ReplyI don't think their is any literature that states what you want, but any hvac tech should know that 1" is too much static. Maybe call carrier tech service and see what they say?
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http://www.manualslib.com/manual/197...page=13#manualOriginally Posted by jtrammel
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I don't think their is any literature that states what you want, but any hvac tech should know that 1" is too much static. Maybe call carrier tech service and see what they say?
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Designer Dan
Thanks, that is similar to what I have for my unit with the same range.
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I tried calling carrier. They told me to hire another contractor to get a second opinion. This is my second contractor. Additionally, I live in a rural area and there are not many Carrier dealers that are willing to travel to me.
Thanks for the York chart. My installation manual has one similar to it without the the shading in the area .6-1.0 range. I guess I'll just wait until the current contractor declares it fixed and deal with it then. With any luck he'll get the static pressure down and I won't have to worry about it (I'd be surprised).
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It siunds like it will take some major duct revisions to get it down to where I would like to see it
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If high stage is the problem, avoiding it might be a work around until you either completely replace your duct work or install a pump that matches your duct work.
Try this - don't use setback in heating mode. You might get the pump to carry the house to much lower temperatures. It'll kick to propane for recovery. It takes a lot of horsepower to recover, and not so much to maintain.
Might try leaving it alone for cooling also. Recovery will kick the pump to high.
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I didn't reread the whole thread, but rather than replacing ducts, you might have good luch putting in better quality commerical grade registers and increasin the register size as well. Then maybe just add another return soemwhere. Small changes can make a big difference.
I think you can set the Infinity control to lockout high stage altogether. You cna also set it to "comfort" and minimum air flows if you haven't already.
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Moto, here's something to get your head around...
Had a chat yesterday with a guy in Nevada. He started talking about how they design. He's designing systems to run at 600 cfm/ton!
Also, these systems are running at about .2 static.
Their orientation is the don't want any energy going to latent removal. Still kinda sinking in for me, I expect you'll have some thoughts on this.
SO, locking out high, yes, but set to efficiency rather than comfort.
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I've locked out the furnace until 32 degrees and that is a reasonable workaround for the time being. It prevents the unit from switching to propane unless it is really necessary, and the unit will run at high stage during colder temperatures. I don't mind replacing/increasing the ducts (and registers - thanks for the suggestion) to address the problem. That was my assumption of what was necessary when I hired the second contractor, and that is what he proposed to fix the problems. However, it wouldn't be in scope of what he proposed to replace the whole unit. Like I said earlier, at some point he is going to declare the ductwork adequate and that he is done. When I put him under contract I stated that I expect the unit to be operating within Carrier guidelines when he is finished. I suspect the static pressure reading will be higher than what most people on this forum would like to see. I believe I am on firm ground that anything above 1” is unacceptable, and I would also need some margin for a dirty filter (how much?). Beyond that, I haven’t found anything stating that the pressure would be higher than Carrier guidelines.
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That is a contract I'd like to see. Can you share it, or at least the exact wording around "operating within Carrier guidelines"?
My mother has the same pump.
She called on a cold night asking if the cool air coming out of the registers indicated a problem. She went on to say the house was maintaining 70f.
I instantly knew what had happened, and now use the strategy whenever possible to learn true load/capacity crossover. The installer inadvertently locked out the furnace.
2300 sf home, 3 ton infinity hybrid, heats without a problem to 7f. Probably would go to sub zero before backsliding.
Not sure if this causes lightbulbs to go off, it did for me.
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