Why is my house so hot??

[CourierDriver]

I did installs for many years, a two story house needs 2 units at least, total tons of cooling for ur home should have been 3 to 3.5 tons of airconditioning depending on the heat load calculations the contractor should have done. It will not get any better, your unit is undersized for sure. sky

 

[Papa Bear]

How are your neighbor's units working? Are they cool?

65F seems quite warm for an A/C duct output, the duct in our bedroom is blowing 55F air.

 

[Steve S]

Originally Posted By: LT4 Vette
We have a Carrier A/C unit and it has no problem cooling and keeping the house at 70 degrees, we also have a bunch of ceiling fans cooling the house. We have to use A/C 10 months out of the year down here.

I set the temp at 80 went we are not home and 69-70 when we get home.
In Fla its the hunidity for sure .Here in Redding Calif it is dryer and swamp coolers work great and to me 100* or lower is comfortable if the temps go over 100* or it is humid I am hot.

 

[StevieC]

Patman I hear you... Our A/C was set to 21C this morning at 8am and the temperature in the house is now 25C. We haven't touched the thermostat, just the heat outside is so bad the A/C unit can't keep up!

 

[ryansride2017]

Originally Posted By: Papa Bear
How are your neighbor's units working? Are they cool?

65F seems quite warm for an A/C duct output, the duct in our bedroom is blowing 55F air.


Your exactly right. Patman, you don't need to be looking at insulation or anything else at this point. You need to take a look at your AC unit. Your cold supply should be considerably colder coming out of your vents than 65 degrees. With that kind of delta temp, there is no wonder your sitting at 81 degrees. That's the equivalent of trying to heat your home on a 0 degree winter day with 80 degree supply air from your furnace. Just isn't going to happen.

 

[duaneb9729]

Start with replacing the filter, every three months is a 3m filter idea that isnt good for your equipment or your comfort.

check the condenser for a build up of cotton wood or other stuff, if it has that just hose it off starting at the top of directing the water flow toward the bottom of the unit instead of trying to push it though.

have a qualified service tech check the charge.

rules of thumb for a/c sizing are barely rough guides, the earlier stated "guides" are for ramblers all those "guides" go out the window for town houses and multiple story tall homes.

Attic vents do plug up like your a/c condenser does.

attic ventilation is just as important as anything above.

these are my opinions based 32 + years in the hvac business

 

[Garak]

Originally Posted By: Patman
It's a pretty hot day here today, it's currently 93 degrees, and my air conditioning has been running non stop since about 8am (it's now 3:30pm), but yet the main floor has stayed at a constant 81 degrees (where the thermostat is) and my bedroom is now 83 degrees (even with all the blinds completely closed)


You Ontarians just need to insulate houses to "Saskatchewan standards" and you'll be fine.

 

[fdcg27]

Are you letting the hot air out?
That is, do you have adequate ventilation in the roof to evacutate hot air from the loft space?
We had a new roof put on last year, and I decided to have ridge vents put in.
It has made an enormous difference.
It is ninety something here today, and the house is pretty comfortable.
If you don't have sufficient ventilation for really hot weather, add some.
It will really help.

 

[duaneb9729]

oh one more thing, typically home a/c units are designed to keep the house 15 degrees cooler than the outdoor air, to get one to cool your house more may depend on the company your dealing with or simply asking to see your cooling load calc. and asking about the "delta T" line, or the temp differential.

 

[StevieC]

I can't wait for the FREE A/C weather to come back... WINTER!

I love it to death...

 

[dkryan]

Originally Posted By: fdcg27
Are you letting the hot air out?
That is, do you have adequate ventilation in the roof to evacutate hot air from the loft space?
We had a new roof put on last year, and I decided to have ridge vents put in.
It has made an enormous difference.
It is ninety something here today, and the house is pretty comfortable.
If you don't have sufficient ventilation for really hot weather, add some.
It will really help.


I totally agree with fdcg27. A continous ridge vent is a major first start. Being in a condo-townhouse, however, I question whether one is installed? Do you at least have box vents installed on the backside of your roof? You want one or the other, i.e., box vents or the ridge vent, not both.

I have the same issue in my two-story, 2300 square foot home. It has a ridge vent and a Carrier Infinity system that is only four years old. Yet the upstairs rooms are at least six+ degrees warmer than the first floor, and nowhere near as cool as the walkout basement area.

I've researched this issue in-depth the past month. I've learned that it is quite normal for two-story homes to have a temperature variance of five to seven degrees between the first and second floors. Piling on more insulation in the attic beyond "normal" insulating recommendations will do little good.

I've settled on 38" tower fans in the upstairs area and ensuring the HVAC system has been checked and is performing at a peak level.

Friends in the "hotter" regions of the U.S. have multi-zoned areas for HVAC and the requisite thermostats to match. It's almost a mandatory requirement for survival in Memphis and much further southwest.

