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I have 2.5 ton residential split unit, it said to be 400cfm

I have 2.5 ton residential split unit, it said to be 400cfm per ton , so it will be suppling 1000 cfm, when installing new duct work, do i need to have all supply vent total equal to 1000 cfm? What i am trying to do is because there is three rooms total 800 sqft 2nd floor. The air handler is far away from two of the rooms i tried to push a stronger air flow to the rooms.I am currently using two 10 inch flex duct from the plenum and use a Y to split two 8" flex ducts. Can i just leave it like this? Because one 10inches supply only 300 cfm, so i only have 600 cfm supplying, would this choke the system?

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D.E. Anderson

Industrial Refrigeration Service Manager

 
222 satisfied customers
When replacing a flow sensor on a 100 ton CGAM chiller

When replacing a flow sensor on a 100 ton CGAM chiller Trane, do you have to drain the water from the evaporator?

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Brian HVAC Guy

HVAC/R Consultant

High School

 
1,326 satisfied customers
I have a lennox split residential unit. It is running a low

I have a lennox split residential unit.It is running a low superheat and it is not cooling well. It is a fixed orifice.I replaced the air filter, changed blower fan capacitor and even washed the evaporator. The superheat didnt change a bit.Evaporator 48.7FSuction line 51-55FCondenser 108.7FLiquid line 92FThere is a kink at the suction lineI washed the Outdoor unit

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Airheatman

Heating & Air Conditioning Contractor

6 years college

 
9,380 satisfied customers
I have a gree minisplit system model ri012hp115v1a0 When I

I have a gree minisplit system model ri012hp115v1a0When I arrived the customer had the unit off. I turned the unit on, the compressor came on the suction pressure started dropping all the way to -9, red light flashing 8 times, green light flashing steady, yellow light steady flash, after about 30 to 45 seconds the suction pressure started climbing. It has now held steady at 117 psi with 4 deg. Superheat for a good 15 minutes.Is this a normal start up??

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Phil

Consultant to Engrs, Govt & Contractors

Degree, Mech Engr Technology

 
9,496 satisfied customers
My units are pumped down and in a vaccum - nothing in the

My units are pumped down and in a vaccum - nothing in the line set or outside condenser. My questions are:I am aware of how to charge by sub cooling and have an appropriate manifold (SMAN4) and the coils have a TXV installed. What I am unclear on is how a long line set could affect the charging procedure. While I haven't measured the lines yet, I'd estimate them to be around 55-60 ft from the outside condenser.Question 1 to properly charge:Is it A:Line set length doesn't matter - once you get the correct sub cooling measurement on your manifold you know the system is properly charged and column of liquid is reaching the TXV.Is it B: Measure line set, add required refrigerant (3oz for every 5ft when length is greater than 15 ft) measure sub cooling and either further add coolant or remove?Is it C: Some other combination?Question 2:Pulling the lines and condenser into a vacuum - does the oil get pulled out or does it stay and not boil off? I plan to run the vacuum again for an hour prior to recharging or until I get 500 microns or less.Thanks!

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Brian HVAC Guy

HVAC/R Consultant

High School

 
1,326 satisfied customers
Adding freon to a Gemini split system and my gh pressure

Adding freon to a Gemini split system and my high pressure line froze

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D.E. Anderson

Industrial Refrigeration Service Manager

 
222 satisfied customers
I have a two story house, upstair unit wont cool in the day

I have a two story house, upstair unit wont cool in the day time the temp goes to 80F, but night time is good goes to 69FSuction saturated temp41FSuction line 53FLiquid saturated temp 126FLiquid line 90FAmbient temp 90FIndoor 80FSupply 61FReturn 79FWhy is not cooling down?

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HVAC Guru

Service Technician

Associate Degree

 
22,656 satisfied customers
Swapped out compressors in new 5 ton condenser from single

swapped out compressors in new 5 ton condenser from single to 3 phase,vacuumed and began to charge but see no liquid going through sight glass at evaporator, and pressures are equal on high and low side. compressor amps test at 75% of normal. compressor is running

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Phil

Consultant to Engrs, Govt & Contractors

Degree, Mech Engr Technology

 
9,496 satisfied customers
My AC air supply is only 74F during outside air is 90F.

My AC air supply is only 74F during outside air is 90F. Please help me.

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HVAC Guru

Service Technician

Associate Degree

 
22,656 satisfied customers
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