Emergency backup direct vent propane heater options
Looking for some advice on a backup heat source for a new home primarily to prevent pipe freezing for longer electricity outages. Most folks in our area recommend direct vent propane heaters but I’m a bit overwhelmed looking at all the options.
1. Rinnai seems to have great reviews but require a 120V connection for ignition and I’d like to avoid needing a battery backup for this.
2. Martin uses a piezoelectric igniter but the reviews don’t seem quite as great and the penetration needed for installation is very large.
Does anyone have strong recommendations for a particular brand of direct vent heaters?
Another question was about how to potentially seal the intake penetration when not in use. We haven’t done our final blower door tests as we still have some penetrations and basement finishing to complete but we are aiming for < 1.5 ACH. I’m not sure how the internal valves work on these heaters. Would their be air leakage through the heater when the unit is not in use. It seems like a waste to have a large penetration in a tight envelope only for emergency backup purposes.
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The first question is how likely are you to have a power outage long enough to freeze your pipes.
In the last 5 years my record is 10 hours but my line is underground and am close to the state road. If your wires are on poles that run thru a mile of woods you can expect more outages.
A tight well insulated home could go a week or more in mild weather. Where I live the big power outages are from ice storms and they happen very close to freezing I call that mild.
You may enjoy this video about freezing pipes. Note PEX pipes seem much more likely to survive freezing.
https://www.youtube.com/watch?v=w9W466z5Cwk
I have a Heat-N-Glow propane fireplace that will operate with 2 D cells if the power is out.
Consider getting a generator large enough to run your heat pump if you have an unreliable grid connection.
Walta
Exactly
8 kw gasoline generator cost me under a grand a couple years back. We lose power a day at a time regularly.
You could spend more on a heating system and still sit in the dark.
Water freeze ups are usually from air leaks or stupid plumbing.
In a new house I would not expect them to happen until it really really gets bad.
You could try an Empire direct vent heater set on a thermostat so it only comes on when the room temp drops below the set point.
https://empirezoneheat.com/products/direct-vent-wall-furnaces/direct-vent-wall-furnaces/
While it's unlikely I will ever have my encapsulated crawlspace get cold enough to cause pipes to freeze I appreciate having a ~$30 freeze miser on one of my hose bibs that is the farthest from the supply. It starts dripping as soon as it cools down to 37 degrees fahrenheit with the rate increasing as it gets cooler. The underground water supply from the city stays in the 50s/60s so as it flows through it warms the pipes, no electricity required and not much water. If I ever get a "smart" water shutoff I'll have to make sure the freeze miser doesn't make it shut off the water.