Printable View
An HVAC issue
In cold area winter, fresh air need heating before go into AC space. It's easy to be frozen while using water heating coil. What's the best way for it? Electrical heating /heat pump heating /other ways?
Have you any experience in it shearing with me?
thanks
regards
LC:)
If there's warm water in the coil, no problem with winter.
If otherways the heating may be off at any time, either install temperature-controlled louver and fan, or use antifreeze brine.
I would go for the first option, also because the minimum supply air temperature cannot be too low, and by closing louver and stopping fan you would avoid that.
I personally recommend indirect free cooling, with DX water cooled AC, and three way valve on the eg condenser water, so that the dry coolers would deliver condensing water in summer, and free cooling water in winter in a chilled water coil.
No experience.
But still for small systems according to me electrical heating would be the simplest way.
Hi,
For preheating of air you can you following options:
1. Electrical heaters can be used for heating the outside air. However the cost of electrical heating is very high.
Advantage of using electrical heaters is once u install it you have zero maintenance.
2. Hot water is also a good option, However you will have to provide hot water coil, valves and piping. Therefore this option has a higher initial cost but a lower running cost.
3. If boiler is available then u can consider the option of steam also.
Regards
I'm sure there are air-to-air heat exchangers out there that pre-heat the in-coming air with the out-going air, I know Daikin do them. Supplemental heating would still be required though I would've thought in colder climates:)
Consider an air-to-air heat exchanger like Munters-Rotair, or Wingwheel, to maximise heat recovery from exhaust air, generally in the +23'C range. Or cycle exhaust fan on a time basis, driven by air analysis sampling system [co2 ]in supply air, ie reduce cold air introduction.
magoo
I'm not sure the poster is interested in a three years old thread.
It's still a topic, I think:)