting down the A/C sooner, while the 2nd floor remains hot.

Think about. What's the problem? It's too warm upstairs. So you want the furnace to suck some of that too-warm air back down to be returned as cooler air. 

The too-cool basement is a separate problem.


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## agent99

OhGreatGuru said:


> Blocking the upstairs air return ducts is counterproductive.


It really won't make much difference. The air returns are intended for heating. Cold air will return via open doors and stairs anyway. A first step might be to partly close dampers on lower floors. This will help push more cold air out of the upper floor registers. But because these are heating registers, much of that cold air willl just slide downstairs via the return ducts or open doorways. The cold air needs to get better mixed on the upper floor. Ceiling fans are one way. Another is to use register booster fans. They can be a bit noisy though.


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## Userkare

I have a single storey house + basement. The cold air return in the basement is very close to the furnace and it's turbo-charged, i.e the air is pushed into it by a fan, in addition to the internal furnace fan. I've been using the basement air to cool the main floor, and have empirically seen that it works - even if the science says it shouldn't. After a week of really hot days though, with the air circulating throughout the whole house, it tends to even out the temperature between the basement and upstairs, and the benefit diminishes. 

My thermostat produces stats of how much time is spent in various operating modes. Without detailed environmental data for each minute counted, I can't say for sure how much of actual COOL mode operation would have been used in place of the FAN-ONLY time, but would guess it could be significant.

Usage Total: 1540326 min
ALL_OFF : 1013504 min
HEAT_L1 : 225849 min
HEAT_L2 : 66491 min
COOL_L1 : 1624 min
COOL_L2 : 1496 min
FAN_ONLY: 231362 min


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## HomeChef

Like these suggestions and use most of them. We do run the fan on all the time to try and get the cold air up. Our house is very tall (12 ft ceilings on main floor) and despite being new and having a 3 zone damper system (basement, main and upper) I think the fan has a difficult time pushing the air up that high. 

I was reading about these "register boosters" that HomeDepot sells that you can install on the upper floor to get a "boost". Any thoughts on if these are worth it?

https://www.homedepot.ca/en/home/categories/building-materials/ventilation-and-ductwork/registers-and-grilles/register-boosters.html


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## like_to_retire

Userkare said:


> I have a single storey house + basement. The cold air return in the basement is very close to the furnace and it's turbo-charged, i.e the air is pushed into it by a fan, in addition to the internal furnace fan. I've been using the basement air to cool the main floor, and have empirically seen that it works - even if the science says it shouldn't. After a week of really hot days though, with the air circulating throughout the whole house, it tends to even out the temperature between the basement and upstairs, and the benefit diminishes.


Interesting. It's somewhat the same theory I use in my single storey house + basement. When I shut off all output dampers in my basement and leave the basement cold air return alone, it creates a low pressure that forces upstairs air to the downstairs. I know this because the door to the basement will now slam itself shut from that air rush if you hold the door open about six inches and then release it, the door will slam shut from the air flowing down the stairs.

This allows the air to be cooled as it moves through the basement and the cold air return passes all that air along with already cool basement air into the cold air return that is at floor level. Yes, the upstairs cold air returns also move air from upstairs back to the furnace, but a lot of air is moved downstairs to be cooled naturally.

My air conditioner simply runs less when I do this, but as you pointed out, it does tend to raise the basement temperature somewhat, so it shows it's doing its job.

I've used this method for years and so was surprised when earlier it was mentioned to be sure to always shut your basement door.

ltr


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## Userkare

Also, I believe an added benefit to circulating the basement air throughout the whole house, is that it doesn't allow a pool of stagnant cold damp air to accumulate in the basement, promoting mold growth.


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## agent99

HomeChef said:


> I was reading about these "register boosters" that HomeDepot sells that you can install on the upper floor to get a "boost". Any thoughts on if these are worth it?
> 
> https://www.homedepot.ca/en/home/categories/building-materials/ventilation-and-ductwork/registers-and-grilles/register-boosters.html


The type that you posted look like they may have to exactly fit the existing duct size? I posted a picture earlier of a type that sits on top of the existing register and does not have to be an exact fit. I have one of those, almost brand new in box. I bought it but found we didn't need it. It's called a Suncourt Equalizer EQ2. Thermostatically controlled, so only runs when needed. Came from Home Depot on-line but available at Lowes, CT and maybe Amazon too? As mentioned before, a bit noisy when room is quiet.

