DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   HVAC (http://www.diychatroom.com/f17/)
-   -   22 vs 410A on a hot day (http://www.diychatroom.com/f17/22-vs-410a-hot-day-168488/)

sammy37 01-07-2013 02:42 PM

22 vs 410A on a hot day
 
Can someone verify for me that a 410A unit will not cool as well as 22 does on a very hot day?
I'm wanting to replace the unit on my house with a smaller unit and have been told that a 410A unit will not keep up the same.
When you guys do manual J's, do you have to take this into account?

digitalplumber 01-07-2013 03:07 PM

Never heard this subscribing to see what the experts say.

Technow 01-07-2013 03:56 PM

A 24000BTUH R-22 condenser is the same as a 24000 BTUH R410A condenser

The manual J gives you the load on the house....a manual S is used to match the condenser to the manual J.

sammy37 01-07-2013 04:10 PM

This will be a package unit. I've heard in very hot weather that 410A cannot keep up like a 22 unit.

sammy37 01-07-2013 04:11 PM

Seems like I've heard beenthere mention this somewhere along the line, maybe he'll be along soon.

Technow 01-07-2013 04:39 PM

Quote:

Originally Posted by sammy37 (Post 1088428)
This will be a package unit. I've heard in very hot weather that 410A cannot keep up like a 22 unit.

Quote:

Originally Posted by sammy37 (Post 1088431)
Seems like I've heard beenthere mention this somewhere along the line, maybe he'll be along soon.

Yeah, I am sure he will:thumbsup:

Just make sure they don't give you a 22000BTUH R410A condenser instead of a 24000 BTUH R22 condenser. :whistling2:

beenthere 01-07-2013 04:59 PM

R410A does drop off in capacity at high outdoor temps. At 115F outdoor temp a 2 ton R22 will have more capacity then a 2 ton R410A unit will. And as it gets hotter the difference increases. So it comes down to where you are located, and where you will have your condenser or package unit installed. My area, it doesn't matter. In Death Valley it will definitely matter.

A Manual J actually only tells you the capacity you need. Manual S is what tells you the size unit by giving you the derates and multipliers to use.

sammy37 01-07-2013 10:14 PM

So educate me here. As a person that has grown up in oversized country, what is the optimum setup for summer cooling? Should a unit run constantly on a hot day? Is it really cheaper to have a small unit run all day, as opposed to a larger unit that cycles off and on through the day?

I have only seen one example of a proper sized or possibly undersized setup, it was at my in laws house in Austin TX. They have a 1900 sq ft old 1980's tract house with a new 2 ton Bryant unit that runs all day long and doesnt really hold the set temp but the house was very comfortable and they say their power bills are quite cheap. I bet if someone was to run a load calc, it would come in higher than what they have. Is going smaller than what a load calc calls for bad? I wouldnt try it on a customers house but I dont mind trying it on my own.

There is a house in our neighborhood that is bigger than ours, it's 1920 sq ft, they are running a 3 ton unit. I wouldnt have believed it till I noticed the small unit on their roof and stopped to ask how they like it. He replied that they have all original insulation, windows and they run it at 78 with no problems. Their house originally came with a 4 ton unit.

digitalplumber 01-07-2013 10:21 PM

S37' what I can tell you in my home in Houston Texas. Originally builder installed 2 3 ton units. Changed them to 2 4 tons and could not be happier. 1 up and 1 down. Each is responsible for 1800 square feet.

Upstairs cycles even on super hot days and does the job!

beenthere 01-07-2013 10:37 PM

Quote:

Originally Posted by sammy37 (Post 1088688)
So educate me here. As a person that has grown up in oversized country, what is the optimum setup for summer cooling? Should a unit run constantly on a hot day? Is it really cheaper to have a small unit run all day, as opposed to a larger unit that cycles off and on through the day?

I have only seen one example of a proper sized or possibly undersized setup, it was at my in laws house in Austin TX. They have a 1900 sq ft old 1980's tract house with a new 2 ton Bryant unit that runs all day long and doesnt really hold the set temp but the house was very comfortable and they say their power bills are quite cheap. I bet if someone was to run a load calc, it would come in higher than what they have. Is going smaller than what a load calc calls for bad? I wouldnt try it on a customers house but I dont mind trying it on my own.

There is a house in our neighborhood that is bigger than ours, it's 1920 sq ft, they are running a 3 ton unit. I wouldnt have believed it till I noticed the small unit on their roof and stopped to ask how they like it. He replied that they have all original insulation, windows and they run it at 78 with no problems. Their house originally came with a 4 ton unit.

Just to cover the load, plus 15%.

The tightness of the home determines how comfortable the home will be with a "under sized" unit. if the humidity is kept down, it will feel comfortable. if it can't keep the humidity down it on't feel comfortable.

beenthere 01-07-2013 10:39 PM

Quote:

Originally Posted by digitalplumber (Post 1088696)
S37' what I can tell you in my home in Houston Texas. Originally builder installed 2 3 ton units. Changed them to 2 4 tons and could not be happier. 1 up and 1 down. Each is responsible for 1800 square feet.

Upstairs cycles even on super hot days and does the job!

Unless you had your duct work altered, good chance your only getting 3 to 3.25 tons worth of cooling. And it was your under sized duct work that was the problem, not the A/C size.

What is the temp difference across the evap coil.

sammy37 01-07-2013 11:05 PM

Having been in many houses in Vegas that were set at the 77-80 degree range, I found them to be downright uncomfortable when the unit was off.

Spending a week in Texas with their house running at 78 degrees I was comfortable, because the unit was constantly running. With my oversized unit here at our house, I have to run it 75 degrees or less to stay comfortable with the cycling on and off. I know we can use ceiling fans and we do but it's not the same for me.

The main reason I asked about the r22 vs 410a, was because the small 3 ton unit on our neighbors house is r22.
I have an r22 3ton unit sitting in my garage that I was going to throw up on my roof but turns out it has a leaky evap coil and I dont want to mess with getting it fixed.

Now, I'm forced to buy a new 410a unit and dont want to screw up and buy one that is too small, it was all fine and good when I had the freeby unit to put up there.

sammy37 01-07-2013 11:38 PM

The other reason, I want to get rid of the heat pump and go back to gas.

carmon 01-08-2013 12:23 AM

115.... oh my.... no worries here.....410 it is...lol

beenthere 01-08-2013 05:08 AM

Quote:

Originally Posted by sammy37 (Post 1088730)
Having been in many houses in Vegas that were set at the 77-80 degree range, I found them to be downright uncomfortable when the unit was off.

Spending a week in Texas with their house running at 78 degrees I was comfortable, because the unit was constantly running. With my oversized unit here at our house, I have to run it 75 degrees or less to stay comfortable with the cycling on and off. I know we can use ceiling fans and we do but it's not the same for me.

The main reason I asked about the r22 vs 410a, was because the small 3 ton unit on our neighbors house is r22.
I have an r22 3ton unit sitting in my garage that I was going to throw up on my roof but turns out it has a leaky evap coil and I dont want to mess with getting it fixed.

Now, I'm forced to buy a new 410a unit and dont want to screw up and buy one that is too small, it was all fine and good when I had the freeby unit to put up there.

How tight is your home. The tighter it is, the lower the humidity will be.


All times are GMT -5. The time now is 11:21 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved