no sir
Having a Carrier Infiinity 96 installed as we speak. It's going in my office and above the master bedroom so I wanted a very quiet unit. The variable speed blower being "whisper quiet" was a big selling point.
However, my installer just told me the blower will only run on full speed for AC, due to cold air being harder to push. Does that mean that 6 mos of the year there will be no variable speed advantage, and that the unit will be considerable louder during those mos?
no sir
What kind of BS is that??? I hope your installer is being supervised by someone competent.
If everything was always done "by the book"....the book would never change.
The fan speed has to be adjusted accordingly, not fullspeed.
Your installer is correct in one respect: Cold air is more dense and can be heaver than warm air i.e. harder to push. However this will not be significant unless you are pushing a large volume of cold air vertically for a great distance.Originally posted by krxman
Having a Carrier Infiinity 96 installed as we speak. It's going in my office and above the master bedroom so I wanted a very quiet unit. The variable speed blower being "whisper quiet" was a big selling point.
However, my installer just told me the blower will only run on full speed for AC, due to cold air being harder to push. Does that mean that 6 mos of the year there will be no variable speed advantage, and that the unit will be considerable louder during those mos?
Your Air handling unit (AHU) will need to supply a minimum of 400 CFM per ton of cooling. It might be that your AHU blower may need to run at full speed to meet the min. CFM/ton requirement.
Typical residential thermostats will energize the G (fan on option) circuit on a call for cooling, this will energize high speed fan.
Perhaps your installer didn't feel like explaining this to you.
Post a topic and ask Dash to explain this to you.....they don't call it a variable speed because it runs on high all the time....there are more controls and that fan can ramp up or down. Did you get an Infinety control with it? I believe it will slow the fan down to remove more latent heat.
If everything was always done "by the book"....the book would never change.
Thanks for replies. I especially appreciate the detailed response. A couple questions:
The AHU is above or horizontal to rooms it services, so no air going up.Originally posted by journeymen
Your installer is correct in one respect: Cold air is more dense and can be heaver than warm air i.e. harder to push. However this will not be significant unless you are pushing a large volume of cold air vertically for a great distance.
Is that so the evap. coil doesn't freeze? It's a 3.5 ton unit, so that would mean it needs to move 1400 CFM? Would that requre the blower running at full speed?Your Air handling unit (AHU) will need to supply a minimum of 400 CFM per ton of cooling. It might be that your AHU blower may need to run at full speed to meet the min. CFM/ton requirement.
Not sure what this means... Could you explain?Originally posted by journeymen
Typical residential thermostats will energize the G (fan on option) circuit on a call for cooling, this will energize high speed fan.
Thanks!
First we need to know what type of thermostat you have, Infinity or other? This makes a huge difference.
Is that adjustment made by me (w/the t-stat) or by installer (on the control board)?Originally posted by 2hot2coolme
The fan speed has to be adjusted accordingly, not fullspeed.
I have what appears to be a fairly simple Honeywell - don't have the model no. handy but I can get, if need be.Originally posted by journeymen
First we need to know what type of thermostat you have, Infinity or other? This makes a huge difference.
That simple Honeywell explains the info your installer gave you. Yes, the Honeywell will energize high speed fan on a call for cooling.Originally posted by krxman
I have what appears to be a fairly simple Honeywell - don't have the model no. handy but I can get, if need be.Originally posted by journeymen
First we need to know what type of thermostat you have, Infinity or other? This makes a huge difference.
Request the Infinity controller. It will allow var. speed operation in cooling.
Get the Inffinity controller, you'll find it worth the extra money.
No, the blower doesn't have to move a min of 400 cfm per ton, it varies from high humidity areas to low humidity ares what it needs to move.
On a signal from Y, VS blowers don't go to high speed. It takes a signal to Y also.
I agree with the guys, get the Inffity t-stat on your inffinty air handler..
With that, you can ontrol the air flow/humidity.
If the dealer won't do it, then time to find someone else.
Just got off the phone w/the installer. He says the reason the AC will run on high is that it is not a Carrier Infinity but an Ameristar single stage unit. He says I need an Infinity Carrier AC to reap the benefits of the Infinity Control thermostat. Is that right?
First the other guys are right- you need the infinity controler for the best use of your system. No you do not need the Infinity AC unit to utilize variable speed.
the infinity controller allows you to control the humidity in your house. the whole point of a variable speed fan is to slow down the airflow to get the most efficiency by removing the humidity in cooling and warmer air temps in heating. there is no point in having the infinity furnace without the control. With the proper settings your fan will ramp up and down between 200 to 400 cfms based on humidity, comfort levels etc.
good luck.
Okay another update. Talked to the installer again (actually he's the sales rep for the company). I told him about this forum and the info I was getting here that contradicted his view regarding the benefit of the Infinity Control thermostat. I am convinced by the comments here that I need the IC t-stat. But want to be sure he doesn't have some info regarding my system that you all don't - info that might make a difference.
He said he's pretty sure that in order to reap the benefits of the IC thermostat (and thus to justify the additional cost, which will add 10% to the job) I need not just the outside Infinity condensing unit, which I lack, BUT ALSO the inside coil that goes with it. He said that the coil he installed does not have a certain valve (3 letters, begins with T, I believe) that is needed. He said that w/out that valve on the coil, the IC t-stat would accomplish little of value - at least in AC mode.
But to his credit he said I should ask you guys to be sure.
[Edited by krxman on 11-12-2005 at 11:53 AM]
Before reading your last post I was going write in to clarify the "infinity" we were talking about because Carrier was calling their high efficiency furnaces the infinity series before this control stuff came out, and they are not the same thing. Your last post suggests that you have the new infinity that we are all talking about. Your dealer is partially right without a TXV/TEV your benefits are minimal. You still don't have to have the infinity outdoor unit, but you should have a higher efficiency cooling unit than you have in order to fully utilize the control. Which begs the question. Why did this guy sell you the top-of-the-line furnace and what sounds like the basic cooling system?
Unless you are in an area of the country that is heating more than cooling or on a tight budget. We are not contradicting your guy we just don't know the whole story.
"put down the can of worms, and slowly back away"
The whole story, in a nutshell, is this: We're doing a major renovation of the home, including new HVAC installations in basement and attic. The GC recommended an HVAC guy who I met w/and thought sounded like the right guy for the job. We agreed he would install quiet, high eff American Standard equipment, which I assumed meant Freedom 90 units. Didn't read the fine print. Come to find he's installed two Ameristar systems which are not bad units for the money but not what I expected. The attic system in particular needs to be ultra quiet because the attic will be my home office and the furnace is right above the master bedroom. The one-stage, single speed furnace he installed is not loud, relatively speaking, but by no means is it ultra quiet. Also, the evap coil on attic system could only be installed one way: w/the fittings and service panel opposite the furnace service panel and completely inaccessible. After I found out he had lied to me about pulling a permit, I told him he had the option of first getting a permit and then pulling out the furnace and coil and putting in an ultra quiet system that was fully accessible or I'd hire someone else (w/the money I still owed him) to do it. He decided not to do it. I called in the company that does our HVAC maintenance and got a bid to install an Infinity 96 furnace and coil to replace the Ameristar furnace and coil. I was told in another post here and by my installer that there was no incompatibility between the Infinity furnace and the Ameristar outside unit, so I went ahead w/the job.
Now it appears I may have to replace the outside unit - which doubles the cost of the job - or live w/a lot less functionality (and quiet) during the summer. Unless anyone here has a better idea...
Wheres Dash when you need him.
Hey Krxman, where is your location?
Best wishes -- P.Student