Need some technical explainations...

[oodssoo]

Hello everyone,

I am a new member to this site, and look forward to any and all informative, experienced, and intelligent responses and remarks from all of you.

The one question I could generally put out via this post is this:

"What can I do to increase the cooling and heating capacity by my HVAC system?"

Two bits of information about my system:

1) The Rheem condensor unit model number is 15PJL30A01 and is coupled with a 2 stage air handler in the attic space.
2) The house is 2 stories and is about 1500 sq/ft.

Firstly, in the years of being a home owner, I have noticed that when the vent/register is removed, a lot more air comes out through the duct. So, I am wondering if I could get some recommendations from you all on a better "flow" vent/registers.

Secondly, at the time of install of this particular HVAC system two years ago, the techs touched briefly on the fact that my air-handler can be adjustable to handle up a 5-ton setup. Against my request, they "had" to set it to a 2 ton setting to fit my home sq/ft. A question here is whether or not, I could simply make the adjustment to increase more airflow through the ducts. And, please correct me if I am wrong, but logically, by having more air flow, wouldn't I get more cooling/heating.

Thirdly, by constructing a shading structure over my condensor, I believe, for an example, this will help to separate most of direct sunlight and thereby yielding a better heat dissapation at the condensor in the summer time... (given the current 105 degree F temps in the Southeast of US where I'm from)

As you advise me about the 3 topics I have covered here, I thank you in advance. I look forward to your responses tailored to my questions here...

oodssoo

[catmanacman]

For a 2.5 ton unit you should be flowing about 1000 cfm in a dry climate you could flow 1200 cfm if you are set for 2 ton thats 800 cfm this is assuming your duct work will flow that much air

[Cooked]

.............."What can I do to increase the cooling and heating capacity by my HVAC system...............

The painful answer is absolutely nothing. You might be able to take some steps to increase comfort and efficieny but not capacity.

I'd track down a certified TAB tech (testing and balancing) it will make a night and day difference.

[oodssoo]

For a 2.5 ton unit you should be flowing about 1000 cfm in a dry climate you could flow 1200 cfm if you are set for 2 ton thats 800 cfm this is assuming your duct work will flow that much air


The painful answer is absolutely nothing. You might be able to take some steps to increase comfort and efficieny but not capacity.

I'd track down a certified TAB tech (testing and balancing) it will make a night and day difference.

Without unfocusing other to respond to my post, in referencing my 3 points, other than "capacity", could you possibly shed some light?

Thank you again...

[udarrell]

Hello everyone,

I am a new member to this site, and look forward to any and all informative, experienced, and intelligent responses and remarks from all of you.

The one question I could generally put out via this post is this:

"What can I do to increase the cooling and heating capacity by my HVAC system?"

Two bits of information about my system:

1) The Rheem condensor unit model number is 15PJL30A01 and is coupled with a 2 stage air handler in the attic space.
2) The house is 2 stories and is about 1500 sq/ft.

Firstly, in the years of being a home owner, I have noticed that when the vent/register is removed, a lot more air comes out through the duct. So, I am wondering if I could get some recommendations from you all on a better "flow" vent/registers.
The diffuser should be able to flow the required CFM volume of air at a desirable velocity of around 600-fpm; should also be selected for required throw, etc.

Secondly, at the time of install of this particular HVAC system two years ago, the techs touched briefly on the fact that my air-handler can be adjustable to handle up a 5-ton setup. Against my request, they "had" to set it to a 2 ton setting to fit my home sq/ft. A question here is whether or not, I could simply make the adjustment to increase more airflow through the ducts. And, please correct me if I am wrong, but logically, by having more air flow, wouldn't I get more cooling/heating.
They should not have set it for 2-Ton; airflow is set for the amount of CFM required through the indoor coil & the humidity level of the indoor air.
The duct system should be sized for 2.5-Ton & the blower set for 1000 up to 1150-CFM; in a real dry indoor condition, up to 1200-CFM.

Thirdly, by constructing a shading structure over my condenser, I believe, for an example, this will help to separate most of direct sunlight and thereby yielding a better heat dissipation at the condenser in the summer time... (given the current 105 degree F temps in the Southeast of US where I'm from)
It might help some, providing it does not block the flow of discharge air away from the condenser.

As you advise me about the 3 topics I have covered here, I thank you in advance. I look forward to your responses tailored to my questions here...oodssoo
Hope that helps.

[beenthere]

Blower should be set to 1000 CFM instead of 800. However, your return and supply system may become a bit loud.

Post pics of your registers, so we know what they are/look like.

Shading the condenser won't help. The over hang would need to be several foot above teh condenser so as not to interfere with its air flow, and cause recirculation of the heated air.

[oodssoo]

Thank you guys, foregoing the 1st and 3rd point made in my post, I'd like to focus on the 2nd point - CFM setting.

How would I check for the setting at which it is set (800 cfm vs 1000 cfm)?

Additionally, I'd like to know, beenthere, by the way you replied, it seems to me that you know the cfm setting is definitely incorrect. If I am right in assuming you know for sure, could you educate me on your reasoning?

