HVAC Energy Conservation

Carmen Said:I came across this site last night, after searching the web for answers. We just installed a TRANE 16Seer on our 2100 sf home. Compared to last year, at this time, my bill has doubled. Last year during summer (with 2 MasterCools installed, one running 24 hours, the other about 10 hours), my bill was under $200. This year, with our new HVAC, in addition to new windows all around the house, my bill was over $300. What am I doing wrong? - Carmen———————————-Hi Carmen,I am new to blogs & blogging. My web site is my main stay.I do not have enough information to do any kind of analysis, however, it could be a poor install & setup of the equipment, refrigerant lines & the ductwork system.Your unit is costing you a fortune, the first thing to look for is hot air getting into the Return Air duct system, that would overload the evaporator & condenser & run your costs way up. What is the F-Temperature rise/split from the outdoor condenser above the outdoor temperature. it appears that you live in a dry climate.So, your unit is costing you a fortune, I need to have the temperatures below, - that you can easily take for me:“Copy only the data portions & paste in your Word-Processor, make a couple hard-copies, then send me what you take, & get as much of this data as your Tech will provide for you.” You can delete the (You &/or Tech) before you make hard copies for your Tech.  This is very important: Always tell the tech that you want all the data he takes, clearly recorded with your billing!I can run the temperatures data you take with an accurate CFM Airflow & ball-park the Nominal BTUH your new A/C is delivering, at those conditions.TROUBLE SHOOTING DATA - (You or Your) HVAC TechFor my information concerning summer design & your climate, provide your state & nearest large city __________TONNAGE of Unit or outdoor condenser model number: ___________You or tech-TXV or orifice metering device? _______You or Tech, - not real critical to this analysis  Outdoor condenser’s discharge-air-temperature _____You- Out-Door temperature: ____You- Condenser air Temp  split _____You- Indoor Total-ESP - External Static Pressure  ____ Tech- All Supply Air velocities in FPM: ___ Measure supply register’s louvered area. Tech- I’ll do the math for the total CFMSuction line pressure ___Tech- Suction-Vapor line temperature: ___Tech- Saturated Suction Temp – Gage - Suction Saturated Temperature. ___Tech- Superheat ______Tech- Head pressure _______Tech- SCT – Gage - Saturated Condensing Temp _______Tech- Small Liquid line - temperature: _______You- Subcooling: _______Return Air temp DB &, WB or %RH: _______Tech- Supply Air temp DB, WB &/or %RH: _______You- could take a cotton cloth & wet with room temperature water, wrap it around the thermometer & use it for the wet bulb temps above.Except for the Pressures, Superheat & subcooling you can take most of the other Temp readings for me.My advice: to every user, get a low cost humidity gage at a local hardware store & see what the percentage-RH is in your home, I can cross-reference that to the wet bulb depression so you could use the humidity gage instead of wet or use both.If you want to save money you will take the time when it is hot & warm in the house to take all the dry bulb & wet bulb temp data!Anyone is welcome to use the Data Collection for use as they see fit!“Copy only the data portions & paste in your Word-Processor, make a couple hard-copies, then send me what you take, & get as much of this data as your Tech will provide for you.”My monthly electric bills run $45.00 or less, & I keep very cool, in a 1937 farm home, even in 104-F Heat Index!Are your electric bills too high? Visit my many HVAC web pages at:http://www.udarrell.com/airconditioning-sizing.html

For Techs a Trouble Shooting chart, for HVAC Techs & HVAC User’s a Service Data Chart to check BTUH Performance:

http://www.udarrell.com/ac-trouble-shooting-chart.html

I am here to help you Conserve Energy & save a lot on your monthly utility bills.

A high percentage of HVAC systems are operating way under their Rated Efficiency!

Below is an example of this problem with a (Thermo Pride OL 11 Low Boy Oil Furnace)Scan of My Oil Furnace Blower Curve While the image loads switch back & read this pageOIL HEAT FUEL COST COMPARISONS New!The design of the some OIL furnaces’ with their ultra large heat exchanger coming to near the top of the furnace and the blower set to the side at the bottom of the furnace, can be an engineered airflow problem. The blower set to the side blows against the heat exchanger and the back of the furnace which blocks directional airflow velocity thus generating high initial velocity & static back pressures against the blower.Most installers set the A-Coil directly on top of an oil furnace with no transitions resulting in another restriction, between the huge HEAT-Exchanger resulting in blocking of directional velocity airflow, killing velocity flow & causing a huge leap in (ESP) static pressure.A Major “Oil Furnace” Airflow Problem Fix - Regal & Hallmark & nearly all Oil Furnaces - Installation manuals:  http://www.boyertownfurnace.com/ProductDocuments/index.aspx  Download the installation & service manuals:  http://www.boyertownfurnace.com/ProductDocuments/HallmarkONLYManual042909.pdf 
If the oil furnace is used in connection with summer air conditioning the evaporator coil must be installed at least 6” above the oil furnace for proper airflow. Distances less than 6” will result in decreased airflow.Make sure outlet supply air takeoffs are NOT blocked by the coil. In all cases, refer to the manufacturers’ data for static pressure losses to ensure the total system static pressure does not exceed 0.5” WC.

MOLO Plumbing & Heating sets the A-Coil at least 6″ above a Thermo Pride OL 11 oil furnace. They know the importance of unrestricted airflow!

 http://www.molocompanies.com/plumbingandheating/index.html

Visit the HVAC links at the bottom of the pages.

Edit: 08/03/08, Carmen, your initial post is in the unnoticeable uncategorized comment section!

udarrell - Darrell, Contractor Tech from mid 1970’s    >Darrell Cynergy Home HVAC Energy Raters Listen While Reading

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