Improve efficiency of heat recovery wheel

[slynk]

Hi everyone,

Just wondering if anyone knows how to improve the efficiency of a heat recovery wheel? Other than good maintainance to ensure its performance, is there any other way to enhance it further? For eg, increase speed of rotation etc. I can't seem to find much info on how a heat wheel is designed.

Thanks!

 

[walz]

Be specific in using the terminology. Your question is about effeiciency of wheel, but i guess you mean to say effectiveness.

Effectiness (Sensible & latent) is normally obtained from the manufacturer data if we give them our airflows across the wheel. but it depend upon the following
1. Exchanger construction (including configuration, heat transfer material, moisture transfer properties, transfer surface area, airflow path, distance between heat transfer surfaces and overall size)
2. Inlet conditions dor both air streams including pressures, velocities, temperatures and humidities.

Having a wheel selected once. efficiency can be improved by varying the airflows and temperature difference across the wheel.

 

[slynk]

Thanks for the correction, walz.

I already have recovery wheels installed on site, but I was wondering how I can further harness the cold energy from the exhaust air with the current system?

Other than increasing the exhaust air flow through the wheel, any other ways I can increase energy transfer?

 

[walz]

Offcourse slynk

pay more money and you can get more energy recovered. What do i mean is that go for a bigger wheel size (higher model No). becuase you can increase the airflows upto a limit only. by increasing the wheel size, the energy gets transferred in a bigger amount. cuz the airflows remain same, while the surface area gets increased, the velocity of airstreams get reduced. and energy get transferred more efficiently

 

[ChrisConley]

You could add a second wheel to the airstreams, if you can fit it in and your fans could handle the additional static.

You could add a dessicant to the wheel, if it isn't already a total recovery wheel.

 

[AnotherEllis]

You don't harness "cold energy," you transfer heat. Step one would be dialing in the terminology and thoroughly understanding what you are trying to accomplish from an energy and psychrometrics standpoint.

It basically comes down to the material limitations of the equipment. The same wheel can be substantially more effective at lower air flows. Select for ARI rated effectiveness. If it's in, then you might have no viable options for enhanced effectiveness.

It's up to the manufacturer's to come up with the better mousetrap.

 

[coldmaster]

If your sweet energy recovery gear is really working nice...document the energy consumption. take a look at the loads...are there opportunities to conserve? You may save "less" energy with your fancy gear if you reduce the load, but you'll be using less energy overall, which has gotta look good on the final report. Plus the "effectiveness" of the gear is bound to go up...(going with the whole surface area argument)...put that on the cover!