Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-26-2015, 06:41 PM   #1
3 Rivet Member
 
2011 27 FB International
Vancouver , British Columbia
Join Date: Aug 2014
Posts: 204
HRV/ERV systems for fresh air during the winter

I'm curious if anyone has considered an HRV/ERV system in an Airstream. I'm finding we're tightening things up for the winter to keep warm, and though we always have a fanstastic fan vent cracked about an inch, today I ran one of the fans for an hour to cycle/freshen the air. In our old hot water heated condo we used to keep windows open except on the coldest days, we're missing that fresh air a bit.

http://www.ecohome.net/guide/choosing-between-hrv-erv
__________________

__________________
mixedpuppy is offline   Reply With Quote
Old 11-26-2015, 07:02 PM   #2
Rivet Master
 
cameront120's Avatar
 
1972 25' Tradewind
North Vancouver , British Columbia
Join Date: Feb 2006
Posts: 3,422
Images: 23
We use these in Passivhaus construction where the building envelope is very tight (less than 0.6 air changes per hour under 50Pa. By comparison, and Airstream is not nearly tight enough to warrant the expense of an HRV. These units are also pretty large, so you would need to figure out where it would go and what you'd be willing to give up (space-wise). When I was living in my Airstream during the winter months, I found that cracking a front and rear vent with the fan going did a pretty good job of expelling condensation while providing fresh air.
__________________

__________________
Cameron & the Labradors, Kai & Samm
North Vancouver, BC
Live! Life's a banquet and most poor suckers are starving to death! - Mame Dennis
cameront120 is offline   Reply With Quote
Old 11-26-2015, 07:40 PM   #3
Rivet Master
 
AnnArborBob's Avatar
 
2014 27' FB Eddie Bauer
Chelsea , Michigan
Join Date: May 2010
Posts: 1,764
Images: 12
Look at the size of the holes in the floor for the plumbing penetrations and you will quickly realize that Airstreams provide plenty of passive fresh air!
__________________
Bob Martel
WBCCI# 5766
AnnArborBob is offline   Reply With Quote
Old 11-26-2015, 08:07 PM   #4
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,300
Quote:
Originally Posted by AnnArborBob View Post
Look at the size of the holes in the floor for the plumbing penetrations and you will quickly realize that Airstreams provide plenty of passive fresh air!
Not really, because "passive" ventilation through floor penetrations doesn't actually move air, it only allows equalization of air pressure between inside and outside. With that kind of passive ventilation you don't really get airflow through your floor penetrations; most of your air exchange actually comes from opening and closing your door as you go in or out.

There is one exception— you will get good passive ventilation if you have one window open upwind when there's a good breeze blowing, and another window open downwind so that the wind takes the place of a fan.

But for proper ventilation all the time regardless of wind speed, there's no substitute for an exhaust fan and a cracked-open window.
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 11-26-2015, 10:11 PM   #5
Rivet Master
 
2015 30' FB FC Bunk
Ayer , Massachusetts
Join Date: Nov 2013
Posts: 886
My window is calibrated to ASHRAE 62.2.
__________________
Ted S. is offline   Reply With Quote
Old 11-26-2015, 10:56 PM   #6
Rivet Master
 
cameront120's Avatar
 
1972 25' Tradewind
North Vancouver , British Columbia
Join Date: Feb 2006
Posts: 3,422
Images: 23
Quote:
Originally Posted by Ted S. View Post
My window is calibrated to ASHRAE 62.2.
You mean it opens?
__________________
Cameron & the Labradors, Kai & Samm
North Vancouver, BC
Live! Life's a banquet and most poor suckers are starving to death! - Mame Dennis
cameront120 is offline   Reply With Quote
Old 11-26-2015, 11:14 PM   #7
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,300
Quote:
Originally Posted by Ted S. View Post
My window is calibrated to ASHRAE 62.2.
ASHRAE 62.2 calls for
CFM of continuous forced ventilation = .01×Floor area + 7.5×(#bedrooms+1) for the trailer as a whole;
plus 50 CFM on demand for the bathroom (but ASHRAE 62.2 doesn't make a distinction with regard to the split baths found in some Airstreams so do they count as one or two baths?);
plus 100 CFM on demand for the kitchen.
Open windows count as a 20 CFM credit (reducing required forced ventilation by 20 CFM each) but only one window per exhaust fan can be counted. However, if memory serves ASHRAE 62.2 is non-specific as to the opening size in square inches of an open window, so a cracked-open window theoretically counts the same as a wide-open window with regard to the formulas.
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 11-26-2015, 11:28 PM   #8
3 Rivet Member
 
2011 27 FB International
Vancouver , British Columbia
Join Date: Aug 2014
Posts: 204
ASHRAE 62.2 lol

I have found these:

EKO 1.5 HRV Air Exchanger | Venmar
https://foursevenfive.com/product/lunos-e%C2%B2/

The Lunos looks very interesting, sized about right that they could be used inside one of the overhead cabinets, perhaps right above the stove exhaust [in that convenient empty wasted space at either end], maybe a second above the fridge, taking advantage of the fridge vents (probably a bad idea due to propane use?) and avoiding additional exterior modifications.

The eko is larger, but at 10” x 10” x 14.25” it's not out of the question if one was willing to loose some storage under the couch.
__________________
mixedpuppy is offline   Reply With Quote
Old 11-26-2015, 11:44 PM   #9
Rivet Master
 
cameront120's Avatar
 
1972 25' Tradewind
North Vancouver , British Columbia
Join Date: Feb 2006
Posts: 3,422
Images: 23
Lunos through wall hrv's are a great little unit but expensive. You already have roof vents available that will likely provide you with more fresh air than the Lunos at far lesser cost.
__________________
Cameron & the Labradors, Kai & Samm
North Vancouver, BC
Live! Life's a banquet and most poor suckers are starving to death! - Mame Dennis
cameront120 is offline   Reply With Quote
Old 11-26-2015, 11:56 PM   #10
3 Rivet Member
 
2011 27 FB International
Vancouver , British Columbia
Join Date: Aug 2014
Posts: 204
Quote:
Originally Posted by cameront120 View Post
Lunos through wall hrv's are a great little unit but expensive. You already have roof vents available that will likely provide you with more fresh air than the Lunos at far lesser cost.
I'm sitting in Capilano right now in the airstream. Other than fresh air, we're keeping pretty confortable, but at -1c turning on the roof vents at this temperature would freeze us out pretty quickly. Thus the consideration for something like Lunos. We can tighten down even the roof vents and still have ventilation that looses much less heat.
__________________
mixedpuppy is offline   Reply With Quote
Old 11-27-2015, 11:06 AM   #11
Rivet Master
 
cameront120's Avatar
 
1972 25' Tradewind
North Vancouver , British Columbia
Join Date: Feb 2006
Posts: 3,422
Images: 23
I spent a winter in my Tradewind and found that interior temperatures didn't change a great deal with vents open a crack and a fan going due to the entire trailer being a poor insulator against cold. The entire trailer is 1.5" of fibreglass insulation encased in metal punctured at regular intervals with glass. That insulation offers an insulating value of R5.14 which is effectively reduced to much less than that due to the thermal bridging created by each of the aluminum ribs and the window and vent penetrations. There is nothing in it's manufacture that would be recommended for construction in a cold climate. Even with an HRV, I suspect the trailer will still be cold without relying on the furnace turned up to maximum. You would simply be throwing good money after bad.
__________________
Cameron & the Labradors, Kai & Samm
North Vancouver, BC
Live! Life's a banquet and most poor suckers are starving to death! - Mame Dennis
cameront120 is offline   Reply With Quote
Old 11-27-2015, 07:47 PM   #12
Rivet Master
 
2015 30' FB FC Bunk
Ayer , Massachusetts
Join Date: Nov 2013
Posts: 886
Quote:
Originally Posted by Protagonist View Post
ASHRAE 62.2 calls for
CFM of continuous forced ventilation = .01×Floor area + 7.5×(#bedrooms+1) for the trailer as a whole;
plus 50 CFM on demand for the bathroom (but ASHRAE 62.2 doesn't make a distinction with regard to the split baths found in some Airstreams so do they count as one or two baths?);
plus 100 CFM on demand for the kitchen.
Open windows count as a 20 CFM credit (reducing required forced ventilation by 20 CFM each) but only one window per exhaust fan can be counted. However, if memory serves ASHRAE 62.2 is non-specific as to the opening size in square inches of an open window, so a cracked-open window theoretically counts the same as a wide-open window with regard to the formulas.
Wow, that's pretty good. My post was actually a joke, I am a HERS Rater and deal with this standard often. We also build houses but typically install continuous Panasonic bath fans.

I guess I just feel if we start talking HRVs/ERVs were about as far from sleeping under the open sky as possible....
__________________
Ted S. is offline   Reply With Quote
Old 11-27-2015, 08:03 PM   #13
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,300
Quote:
Originally Posted by Ted S. View Post
Wow, that's pretty good. My post was actually a joke, I am a HERS Rater and deal with this standard often.
Even as a joke, citing a standard to an engineer is like playing Russian Roulette with a machinegun— you'll get what's coming to you, and how!
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is offline   Reply With Quote
Old 11-27-2015, 08:33 PM   #14
Rivet Master
 
2015 30' FB FC Bunk
Ayer , Massachusetts
Join Date: Nov 2013
Posts: 886
Quote:
Originally Posted by Protagonist View Post
Even as a joke, citing a standard to an engineer is like playing Russian Roulette with a machinegun— you'll get what's coming to you, and how!
I take it you are a mechanical engineer?
__________________

__________________
Ted S. is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where'd the propane go during winter storage? lisano LP Gas, Piping, Tanks & Regulators 13 06-12-2015 03:20 PM
Trailer towing during winter Danny Bell Winterizing, Storage, Carports & Covers 7 10-12-2014 06:13 PM
What do you do with your Hensley during the winter? dmcummins Hitches, Couplers & Balls 7 01-11-2011 07:12 PM
Polish During the Winter? star kitty Cleaning, Stripping & Polishing 3 12-06-2010 06:35 PM
Battery Charging During Winter John and Anne General Motorhome Topics 8 02-29-2004 09:58 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:48 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.