Variable Speed Fans? Humidity? - HVAC - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread
Display Modes
Old 06-24-2020, 12:01 PM   #1
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

variable speed fans? Humidity?


Hi,
Will getting a variable speed handler on a 1.5 to 2 ton split heatpump system make a good bit of difference in terms of pulling humidity out of the air and air quality? I do plan on putting in a uv light on the coils if that makes a difference...

Especially if the condenser is only single stage?

Still in analysis paralysis.
wraiththe is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-24-2020, 12:17 PM   #2
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 22,469
Rewards Points: 244
Default

Re: variable speed fans? Humidity?


Variable speed air handlers if they have a ECM Variable speed motor are good for constant air circulation as the motor uses a LOT less power than a fixed speed PSC motor. Plus you can run them on continuous at a much lower speed which is quieter and less drafty.

They won't remove much more moisture than a properly setup multispeed motor with a single stage unit. You can tweak the airspeed +/ 5% on them and get a bit better humidity removal but it is not a huge improvement considering the extra cost of the motor.

ECM motors have ball bearings and can run longer w/o seizing up than PSC motors but they cost 4x as much to buy and are pretty expensive.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-24-2020, 12:25 PM   #3
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by yuri View Post

ECM motors have ball bearings and can run longer w/o seizing up than PSC motors but they cost 4x as much to buy and are pretty expensive.
Most new systems have ECM dont they?

Would replacing a multi-speed ECM be much more expensive than a Variable speed ECM?
wraiththe is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-24-2020, 01:09 PM   #4
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 22,469
Rewards Points: 244
Default

Re: variable speed fans? Humidity?


The X13 are 4 speed ECM motors but a true variable speed has infinite speeds ( almost ).

The variable speed ECM have a lot more electronics and expensive parts vs a simple 4 speed X13. That drives up the cost.

The variable speed ECM is the most expensive followed by the X13 fixed speed ECM followed by the old school PSC which are starting to go obsolete on new units.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Old 06-24-2020, 06:13 PM   #5
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

Re: variable speed fans? Humidity?


So then, if I do not have money to burn, Multispeed ECM (I have only seen 3 and 5 speeds... that I know of) might be a better option in case one breaks...

I know this is only partially related (Humidity) I know it is more complicated than this...
Since I am 1100 sq ft.. that is in the middle for 1.5 and 2 ton compressors.
Most are saying do the 2 ton. If I had a 2 stage, would that help pull more humidity out of the air? Running at +66% sounds like it would run like a 1.33 ton compressor? Would that even work with a multispeed handler?

The variable speed motors seem to be available for @300?
wraiththe is offline   Reply With Quote
Old 06-24-2020, 06:41 PM   #6
RRH
Member
 
Join Date: Nov 2016
Posts: 795
Rewards Points: 1,590
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by wraiththe View Post
So then, if I do not have money to burn, Multispeed ECM (I have only seen 3 and 5 speeds... that I know of) might be a better option in case one breaks...

I know this is only partially related (Humidity) I know it is more complicated than this...
Since I am 1100 sq ft.. that is in the middle for 1.5 and 2 ton compressors.
Most are saying do the 2 ton. If I had a 2 stage, would that help pull more humidity out of the air? Running at +66% sounds like it would run like a 1.33 ton compressor? Would that even work with a multispeed handler?

The variable speed motors seem to be available for @300?
My area . Virginia .
For that size the question would be 2 or 2 /12 ton for some.
RRH is online now   Reply With Quote
Old 06-24-2020, 07:51 PM   #7
An old Tradesmen
 
Join Date: Oct 2008
Location: Somewhere
Posts: 39,278
Rewards Points: 124
Default

Re: variable speed fans? Humidity?


A VS blower will help remove a lot more humidity/moisture than any multispeed motor will.
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 06-24-2020, 10:56 PM   #8
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by beenthere View Post
A VS blower will help remove a lot more humidity/moisture than any multispeed motor will.
Thanks! Just to be sure: is this true for pairing it with a single stage -

as well as a 2 stage compressor???
wraiththe is offline   Reply With Quote
Old 06-25-2020, 05:08 AM   #9
An old Tradesmen
 
Join Date: Oct 2008
Location: Somewhere
Posts: 39,278
Rewards Points: 124
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by wraiththe View Post
Thanks! Just to be sure: is this true for pairing it with a single stage -

as well as a 2 stage compressor???
Yes.


