HVAC thread # 312

[Road Guy]

[SIZE=medium]Alright so I know we have a hundred of these threads..[/SIZE]

[SIZE=medium]Everything was going well on the new house until it got hot outside (WTF is it 99 degrees?) – Another thread..[/SIZE]

[SIZE=medium]So we have a two story house with an unfinished basement. We have a 2.5 ton unit which is housed in the basement. I don’t recall the SF of our house but this is basically the max size unit for our house.. I really think this is too small of a unit, I think at our old house in GA, which was bigger by 1000 SF, but we had a 2 ton unit for each floor (& in August both of those things ran 20 hours a day to keep the house at 79 degrees)[/SIZE]

[SIZE=medium]So as you can imagine, basement is like an ice box, main floor is very comfortable, upstairs, sweltering hot..[/SIZE]

[SIZE=medium]There is a sticker on the HVAC unit with some type of certification BS: This unit was perfectly designed for this home… We had them service the unit before we bought the house, it got a clean bill of health, [/SIZE]

[SIZE=medium]We called the service company, they actually came out for free and basically said “ man it’s just hot outside”… I even asked about a bigger unit and he said he actually wouldn’t recommend it because we would pay more throughout the year when we really only need it for 2 months a year here? Also apparently there is some BS that I have to get a permit to put in a new unit and they “don’t like” to allow you to upsize your HVAC- total BS! I thought I didn’t live in Boulder County?[/SIZE]

[SIZE=medium]They recommended we close all the main floor vents to push more cold air upstairs, which did worked a little.. Also the basement has 4 vents, which I closed; I also wanted to ask about sealing them off completely. I can still feel a lot of air loss coming through the basement vents (unfinished- not really needed) but I would do it so I could unseal them during winter to keep pipes and such from breaking..[/SIZE]

[SIZE=medium]There are return vents upstairs to help suck the air down from the second floor to remove the hotter air, What I really wish I could figure out is how to push more of the cold air in the basement to the second floor?[/SIZE]

[SIZE=medium]For what I paid for this house I should be able to lie in my bed at night and not sweat right? Well I may sweat during pre- sleep activities, but after that I need to be cold to sleep..[/SIZE]

[SIZE=medium]Options ?[/SIZE]

[SIZE=medium]The roof has a lot of vents but not an attic ventilation fan. But since the hvac unit is in the basement I am not sure if this will work that much? But this is only a few hundred bucks and a self install I can do.[/SIZE]

[SIZE=medium]Thinking about just buying two of those tower fans that have a built in air conditioner with them to use these two months or so? Might be the cheapest option?[/SIZE]

[SIZE=medium]May just buy a bed for the basement?[/SIZE]

[SIZE=medium]We have been able to be very comfortable with the windows open at night after 7:00 up until around 2 weeks ago…[/SIZE]

[SIZE=medium]The people that we bought the house from had one of those NEST devices installed, which is pretty cool, I can change the temp setting from my phone. For example today we are gone all day but I can crank the air down when I leave work… it also gives you great “data” i.e. it told us that yesterday the air ran for[/SIZE]

[SIZE=medium]I feel pretty good about the insualtion and other weatherproofing parts of the home, I am going to explore more of this this weekend. I know they energy companies will do an energy audit of your home but I imagine they send out some high school graduate with a checklist that I can print of the interent myself..[/SIZE]

 

[Ship Wreck PE]

I had to buy a vent booster one time. It plugs into 120 volt outlet and sences when AC is on. It has a fan that pulls more air into room.

 

[Road Guy]

did you install that (in line) in the vent? or is that something that you can put on at the exit part of the vent?

 

[Ship Wreck PE]

Had floor vents and it just sat on top of it.

Looks like a thin shoe box. Only cost like $30.00

 

[Road Guy]

Thanks.... Home Depot?

 

[Ship Wreck PE]

Yes or eBay, Amazon,

 

[Supe]

They also have inline boosters that splice into the duct work that are more efficient. This was recommended to me by one of the AC guys for the movie theater room, which is over the garage, which isn't heated/cooled. It can be wired/installed right near the air handler.