From this guy's tests, it looks like those insert type don't do much
https://www.youtube.com/watch?v=Ss_AJKxw_-k


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## HomeChef

agent99 said:


> From this guy's tests, it looks like those insert type don't do much
> https://www.youtube.com/watch?v=Ss_AJKxw_-k


Thanks that's a great video. I forgot to look on YouTube for a review, good suggestion. I notice in the comments of this video it talks about the air blowing at 45 degrees. I think I may try one in one bedroom to start. 

Didn't realize you had written about your vent fan before, sorry for the repeat. I did read through all 4 pages of the thread but must have glazed over your post. Appreciate your comments. Thanks


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## Ponderling

We have a 50 year old two storey plus basement house, with forced air heating and central air conditioning, and yes, upper floor cooling is a challenge in the summer. 

When re-siding the second storey of our house we added 2" of rigid foam board insulation under the siding. This is not for everyone, but if you are doing new siding consider it. It has cut noise from the street, and reduced heating and cooling costs.

We have floor level second storey cold air returns, and low on wall first floor cold air returns. Originally had a ceiling level cold air return (what was the builder's HVAC guy thinking?) Now have a high efficiency furnace that has balanced air exhaust and intake through the side wall. 

So with no chimney to back draft, we cut a new cold air into the basement cold air plenum. About 40% area of the three heat registers in the basement.
In the summer we block off the basement registers. Cold inlet still sucks first floor cold air though the basement for air circulation via the basement door. Only side effect is need to vacuum these stairs more often in the summer. 

On the first floor in cooling season we block off one of the main floor cold air intakes.

On the second floor we place 'chimneys' made of foam core board over the cold air returns. These are about 6' tall, and help to pull the warm air that sits higher in the house back into the air handling system so it can get passed over the AC evaporator.

This summer we are for the first time trying a new time of ac programming, to align better to time of use energy pricing. 
We let the a/c set point sit at 26C from 11am -5pm, and then 23 the rest of the day. This cooling seems to let the house stay ok for sleeping, and main floor, the daytime use floor be ok thorough the day.


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## OhGreatGuru

agent99 said:


> The type that you posted look like they may have to exactly fit the existing duct size? I posted a picture earlier of a type that sits on top of the existing register and does not have to be an exact fit. ... https://www.youtube.com/watch?v=Ss_AJKxw_-k


The majority of residential heat registers (technically a "diffuser") fit a 4"x10" "boot". And the corresponding floor flange is a fairly standard size. But not all. My daughter's 30-yr+ home has some 3" x 10" boots for some reason. The pictures of the Home Depot product make it look as though the heater insert is smaller than the duct would be, but the floor flange is standard. You would have to measure to be sure.


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## Userkare

Ponderling said:


> This summer we are for the first time trying a new time of ac programming, to align better to time of use energy pricing.
> We let the a/c set point sit at 26C from 11am -5pm, and then 23 the rest of the day. This cooling seems to let the house stay ok for sleeping, and main floor, the daytime use floor be ok thorough the day.


23C? Wow, now I feel like a real cheapskate! Our thermostat A/C is set for 28C from 07:00 to 19:00 weekdays. From 19:00 to 00:00 weekdays, and 07:00 to 00:00 weekends, it's set at 27C ( or 26.5C if motion detected ). Then from 00:00 to 07:00 every day it's at 26C.

Mostly we open windows and use the furnace fan to circulate the air. A/C typically runs only when the outside temps get 30C+ for a couple days in a row,


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## Zipper

Let me repeat in case some of you missed it. If you have a laundry chute to the basement from the upper floors put a turbofan at the bottom and force the cold air up. Working for us since 1983.


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## Prairie Guy

agent99 said:


> It really won't make much difference. The air returns are intended for heating. Cold air will return via open doors and stairs anyway.


Returns are for heating AND cooling. In most forced air systems all of the air that passes through the furnace comes from the returns only. If there are no returns in the basement then the cooler basement air is not pulled through the system which exaggerates the imbalance. In most cases it's best to leave all the returns open including those in the basement as that will mix the warmer and cooler air. If there are no returns in the basement then some should be added.

