HVAC (heating and AC) question

[jaywhy]

Should I get an attic fan?
On 90+ degree days my main floor stays under 72ish but my upstairs is 78+. My house (in NJ) has 2 central AC/heat systems.  One is in the attic and my attic is probably 130 degrees right now. An HVAC guy just told me the unit is fine, but being that its sucking in such hot air, and that the ductwork is in such a hot attic, by the time the air gets to my bedrooms it isn't cold. He said I need a good attic fan installed. Though google seems to say they can cause more problems. Any advice?

Thinking about this as well.
Seems to be a choice between better attic insulation or an attic fan.

[knowitall]

Thinking about this as well.
Seems to be a choice between better attic insulation or an attic fan.

Yeah from my hour of google research it’s either:
A) insulate the attic with sprayfoam or other methods. (And close up all vents?)
Or
B) install an attic fan and more vents if necessary, so the air gets vented outside and the attic doesn’t get much hotter than the outdoor temps.
IINM If you have a blower unit in the attic option B is recommended.
I’d love to hear input from HVAC guys instead of what I see on Reddit

[skyguy918]

Not asking but just going to vent a bit.

The HVAC system in our new-ish house was installed so badly, such a terrible job. Despite having a new house with a brand new system, and spray foam, the main floor could barely ever cool down, I would have it running on 68 all day and it still wouldn't feel that cool in my house. I finally brought someone last September to check out my house, but instead of inspecting the house, he quickly shoots in some freon and bills me $400, claiming thats all it needed. But my house is hotter than ever. I brought down another HVAC guy a couple weeks ago and he finds that the condenser and indoor units were mixed up, my 3 ton condenser was hooked up to my tenants 2 ton unit, and the tenants 2 ton condenser was hooked up to my 3 ton unit.

Sure enough we swapped out the units and I feel sufficiently-cool air in my house for the first time ever. There were also issues with the ductwork among other things but can't be fixed. It's really sad how poorly these things are built, many HVAC installations that are being performed in Lakewood should not be acceptable by any means.

My brother had this with a general contractor that put in a 2 to 1 mini split for a partial renovation. He crossed up the power wires, which was causing one room's remote to power on its unit but send coolant to the other room, and vice versa. My brother had to diagnose this himself, which he realized by the fact that it only got cool in either room when both indoor units were powered on.

[The Metzuyan]

Yeah from my hour of google research it’s either:
A) insulate the attic with sprayfoam or other methods. (And close up all vents?)
Or
B) install an attic fan and more vents if necessary, so the air gets vented outside and the attic doesn’t get much hotter than the outdoor temps.
IINM If you have a blower unit in the attic option B is recommended.
I’d love to hear input from HVAC guys instead of what I see on Reddit

Why is option B recommended if the blower is in the attic?

[The Metzuyan]

I did have a attic fan till recently it helped out somewhat i just upgraded to sprafoam in attic and my ac is working alot better  my attic is cool as well

Curious- would you have an estimate for how much you are saving on energy bills per month?

[CountValentine]

Have a furnace/AC with the furnace motor running all the time. Want to guess what it was or should I just say?

[aygart]

Curious- would you have an estimate for how much you are saving on energy bills per month?

My experience in my old house with an attice fan is that when it broke the energy bills were not that different but the AC struggled to keep up.

[CountValentine]

My experience in my old house with an attice fan is that when it broke the energy bills were not that different but the AC struggled to keep up.

If it was struggling then it should have been running more and using more electricity. You would think noticeably.

[CountValentine]

Have a furnace/AC with the furnace motor running all the time. Want to guess what it was or should I just say?

It was the 24v transformer. Unless you know how to read a wiring diagram you would never think it was that. $20 on Amazon.

[Joel]

Curious- would you have an estimate for how much you are saving on energy bills per month?

Can easily be 25%
Depending how well the current attic floor insulation is installed.

[davidd75]

weird last night in NJ my central heat was not blowing out any air upstairs unit so naturally temp dropped to 59(brrrr) so I thought that's it need to call repair man but this morning when I tried again it started blowing air again?

[YitzyS]

weird last night in NJ my central heat was not blowing out any air upstairs unit so naturally temp dropped to 59(brrrr) so I thought that's it need to call repair man but this morning when I tried again it started blowing air again?

Were the filters changed recently? If not, it's possible that there was too much pressure which caused overheating which triggered a one-hour shutoff.

[yos9694]

Another possibility is the condensate drain line froze and got blocked, but thawed in the morning

[davidd75]

Were the filters changed recently? If not, it's possible that there was too much pressure which caused overheating which triggered a one-hour shutoff.

it did not work for like 6-7 hrs

[CountValentine]

Another possibility is the condensate drain line froze and got blocked, but thawed in the morning

These are outside?

[yos9694]

These are outside?

Every setup is custom. Some drip to the outside. Some drain into a sink or sump. Either way is possible to become frozen if the drain hose is in an uninsulated space like the attic.

[CountValentine]

Every setup is custom. Some drip to the outside. Some drain into a sink or sump. Either way is possible to become frozen if the drain hose is in an uninsulated space like the attic.

The installer should know better. It would be like running water pipes in an outside wall.

[nucheiner]

weird last night in NJ my central heat was not blowing out any air upstairs unit so naturally temp dropped to 59(brrrr) so I thought that's it need to call repair man but this morning when I tried again it started blowing air again?

Id guess filter wasn’t changed and froze over. Was there a lot of water around the unit possibly after it thawed out?

[CountValentine]

Id guess filter wasn’t changed and froze over. Was there a lot of water around the unit possibly after it thawed out?

How would the filter freeze?

[sguitarist18]

The installer should know better. It would be like running water pipes in an outside wall.

My contractor did this. Did I mention it's in an uninsulated outside wall, when we had demo'd the room to the studs? When I asked him about it, he said that the studs weren't big enough for the official way the insulation is supposed to be installed. Didn't explain why he didn't a) put in whatever insulation he could fit, or b) discuss with me the option of extending the studs so there'd be more space.

Sorry for the OT rant.