Runtime question


How do you find the ideal runtime for a heatpump, either in cooling or heating modes, assuming the sizing (outside coil, indoor coil, ducts) job was well done ? I see references to "longer runtimes are prefered", but how do you do your homework to find the right values ?
Thank you Jack
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Its called doing a "Manual J" heat load/loss calculation. When its done correctly, the system at design temperatures, it will run continuously to *maintain* the indoor comfort levels.

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Sorry Scooter....the OP asked a simple question, I gave him the simple (short) answer. He did not ask for a crash course in engineering a comfort system.
If *you* want to design a new method of sizing comfort systems for the most efficient operation for *every* condition in every hour in every part of the country, and share it with the rest of the world, great. Just as soon as its an nationally approved method, and accepted by P&I offices across the country, I will be happy to use it if for the benifit of my customers.
Until then, would you be kind enough to keep your derogatory comments to yourself.
Thanx for your support
--

Steve @ Noon-Air Heating & A/C
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YO! What the hell are you doing coming in here and calling one of the true RESIDENTIAL pros in here a hack and putting down his correct answer for a residential homeowner. If you would like to degrade Steve or myself neither one of us hide our e-mail behind some fake email. "worthless typical contractor answer" what an inflammatory remark. ACCA manual J is an internatrionally accepted form of heat load calculation for RESIDENTIAL load calculations. NO we are not graduated engineers, those are the guys that screw everything up and we have to fix it. COMMERCIAL is a different animal, and a much more profitable one at that. Most of us in here are just lowly pond scum RESIDENTIAL contractors, but we do it right. We can send anyone pictures of our work and testimonials from the customers we provide indoor comfort to. Now I realize we are not up to your level of expertise, but do not come here and belittle one of the few contractors in here that is a respectable, do it right, kinda guy. I personally perform a load calc on every install, which is designed for max and min temps, not some rule of thumb hack guestimation, I LOVE FOLLOWING THOSE GUESSTIMATES.
You say yourself that you could care less to perform a calc on some lowly homeowner with a $300 gas bill to save them 10% on their gas bill, but in t6he next paragragh belittle someone who does that. We do not do that. Some fill out a manual form, some use elite, or wrightsoft (which is what I use); and you know what we do care enough about that homeowner who has a $300 gas bill and would like to save a little money, and you know what if the system is designed properly it will probably run all of the time on design days to maintain 75deg and 50% rh, so you are full of shit.
Stick to what your expertise, and before you call someone a hack, get to know them personally, how they perform their work, and what they do to make custoemrs comfortable.
Before you say something about the rare instances of design conditions, we install 2 stage heat and cool for about 70% of our customers.
You # of cycles per hour is greatly influenced by the type of sytem you have, other factors of your home, and outdoor conditions.
--
Bob Pietrangelo
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Conundrum's effort to denigrate others and to promulgate his personal views of his vast experience and intelligence concludes with:
"I've done and proved all of the above calculations for large building

So, after belittling everyone on the board with an aggression not scene since the film Patriot with Mel Gibson attacking those who killed his son, your own conclusion is that the difference between you and Noon is $30, and YOU are too lazy to do the work. Interesting how those whom are so prideful always reveal how little they actually have to boast about. Makes me think of the Shrek when he referred that the little King had a big castle to make up for all his other shortcomings!
Rich

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Bite me Bonzo
*PLONK*

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