Best Of
Re: Difficulty in Properly Sizing Equipment - 2140 Sq Ft New Construction Spray Foam House
I apologize in advance for contributing to a fully hijacked thread…
There's real joy in a quiet, warm home, with nearly endless hot water and affordable energy bills in cold climates. There are different ways to achieve these results and cold climates present unique challenges. Hybrid solutions are exceptional for the state of today's technology as there are not many passive houses out there.
In the meta analysis I cited earlier in this thread, there are a few important points to help clarify comparisons between technologies.
- Cold climate heat pump utilization: "Some home homeowners indeed used their heat pumps dutifully even during the coldest days of winter, but most dropped out at some point as the weather got colder, or never even turned on the systems at all for heating purposes." … "The data curves for the three field studies show that actual electricity consumption was only a small fraction of what would be expected with full heat pump utilization. Note that the actual electrical demand curves are relatively flat below 30 deg F. This indicates very low heat pump utilization below 30°F. Since heat pump power demand increases dramatically as the outdoor temperature drops further, due to increasing heat load plus decreasing heat pump COP, this means further that the homeowner percentage drop-out rate is increasing as the temperature drops."
- The field achieved COP of heat pumps is 2.0 to 2.5 near freezing (30°F); this actual field performance is substantially below manufacturer ratings which have been referenced elsewhere in this thread.
- EVI heat pump output is published to be between 73°F and 91°F for this top performing 26.3 SEER model (see p. 230). This is running at high speed with leaving air velocity of 8.9 ft/sec, so it may not feel cozy and it may not be perceived as quiet. Possibly this and item 2 contributes to item 1; the studies confirm the high rate of homeowner heat pump drop out in cold weather, but they do not positively identify the root cause.
- The most common heat pump refrigerant today, R-410A, will be prohibited on January 1, 2025. A2L (slightly flammable) replacements like R-32 and R-454B (70% R-32) are not currently code compliant unless a state law exempting them has been passed, but they do have the advantage of lower GWP than R-410A.
These issues need to be resolved to greatly increase broad voluntary homeowner use of cold climate heat pumps during freezing temperatures.
Roger
Re: Weil McClain Natural Gas Hot Water Boiler
The most important thing is figuring out why it sooted up. They can do the best cleaning possible and it will be a waste of time if the boiler soots up again. Combustion air supply needs to be checked, the chimney/venting checked, gas pressures checked and a full combustion analysis performed. Hopefully you can find a tech who is trained in combustion analysis and equipped with a digital combustion analyzer.
Re: pro press on baseboard
it is too thin to press to without the reinforcement. you could also solder a fitting to it then press to that. probably could even solder on a npt adapter and screw a press fitting on to it.
mattmia2
Re: correct gpm for open loop geothermal
On the water side of things — I don't know much about the refrigerant side! — as noted it depends a lot on the water quality whether anything in the heat exchanger might get gunked up. Likely not, but a reverse flow flush would do no harm.
However, on the source well side, things can get stickier. From time to time you should check the dynamic drawdown level in the well and keep track of that. If the well is screened, screens can and do clog, which will cause the dynamic drawdown to increase. A well completed as an open hole in rock likely will not do that, but it does no harm to check. A clogged screen can be redveloped, but that is a task very much best left to a really good well driller.
Re: correct gpm for open loop geothermal
@zepfan Should be able to hook the new one up and just open the valves. But with an open system you will have to see what's lurking in the piping. Any filters on the system?
Re: Beckett NX burner
I have noticed that some Draft Controls are more sensitive to the start up of the burner than others. The one that looks like the lid of an old metal coffee can that has the counter weight that looks like some fender washers are very accurate, but do not have that much mass to them so they react too fast to that startup "Puff" no matter how delicate it is. The Draft Regulator from Field Controls model RC seems to be less affected by startup “Puff”. The old Effikal dampers are also good. But I don't know where to get them ever since Field Controls took them over.
Re: Weil McClain Natural Gas Hot Water Boiler
I edited it. Sorry about that. I do have a quote for a new boiler, but if it can be repaired…….I'm told the old ones are much better than what they have these days. Not sure about the efficiency though
Millie