With a single stage, the blower can be set up to move a very low amount of air for the first 30 seconds, and then move only 87% of normal air volume for 7.5 minutes. To aid in moisture removal.


It can also be set up to run slower when ever the humidity is higher than set point of the thermostat.
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 06-25-2020, 08:08 AM   #10
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 22,469
Rewards Points: 244
Default

Re: variable speed fans? Humidity?


It comes down to where you live and what your needs are. If you live in hot humid Florida then you want the most humidity removal so a variable speed ( the other I call X13 ) does a better job but the upfront cost is higher ( usually around $500 Cdn ).

I don't know how many speeds each brand uses and the X13 has 5 speed taps but it depends on the brand ( Lennox etc ) as to how many are used for different functions. I call them 4 speed as I am a furnace guy and PSC motors are usually all 4 speed.

The cost to replace a PSC motor by a dealer is $300-500, X13 $700-800., Variable speed ECM they start at $1000 and go up and you have to buy it from Lennox or Carrier etc as they are programmed to match their equipment.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Old 06-25-2020, 10:54 AM   #11
Member
 
user_12345a's Avatar
 
Join Date: Nov 2014
Location: Canada
Posts: 12,474
Rewards Points: 106
Default

Re: variable speed fans? Humidity?


The slow ramp up is kind of a waste, when the humidity is not too high it's better to go full cfm right away.

It's better to just slow on demand with a humidistat.
__________________
I am not in the business of any trade I give advice on. I have non-professional hvac experience + good knowledge of theory. Attempt repairs at your own risk. Never jump out safeties - especially pressure switches - on a furnace for testing with fuel supply on; use a meter. Do not troubleshoot with live line voltage present unless there's no alternative.
user_12345a is online now   Reply With Quote
Old 06-25-2020, 12:52 PM   #12
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

Re: variable speed fans? Humidity?


This was a duplicate message? Glitched.

Last edited by wraiththe; 06-25-2020 at 01:00 PM.
wraiththe is offline   Reply With Quote
Old 06-25-2020, 12:58 PM   #13
Member
 
wraiththe's Avatar
 
Join Date: Sep 2011
Location: Charlotte NC
Posts: 244
Rewards Points: 349
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by yuri View Post

The cost to replace a PSC motor by a dealer is $300-500, X13 $700-800., Variable speed ECM they start at $1000 and go up and you have to buy it from Lennox or Carrier etc as they are programmed to match their equipment.
That is amazing because the entire handler with the coil and some even with the heater coils are only one or two hundred more than that. (variable speed)
wraiththe is offline   Reply With Quote
Old 06-25-2020, 01:01 PM   #14
Member
 
user_12345a's Avatar
 
Join Date: Nov 2014
Location: Canada
Posts: 12,474
Rewards Points: 106
Default

Re: variable speed fans? Humidity?


parts in general are super expensive.

the module for the variable speed can be replaced separately from the motor at a much lower cost.

the prices listed above are what the contractor charges, it's a lot cheaper if you do the job yourself especially for the psc and x-13 type motor. variable is tricker to diy due to the proprietary programming but i believe there is a generic one out which takes the programming retained on the board.
__________________
I am not in the business of any trade I give advice on. I have non-professional hvac experience + good knowledge of theory. Attempt repairs at your own risk. Never jump out safeties - especially pressure switches - on a furnace for testing with fuel supply on; use a meter. Do not troubleshoot with live line voltage present unless there's no alternative.
user_12345a is online now   Reply With Quote
Old 06-25-2020, 01:53 PM   #15
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 22,469
Rewards Points: 244
Default

Re: variable speed fans? Humidity?


Quote:
Originally Posted by wraiththe View Post
That is amazing because the entire handler with the coil and some even with the heater coils are only one or two hundred more than that. (variable speed)
Yeah that is why we don't replace many compressors in AC units after their 10 yr warranty is over.

The labor and cost of the compressor etc is more than installing a new unit.

The prices I quoted are flat rate pricing which most larger companies use but that pricing is very common with some smaller ones also. My dealer cost on a ECM non X13 is pretty high.
__________________
"Cut it twice and it is still too short".
yuri is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts