Hey pros out there,
I am planning to finally give in and replace my second floor and attic AC/gas furnace. If I am going to shell out the many thousands for it, though, there have been some things I have always thought would make sense and save energy, but it's very hard to figure out if this is even possible! Let me explain the situation and tell you what I am thinking, and you can tell me if I am nuts or if such products are possible or available.
I live in the Raleigh, NC area, in a house of about 4000 sq ft. I have one system that currently serves the second floor and the attic, in three zones wih their own thermostats - the attic (my office, all one big room except for the unfinished part where the inside unit is), the master bedroom/bathroom, and the rest of the second floor (three more bedrooms, 2 bathrooms, and a big open space).
My house faces due west with a big ole expanse of shingles facing west, so in the afternoon, it gets HOT in the attic, even on days when it's pretty cool outside (when it's 50 or 60 degrees outside, it can still hit the upper 70s or even 80 in the attic if the AC is off). The second floor, in contrast, doesn't get nearly that hot when it's cooler outside. In fact, a situation where heating second floor but cooling the attic is not rare, especially in the fall and spring.
I have long thought it would make sense to be able to have a system that did a couple of things, but I have never been able to find a solution for these:
1. When it is hot in the attic but cool on the second floor, would it be possible to have a system that knew to run the fan in both zones to equalize the temperature, taking heat from the attic and dumping it into the second floor, and taking the cool air from the second floor and putting it in the attic?
2. When it is hot in the attic but cool outside, is it possible to have a system that instead of running the AC, would take cool air from outside and pump it into the attic?
Of these two, number 2 is probably more important, as I think there is a fairly substantial number of days when cool air from outside would be enough. I know this because on such days I can open a window and cool it that way, but since I am trying to work in here I hear every dang leaf blower, siren, mower, etc., plus lots of pollen and dust. But I have searched around on this topic and it seems like I am the only person ever to think of this, which is of course nuts.
With regard to number 1, I think a sufficiently "smart" zone board would be enough, but I don't know if that exists.
The most obvious solution - a mini-split system in the attic - I am at this point ruling out. I have one now, and it's broken. Again. This is the THIRD unit that has been in there since I moved in - the home warranty company has replaced it twice and it's still losing coolant, breaking, etc. They do leak tests, tell me it's fine, then it leaks again a couple weeks later, and then they want me to spend *** on refrigerant. So at this point, I'd rather replace it with a multi-speed central system that can actually handle the attic and second floor needs - right now, I have ducts in the attic, but the current system doesn't have enough capacity to cool the attic and the second floor during most of the summer. And I can't use a window AC because of HOA rules.
Any suggestions for products that would accomplish what I need here? Most of the HVAC guys I have talked to are not very savvy about this stuff and when I mention this to them, they look at me like I am nuts. So I would like to at least be able to tell them what they need to look at to see if they'd be wiling to install and design the system.
Thanks!
Please leave pricing out of your posts as it is not allowed by forum rules - thanks.
I am planning to finally give in and replace my second floor and attic AC/gas furnace. If I am going to shell out the many thousands for it, though, there have been some things I have always thought would make sense and save energy, but it's very hard to figure out if this is even possible! Let me explain the situation and tell you what I am thinking, and you can tell me if I am nuts or if such products are possible or available.
I live in the Raleigh, NC area, in a house of about 4000 sq ft. I have one system that currently serves the second floor and the attic, in three zones wih their own thermostats - the attic (my office, all one big room except for the unfinished part where the inside unit is), the master bedroom/bathroom, and the rest of the second floor (three more bedrooms, 2 bathrooms, and a big open space).
My house faces due west with a big ole expanse of shingles facing west, so in the afternoon, it gets HOT in the attic, even on days when it's pretty cool outside (when it's 50 or 60 degrees outside, it can still hit the upper 70s or even 80 in the attic if the AC is off). The second floor, in contrast, doesn't get nearly that hot when it's cooler outside. In fact, a situation where heating second floor but cooling the attic is not rare, especially in the fall and spring.
I have long thought it would make sense to be able to have a system that did a couple of things, but I have never been able to find a solution for these:
1. When it is hot in the attic but cool on the second floor, would it be possible to have a system that knew to run the fan in both zones to equalize the temperature, taking heat from the attic and dumping it into the second floor, and taking the cool air from the second floor and putting it in the attic?
2. When it is hot in the attic but cool outside, is it possible to have a system that instead of running the AC, would take cool air from outside and pump it into the attic?
Of these two, number 2 is probably more important, as I think there is a fairly substantial number of days when cool air from outside would be enough. I know this because on such days I can open a window and cool it that way, but since I am trying to work in here I hear every dang leaf blower, siren, mower, etc., plus lots of pollen and dust. But I have searched around on this topic and it seems like I am the only person ever to think of this, which is of course nuts.
With regard to number 1, I think a sufficiently "smart" zone board would be enough, but I don't know if that exists.
The most obvious solution - a mini-split system in the attic - I am at this point ruling out. I have one now, and it's broken. Again. This is the THIRD unit that has been in there since I moved in - the home warranty company has replaced it twice and it's still losing coolant, breaking, etc. They do leak tests, tell me it's fine, then it leaks again a couple weeks later, and then they want me to spend *** on refrigerant. So at this point, I'd rather replace it with a multi-speed central system that can actually handle the attic and second floor needs - right now, I have ducts in the attic, but the current system doesn't have enough capacity to cool the attic and the second floor during most of the summer. And I can't use a window AC because of HOA rules.
Any suggestions for products that would accomplish what I need here? Most of the HVAC guys I have talked to are not very savvy about this stuff and when I mention this to them, they look at me like I am nuts. So I would like to at least be able to tell them what they need to look at to see if they'd be wiling to install and design the system.
Thanks!
Please leave pricing out of your posts as it is not allowed by forum rules - thanks.
