2017年1月28日 · You can do a similar calculation on the exising gas-burner using 80% efficiency and the all-in retail price per therm. Say you used 110 therms of gas on the last billing, the bill was $136. That's $136/110= $1.24 /therm, source-fuel heat. One therm=100,000 BTU.

2021年7月2日 · My Aquatherm Air Handler System Internal Evaporator Coil has a leak. Just replaced the coil 2 years ago. The system is about 10 years old.

2011年12月15日 · With gas rates so low, though, it's difficult. We pay less than $0.60 per therm for gas because we're a bigger user. Thanks for the compliment, and yes, anyone who reads David Butler's voluminous postings on LinkedIn or in the Energy Vanguard blog should be able to see that he's an HVAC expert.

2017年9月12日 · I was reading an article about HVAC sizing with Manual J & D. Here is my question: If you have data for an existing home -- heating-only therms, furnace run-time (from smart thermostat), HDD, etc for the coldest days of the year for multiple years -- can you calculate furnace sizing in a different way?

2021年11月7日 · When you do the math look at your cost per Therm or cost per KWh., to compare electric vs. natural gas. You may decide to pay more for electric in the short term. nateflanigan | Nov 08, 2021 08:19pm | #4

2025年1月30日 · The other question is efficiency. Based solely on boiler specs, I calculate that the payback period would be 30+ years going from a 78% to 95% efficiency unit at my current therm consumption (savings ~26% per year, or $600) and an install cost of ~$20K (ballpark). However, I know my old unit does not modulate output.

2020年8月28日 · Hello GBA! I’ve read numerous posts about humidity on your forums, but I wanted to run this doozy by you. We had a geothermal split-system with 3 ground loops installed […]

2024年12月13日 · Creating your own Manual J analysis is important for four reasons: (1) Accuracy - you are responsible for collecting the data, and you can examine your results, (2) You will have a Manual J report in hand when you talk to HVAC contractors. If they scoff and tout their "rule of thumb" expertise, thank them for their time and show them the door.

2023年12月7日 · Ty Branaman (HVAC instructor): “Closed loops require purging but less contamination and less energy usage in the pump since what is pushed is pulled in the loop.” Rob Brown (former contractor, now working for a manufacturer): “Open loops are FAR more susceptible to failure.”

6 天之前 · As far as my hvac , I know there is leaks which I have used foil tape to seal any tears . I suspect it’s oversized and the supply vent in a cavity in the closet in the house that goes up to attic . Before it was drywall and studs that led up to the big ugly foil looking box in the attic .