I'd recommend the model "2-120" air conditioner. That's 2 windows down on your 'Vette at 130 kph! Cool!

 

[Nick R]

Your A/C is wayyyy too small for that house. We are renting a ~2000sq ft house right now (with full size basement) and I do believe the original owner (our landlord) had a 4 ton unit installed. It keeps the house cold easily at the set temp (75 usually) but does have to run a bit, on days like today (95 here). If it makes you feel any better, on the drive home from work tonight, my A/C was working fine, but the coolant temp climbed up a bit higher than usual- at 75 miles an hour. It was roughly 10 degrees hotter than usual.

 

[dishdude]

I have a multi-zoned system here at my house in Las Vegas, and it is great. It is 100 outside and 70 on every floor of the house

My house in Pittsburgh I actually had to put a window AC unit in the second floor to supplement the central unit. It would be 85 outside and I couldn't keep the second floor below 78 - and I had excellent insulation. There just wasn't enough duct work to the second floor, and they didn't use mastic when they installed the duct work so I lost most of the air inside the walls.

 

[hemitom]

The nature of the two story beast, hot air rises cold air drops, how to win the fight thats the ?. Make sure upstair returns are all open. 65 degree air temps, i don't care how well your system runs if its under sized your condenser and coil can not cool and dehumidify the air going past the coil fast enough to drop the temps.

 

[Patman]

Originally Posted By: CourierDriver
I did installs for many years, a two story house needs 2 units at least, total tons of cooling for ur home should have been 3 to 3.5 tons of airconditioning depending on the heat load calculations the contractor should have done. It will not get any better, your unit is undersized for sure. sky


I've figured all along that they were undersized, since my neighbors all have the same problem as me. Up here in Canada it's unheard of to have two units though, I don't know a single person up here that has two units. I guess that since it typically doesn't get above 90 degrees very often anywhere in Canada, home builders don't even bother to set up the AC system to be able to handle those kind of temps.

 

[hemitom]

You can can get away with one bigger unit you just run larger and more duct work to the upper level. In your case way to big a job to start ripping walls and ceilings open.

 

[Patman]

Originally Posted By: StevieC
I can't wait for the FREE A/C weather to come back... WINTER!

I love it to death...


Not me, I'll take this heat over winter any day of the week! My dream is to eventually own a winter home in Florida so that I never have to see a single snow flake or see temps below 40F ever again!

 

[Solo2driver]

Airflow is not a problem, don't worry about the filters. DO check your outside condenser coil and hose that sucker off. Blow out the drain line as well, as there usually is a shutoff switch if the drip pan or main drain gets backed up with algae and the water stays in there...the compressor will turn off, but your furnace/air handler will still blow air. You also should check the coil at the furnace/air handler to see if it is dirty. You normally won't get ice on the coils unless the thermostat is set too low (yours was not) or you are low on refridgerant. You may be low, and you really can't check that without a manifold gauge set. The only other "DIY" way to check that is once you've determined that your "inside" coil is clean and your "outside"/condenser coil is clean, that the condenser fan is blowing away HOT air from your outside unit and/or the coils themselves are scorching hot. If they are just about ambient or a little warmer, and both your condenser fan and compressor are running at the same time, then you are low on refridgerant.

Good luck, I work on commercial A/C units daily and while there is not really a lot to them, you can easily troubleshoot them with a little basic knowledge. Yes the attic vents are important and so is insulation, but if you've got plenty of CFM's coming out of the air vents and your DA Temp (discharge air temp) is only mid-60's, you may/probably have either blocked/dirty coils or low refridgerant.

 

[duaneb9729]

since you work in commercial units you are accustomed to more static pressure to work with, as well as not ever having to deal with the 3M or similar filter restricting the return air duct. Not doubting your abilities at all solo2driver but you cant discount any of his system at this point.

 

[Solo2driver]

Most of my work is on 4 and 5 ton package units for school classrooms (2 rooms per unit), as well as smaller 2-ton residential-type units....very similar really. But no worries.

I do think it's funny some of the filters I see people buy at home depot/lowes / etc....I used to be like that though. Folks buy these super-tight Filtrete filters that may trap very small particles but load up like crazy very quickly...my own house was like that when I had by 2 cats and a dog. IMO a nice-flowing MERV8 filter is more than adequate even for institutional applications and can last up to a year without creating undue restriction and still keep the air supply and inside coil clean. I can suggest one if anyone would like, as I am not a fan of most of the off-the-shelf stuff.-- http://www.camfilfarr.com/cou_us/products/medeff/3030.cfm and they are cheaper than the 3M stuff. I have no affiliation other than I use them on the school my kids go to

But in PatMan's case, seeing that he changes his filters every 3 months and likely has probably looked at his filter, as well as felt the air coming out of the vents enough to check their temp (and probably would have noted if he felt decreased flow), I don't think it's an air handler issue.