HVAC-Talk: Heating, Air & Refrigeration Discussion banner
Cancel
Create thread New Forums

Welding Shop Air Exchange System

Jump to Latest
1 - 20 of 28 Posts
J

johnl

· Professional Member
Joined
·
553 Posts
Discussion starter · #1 ·
If anyone has not seen these units before, they use corrugated plastic pipe for the heat exchange area and work on the theory of displacement ventilation. (supply a smaller amount of air at low velocity at or near floor level and "push" the contaminated air up and into the exhaust). Thats a quick explanation anyway.
These units are 2000cfm each and with an outdoor ambient of -25deg and a ceiling temperature of 75deg, they will supply air out the 4" vents at around 70-71deg.
Image

Image

Image

Image

Image

Image

Image

Image
 
#2 ·
I've been to 3 country fairs and a goat roping, and I ain't never seen nothing like that.....:eek2:


Nice install.....:yes:
Who makes that...??
 
Save
Like Like
#4 ·
How do they keep the system clean? Looks nice now, but without some form of filtration won't they get full of crap in the spiral?
 
Save
Like Like
Discussion starter · #5 ·
The velocities in the spiral are high enough that any crud in the air gets taken right outside. I asked the same question when we took the product line. It was actually one of our customers that found these and wanted to try one instead of the direct fired make up air unit and ceiling exhaust fan that I had quoted him. We agreed to install it and really liked how they worked so we approached the manufacturer and started selling them. On this system the customer will see a 1 year payback as opposed to going with a direct fired unit and exhaust fan.
 
Discussion starter · #6 ·
Sorry Sline I didn't see the second part of your post. Environmental Air Solutions out of Coralville IA makes them. Really simple units and they work very well. We have installed 7 of them in the last 6 months. I think they will take off quite well here.
 
Discussion starter · #8 ·
As soon as the electricians have everything wired I want to do a smoke bomb test on this install. If I can do it before they move production into the building I will try to take video of it and post it.
 
Discussion starter · #11 ·
I cant see it cracking, it looks to be a good quality plastic similar to other fans that we use for farm use. The manufacturer has been making these units for quite a while and they have them installed as far north as Fairbanks Alaska so they see some pretty harsh weather.
We are starting to use these units in place of gas fired make up air units and ceiling exhaust fans. We are trying to get more into energy saving alternatives for customers and looking at things like VFD drives on fans and compressors, air exchange vs makeup air units etc.
We are lucky in Manitoba as we have pretty cheap hydro and gas but a lot of customers are making choices based on operating costs and if we look more at that and show customers alternatives we end up getting the odd job that we may have otherwise lost.
I will show you guys the calculations that I did for this customer just to give you an idea.

With our rates, a direct fired MUA costs aprox. $1.07/cfm per year to run. (10000 cfm unit costs roughly $10,700.00/yr for gas and hydro)
In this install we required 10,000 cfm of air exhaust. For this particular installation, the direct fired system was going to cost around $48,000.00 installed with the gas lines, ductwork etc. giving them a 1st year cost of roughly $58,700.00.
These units will cost around $50g to install and about $2163.00 in hydro giving them a first year savings of $6537.00 and around $8537.00 per year after that.
So for this particular job HRV's were a very good alternative.
We will definitely lose out on maintenance long term vs gas fired equipment, but on the other hand we gained a customer that we may not have had who has other equipment that will require service.
 
#12 ·
That looks like a great idea, I'll have to keep that in mind if I ever run across a job like that.

Installation looks great too

I'm curious tho, I wonder if we could make a smaller version of that for my bathroom? haha
 
Save
Like Like
Discussion starter · #14 ·
Thanks, I was going to post the site but I didn't know if it was allowed.
They are a pretty cool unit. If you click on the efficiency link they have some data from actual installs showing outdoor temp and ceiling temp vs supply temp.
They work extremely well in shops that have high ceilings and use ceiling mounted unit heaters for heat. I think we have all seen places like these where the floor temp is 65 and the ceiling temp is 100 plus. In those cases the supply air temp will actually be higher than the temperature at working level and take a lot of stress off of the heaters.
I have a quote into a canadian tire store right now where they have 24 foot ceilings and ceiling mounted gas fired unit heaters (very dumb set up) Even with ceiling fans there is a 35 degree temperature difference between floor and ceiling and they have a history of thrashed heat exchangers in the unit heaters.
Putting one of these units in I should see roughly a 90 degree supply air temp out the supply tubes which should shorten the run time on the unit heaters and get the ceiling temperature down to a more normal level.
 
#15 ·
How well would this work in the south when the ceiling temp is 120 outdoor 98. not sure if i like everything stuffed in the end like that. I would of spaced out some 4 inch saddle taps , but you did pull it off and it looks clean
 
Save
Like Like
#16 ·
So how did this job turn out? Is client happy? Easy to set up? I may want to consider this system on upcoming project.
 
Save
Like Like
Discussion starter · #17 ·
These units are definitely tailored to areas with cooler winter climates. If you are in an area with a ceiling temp of 120 and an outdoor ambient of 98 you would not need heat exchange. If you were in a climate such as that but still had cold winters you would simply shut down the intake fans in the summer and use louvers in the wall for summer air makeup.
Everything being stuffed in the end is the basis of the design of these units. In order to do something with saddle taps you would either have to increase the size of your exhaust duct quite a bit to give room for the 90's and you would have poor heat exchange or you would have to increase the length of the exhaust duct and would have to increase the duct size again losing heat exchange.

This job turned out very well and the customers we have installed these units for are very happy with them. They are very easy to install and it takes 2 techs aprox. 20hrs to do a "normal" installation. The big payback comes in winter when they arent paying to heat that makeup air near as much.
 
#19 ·
I am very interested in this system, is there a limitation to the size of shop that this can be used in? I am looking at this in a welding shop that is 21,000 sq' 27'ceiling in stead of a air make up
 
Discussion starter · #20 ·
There is no limitation to the shop size at all. We have had very good success with them with zero complaints or issues to date. The shop in these pictures is aproximately 60x90 if I remember right.
The nice thing about this style of setup vs conventional air makeup and exhaust is that if you are only working in one area you dont have to run full airflow throughout the whole building.
If you want any more info let me know and I will be glad to help.
 
1 - 20 of 28 Posts
You have insufficient privileges to reply here.
About this Discussion
27 Replies
13 Participants
Last post:
johnl
HVAC-Talk: Heating, Air & Refrigeration Discussion
posts
5M
members
275K
Since
2000
The #1 HVACR Community
Full Forum Listing
Explore Our Forums
AOP Residential HVAC/Refrigeration(Beenthere Zone) General Discussion Tech to Tech Chat - Residential Controls Refrigeration & Ice Making