1. Leave all the returns open all the time
2. In cooling season close basement registers and ensure upper registers are fully open
3. In heating season open some basement registers and close or partially close some of the upper registers
4. Accept that hot air rises and the best you will be able to do is minimize the difference. Leaving the furnace fan on ensures that air is pulled from all floors and mixed together and then re-dispersed.


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## AltaRed

Agree with Prairie Guy. Got to have fully functional returns on both floors. We also have to leave our furnace fan on, especially when we have guests (all located on bottom floor of our walkout rancher).

Dual (zone) systems should be a building code requirement in my opinion in houses of 2 or more floors.


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## Bruins63

AltaRed said:


> Agree with Prairie Guy. Got to have fully functional returns on both floors. We also have to leave our furnace fan on, especially when we have guests (all located on bottom floor of our walkout rancher).
> 
> Dual (zone) systems should be a building code requirement in my opinion in houses of 2 or more floors.


I have the same problem...I now run a dehumidifier...70 degrees in the basement now...yup, my power bill will suffer but it doesn’t feel like a “basement” any more...


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## Userkare

Bruins63 said:


> I have the same problem...I now run a dehumidifier...70 degrees in the basement now...yup, my power bill will suffer but it doesn’t feel like a “basement” any more...


I agree. If you're going to pump the air from the basement, a dehumidifier will keep that air from being too damp and musty smelling. My only issue with that is I have had terrible luck with dehumidifiers; they seemed to be designed to last for no longer than the warranty period. To add insult to injury, you have to pay a fee to dispose of a dehumidifier.

So, my latest unit failed just 3 days before the 2 year warranty expired ( about 6 months usage really ). I immediately contatced the manufacturer, Hisense; they told me to just bring it back to Loews for a replacement. I did, they had just one left, and the exchange took less than 15 minutes. 

Woopee, finally I beat the odds, but.......

:crushed:

... I had been using a short hose to empty the dehumidifer directly into the sump hole. I set up the new unit exactly the same. Two days later, the "bucket full" light was on, and the hose was 'furztrocken'. Even though the model number is the same, the new unit's design is slightly different than the old one; looking at it, I can't see how the water would even flow through the hose rather than into the internal bucket. I checked, double checked, and tripple checked the instructions; there's no indication that I could possibly have hooked it up wrong. It just says "connect a hose". So now I have to manually empty the water every few days. 

I would exchange it again if I thought a replacement would drain through the hose properly, but there doesn't appear to be anything actually broken, just bad design. Maybe I can rig something with a little aquarium pump to empty it automatically; might be a fun project.


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## like_to_retire

Userkare said:


> ... I had been using a short hose to empty the dehumidifer directly into the sump hole. I set up the new unit exactly the same. Two days later, the "bucket full" light was on, and the hose was 'furztrocken'. Even though the model number is the same, the new unit's design is slightly different than the old one; looking at it, I can't see how the water would even flow through the hose rather than into the internal bucket. I checked, double checked, and tripple checked the instructions; there's no indication that I could possibly have hooked it up wrong. It just says "connect a hose". So now I have to manually empty the water every few days.
> 
> I would exchange it again if I thought a replacement would drain through the hose properly, but there doesn't appear to be anything actually broken, just bad design. Maybe I can rig something with a little aquarium pump to empty it automatically; might be a fun project.


I know in every de-humidifier I have ever used, the hose attachment point is on the water bucket itself. In the one I'm presently using I did have to break a thin piece of plastic in the bucket hose threads to allow the water to flow. This is designed so they don't have to provide a cap on those threads if people decide not to use a hose. I just screw a short hose onto the bucket, and it feeds into my basement drain. I can't imagine emptying that bucket every day.

ltr


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## Userkare

like_to_retire said:


> I know in every de-humidifier I have ever used, the hose attachment point is on the water bucket itself. In the one I'm presently using I did have to break a thin piece of plastic in the bucket hose threads to allow the water to flow. This is designed so they don't have to provide a cap on those threads if people decide not to use a hose. I just screw a short hose onto the bucket, and it feeds into my basement drain. I can't imagine emptying that bucket every day.
> 
> ltr


I had an old Sears unit like that; since it was low profile, the bucket was more like a slide-out tray, and had a hose connection at the bottom front of the tray. They provided a cap for when the hose wasn't used. This Hisense model has the hose attachment above the bucket; there's a hole on the side panel with a little flip-up door to pass the hose through. The instructions say nothing about breaking any plastic, and I don't see anything that would stop water from coming out the hose connection, except that it doesn't. The same hose, in the same place, worked perfectly for the life of the 2 yr old Hisense that it replaced.

