New to the forum, and I did a search but didn't bump into anything. We are just starting to look at building a SIP home likely on a ICF basement. The Gulf Island has no electricity, so we will be using passive solar, and an active solar system, diesel generator and propane for fridge/stove, etc. An HRV seems to be a 'need to have' item in a SIP built home. However, if so does one just need to ensure that the model they choose uses as little power as possible? Thanks. Sherryl.

thanks chris. i had checked with the local expert in powell river. he advised that only one person on the island had a wind turbine and it only produced viable power during winter storms. apparently, he said that with all the trees everywhere on the island that the turbulence created from the trees (need something like 200 clear feet front and back for best operation) really limits the use of wind power, in this area anyways...

You threw me with "Gulf Island" are you in the Pacific Northwest?

haha, yes sorry. off the coast of british columbia.

Yes, I kinda figured as Powell River wasn't ringing a bell .... and not too many trees on Gulf of Mexico islands
But, solar in BC? , Iv'e been to Vancouver and Seattle in January and never saw sun until we left and got above 20,000 feet

Yes, I hear you. It can be pretty gloomy up this way in the winter. However, the 'sunshine coast' does get it's fair share of sun, even in the winter months. There's just not a lot of options for off grid power up this way and solar is employed by almost every home on the islands.

I haven't looked too closely at it or done the math on what it would take, but I've often thought that a reasonable stack with a turbine vent on the top hooked up to the exhaust port of an HRV's heat exchanger might get the air exchanges you need in a coastal wind zone.



This approach has worked as an effective enhancement for slab-depressurization (radon control) systems, which are a lot higher head than any mere ventilation system.  Typical turbines for 4-6" stacks pull on the order of 100-150cfm in 5mph type winds. 

At the very least it lowers the impedance of the HRV exhaust, lowering the load on the motor. It may make balancing the HRV pressure a bit tricky (or impossible) though.

It'll put the house under significant negative pressure in a high wind, so it's best if any combustion appliances are direct-vent/sealed combustion to fully avoid backdrafting conditions.