 

[Road Guy]

what I would like to do is install cut off's closer to the main "T" so that closing the downstairs vents is more efficent. We have the all metal non insulated ducts which make installing that a llittle easier. I am sure we are losing some by the air traveling from the T to the duct (10') to the rfegister-which is closed off.. be nice to be able to go down in basement and turn some of them off at the source so more goes upstairs...I am sure we will have opposite problem in winter (but hopefully not as bad)

 

[MetsFan]

^^ That's probably your cheapest option. You can buy an air damper from Home Depot and install it at the main branch take-offs to the basement. Are there return vents at each floor? If so, you might try closing those off too so you get the cool air going up to the second floor.

Is the floor of your attic well insulated? That could be another source of heat gain to the second floor.

Typically for a residential house, you want about 450-500 square feet per ton, so for your 2.5 ton unit, you should be at around 1200 sf.

 

[goodal]

Here goes...

I would place something over the grilles in the basement that is easy to remove for changing of the seasons. I was thinking a big flexible magnet but I don't think your ductwork is magentic. You should probably install the attic vent and control it with a thermostat set to ~85F.

The real problem is you have one unit serving 3 floors. It will NEVER work right in cooling mode. The top floor will always be hotter than the lower floors because of the heat gain from the roof. I had a setup just like yours at the last house. The only true remedy is more thermostats. The cheapest is the indoor ac units that you can roll in and out at will. The best ones will have two pipes that terminate at a window. One brings air in for the condensor and the other discharges the hot air to outdoors. They make them with one hose, but they don't work as good because the unit is sucking your nice, conditioned air through and blowing it outside. Another idea is a ductless mini split (mitsubishi) unit. If the 2nd flr is one large room this would work perfect. They do have units with one outdoor unit that can serve multiple inside, but that gets pricey fast.

Hope that helps.

 

[Road Guy]

then I am hosed if thats the case.. I noitced that most of the houses around me have a similar size ac unit. It was put in in 2005.... if i can just get through this summer I can deal with next year hopefully... ..

Will also check out the dampeners from HDepot..

And basement is really well insulated.....

 

[engineergurl]

duct tape-

HA HA HA HA

but seriously, tape off the vents temporarily? at my last job, we had the kind of vents you couldn't close so we shoved paper into them and it worked fine

 

[Supe]

I'll second Goodal's recommendation of the Mitsubishi units too. My father just had one installed in their family room (tall ceiling, big separate edition to the house, not well insulated, lots of glass windows, slab foundation), and said that thing will actually make it cold in that room in the middle of summer. Much cheaper alternative to new duct work/air handler/units.

 

[Road Guy]

I agree its small (yeah thats what she said) ....

I dont think the intent was for the unit to heat / cool the basement, I think thats just where it happens to be, Im not sure why they have registeres in the basement other than maybe to keep basement above freezing (its only 2 vents for 800 SF) during the zero degree days in Denver...

 

[Road Guy]

Bumping last year’s thread and I thought some of you would find this interesting / useful.

So this year we go to turn the AC on and nothing is coming out, last year was bad but this was worse, check filter, its good, replace anyways, kick the thing a few times, nothing happens..

Break down and call some AC people that we had heard some good stories on..

So while we are “mostly diligent” in replacing our air filter, apparently the previous owners either never did or just had a critical flaw (we have owned this house just under a year)

If you have low air flow take the side panel off your furnace (just above where the air filter goes) the air is blown over the coils to create the “cold” well ours it looked like there was a dead cat stuck to the coils (above where the filter goes) The dude pulled what looked like 5+ year of dust, crap, dirt and pet fur off the coils that literally when it fell to the floor I first thought it was truly a dead animal it was so thick..

A few minutes later the entire house was damn near ice cold…

I never would have thought to check that since you would think the filter would catch that but the ac guys said that was one of the worst they had ever seen and again looked like the previous owner probably changed the filter maybe once a year.

Just thought I would pass along cause I could have saved myself the $85 service call but at least it didn’t keep running and break the system..

 

[goodal]

Animals inside = Bad