Preheating for recovery

AIRMEN ADVISE …

HOW TO CHOOSE A RECOVERY UNIT - PREHEATING YES OR NO, WHAT IS ANTI-FREEZE PROTECTION

What happens in the winter in the recovery unit

The so-called preheating serves to preheat the outside air that enters the recuperator. The problem mainly concerns diagonal countercurrent heat exchangers, which have high efficiency. As described in the previous article, the recuperator consists of fine, shaped lamellas through which cool outdoor air flows in one direction and warm, sometimes very humid, air from the interior flows in the other. In the normal case, the exhaust air will heat up the entire recuperator. It thus transfers heat along the entire length of the exchanger. In winter, water vapor condenses on the walls of the recuperator, which further increases the efficiency of recuperation. However, if the outside temperature is e.g. below -5 °C for a long time and the inside 20 °C, then it may happen that the exhaust air does not have sufficient capacity to heat the recuperator along its entire length. This creates a risk that the resulting condensate may begin to freeze, increase its volume and irreversibly destroy the delicate lamellae of the recuperator within a short time.

Antifreeze protection of recovery units

Due to the possibility of recuperator freezing, almost all units are equipped with so-called anti-freeze protection. It monitors the temperatures at the exhaust from the unit and in the event of a drop below a given temperature, e.g. 2 °C, it triggers a certain type of protection. Each manufacturer solves this problem in its own way.

A) The basic solution to antifreeze protection is to turn off the unit (e.g. EHR 140 Akor ).

B) Some units turn off the suction into the house for a certain time, so that the exhaust air quickly warms up the recuperator. Then it switches back to normal mode. The representative is units from the 2VV company.

C) A more sophisticated procedure is to simply lower the inlet to the outlet. At certain intervals, the unit measures the temperature and accordingly either reduces the supply by another 25%, or on the contrary increases it and the unit returns to normal.

D) An interesting way is to use mixing. EHR 280 AKOR or EHR 325 AKOR units are known for this solution. If necessary, it does not suck in 100% of the air from outside, but part of the incoming air is sucked in through the so-called fifth throat of the unit. The problem may arise if the unit is not placed in a completely clean space or a space where negative pressure must not occur (fireplace, gas appliances, etc.). This creates a negative pressure in the entire house.

This solution can be used with MSK-AFP on all units without preheating.

E) The last 100% effective solution is integrated air preheating in the unit or preheating on the suction pipe (ground, water, electricity, …)

How preheating works and what are the types of preheating

By using any functional type of preheating, it is ensured that the unit does not fall into the so-called frost protection mode. This means that it always supplies and removes the amount of air that you need.

1) Ground exchanger

it is 100% effective when done correctly. However, there is the suitability of the subsoil, the size of the plot, the initial investment, the increased power of the fans (which must overcome the higher pressure loss), the aspect of hygiene and the necessary service. However, a big advantage is the possibility of "pre-cooling" the intake air in the summer.

2) Water exchanger

is usually placed on the intake manifold. The problem is its possible freezing and related measures. So we are getting into a situation where we are dealing with two anti-freeze protections at once. This can of course be circumvented by using a medium with a lower triple point temperature. The advantage is economically lower consumption (we use the main heating source for a family house, e.g. gas or heat pump).

3) Electric heater - INTEGRATED in unit or DUCT

They are the most common types of preheating of recuperation units at all. The advantage of integrated preheating is problem-free assembly without any restrictions. The only disadvantage is the increase in the price of the unit. With pipe heaters, it is necessary to observe fire safety measures, such as: - in front of and behind the heater it is necessary to install at least 0.5 m of steel pipe to avoid contact with flammable parts - use of an air flow sensor or a pressure sensor to block the operation of the heater in the event of a drop flow, or flow rates below the permitted limit.

You must have thought, what is the point of saving energy by recuperation and then heating the air with an electric heater with a power of 1.4 kW?

This is of course a good question, so it is good to choose an adequate heater and in case of very low temperatures reduce the power of the unit. The heaters are manufactured in such a way that they only preheat the air as much as is needed, so they are continuously regulated (0-100%), so if the temperature outside is close to 0 °C, then the consumption is really minimal. Electric heaters are usually equipped with heating coils or so-called PTC elements, which, in our experience, are somewhat more economical.

In general, we recommend that you study the instructions for your chosen unit in detail and familiarize yourself with the logic of the unit's anti-freeze protection. If the information is not available, please inform us and we will try to find it directly with the manufacturer.

If you need a personal consultation, call or write!

Pipeline electric preheaters: HERE

Units with integrated preheating: VENUS , SAVE

Units with mixing flap: EHR 280 AKOR and EHR 325 AKOR

Information

Project "Measurement of parameters of air-conditioning components of Luftuj

Video of the Luftuj - Aquatherm Prague 2024 booth

Which servo drive to choose for electronically controlled flaps in the recuperat

We are rooting for Kristýna Otcovská at the European Championships in biathlon i

Fly to Aquatherm 2024, Prague

New presentation video of the company Luftuj sro

Christmas holidays - all-race vacation

We lectured at the 2023 Ventilation and Air Conditioning Conference

Visit us in September at the ForArch trade fair in Prague

Atrea comes with a new generation of Duplex Pro and Pro-V units

HOLIDAY 5.-7.7.2023

We trained...

VACATION 5-9/6/2023

Fly for the first time at ISH in FRANKFURT n/M

DUPLEX units switch to a new generation of regulation

An example of self-help installation of recuperation pipelines in a residential

We lectured at the STP seminar - How to prepare the recuperation system for serv

Thank you for visiting our stand at For Arch 2022

Fight at FOR ARCH 2022

5% discount for the whole of June

Aquatherm Prague 2022 news

We start tomorrow - Aquatherm 2022 is just starting

Luftuj at Aquatherm in Prague 19-22 April 2022

EPE x ADURO part 2

EPE x ADURO part 1

The website for Slovakia is being prepared

WE ARE CELEBRATING 10 YEARS, CELEBRATE WITH US WITH A 10% DISCOUNT

Pipeline recuperation in bungalows

The end of the year marks the completion of construction, service and projection

Recovery and direct extraction from the toilet bowl

New photo studio and print farm

ACTION ON DALFLEX 90 and 75 mm HYGIENIC PIPE

Tool for cutting flexible pipe

New articles in the advisory

Intake and exhaust recovery

Use of heat from the fireplace using a recovery unit

CELEBRATING THE 100TH PIECE OF PROTECTIVE SHIELD FOR DOCTORS MANUFACTURED

Shields for hospitals - production started

Filters and recovery during the COVID-19 pandemic

Filter fabrics F7 and filter bags - SALE STOPPED

OPERATIONAL MEASURES DURING THE PANDEMIC

Implementation of ventilation with recuperation in SVATOŇOVICE Kindergarten and

We are starting the sale of Globovac Play central vacuum cleaners

Central vacuum cleaner - why?

google8fbb401f85849981.html

Filters for recovery

Components

Implementation process

Cleaning the air conditioning system of a family house

Comparison of local recovery units

Recuperator and recuperation efficiency

Preheating for recovery

Installation of a central vacuum cleaner

Central vacuum system piping installation

Self-help recovery II

Self-help recovery I

Recovery vs. air conditioning

Recovery vs. hood

How the recuperator and the recuperation unit are made

We are testing

Recovery service

Self-help recovery

What is recovery

What pipes for the recovery system?

Best seller

Nastavení Cookies
Cookies

Naše webové stránky používají soubory cookies, které nám pomáhají s jejich vylepšováním. Abychom cookies mohli používat, musíte nám to povolit. Kliknutím na tlačítko "OK, souhlasím" udělujete tento souhlas.

Nastavení OK, souhlasím
×
Nastavení souborů cookies

Cookies jsou malé soubory, které webové stránky (i ty naše) ukládají ve Vašem webovém prohlížeči. Obsahy těchto souborů jsou vyměňovány mezi Vaším prohlížečem a našimi servery, případně se servery našich partnerů. Některé cookies potřebujeme, abychom webová stránka mohla správně fungovat, některé potřebujeme k marketingové a statistické analytice. Zde si můžete nastavit, které cookies budeme moci používat.

Nezbytné cookies
Nezbytné cookies
Jedná se o technické soubory, které jsou nezbytné ke správnému chování našich webových stránek a všech jejich funkcí. Používají se mimo jiné k ukládání produktů v nákupním košíku, zobrazování produktů na přání, ovládání filtrů, osobního nastavení a také nastavení souhlasu s uživáním cookies. Pro tyto cookies není zapotřebí Váš souhlas a není možné jej ani odebrat.
Ovlivňuje funkce:
  • Konfigurační cookies
Analytické cookies
Vypnuto Zapnuto
Analytické cookies
Analytické cookies nám umožňují měření výkonu našeho webu a našich reklamních kampaní. Jejich pomocí určujeme počet návštěv a zdroje návštěv našich internetových stránek. Data získaná pomocí těchto cookies zpracováváme souhrnně, bez použití identifikátorů, které ukazují na konkrétní uživatelé našeho webu. Pokud vypnete používání analytických cookies ve vztahu k Vaší návštěvě, ztrácíme možnost analýzy výkonu a optimalizace našich opatření.
Ovlivňuje funkce:
  • Google Analytics - analytická návštěvnost
Personalizované cookies
Vypnuto Zapnuto
Personalizované cookies
Používáme rovněž soubory cookie a další technologie, abychom přizpůsobili náš obchod potřebám a zájmům našich zákazníků a připravili tak pro Vás výjimečné nákupní zkušenosti. Díky použití personalizovaných souborů cookie se můžeme vyvarovat vysvětlování nežádoucích informací, jako jsou neodpovídající doporučení výrobků nebo neužitečné mimořádné nabídky. Navíc nám používání personalizovaných souborů cookie umožňuje nabízet Vám dodatečné funkce, jako například doporučení výrobků přizpůsobených Vašim potřebám. 
Marketingové cookies
Vypnuto Zapnuto
Marketingové cookies
Marketingové (reklamní) cookies používáme my nebo naši partneři, abychom Vám mohli zobrazit vhodné obsahy nebo reklamy jak na našich stránkách, tak na stránkách třetích subjektů. Díky tomu můžeme vytvářet profily založené na Vašich zájmech, tak zvané pseudonymizované profily. Na základě těchto informací není zpravidla možná bezprostřední identifikace Vaší osoby, protože jsou používány pouze pseudonymizované údaje. Pokud nevyjádříte souhlas, nebudete příjemcem obsahů a reklam přizpůsobených Vašim zájmům.
Ovlivňuje funkce:
  • Google Ads