I'm thinking design flaw b/c it seems that I'm not the only one to experience this... https://www.bestbuy.com/site/questi...question/c1d468c0-988e-3b03-bbbc-80cbe9300e8c

As for daily emptying it, I think I have a DIY pump solution. https://www.amazon.ca/dp/B01MYMNNIN/ref=pe_3034960_236394800_TE_dp_2 and some parts from the failed projects bin.


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## Prairie Guy

Years ago I had an old dehumidifier that had no hose attachment. I just drilled a hole in the bottom of the reservoir and parked the unit right over the floor drain .


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## Mukhang pera

Today I got around to taking a look at this thread. The title - cold basement, hot upper floor - had me thinking it might pertain to some kind of sexual dysfunction. But no, it's actually about home heating and cooling issues.


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## Dilbert

Mukhang pera said:


> Today I got around to taking a look at this thread. The title - cold basement, hot upper floor - had me thinking it might pertain to some kind of sexual dysfunction. But no, it's actually about home heating and cooling issues.


LMAO!:excitement:


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## Userkare

Mukhang pera said:


> Today I got around to taking a look at this thread. The title - cold basement, hot upper floor - had me thinking it might pertain to some kind of sexual dysfunction. But no, it's actually about home heating and cooling issues.


Reminds me of the guy that goes to the psychiatrist's office....

The doctor says "We're going to do some symbol association tests. Tell me the first thing that comes to your mind when I draw each symbol."
The doctor draws a straight vertical line, the patient says "sex".
The doctor draws a straight horizontal line, the patient says "sex".
The doctor draws a circle, the patient says "sex".
The doctor says "My God, you're obsessed with sex". The patient says "Me? You're the one drawing all the dirty pictures"


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## like_to_retire

Userkare said:


> This Hisense model has the hose attachment above the bucket; there's a hole on the side panel with a little flip-up door to pass the hose through. The instructions say nothing about breaking any plastic, and I don't see anything that would stop water from coming out the hose connection, except that it doesn't.


You have to realize that just like the thin breakable plastic that needs to be broken on my bucket (to allow the water out the hose connection) is catering to the majority of users who don't use a hose. They buy the unit and empty the bucket and they're happy. They offer the hose capability to a few who want that, but to do so you have to 'enable' it to get it to work.

I have little doubt this is the case with your unit. Do more investigating before you resort to pumps to empty the bucket. 



Prairie Guy" said:


> Years ago I had an old dehumidifier that had no hose attachment. I just drilled a hole in the bottom of the reservoir and parked the unit right over the floor drain .


Nice.

I have always used a hose on my units, and one day I wondered just how much water was being generated, so I capped the hose output and then came downstairs in a few days and the unit was shut off. Yep, full bucket. Holey crap, that thing is really doing a job in the humid summer months.

ltr


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## Userkare

like_to_retire said:


> You have to realize that just like the thin breakable plastic that needs to be broken on my bucket (to allow the water out the hose connection) is catering to the majority of users who don't use a hose. They buy the unit and empty the bucket and they're happy. They offer the hose capability to a few who want that, but to do so you have to 'enable' it to get it to work.
> 
> I have little doubt this is the case with your unit. Do more investigating before you resort to pumps to empty the bucket.
> 
> ltr


I wish that were the case, but I have investigated as much as I can without taking the whole thing apart with a sledgehammer.

https://www.hisense-canada.com/asse...Hisense-Dehumidifier-UserManual_ENGLISH_0.pdf Page 7, Option 2 ( I don't have the unit with built-in pump ). If there was something that needed to be removed to enable this capability you would think the user manual would mention that?

Also I see absolutely nothing that looks like it needs to be removed; most of the water path is enclosed in a sealed plastic housing, so I can't see how water is diverted to the hose. As it's designed, if water should come out of the hose attachment without any hose being there, it would just drip into the bucket anyway - so no need to block it off. The note at the end of that section in the user manual says to simply remove the garden hose to go back to bucket mode.


