Author Archives: kurtshafer

9-7-19 News is the whole whole house fan industry is in disarray

This just in – Dane from QuietCool called me to point out that it is unfair for me to say that QuietCool wrongly publishes higher performance figures along with their HVI-916 performance results when other suppliers of whole house fans do the same. I did some research – see below – and he is right. His model number ES-7000 has been tested to HVI-916 and pulls 5170 CFM. His QuietCool specification sheet says it pulls 6,878 CFM on high speed. Under that QC adds “HVI-916 5170”.  Dane pointed out Triangle Engineering as an example. I did some research and he is absolutely correct. Triangle shows their model CC3623 rated at 10,600 CFM when the HVI-916 tests show just 5163. 

As I am writing this I must say I really missed this huge difference. Thank you, Dane, for pointing it out. 

Their 1/2 HP CC3623 is shown by them to pull 10,600 CFM. But here is what the HVI-916 test shows – this is from the CA Dept of Energy database. It shows the air flow is 5163. 

I called Triangle Engineering to get their input on this and the manager of engineering James Quinn said that the CA database is the source and he had no further comment. I was not able to get him to tell me anything about what test they use to justify their inflated flow specs. 

I just learned that Bob Krell has taken over Home Energy Magazine and their Pros Forum (homeenergypros.org). I am writing him to encourage him to add a significant section to address this incredible inconsistency in the whole house fan market. 

So, Dane, please accept my apology for giving you a bad time. I see your point!

Here are the top sources – All the specs below are proven by having been tested to the Home Ventilation Institute’s test spec,  HVI-916. The fans made by each company are very similar designs – 24 inch blades on 3/4 HP motors. These have shown to be the best in the industry. The reason Tamarack is the leader is because of their higher performance blade. Thorwaldson is now selling the Tamarack fan as well as the VentCool fan and offering an infinitely variable speed option. Kurt Shafer, founder and inventor, now has the only rooftop mounted whole house fan and he makes it using any of the fans below. The huge difference is that without the flexible duct in an attic to restrict air flow, the aif flow is expected to be over 7000 CFM with the Tamarack design and over 6000 with the VentCool or Airscape design. 

Tamarack         5800 CFM
Thorwaldson   5800 CFM
Airscape           5202 CFM
VentCool          5202 CFM
QuietCool          5170 CFM

Page revised 9-7-19