Thirdly, but not the least, do you all agree on the logic of "more cfm" (in my case) means more cold/hot air? (The noise level is not an issue here - just looking for optimal level of performance)

Thank you again.

oodssoo

[beenthere]

You said they set it to 800 CFM. You have a 2.5 ton unit. Which nominal air flow for a 2.5 ton is 1000 CFM.

[oodssoo]

You said they set it to 800 CFM. You have a 2.5 ton unit. Which nominal air flow for a 2.5 ton is 1000 CFM.

Thanks, beenthere, for clarifying.

Reading my original post, I stated "2 ton". But your comment about "2.5 ton" makes me curious about which it is! :)

Can you, or anyone here, tell me how I could check on the ton setting?

ps. I have been able to identify that the temperature at the registers are at the same temperature set at the t-stat. Is this correct? Or should the air coming out of the registers be lower than the t-stat setting?
ps. #2 --> I've finally been able to locate the model number for my system - Rheem AC 15PJL30A01(condenser) & RHLLHM3617JA (airhandler) - reference (http://globalimageserver.com/fetchDocument.aspx?id=37854e35-ecad-4b7d-9f7f-5dea178927d0) for Heat Pump/Condenser and reference (http://globalimageserver.com/fetchDocument.aspx?id=f1b7728f-4d97-4c2a-874d-7e1ccc8b5c80) for Air Handler


Thank you again.

[beenthere]

Should be coming out colder then room temp when the A/c is running.
Your condenser is a 2.5 ton.

[oodssoo]

Should be coming out colder then room temp when the A/c is running.
Your condenser is a 2.5 ton.

Reading the available literature about my condenser, it is capable of nominal 1.5 to 5.0 ton cooling.

http://globalimageserver.com/fetchDocument.aspx?id=dee1930b-7247-41d6-bbd1-418d7f6afc78

How could I confirm if it is a 2 ton vs 2.5?

Thank you (by now, a "thank you" should be considered a given from me)...

:)

[oodssoo]

Bump

[Sammer VII]

the "30" in the model number is the BTU output. 30 = 30,000 BTU Divide by 12,000 equals 2.5 tons of cooling. 12,000 BTU = 1 ton capacity.

As far as adjusting the CFM it is recommended a certified technician perform the work.

Typically you look for 18-20 temp difference between the return air and supply air.

[oodssoo]

the "30" in the model number is the BTU output. 30 = 30,000 BTU Divide by 12,000 equals 2.5 tons of cooling. 12,000 BTU = 1 ton capacity.

As far as adjusting the CFM it is recommended a certified technician perform the work.

Typically you look for 18-20 temp difference between the return air and supply air.

Thank you, Sammer and everyone providing all input to my situation.

During the hottest part of day this evening, the return air was at 78 while the supply air was at 69 to 70... Once the hottest part of day passed, the return returned to 73 (set temp at t-stat) and supply returned to 58 to 59.

I was able to get to the fan speed adjust board. Of course, the next step for me is to know what is what in order to determine the course of action. Does anyone know or has a way to find out the what the setting stands for?

In getting into the actual machine, I confirmed the model is RHKLHM3617JA rather than RHLLHM3617JA. I don't think it makes a difference, but should clarify. http://www.rheem.com/documents/rhkl-specification-sheets

(to be continued)

[timebuilder]

Thank you, Sammer and everyone providing all input to my situation.

During the hottest part of day this evening, the return air was at 78 while the supply air was at 69 to 70... Once the hottest part of day passed, the return returned to 73 (set temp at t-stat) and supply returned to 58 to 59.

I was able to get to the fan speed adjust board. Of course, the next step for me is to know what is what in order to determine the course of action. Does anyone know or has a way to find out the what the setting stands for?

In getting into the actual machine, I confirmed the model is RHKLHM3617JA rather than RHLLHM3617JA. I don't think it makes a difference, but should clarify. http://www.rheem.com/documents/rhkl-specification-sheets

(to be continued)

If you read the rules, we do not supply DIY advice, and you just reached that point.

Have a professional come and address the issues of your concern.

[oodssoo]

Thanks, timebuilder.

I wasn't aware that my inquiry qualified exactly as DIY, so long I accept all of the responsibility.

Moving on, however, I'd like to follow up by asking why would I have 2 different Return/Supply temperatures. I think I may know the answer to this quandry, but I welcome your feedback.

(If there is a link to this very question already, please simply post it in this thread, so I would not start yet another thread over the same topic) :)

Thanks.

oodssoo

[energy_rater_La]

I think when you open the unit and ask for clarification of what
the switches control..that you are in diy territory.

re-phrasing the questions doesn't change that.

best of luck.

[XcelTech]

Oodssoo,

Let me answer your question with more questions.

If I want to make a coke cold do I place it on the counter and wait or stick it in the refrigerator.

Why?

So if your air is suppose to make your house colder, what would it have to do to do that?

You are at the point were you need a trained professional to track down your problem.

Good luck sir I hope you get the help you need and service you deserve. :)