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## like_to_retire

Userkare said:


> I wish that were the case, but I have investigated as much as I can without taking the whole thing apart with a sledgehammer.
> 
> https://www.hisense-canada.com/asse...Hisense-Dehumidifier-UserManual_ENGLISH_0.pdf Page 7, Option 2 ( I don't have the unit with built-in pump ). If there was something that needed to be removed to enable this capability you would think the user manual would mention that?
> 
> Also I see absolutely nothing that looks like it needs to be removed; most of the water path is enclosed in a sealed plastic housing, so I can't see how water is diverted to the hose. As it's designed, if water should come out of the hose attachment without any hose being there, it would just drip into the bucket anyway - so no need to block it off. The note at the end of that section in the user manual says to simply remove the garden hose to go back to bucket mode.


Well, it looks like the hose drains the bucket as it reaches full, rather than a standard hose connection that is located at the bottom of the bucket. Goofy, but still fine. 

It tells you where the garden hose connects to the side of the bucket, and so when the bucket gets full it overflows to the garden hose connector. How could this not work?

ltr


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## Userkare

like_to_retire said:


> Well, it looks like the hose drains the bucket as it reaches full, rather than a standard hose connection that is located at the bottom of the bucket. Goofy, but still fine.
> 
> It tells you where the garden hose connects to the side of the bucket, and so when the bucket gets full it overflows to the garden hose connector. How could this not work?
> 
> ltr


No actually the hose isn't connected to the bucket. The bucket can be completely removed and the hose stays connected to a plastic housing located in the main body of the dehumidifier.


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## like_to_retire

Userkare said:


> No actually the hose isn't connected to the bucket. The bucket can be completely removed and the hose stays connected to a plastic housing located in the main body of the dehumidifier.


Dang, you must be missing a part then. That's all I can think.

Myself, I'd probably be drilling a hole in the bucket and adding a hose connector onto it. Job done.

ltr


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## gaspr

I can't help but think that the best solution for those with this problem is to install a "cool only" mini split system to the upper floor area. Relatively cheap, quiet, very efficient, and you will find that your central air system will run very seldom or not at all. Especially if there is an open stair case. Run the fan on the central system at low speed to mix and distribute the air. Don't over size the unit...the more it runs, the better it will reduce humidity which is key to indoor air comfort. And never open windows at night...that just introduces unwanted humidity which exacerbates the problem.


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## Prairie Guy

gaspr said:


> I can't help but think that the best solution for those with this problem is to install a "cool only" mini split system to the upper floor area.


I'd call that a last resort option. One should first ensure that there are proper returns on all floors and that the ducts are fully open on the upper floors and closed on the lower floors. That's the least expensive solution (it may cost nothing) and should be tried first. Don't spend any money until after the return and venting issues have been fully investigated and tried.


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## gaspr

Prairie Guy said:


> I'd call that a last resort option. One should first ensure that there are proper returns on all floors and that the ducts are fully open on the upper floors and closed on the lower floors. That's the least expensive solution (it may cost nothing) and should be tried first. Don't spend any money until after the return and venting issues have been fully investigated and tried.


Sure, try that first but in my experience it will do little to mitigate that pool of warm buoyant air that remains trapped at the ceiling. Return air ducts are almost always at floor level on upper floors which works great for heating but not so much for cooling. 
Meanwhile, even with lower ducts closed it will still be too cold on the lower floors because of leaky ductwork.


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## Prairie Guy

gaspr said:


> Sure, try that first but in my experience it will do little to mitigate that pool of warm buoyant air that remains trapped at the ceiling. Return air ducts are almost always at floor level on upper floors which works great for heating but not so much for cooling.
> Meanwhile, even with lower ducts closed it will still be too cold on the lower floors because of leaky ductwork.


Returns are usually located between wall studs. If you want to pull air from the ceiling it's a simple matter to add a vent near the ceiling directly above the one on the floor. The space between the studs and drywall forms a channel and the upper or lower return can be open or closed depending on the season.

Ducts may be leaky but they may not be and even if they are it may be an insignificant amount not worth worrying about.

As I stated...try the simplest solution first before spending money on a second AC unit that may not be needed.


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